third progress report from the independent review...

Breast Cancer at the ABC Toowong Queensland: Third Progress Report from the Independent Review and Scientific Investigation Panel – 21st December 2006

A. Introduction The Independent Panel has prepared a third progress report on its investigations for ABC management and staff for two main reasons. • First, the Panel Chair, Professor Bruce Armstrong, had hoped the Panel’s work

would be complete and that it would report by Christmas. It has almost but not entirely completed its task, so the Panel has prepared this third progress report to inform management and staff about what has been done and found to date, and what yet to be done.

• Second, the Panel said in its first report (Attachment 1, page 6) that as soon as it had completed its estimation of the ratio of the observed number of breast cancers in women employed at Toowong to the number expected from the recorded rate of breast cancer in Queensland it would report the results to management and staff. It has completed this work and therefore presents the findings on the epidemiology of breast cancer on the Toowong site here.

This report is longer and more detailed than might be expected but has to be because of the need to give management and staff as much information as possible to help interpret the results and to decide what action might be taken.

Sections B and C report on the Panel’s work and each numbered heading represents the major tasks set out in the Panel’s first progress report. Section D summarises the work yet to be done. Section E offers the Panel’s interpretation of and conclusions on its findings on the epidemiology of breast cancer at the ABC Toowong.

B. Epidemiology of breast cancer at the ABC Toowong

1. Collate information on total female workforce from 1st January 1995 to present to allow the accurate estimate of person years of employment of female staff members during this period

The Panel asked Dr Peter Baade, Biostatistician and Senior Research Fellow in the Viertel Centre for Research in Cancer Control at the Queensland Cancer Fund, to assist it with its investigation into the epidemiology of breast cancer at the ABC Toowong. Dr Baade did the work described in this sub-section and in sub-section 4 below in consultation with Associate Professor Joanne Aitken, a Panel member and Director of Cancer Registries and Consultant Epidemiologist in the Viertel Centre.

The ABC provided information to Dr Baade on the female workforce for the period 1st January 1994 to 30th June 2006 from the ABC Toowong employment records. The Panel decided to extend the period covered by the investigation back from 1st January 1995 to 1st January 1994 when it found that a woman had had breast cancer diagnosed in 1994 while working at Toowong. This extension was consistent with the Panel’s intention to include all known cases in the investigation.

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The ABC had two staff payroll/workforce systems during the time covered by the investigation. Together, these systems identified 550 women who had been employed at Toowong at any time in these 12.5 years. • These women worked at Toowong for an average of 3.3 years in the period. Forty

had worked there for the whole investigation period (12.5 years), while 16 women had worked there for less than a month (30 days).

• More than half the women (59%, or 324 women) had worked at Toowong between 1st January 1994 and 27th August 2001 (the part of the investigation period covered by the “TIACS” payroll/workforce system). Over two-thirds (67%, 370 women) had worked there between 27th August 2001 and 30th June 2006 (the part covered by the SAP payroll/workforce system). About a quarter had worked there in both periods (26%, n=144).

• In the first period, 30% of women staff members were recorded as working in the newsroom. This increased to 41% in the second period.

• Most women were aged in their 20s (47%) or 30s (28%) when they entered the time covered by the investigation (1st January 1994 or the date they commenced their employment at Toowong, if later); 3% were aged 18-19, 15% were in their 40s, and the remainder (7%) were aged 50 years or older.

To estimate how many of these 550 women under normal circumstances would be expected to develop breast cancer, the panel had to allow for both their age and the duration of employment with the ABC during the investigation period. For example, if a woman had just turned 34 years when she entered the investigation period (eg joined the ABC at Toowong) and was just about to turn 43 years at the end of the investigation period (ie 30th June 2006) she would contribute 1 person year to the 30-34 year age group, 5 person years to the 35-39 year age group, and 3 person years to the 40-44 year age group – a total of 9 person years.

This calculation was done for each of the 550 women and the numbers of person years added up in each age group across the whole period of the investigation. The numbers obtained for each age group are shown in the table below (the youngest woman employee during the period was 15 years of age and the oldest 73). Casual, part-time and full-time employees were treated the same when calculating person years. The total number of person years during the investigation period was 1,810.

Age distribution of person years for women in employment with the ABC at Toowong in the period 1st January 1994 to 30th June 2006

Age group Person years



15-19 years 14.8 35-39 years 283.4 55-59 years 86.4 20-24 years 217.2 40-44 years 215.2 60-64 years 53.2 25-29 years 293.4 45-49 years 162.5 65-69 years 3.3 30-34 years 337.1 50-54 years 141.1 70-74 years 2.0

2. Identify all possible female staff members with breast disease during the relevant time period

Members of the ABC Staff Reference Group for the investigation gave the information they had or could find on women with a breast cancer diagnosis who worked at the ABC Toowong to Ms Deb Beel, whom the ABC had asked to support

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the Panel. With one exception, Ms Beel contacted all these women, obtained their agreement to be contacted by the Panel and gave their names and contact details to the Chair of the Panel. In the exceptional case, a former ABC Toowong employee who had breast cancer diagnosed while employed at Toowong, located another woman and obtained her agreement to be contacted by the Panel.

A total of thirteen women were identified and all agreed to be contacted.

Professor Armstrong sought each woman’s agreement to be interviewed by a Panel member and to give access to information on the pathology of her breast cancer. All women generously agreed to both requests.

Pathology information was obtained for all 13 women.

Invasive breast cancer was specified in 11 of the 13 women. One of the other two had a mucoid carcinoma, which while not specified as invasive is always invasive so we treated it as such for the purposes of this investigation. One had “duct carcinoma in situ of the breast” (DCIS), a lesion whose cells look like breast cancer but in which there is no microscopic evidence that these cells have invaded normal tissue around it.

3. Develop a questionnaire and conduct face-to-face interviews with these women to gather as much relevant information as possible about them and their possible exposures

A questionnaire was developed with the assistance of Ms Lesley Walker, an environmental epidemiologist who was engaged to assist the Panel (see Attachment 2).

Professor Malcolm Sim, a Panel member, interviewed all 13 women in early to mid October 2006. It was established at interview that two women, in addition to the one woman who had DCIS rather than invasive cancer, fell outside the predefined, primary scope of the epidemiological investigation, which was women diagnosed with invasive breast cancer while they were employed at the ABC Toowong in the period 1st January 1994 to 30th June 2006. One of these women was diagnosed with breast cancer several decades after leaving her employment with the ABC and the other, while a regular radio interviewee at the ABC, had never been an ABC employee.

Information about these women of direct importance to the epidemiological investigation is summarised separately for the 10 women who were in the primary scope of the investigation and the 3 who were not.

a. Age and employment history

Women in scope Five of the 10 women were <40 years of age when diagnosed with breast cancer, 4 were 40-49 years of age and one was 50+ years of age. They had worked at the ABC Toowong site for 6 to 18 years, median 11 years, and had begun working there between 1983 and 2001, median year 1990.

Seven of the 10 women reported working in the newsroom. The other three either didn’t work there at all or made only occasional visits as part of their work. Of the

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seven women who worked in the newsroom, five spent at least part of their working time at one of the six workstations at the TV production desk on the lower floor of the TV building. The other two women who worked in the newsroom worked at other workstations in the vicinity of the TV production desk.

Three of the 10 women worked shift work most of the time, six some of the time and one none of the time.

In November 2003 in Australia, 12% of women who worked full time and 14% who worked part time had done shift work in the preceding 4 weeks1.

Women out of scope These women were 50-60 years of age at diagnosis of breast cancer. As noted above, one had never been an ABC employee, one worked there less than two years and one more than 20 years. They had first worked at Toowong between 1965 and 1992.

One of the three women reported working at the TV production desk in the newsroom. Neither of the other two worked in the newsroom.

Two of the three women worked shift work.

b. Diagnosis of breast cancer

Women in scope One of the 10 woman said that her diagnosis of breast cancer had been made after requesting a screening mammogram because of the apparent cluster of breast cancers at ABC Toowong. Three of the 10 said it had resulted from attendance for a routine screening mammogram. Two of the 9 cancers with known pathology were reported to have very small invasive components – 1mm and 3.3mm, the diagnosis of one having been prompted by knowledge of the cluster. The remaining 7 cancers ranged in diameter from 13mm to 100mm, median 15mm.

Women out of scope Two of these 3 women had their cancers diagnosed through attendance for routine screening mammography. None was prompted by knowledge of the apparent cluster. Both invasive cancers were small.

4. Estimate the number of breast cancers that would have occurred in women employed at Toowong if they had developed breast cancer at the same rate as all women in Queensland and compare it with the number that have actually occurred.

This was a key task for the Panel because the fundamental question which needed to be answered was whether or not the observation of a group of female ABC Toowong employees diagnosed with breast cancer during the period 1st January 1994 to 30th June 2006 indicated an unusually high incidence of the disease.

Dr Peter Baade, Biostatistician and Senior Research Fellow in the Viertel Centre for Research in Cancer Control at the Queensland Cancer Fund did the analysis for the Panel. His work and his report, in addition to being critically reviewed by Panel

1 Australian Bureau of Statistics. Working arrangements, Australia, November 2003. Catalogue number 6342.0

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members, were independently reviewed by Professor Michal Abrahamowicz, Professor in Biostatistics, Department of Epidemiology and Biostatistics, McGill University, Montreal, Canada, an expert in the field. Dr Baade’s full report is at Attachment 3

a. Method of analysis Dr Baade compared the numbers of women diagnosed with the number that would have occurred had ABC Toowong employees been at the same average risk of breast cancer as Queensland women of the same age. Information to calculate this background risk was obtained from the Queensland Cancer Registry and the Australian Bureau of Statistics.

While it sounds simple, the calculation is actually complex. It needed the data discovered under sections 1, 2 and 3 above. Then Dr Baade did meticulous calculations to take account of the ages of the women who worked at Toowong and their years of employment in comparison with the information from same-age women in the general Queensland population.

To make the results of the analysis as easy to follow as possible, Dr Baade computed the ratio of the observed number of confirmed cases of breast cancer in ABC employees at Toowong in the study period with the number that would have been observed had ABC women experienced the same rate of breast cancer as all Queensland women (the “expected” number). This is called the standardised incidence ratio.

If the observed and expected numbers were the same, the ratio would be 1, indicating no difference between the incidence of breast cancer in ABC women and that in all Queensland women. If the ratio were to be more than 1 according to the statistical calculations, it would indicate a higher rate of breast cancer in ABC women. If it was less than 1 it would indicate a lower rate in ABC women.

Things are never certain in such calculations, so to know how confident we can be about them, statisticians estimate something called the 95% Confidence Interval. This gives the range around the number quoted in which we can be 95% certain its true value lies.

Another way of checking on the number is to calculate the probability that any difference we find between it and a value of 1 could have occurred purely by chance. This is called the P value; the smaller it is, the less likely it is that the difference is due to chance.

The standardised incidence ratio calculation does not take account of any possible differences between women working at the ABC Toowong and the general Queensland female population in characteristics related to breast cancer risk except differences in age distribution, which were accounted for by calculating expected numbers of cases within specific age groups.

b. Results of analysis As outlined in sections 2 and 3 above, there were thirteen women notified to the Panel as having worked at ABC Toowong and having had breast cancer diagnosed. Two of these 13 women did not meet the requirement for this analysis that they were

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employed at Toowong at the time their breast cancer was diagnosed; one did not meet the requirement that she have an invasive cancer. Thus 10 women met both criteria and are included in the analysis.

Given the age of women employed at the ABC and the incidence of breast cancer in Queenslanders, we would have expected 1.6 (one point six) cases; that is between one and two women diagnosed with invasive breast cancer.

Thus with an observed number of ten women with invasive breast cancer, the standardised incidence ratio was 6.25 (six point two five). This number was obtained simply by dividing 10 by 1.6.

The lower end of the confidence interval was 3.0 (three point zero).

That means the incidence of breast cancer among female employees was 95% likely to be at least three times higher than expected for the time period of the study.

The P value was 0.000001, which means that there is a 1 in 1,000,000 probability of a group of cases of breast cancer this large or larger occurring by chance at the ABC Toowong if women at the ABC really had the same incidence of breast cancer as all women in Queensland.

When there is an association between working in a particular place and an increased incidence of a cancer it is often observed that the incidence of the cancer increases with increasing length of employment there. To see if this was the case at Toowong, Dr Baade also calculated the “hazard” of developing breast cancer per year of employment while taking account of the fact that women were also getting older the longer they were employed. He expressed this as a “relative hazard” or a risk relative to what it was at the time a woman started work at the ABC.

This relative hazard turned out to be 1.12 (a 12% rise in risk of breast cancer per year of employment). The lower limit of the confidence interval was 1.02 (a 2% rise in risk per year of employment) and the P value was 0.022; that is, about a 1 in 45 chance that this increasing risk with longer employment was just a chance finding.

C. Additional investigations

1. Workplace and other exposure history of women who have had breast cancer

The Panel asked women about known or suspected risk factors for breast cancer and these are outlined below. Information obtained at interview is given here only for the 10 women who were in the primary scope of the epidemiological investigation (see above). In addition, where possible, we have given comparative data for women of a similar age in the Australian population in the same time period.

a. Family history None of the 10 women reported any family history of breast cancer.

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b. Body height and weight The ten women reported heights of 151cm to 176cm, weights of 55kg to 98kg and body mass indexes of 20.1 to 37.7 kg/m2. On the basis of the body mass index five of the women could be considered to be overweight.

In 2001, 44% of Australian women 25-64 years of age were overweight2.

c. Smoking Five of the ten women had ever smoked and none were current smokers.

In 2004, 50.3% of Australian women 30-59 years of age reported having ever smoked3 and 19.1% were current smokers.

d. Alcohol drinking Eight of the ten women reported having at least one drink of alcohol a week, 3 averaged one or more drinks a day, none more than two drinks a day.

In 2004, 45% of Australian women 30-59 years of age reported drinking alcohol at least once a week and 6% reported drinking every day1.

e. Exercise Eight of the 10 women engaged in exercise at least 2-3 times per week; five engaged in strenuous exercise at least 2-3 times per week.

In 1999, 82.4% of Australian women 30-59 years of age did some physical activity each week and 51.8% did sufficient to gain some health benefit4.

f. Menarche The average age at menarche (onset of periods) of the ten women was 13.0 years.

This is the same as that reported from Australian women surveyed between 1979 and 19865.

g. Menopause Only one woman would have been likely to be menopausal. None had taken menopausal hormone replacement therapy.

h. Oral contraceptive use All 10 women had used oral contraceptives for periods varying from 2 to 18 years, average 9.4 years.

In Australia in 2001, 79% of women 30-49 years of age had ever used oral contraceptives6.

2 Australian Institute of Health and Welfare. Differentials in overweight and obesity among adults, 1989-90 to 2001. AIHW Bulletin No. 11. Canberra: AIHW 2003 3 Australian Institute of Health and Welfare. 2004 National Drug Strategy Household Survey: First Results. Drug Statistics Series No. 13. Canberra: AIHW 2005 4 www.aihw.gov.au/publications/health/papaa/papaa-c02.pdf 5 Morabia A, Costanza MC. International variability in ages at menarche, first livebirth, and menopause. World Health Organization Collaborative Study of Neoplasia and Steroid Contraceptives. American Journal of Epidemiology 1998; 148: 1195-205

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i. Childbearing Three of the women had not borne a child. The seven women who had borne a child, had their first child between 25 and 34 years of age, median age 28 and average age 29.4 years of age. One had 1 child, four had 2 children, and two had 3 or 4 children. The average number of babies per women was 1.6.

Given birth rates in 1999 it was estimated that 26% of women in Australia would remain childless. In Australia in 1996, the mean age at first nuptial birth was 28.7 years. Since the late 1990s, the number of babies per woman in Australia has been 1.8 or below7.

j. Breastfeeding Each woman who had borne a child had breastfed for an average of 2.3 to 12 months per child (median 7 months).

In 1996 and 2001, the median duration of breastfeeding by women in Australia was about 6 months with about 12% of children not being breastfed at all8.

k. Educational attainment For six of the women the highest educational qualification was a university degree or a diploma. One had reached year 12 and 3 year 10 at school.

In 2005, 51.3% of Australian women 25 to 54 years of age had a post-school certificate, diploma or degree9.

2. Conduct a review of the world’s scientific literature on environmental risk factors for breast cancer

To provide the necessary background to understanding and interpreting findings reported elsewhere in this report, we have prepared a brief review of the literature focused on recent, relevant published reviews

The 2006 third revision of a major text on cancer epidemiology and prevention gives a broad overview. The table below summarises the familial, environmental and lifestyle risk factors identified in its authoritative chapter on breast cancer. In addition to these, it identified some previously suspected risk factors that are now thought not to cause breast cancer: • Exposure to organochlorine pesticides; • Active smoking and passive smoking; • Use of underarm deodorants and • Breast implants.

6 Yusuf F, Siedlecky S. Patterns of contraceptive use in Australia: Analysis of the 2001 National Health Survey. Journal of Biosocial Science 2006 Nov 23 [Epub ahead of print] 7 Australian Bureau of Statistics. Australian Social Trends, 1998, 2001, 2002. Catalogue number 4102.0 8 Australian Bureau of Statistics. Breastfeeding in Australia, 2001. Catalogue number 4810.0.55.001. 9 Australian Bureau of Statistics. Education and training experience, Australia, 2005. Catalogue number 6278.0

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a. Familial, environmental and lifestyle factors associated with risk of breast cancer Summarised from Colditz G, Baer HJ and Tamimi RM, Breast Cancer, in Shottenfeld D and Fraumeni JF, Cancer Epidemiology and Prevention Third Edition, New York, Oxford University Press 2006: 995-1012

Risk factor Comment

Family history of breast cancer Risk increases with increasing number of relatives with a history of breast cancer

Socioeconomic status (SES) Risk higher in women of higher SES Age at menarche Risk is higher in women with an earlier menarche Age at first full-term pregnancy Risk is higher in women with a later first full-term

pregnancy Number of births Risk is higher in women who give birth fewer

times Breastfeeding Risk is higher the shorter the time a woman breast

feeds her babies Oral contraceptive pill use Risk is increased by a small amount while taking

the pill Age at menopause (natural or artificial)

The later the age, the higher the risk

Hormone replacement therapy Risk is increased while using HRT Body height Risk is greater in taller women Body weight or obesity Risk of post-menopausal breast cancer is increased

in overweight and obese women Alcohol intake Risk increases as alcohol intake increases Physical activity Risk is higher in those have less physical activity Ionising (nuclear) radiation Risk increases with increasing exposure

A separate chapter on occupation and cancer listed workplace exposures that are considered to definitely or probably cause cancer. None of these exposures were known to cause breast cancer specifically.

b. Occupational and environmental chemical exposure The most recent comprehensive review of occupational and environmental chemical exposure and breast cancer observed10: • Increased incidence rates of breast cancer have been observed repeatedly in

women in white collar jobs. They are related to both socioeconomic status and late childbearing.

• Occupational studies provide fairly consistent evidence that increased risk independent of socioeconomic status is associated with a few specific exposures: Benzene, organic solvents and PAHs (polycyclic aromatic hydrocarbons, generally produced as a result of combustion). Chemicals with the most

10 Brody JG and Rudel RA. Environmental pollutants and breast cancer. Environmental Health Perspectives 2003; 111: 1007-19.

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consistent human evidence have also been identified as animal mammary carcinogens.

c. Extremely low frequency electromagnetic fields (radiation) The extremely low frequency electromagnetic fields that have been of concern with respect to cancer production are the alternating electrical and magnetic fields (50-60 Hz) produced in proximity to high voltage power lines and electrical devices that have a high current flow. The most recent, comprehensive review of the association of these fields with risk of breast cancer concluded: “The weight of the evidence available today suggests that power frequency magnetic field exposure most likely is not a risk factor for breast cancer development.”11

d. Radiofrequency electromagnetic fields (radiation) Radiofrequency fields cover the whole electromagnetic spectrum from 100 kHz to 300 GHz and include all frequencies used in radio, TV and microwave transmission. A comprehensive review published in 1999 found only two studies of breast cancer, one in Norwegian female radio and telegraph operators and one of 227 men with breast cancer and 300 control subjects. The relative risk of breast cancer in the female radio and telegraph operators was 1.5 (95% confidence interval CI 1.1-2.0) and the relative risk of male breast cancer was 2.9 (95% CI 0.8-10.0) in radio and communications workers. Overall, the author concluded: “The epidemiologic evidence falls short of the strength and consistency of evidence that is required to come to a reasonable conclusion that RF emissions are a likely cause of one or more types of human cancer.”12 There has been no new evidence of substance on radiofrequency electromagnetic fields and breast cancer published since this review appeared.

e. Shift work There is a growing literature on the possible role of shift work on risk of breast cancer, through the suppressive effect that “light at night” has on the release of the hormone melatonin from the pineal gland. This work has recently been reviewed in three companion papers.13 These reviews conclude that there is an increased risk of breast cancer associated with indicators of light-at-night and night shift work. These conclusions are based on studies of breast cancer risk associated with occupations that commonly entail night-shift working and studies in the general population of the relationship of self-reported working hours to breast cancer. While statistically significant results have been obtained, the relative risks observed have generally ranged between 1.5 and 2.0. There was some evidence of dose-response relationships; that is, risk increasing with frequency and duration of shift working.

11 Feychting M and Forssén U. Electromagnetic fields and female breast cancer. Cancer Causes and Control 2006; 17:553-8. 12 Elwood JM. A critical review of epidemiologic studies of radiofrequency exposure and human cancers. Environmental Health Perspectives 1999; 107 (Suppl 1): 155-68. 13 Stevens RG. Artificial lighting in the industrialized world: circadian disruption and breast cancer. Cancer Causes and Control 2006; 17: 501-7. Hansen J. Risk of breast cancer after night- and shift-work: current evidence and ongoing studies in Denmark. Cancer Causes and Control 2006; 17: 531-7. Davis S and Mirick DK. Circadian disruption, shift work and the risk of cancer: a summary of the evidence and studies from Seattle. Cancer Causes and Control 2006: 17: 539-45.

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f. Psychological factors Stress and an individual’s response to it are popularly believed to be important factors in causing cancer. A recent critical review of psychological factors and cancer development concluded that: “…there is not any psychological factor for which an influence on cancer development has been convincingly demonstrated in a series of studies.”14 In an earlier review focusing specifically on breast cancer, and commissioned by Australia’s National Breast Cancer Centre, the authors concluded: “In general, the evidence for a relationship between psychosocial factors and breast cancer is weak. The strongest predictors are emotional repression (especially of anger) and severely threatening life events that would include the loss of a significant other. Although the available evidence does not support a major role for psychosocial factors in breast cancer development, few studies have been of sufficient quality to state definitively that such a role does not exist”15.

3. Measurement of electromagnetic radiation The Panel asked Dr Geza Benke, an expert occupational hygienist and senior research fellow in the Monash University Centre for Occupational and Environmental Health (of which Professor Sim is the Director), to visit the ABC Toowong site and, among other things, to: • View the workplaces and specify the measurements that should be made of

exposure to electromagnetic radiation on the site; and • Ascertain the history of use of equipment emitting radiofrequency (RF)

electromagnetic radiation on the site, including when equipment was installed, upgraded or decommissioned.

Dr Benke visited Toowong on 13th November 2006 and prepared a full report to the Panel following his visit (see Attachment 4). His conclusions with respect to electromagnetic radiation are summarised below.

a. Ionising radiation There is no documented history of the use of ionising radiation on the site and it is unlikely that any irradiating apparatus, such as X-ray or industrial radiography machines, or radioisotopes, has been used there. Radiation contamination of the site could only be possible if construction material had been inadvertently contaminated before it arrived there, an extremely unlikely occurrence. Radon gas exposure is unlikely, but possible. Radon gas can build up in cellars and well sealed buildings but a survey undertaken by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) about 20 years ago found that exposure to it inside Australian buildings and dwellings was negligible.

b. Radiofrequency (RF) radiation There are numerous RF communications devices located on the Toowong site. A history of the equipment on site before 1980 was not available. It appears, however,

14 Garssen B. Psychological factors and cancer development: Evidence after 30 years of research. Clinical Psychology Review 2004; 24: 315-338. 15 Butow PN, Hiller JE, Price MA, Thackway SV, Kricker A, Tennant CC. Epidemiological evidence for a relationship between life events, coping style, and personality factors in the development of breast cancer. Journal of Psychosomatic Research 2000; 49: 169-81.

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that most of the equipment on site was added in the past twenty years, with little replacement of older receivers and transmitters. It can be assumed, therefore, that the current RF exposure levels on the site are probably higher than at any previous time.

The THL RF Hazard control document of 16th February 200416 indicated that the most prominent RF source on site is the 7 meter satellite dish on the TV building rooftop. The three VHF antennae also have high maximum power. The RF sources on site cover a wide range of frequencies and power outputs. In these circumstances it is advisable to assess the broadband exposures in the offices below.

The EMC RF survey17 showed that in all the office work areas in the TV building the levels were below the detection limit of the survey meter (<2 V/m). This is not surprising in view of the RF sources currently in place and the known high directionality of these sources. Since the broadband measurements do not indicate any substantial exposure to RF it is unlikely any narrow band measurements would detect any important levels of exposure in the office areas.

EMC had recorded some unusually high RF emissions near to security card readers. Staff members were concerned that if they were carrying books, bags or equipment, they might bring their chest close to the card reader and perhaps be exposed intermittently to high levels of RF radiation. The EMC report indicated that at 5 centimetres distance from the card reader the levels were only about a quarter the ARPANSA reference levels. In addition, given the brief exposure periods over the course of a work-shift, perhaps 1 to 2 minutes per day, the time-weighted average exposure should be very low.

c. Extremely low frequency (ELF) radiation ELF exposure has not been measured in the TV building. Given the high concentration of communications equipment in many of the workstations in this building, exposure is expected to be higher than in a normal office environment. The power requirements of the ABC Toowong site are clearly high, given that it has its own substation. Thus the power intensive sources and high power frequency currents required for high ELF exposures are present on the site.

d. Measurements Dr Benke recommended that: • Since ionising radiation is the only known environmental exposure that is known

with certainty to increase breast cancer risk, it would be prudent to measure radiation dose rates, monitor for contamination and measure radon gas concentrations in the TV building; and

• An extremely low frequency electromagnetic radiation (ELF) measurement survey should be undertaken on the ground and first floor of the TV building. This should involve dosimetry to workers in various workstations on both floors.

16 RF Hazard Control Document Toowong Studio Brisbane Australian Broadcasting Commission – Date of Survey 16th February 2004 – THL Australia 17 Electromagnetic radiation survey conducted for Australian Broadcasting Corporation at 600 Coronation Drive, Toowong, Qld Australia. Report number B050401, issue date 2nd May 2005. EMC Technologies Pty Ltd.

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At the Panel’s request, the ABC has commissioned ARPANSA to make these measurements in accordance with Dr Benke’s specifications (see Appendix 1, Attachment 4). Mr Ken Karipidis from ARPANSA visited Toowong on 18th December 2006.

While reporting of Mr Karipidis observations is not yet complete, he has given the following information: “Spot measurements were made at numerous locations on the ground and first floors of the TV building. The average magnetic field level was about 1 milliGauss (mG). Personal exposure measurements were also done by measuring the magnetic field exposure of three staff members (one each from the ground and first floor of the TV building and one from the radio building) for 4 hours. The time-weighted average exposures were 0.3 and 0.6 mG for the volunteers from the ground and first floor of the TV building respectively and 2 mG for the volunteer from the radio building. In general these measurements indicate that the levels are lower than what is usually encountered in a normal office environment”.

4. Documentation of history of the Toowong site relevant to possible sources of carcinogenic exposure

Dr Benke was also asked to: • Ascertain the history of possible exposure to carcinogenic chemicals on the site –

eg, chemical waste, pesticides (eg termite control), solvents, PCBs, heavy metals, formaldehyde (as from building material or furnishings), flooding; and

• To do so by viewing relevant site records relating to sources of non-ionizing radiation and chemical exposures and interviewing current or past members of staff who may be in a position to recall any relevant exposure sources or episodes.

His full findings with respect to these requests are reported in Attachment 4. In summary, he made the following observations.

a. Asbestos Materials containing asbestos (mainly asbestos cement sheeting, asbestos vinyl tiles and millboard) had been used in the construction of the TV building. These materials were removed over two periods, in the late 1980s and in about 2000, by an approved asbestos removalist working in accordance with Queensland occupational health and safety regulations. Dr Benke judged that staff members would have been unlikely to have been exposed to asbestos during these removal processes.

b. Environmental tobacco smoke (ETS) Smoking was banned inside ABC Toowong buildings in March 1989. ETS exposure would have occurred before that time. Dr Benke had no basis on which to judge whether that exposure was greater than was experienced generally by the Queensland female population at the time.

c. Pesticides The Toowong site was a residential premise before the construction of the ABC buildings in the 1960s. Heavy use of pesticides on the site during that early period is therefore unlikely. Organochlorines would be the main pesticides of concern because of their suspected cancer causing properties. The use of these chemicals inside

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buildings was discontinued in Queensland in the early 1980s. Limited use, however, continued around the exterior of buildings and under slabs until about 1995. Arrest-a-Pest has been the pest control contractor for the ABC Toowong since at least the early 1980s. Dr Benke spoke to Mr Chris Hill, who had been employed by Arrest-a-Pest since 1989; Mr Hill said that no significant quantities of organochlorines had been used by Arrest-a-Pest on the Toowong site.

d. Water The ABC Toowong is supplied by Brisbane Water. Contamination of the ABC’s water supply by heavy metals would be possible if there had been contamination of the piping from some outside source or there was significant corrosion of old piping.

e. Other possible chemical contamination issues (i) Tanks removed from the car-park area in 2000

Two petrol tanks that had been unused since 1996 were removed from the Toowong car-park in 2000. This time period would have permitted evaporation of any volatile hydrocarbons trapped in the tanks or soil. Soil measurements taken at the time of the removal showed no contamination.

(ii) Cleaning the air-conditioning system Contact was made with Mr Bruce Clayton of Haden, the air-conditioning contractors for the Toowong site. He said that the condensate trays were cleaned infrequently with a common, soap-based detergent to remove slime. The ductwork is vacuumed on an infrequent basis. The filters are not cleaned but replaced about once a year. The heat exchangers are cleaned infrequently with a chemical named Coil and Filter cleaner AK manufactured by Sterile-Care Pty Ltd. The Material Safety Data Sheet (MSDS) for this product indicates that the active ingredient is a quaternary ammonium compound and it also contains alkaline salts. Neither of these is considered or suspected to be a carcinogen.

(iii) Ceiling tiles The ceiling tiles in the ground floor of the TV building were installed in 2000. These are Armstrong RH90 tiles manufactured in the USA. The MSDSs currently on the Armstrong website (http://www.armstrong.com/commceilingsna/msds_search.jsp) show that the commercial ceiling tiles all contain mineral wool fibre and fibrous glass, and some contain hydrous aluminium silicate. Each of these is (hydrous aluminium silicate) or may be carcinogenic if inhaled. There is no evidence, however, that they cause breast cancer. Prior to installation of these tiles in 2000, there were vinyl-coated Gyprock ceiling tiles in the building. They are unlikely to have produced any off-gassing of volatile organic compounds such as formaldehyde, n-hexane, n-pentane, xylenes, toluene or 2-methyl butane.

f. Measurements Dr Benke recommended that drinking water from taps on the ABC Toowong site be tested in accordance with the NHMRC Australian Drinking Water guidelines 2004.

The Panel has asked the ABC to have this testing done by the Brisbane Water Scientific Analytical Services Laboratory, which is NATA accredited for the

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http://www.armstrong.com/commceilingsna/msds_search.jsp

extensive range of tests that it does. A Brisbane Water officer collected water samples on 15th December; results of testing can usually be expected in about 10 days from testing.

D. Work in progress Progress has been reported above on several tasks that are yet to be completed. They are: • Conduct of a review of the world’s scientific literature on environmental risk

factors for breast cancer. We hope to complete this work by the end of January 2007.

• Measurements of ionising and ELF radiation in the TV building. ARPANSA has made spot and limited personal monitoring measurements of ELF in the TV building with one personal monitor also deployed in the radio building. A formal report on these measurements will be available early in January 2007. A decision will then be made on the need for more extensive personal monitoring. The measurements of ionising radiation have yet to be scheduled.

• Testing of drinking water. Brisbane Water has taken the water samples required. The results should be available in early January 2007.

We have sent a questionnaire to 12 women who are or were employed at the ABC Toowong and who had a breast tumour or lump treated, which was not thought to be cancer. The questionnaire inquires about each woman’s breast lump or tumour, work and workplaces at the ABC and use of mammography, using a sub-set of the questions in Attachment 2. Each woman has also been asked to provide or permit access to a copy of the pathology report on the breast lump or tumour. This investigation seeks to determine the exact nature of these other tumours or lumps and to determine if there is any similarity between the nature of the women’s work and workplaces at the ABC and those of the women who have had breast cancer. Some completed questionnaires have been returned. It is unlikely that this work will be finished until mid-February because of the probable difficulty in obtaining responses from doctors to requests for pathology reports during January.

E. Interpretation of and conclusion on the epidemiological findings

1. Interpretation We have considered a number of possible explanations for the results of our investigation of the epidemiology of breast cancer at the ABC Toowong.

a. Chance Our statistical findings suggest that the risk of breast cancer in women working at the ABC Toowong from 1st January 1994 to 30th June 2006 was some six times higher than that in the general population of women in Queensland. We have estimated that there is a 1 in a million probability that the observed or a greater number of cases of breast cancer might arise simply by chance.

In spite of this very low probability, chance is still a possible explanation for this finding. The larger the overall population in which a disease occurs, the more likely it is that a chance cluster of the disease will occur somewhere in a particular period.

15

This cluster of cases of breast cancer occurred in a workforce of, on average, about 150 women. Suppose that we divide the whole Australian female population 15-64 years of age into randomly selected groups of 150; there would be about 40,000 groups. If each group has a 1 in a million chance of developing 10 or more cases of breast cancer over about 10 years, we would need about 25 such periods, that is 250 years, to be reasonably certain of getting even one cluster of 10 or more breast cancer cases (25 times 40,000 = 1 million). Thus even in this wider context, the cluster of breast cancers at Toowong appears very unlikely to be a chance event.

b. Risk factors unrelated to work or the working environment at Toowong It is possible that women working at ABC Toowong are at an unusually high risk of breast cancer because of risk factors unrelated to work or the working environment there, again possibly as a result of the play of chance but also because of a range of factors that attract people to different work or workplaces. Because of this possibility we documented risk factors in the women who had been diagnosed with breast cancer to give some indication of the distribution of risk factors in the underlying workplace population. Our findings have been described in Section C part 1. On most counts, the women with breast cancer were similar in their risk factors to the general female Australian population of the same age. They did, perhaps drink more alcohol than average, but they were still within national guidelines. They may also have been more inclined to use oral contraceptives than Australian women in general. Neither of these is a particularly strong risk factor for breast cancer and there is no possibility that the small differences we observed in them could explain a six-fold (or even three-fold) increase in risk of breast cancer in ABC Toowong women.

c. Higher levels of breast cancer screening in ABC Toowong women The Panel thought initially that awareness of the number of breast cancer cases at Toowong would have prompted women to seek breast cancer screening when they might not otherwise do so. This could increase the number of cases diagnosed. Indeed one of the women diagnosed with breast cancer had sought screening as a result of her knowledge of the number of cases. If she is removed from the observed number of women with breast cancer, the standardised incidence ratio falls to 5.63 and its lower confidence limit to 2.6. This is still a substantial and highly significant increase in risk. Three of the other women had their breast cancer diagnosed when they attended routinely for a screening mammogram. Does this indicate a higher level of screening in this population than in the general population? Probably not; about 35% of breast cancers in women 50-69 years of age in Australia, the target population for breast screening, are first detected by screening. While those detected by screening were aged 41, 43 and 50 years, there is a continuing high level of screening outside the organised program, which would suggest that 3 breast cancers detected by screening out of a total of 10 is about the number expected in the population.

d. Error in the estimates of breast cancer incidence at Toowong There are three possible sources of error: ascertaining the number of cancers, counting the number of person years in the employed women at Toowong and calculating the expected number of breast cancer cases. The last has been carefully checked by Dr Baade and Associate Professor Aitken and been the subject of external review by Professor Abrahamowicz. We are confident there is no error there. We thoroughly checked all the ascertained cases of breast cancer, confirmed that they were in the scope of the investigation and obtained histopathology reports. The only possible

16

error is under-ascertainment of breast cancers in women at Toowong, and this would have produced a falsely low standardised incidence ratio, not a falsely high one. ABC staff records were used to estimate the person years. While concern had been expressed at the possibility that some casual employees might have remained on the “books” for a period after they stopped working any hours at Toowong, this would have inflated the number of person years not diminished it, and led to an underestimate of the standardised incidence ratio.

e. Risk factors related to work or the working environment at Toowong By a process of exclusion we arrive at this as the likely explanation for the high incidence of breast cancer at the ABC Toowong during the period of study. Its plausibility is enhanced by the evidence that risk increased with increasing duration of employment with the ABC and, arguably, by the concentration of cases of breast cancer in women who had worked in the newsroom. It is also a matter of concern, but not easily explicable, that the increase in risk of breast cancer, relative to that in the general Queensland population, was much greater in younger than older women.

What are the risk factors that could be responsible? We have failed to pinpoint any strongly plausible risk factor. While some investigations are still to be completed, it appears highly unlikely, on the basis of lack of evidence of unusual levels of exposure and lack of evidence that particular exposures increase risk of breast cancer, that any of the following are responsible:

• Radiofrequency electromagnetic radiation • Extremely low frequency electromagnetic radiation • Chemical contamination of the site

We have noted, though, the evidence relating shift work to risk of breast cancer and it does appear that there is an unusually high level of shift work in this population, at least among those who were diagnosed with breast cancer. While we offer this as a possible explanation, present evidence on it as a risk factor for breast cancer does not suggest that it would be strong enough to explain a six-fold, or even perhaps a three-fold increase in risk in an exposed population.

2. Conclusions

• There is a real increase in risk of breast cancer in women working at the ABC Toowong that may have been caused by some aspect of work or the working environment at Toowong.

• It is highly unlikely that this increase has been caused by exposure to radiofrequency or extremely low frequency electromagnetic radiation on or to any chemical contamination of the site. The conclusion with respect to chemical contamination is limited by the present lack of results of the testing of water from the site.

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Attachment 1

Breast cancer cluster, ABC Toowong Queensland First progress report of the independent Review and Scientific Investigation Panel: Outline of proposed approach to its task

Background Female staff members employed by the ABC at its premises in Toowong, Queensland, have reported what appears to be an unexpectedly large number of cases of breast cancer covering a period from the beginning of 1995 to the present. Particular concern has been expressed at the occurrence of a number of cases in the TV newsroom, and at the relative youth of those affected. Action to address this issue began in February 2005 and has included:

• Engagement of a senior occupational health physician from Health Services Australia (Health for Industry) to advise on the issue;

• Involvement of the ABC’s Employee Assistance Provider – Davidson Trahaire Corpsych;

• Conduct of a radiofrequency electromagnetic radiation (EMR) survey of the ABC Toowong site by EMR technologies; and

• Investigation of the occurrence of breast cancer in women on the Toowong site by Queensland Health.

Staff concern about the breast cancer cases at the Toowong site was increased in July 2006 with the report of another staff member diagnosed with breast cancer.

The Independent Review and Scientific Investigation Panel In response to the situation, the ABC’s Managing Director, Mark Scott, invited cancer and environmental epidemiologist, Professor Bruce Armstrong, Director of Research at the Sydney Cancer Centre, to constitute and lead an independent Investigative Panel with the following terms of reference:

1. Review the scientific work undertaken to date on the reported breast cancer cluster at Toowong including efforts made in 2005 to identify any cause;

2. Consider submissions and briefings from the staff-elected Staff Reference Group (SRG) and communicate with the SRG on the Panel’s work and plans;

3. Advise the ABC on further investigations that should be made to identify any cause for breast cancer clustering at Toowong;

4. Oversee the conduct of any such further investigations; and 5. Advise the ABC on any actions that should be taken in the light of the

Panel’s review of existing information and the results of any further investigations done.

Dr Norman Swan, Producer and Presenter of the ABC’s Health Report, Professor Malcolm Sim, Director of the Monash Centre for Occupational and Environmental Health, and Associate Professor Joanne Aitken, Director of the Viertel Centre for Research in Cancer Control at the Queensland Cancer Fund, are the other expert

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members of the Panel. At Professor Armstrong’s request, the ABC has engaged Ms Lesley Walker, an environmental epidemiologist, to assist the Panel.

The Panel is independent in the sense that it: • Will seek to apply sound scientific principles to its review and

investigations and to apply only those principles when formulating its advice;

• Is freely able to speak with both management and staff about its investigations and their outcomes and to seek information from and through both; and

• Will provide its progress and draft final reports to management and staff (through the SRG) at the same time; and

• Will take account of issues that both management and staff raise from the draft final report in preparing its final report.

The panel met for the first time on the 7th August in Brisbane. The following sections of this document were prepared following this meeting and summarise the Panel’s initial views on how it will approach its task.

Summary of work undertaken to date The Panel had access to and viewed the following reports on investigations relevant to the cluster of breast cancer cases that had been undertaken to date:

1. RF Hazard Control Document Toowong Studio Brisbane Australian Broadcasting Commission – Date of Survey 16th February 2004 – THL Australia

This report identified the following radio frequency (RF) electromagnetic radiation sources on the site:

and identified the following RF hazards with reference to the ARPANSA (2002) reference levels applicable to the site:

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2. Questionnaire – Breast cancer cluster study, Australian Broadcasting Corporation Toowong – Dr Keith Adam, Health for Industry

Dr Adam was engaged to: complete an exposure history [for cases of breast cancer]; confirm cases through accurate clinical diagnosis; educate staff about the occurrence of disease; review the results of the testing by EMC Technology; and provide the ABC with an evaluation report. The Review Panel understands that: • Dr Adam gave a lecture to the staff; • Dr Adam developed and circulated questionnaire to employees reported to

have had breast cancer; • Some questionnaire recipients were concerned that the questionnaire did not

adequately address possible hazards in the workplace; • Few questionnaires were completed and staff members withdrew their

cooperation with Dr Adam’s investigation; and • Dr Adam did not prepare an evaluation report.

3. Electromagnetic radiation survey conducted for Australian Broadcasting Corporation at 600 Coronation Drive, Toowong, Qld Australia. Report number B050401, issue date 2nd May 2005. EMC Technologies Pty Ltd.

EMC Technologies did a survey of broadband RF electromagnetic radiation (electric fields 100 kHz to 45 GHz and magnetic fields 100 kHz to 30 MHz) on the ABC Toowong site on 4th to 6th April 2005. Results of this testing were reported to the staff on 6th May 2005. All the tests were reported as complying with reference levels of ARPANSA. Measurable levels were reported in proximity to security card readers and areas inside outside-broadcasting vans.

4. Queensland Health investigation into concerns about a breast cancer cluster in women working at the ABC studios, Toowong. Queensland Health, December 2005

In May 2005 Queensland Health was requested by concerned ABC staff members to investigate whether there were more breast cancer cases in the female workforce than would be expected and to consider whether the working environment might be responsible for the development of breast cancer in affected

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women. The results of the investigation were reported in December 2005. The report concluded that:

• The occurrence of eight cases of proven breast cancer in a small workplace over this time period raises the likelihood that this is a statistical excess of cases;

• Applying standard epidemiological techniques, where the workplace per se rather than a specific environmental factor is considered the risk, proved to be difficult as it was not possible to fully identify and accurately quantify the exposed population. A definitive, valid statistical conclusion about the expected number of cases in the workplace over the period could not be drawn from the data;

• Therefore, in this instance, where the epidemiological investigation was unable to definitively answer the initial question related to excess of cases an environmental appraisal of the workplace was undertaken;

• The subsequent environmental appraisal did not indicate any plausible exposures that would explain a significantly elevated number of breast cancers.

In response to a request for clarification, Queensland Health provided the following additional conclusions in February 2006:

• There remains a likelihood that there is an excess of breast cancer cases in this workplace, however the size of any potential excess cannot be exactly quantified;

• An excess would most likely be due to coincidence, but an excess may be due to factors, which in the present state of scientific knowledge, are unknown or unrelated to the workplace. Given the current state of scientific knowledge and that the investigation focussed on the workplace, workplace-related factors are considered an unlikely explanation.

Panel members reached the following conclusions from their review and discussion of these documents:

1. It has not yet been established whether the observed number of cases of breast cancer in female employees of the ABC at its Toowong premises is greater than might reasonably be expected in a female workforce of its size and age distribution;

2. RF levels measured in different locations in the ABC Toowong premises, including in proximity to where some of the affected women worked in the TV newsroom, were reported to be generally below the detection threshold for the instrument used. This conclusion, however, seems to be based on spot measurements at each location. Longer-term monitoring of RF levels is likely to give a more accurate estimate of usual exposure, as they will take into account the intermittent operation of some equipment.

3. As reported, the investigations done so far appear not to have considered the full range of other possible exposures on this site.

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We therefore recommend that further investigations are done.

Epidemiology of breast cancer on the Toowong site Following its review of the documents and discussion with the Staff Reference Group (SRG), the Panel concluded that an epidemiological study should be conducted, covering the period 1st January 1995 to the present. This would encompass the relevant period during which the cases of breast cancer were diagnosed.

From information available to it, the Panel believes that it is possible to prepare a reasonably accurate estimate of the number of person years of employment of female staff members on the Toowong site of the ABC that can be used to estimate expected numbers of breast cancers.

The Queensland Health report stated that there were 8 cases of breast cancer in ABC employees at Toowong in the periods 1995 to 2005. Another case has been reported since, making 9. Members of the SRG suggested that the number could be as high as 11 or 12. The SRG expressed its willingness to collate workforce knowledge of cases of breast cancer diagnosed in ABC employees at Toowong during the period specified above. Given the publicity surrounding the issue of breast cancer in ABC employees at Toowong and the salience of the issue to them, we consider that the staff’s collective knowledge of cases of breast cancer in their work colleagues should provide complete or near complete enumeration of these cases.

We recommend that:

1. The ABC collates information on its whole female workforce in the period from 1st January 1995 to the present that would allow accurate estimation of the person years of employment for female staff members during this period. We will advise on how this should be done.

2. The assistance of the whole staff is sought, through the SRG, in identifying all cases of breast cancer diagnosed in this period in women while they were employed by the ABC on the Toowong site. It is important to ensure that all possible breast cancer cases are identified. Whatever process is followed in doing this should ensure that women who are identified are asked if they consent to their names and contact details being given to the Panel before any such disclosure is made.

3. The Panel seeks a standard set of information from women who have had or may have had breast cancer. For the purposes of the epidemiological study this would include: date of birth, date of diagnosis of breast cancer, circumstances leading to diagnosis (eg, mammographic screening in the absence of specific symptoms, or after feeling a lump or onset of some other breast symptom) and pathological details of the breast cancer. To obtain this latter information, it may be necessary to ask women to provide the Panel with consent to obtain medical information from their treating doctor.

4. The processes in (2) and (3) are approved by an appropriately constituted human research ethics committee before any identifiable personal information is disclosed to the Panel.

5. The Panel uses the information obtained in (1) and (3) to estimate the ratio of the observed number of breast cancers to its expected number (based on the person

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years of employment and Queensland Cancer Registry estimates of breast cancer incidence in Queensland for the period 1995 to the present) and the 95% confidence interval for the ratio. These calculations would be based on rates of invasive breast cancer. Sensitivity analyses would be done based, for example, on different ways of counting person years for casual employees, different assumptions about the characteristics of breast cancer in women who had breast cancer but for whom the full information in (3) could not be obtained, and inclusion of women with in situ breast cancer if plausible estimates of its incidence in the whole population could be made, at least for a period, from data held by the Queensland Cancer Registry.

6. The Panel reports the results of the analyses in (5) in a progress report to management and staff as soon as they have been completed and reported to the Panel’s satisfaction.

Additional investigations While it might be argued that no additional investigations should be done until the study of the Epidemiology of breast cancer on the Toowong site has been completed, we consider that it is in both management’s and staff’s interest that some additional investigations proceed in parallel with that into the epidemiology. This will reduce the likelihood of major delay in the Panel’s final report.

Workplace and other exposure history of women who have had breast cancer In approaching women for the brief details required for the epidemiological study, we recommend that additional, more detailed information be sought, as listed below. This information will allow a full assessment of the extent of spatial and temporal clustering of the cases of breast cancer, possible exposures within the ABC Toowong site, and other occupational or non-occupational characteristics that women who have had breast cancer may share. Specifically, we recommend that:

1. Women who have been diagnosed with breast cancer, including carcinoma in situ, while employed at the ABC Toowong between 1995 and the present are asked in detail about their work, work patterns (including shift work) and workplace location histories during their employment with the ABC (at Toowong and elsewhere). An interviewer with occupational health experience and qualifications would undertake these interviews.

2. These women are also asked about their family history of breast cancer and exposure, through lifestyle or other means, to other known risk factors for breast cancer.

Longer term monitoring of RF radiation While the levels of RF have been reported to be lower than ARPANSA reference values in workplaces on the ABC Toowong site, only spot measurements have been made. While there is limited evidence that increased exposure to RF increases risk of human cancer, given the role that RF plays in the ABC’s operations, the possibility of important levels of exposure to it in the ABC Toowong site should be thoroughly considered.

We recommend that there be continuous monitoring of RF over longer periods in areas where there are high concentrations of staff and, in particular, in the TV

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newsroom and in proximity to where the TV news production staff members sit, and at times when all relevant equipment is operational. The exact areas to be monitored will also be guided by the occupational histories given by the women with breast cancer. The measured levels should be compared with benchmark measurements from a range of other workplaces in the telecommunications industry and not just assessed against accepted reference levels for workplaces.

Measurement of extremely low frequency electromagnetic radiation (ELF) ELF is produced by the passage of power frequency alternating electrical current in power lines. While high levels of ELF are commonly associated with high voltage power transmission lines, there are circumstances in which high levels can also occur as a result of the way electrical power is distributed in buildings. High exposure to ELF has been associated with childhood leukaemia, although the current state of scientific knowledge does not suggest an association with breast cancer. Nevertheless, there is concern among ABC staff about levels of ELF exposure at the Toowong site.

We recommend that a survey be made of ELF levels in workplaces on the ABC Toowong site. Continuous monitoring over periods of time should be done in areas where there are high concentrations of staff and, in particular, in the TV newsroom and in proximity to where the TV news production staff members sit. If measurable levels are found, they should be compared with benchmark measurements from a range of other workplaces and not just assessed against accepted reference levels for workplaces.

Documentation of history of the Toowong site relevant to possible sources of carcinogenic exposure While the scientific evidence for ionising radiation being a cause of breast cancer is very strong, there is less evidence for other specific occupational or environmental risk factors for breast cancer. However, due to staff concern about exposure to other possible carcinogens at the Toowong site, such as organochlorine pesticides, PCBs, heavy metals such as cadmium or lead, and organic solvents, it will be important to assess the possible presence of such hazards and, if present, the degree of likely exposure.

We recommend that:

1. A detailed review is undertaken of the literature relating to occupational and environmental exposures as risk factors for breast cancer; and

2. A detailed history of the Toowong site is compiled with a particular focus on: • instances of possible environmental contamination with chemicals – eg,

chemical waste, pesticides (eg termite control), solvents, PCBs, heavy metals, formaldehyde (as from building material or furnishings), flooding; and

• changes in location of RF transmission aerials or other relevant equipment or power transformers and cabling that could have produced a major change in exposure to RF or ELF.

3. Should our review of the epidemiology of breast cancer at the Toowong site suggest that there is an increase in risk of breast cancer on the site that is beyond what might be reasonably attributed to chance variation, it might be necessary to make more extensive environmental measurements on the site. These

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measurements would be guided by results of the review of literature relating to environmental and occupational exposure to breast cancer and would focus initially on exposures that the site history suggests are plausibly present on the site.

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ABC EXPERT PANEL INTERVIEW Attachment 2

NAME OF INTERVIEWER ID NUMBER Day Month Year _____________________________________ DATE NAME OF INTERVIEWEE Day Month Year _____________________________________ DOB BEST CONTACT NUMBER __________________________________________________________________________ LOCATION OF INTERVIEW __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ The questions I’m going to ask you will be about aspects of your health, work and lifestyle that are known or thought to influence risk for breast cancer. To be able to fully investigate the concern about breast cancer we need both the work history and health and lifesyle information. Any questions? The way we have set the questions is in sections, we have started with your work, present lifestyle and leisure activities, we will then go through your whole menstrual history from the start of your periods up to now. Then we will go on to your breast health history and your family history. If at any point if there is anything you feel is relevant for us to know, please feel free to tell me.


SECTION A: WORK HISTORY AT THE ABC AND ELSEWHERE AND RESIDENTIAL HISTORY I WOULD LIKE TO ASK YOU SOME QUESTIONS ABOUT YOUR WORK AT THE ABC 1. WHEN DID YOU START WORKING AT THE ABC? Month Year 2. STARTING WITH YOUR FIRST JOB, I’M GOING TO ASK YOU A SERIES OF QUESTIONS ABOUT EACH OF YOUR JOBS AT THE ABC Job No.

Job title

Main duties

Hours per week

Shift work

Month and year started

Month and year finished

Main location (please mark on the site map)

Any special equipment or exposures you are concerned about

1

2

3

4

5

6


7

8

9

10

11

12

13

14

15


I WOULD LIKE TO ASK YOU SOME QUESTIONS ABOUT YOUR WORK OTHER THAN AT THE ABC 3. HAVE YOU WORKED WITH ANOTHER EMPLOYER? YES NO 4. IF YES, STARTING WITH YOUR FIRST JOB, I’M GOING TO ASK YOU A SERIES OF QUESTIONS ABOUT EACH OF THESE JOBS Job No.

Job title

Main duties

Hours per week

Shift work

Month and year started

Month and year finished

Location Any special equipment or exposures you are concerned about

1

2

3

4

5

6

7


8

9

10

5. IS THERE ANYTHING ELSE YOU WOULD LIKE TO TELL ME ABOUT YOUR WORK AT THE ABC OR ELSEWHERE?

I WOULD LIKE TO ASK YOU SOME QUESTIONS ABOUT PLACES YOU HAVE LIVED 6. STARTING WITH YOUR FIRST RESIDENCE, I’M GOING TO ASK YOU A SERIES OF QUESTIONS ABOUT EACH OF THESE PLACES


Residence

No. Name of town or suburb

Nature of this area, eg city/rural/industrial/farming

Month and year started living here

Month and year finished living here

Any parrticular exposures you were concerned about in this area

1

2

3

4

5

6

7

8

9

10


11

12

13

14

15

7. WHAT WAS YOUR FATHER’S MAIN OCCUPATION? _____________________________________________ 8. WHAT WAS YOUR MOTHER’S MAIN OCCUPATION? _____________________________________________

ABC EXPERT PANEL INTERVIEW

SECTION B I WOULD LIKE TO ASK YOU SOME GENERAL QUESTIONS ABOUT YOU AND YOUR LEISURE ACTIVITIES 1. How tall are you? Feet & Inches OR Cms

and

2. How much do you weigh? Stones & lbs OR Kgs

3. How often do you do any exercise? Give some examples like walking

Rarely/Never 2-3 times a week less than once a week 4-6 times a week Once a week Every day

4. How often do you do strenous exercise like running, aerobics? explain

Rarely/Never 2-3 times a week less than once a week 4-6 times a week Once a week Every day

5. On average, how many hours on a typical weekday would you spend doing sitting down activities like driving, reading, watching television or working at a desk or computer?

<1hr 5-6 hrs 1-2 hrs 7-8 hrs 3-4 hrs >8 hrs

6. On average, how many hours on a typical weekend would you spend doing sitting down activities like driving, reading, watching television or working at a desk or computer?

<1hr 5-6 hrs 1-2 hrs 7-8 hrs 3-4 hrs >8 hrs

NO YES 7. Have you ever been a smoker? If ‘NO’ go to Question 8

Years


7a How old were you when you first started smoking? Number 7b. How many cigarettes do you now or did you smoke each day, on average?

NO YES 7c. Are you an ex-smoker?

Years

7d. For how many years did you smoke? 8. On average each week how much wine, beer or spirits do you drink?

Number 8a. Wine – number of glasses (125ml) per week explain

Number 8b. Beer – number of glasses (250ml of 5%; 500ml of light beer) per week explain

Number 8c. Spirits – number of measures (30ml) per week 8d. What is your marital status? TICK BOX

Single 1 Married 2 Divorced 3 Separated 4 Widowed 5 Other [please specify]: 6

Is there anything else you would like to add?


SECTION B I’D NOW LIKE TO ASK YOU SOME QUESTIONS ABOUT WHEN YOU WERE YOUNGER

Years

9. What age were you when you finished school? 10. What is the highest level of qualification you have completed? TICK BOX

No formal qualification 1 School Certificate (or equivelent) 2 HSC (or equivalent) 3 Trade / apprenticeship 4 Certificate or Diploma 5 Degree or higher degree 6 Other [please specify]: 7

Years

11. How old were you when your periods started ?

NOTES


SECTION C I WOULD NOW LIKE TO ASK YOU SOME QUESTIONS ABOUT YOUR USE OF THE PILL

NO YES 12. Have you ever used the pill (oral contraceptive)?

if No, please go to Question13

Years 12a. Can you remember how old were you when you first went on the pill?

Years 12b. Do you remember how old were you when you last came off the pill?

Years

12c. can we work out how many years in total you did take the pill? (Add together the years and months when she actually took the pill. Do not count the years and months when she was not taking it. Write "0" if she used the pill for less than a year in total) I WOULD LIKE TO ASK YOU SOME QUESTIONS ABOUT PREGNANCIES

Number

13. How many pregnacies have you had excluding miscarriages ?

If None, please go to Question 14 13a. What was the date of birth for each child born, (including stillbirths)? List from eldest to youngest and if they were twins or triplets repeat the same date for each child. And for how many months did you breastfeed, if at all? Breastfeeding, if not breast fed put ‘0’ if breastfed for a month or less put ‘1’

DATE OF BIRTH (if livebirth) Day Month Year Stillbirth Livebirth Breastfed- Months Child 1 Child 2 Child 3 Child 4 Child 5 Child 6


NOW I WOULD LIKE TO ASK YOU SOME QUESTIONS ABOUT THE USE OF HORMONE REPLACEMENT THERAPY (HRT) NO YES 14. Have you ever had a hysterectomy?

Years 14a. If Yes how old were you? DON'T NO YES KNOW

15. Have you ever had both ovaries removed?

DON'T NO YES KNOW

16a. Have you gone through the menopause? NO YES Irregular

16b. Have your Periods now stopped?

If Yes Years

16c. How old were you when they stopped?

16d. For what reason did your periods stop TICK BOX A Hysterectomy and/or removal of overies Post Menopause Medication (pls describe) ________________________ Other (pls describe) _____________________________

NO YES

17. Have you ever used hormone replacement therapy (HRT)? If NO go to SECTION D Years

17a. How old were you when you first started using HRT? NO YES

18. Had your periods stopped before you started using HRT? ("Yes" if you had a hysterectomy before starting HRT)

Years

19. How many years in total you have used HRT? (Add together the years and months when you used HRT – do not count the years and months when you were not using HRT. Please write "0" if you used HRT for less than a year in total)

NO YES

20. Are you now using HRT?


If NO Years 20a., (Name) how old were you when you last used HRT? Is there anything else you would like to add?

NOTES


SECTION D Part 1. The next section is about your breast cancer diagnosis, if you find the questions upsetting or painful just let me know and we can stop for a while or we can come back to the questions later. I WOULD NOW LIKE TO ASK YOU SOME QUESTIONS ABOUT MAMMOGRAPHY, BREAST CANCER AND OTHER BREAST LUMPS 21. When was the breast cancer diagnosed? Month Year

Age 22. How old were you ? 23. How was the breast cancer found TICK BOX

Felt a lump in the breast 1 Some other symptom -if so what____________________________ 2 Mammogram 3

If BY Mammogram

23a. Was this mammogram: TICK BOX A regular screening mammogram (define) done at time it was due? 1 Prompted by publicity or concerns about the occurance of breast ca in women at the ABC 2 Prompted by a symptom or some other factor not related to the publicity at the ABC 3 If yes, what symptom or factor? ____________________________________ 24. How was the breast cancer treated? TICK BOX

Surgically removed - mastectomy 1 Surgically removed - lumpectomy 2 Radiotherapy 3 Chemotherapy 4 Other____________________________ 5

24a. If surgically treated, when was this? Month Year

25. Have you had any other kind of breast lump or tumour in the breast NO YES Including, a prior breast cancer?

If yes, for each instance

25a. When was it found? Month Year


25b. How was it first found? ____________________________________________ ________________________________________________________________ 25c. Was it biopsied or removed surgically? NO YES 25d. What were you told it was? ___________________________________________ ________________________________________________________________ Is there anything else you would like to add?

NOTES


SECTION D - Part 2: Other questions about mammography

26. Excluding any mammograms already mentioned: Had you had any other screening mammograms before diagnosis NO YES of your most recent breast cancer/breast lump

A screening mammogram is an x-ray of the breast used to detect breast changes in women who have no signs or symptoms (asymptomatic) of breast cancer. It usually involves two x-rays of each breast

If NO go to Section E

27. When was your first screening mammogram? Year Month

28. When was your last screening mammogram? Year Month

Number

29. How many screening mammograms in total have you had? Or

Months 29a. On average how often do have a screening mammogram?

Is there anything else you would like to add?

Notes:


SECTION E NOW I WOULD LIKE TO ASK YOU SOME QUESTIONS ABOUT YOUR FAMILY NO YES 30. Do you have any sisters

DON'T

31. Have either of your grandmothers, your mother, or (either/any of) NO YES KNOW your sister(s) ever been diagnosed with breast cancer?

If YES who TICK BOX Your Maternal grandmother Paternal Grandmother Mother Sister(s) (if yes how many) (Name) Age 32. How old was your ____________ when the breast cancer was first diagnosed? and Age 33. How old was your _____________ when the breast cancer was first diagnosed? Age 34. How old was your _____________ when the breast cancer was first diagnosed? Is there anything else you feel is relevant for us to know which hasn’t been covered in this interview?

I WOULD LIKE TO THANK YOU FOR YOUR ASSISTANCE IN COMPLETING THIS INTERVIEW

Attachment 3 STATISTICAL REPORT: Analysis of data relating to invasive breast cancer incidence among women employed at the ABC Toowong Studios 19th December 2006 Peter Baade, PhD AStat Viertel Centre for Research in Cancer Control Queensland Cancer Fund Acknowledgements: The comments resulting from the statistical review of this statistical report by Professor Michal Abrahamowicz (McGill University, Montreal), in addition to those comments provided by members of the ABC Expert Review Panel, added greatly to the clarity and completeness of this report. Overview of methodology The calculations described in this statistical report were primarily based on the standardised incidence ratio (SIR). The SIR is the ratio of the observed number of cases (women diagnosed with breast cancer) at the ABC Toowong studios to the expected number of cases of breast cancer. The expected number of cases is calculated by applying the breast cancer incidence rate of a larger, relevant population to the population of the female staff at ABC studios. For this analysis, we used the total Queensland population as the reference population to calculate the expected number of breast cancer cases among staff at the ABC Toowong studios. We repeated the analysis using the more specific Brisbane population, but as shown in the results in this report, there was very little difference between the two estimates. To calculate the SIR we followed these steps:

1. Calculate the age-specific incidence rate of breast cancer among females in Queensland (A)

2. Calculate the age-specific population at risk (based on the numbers of female staff working at the ABC studios, and the time they worked there) (B).

3. Multiple A * B to get the age-specific expected number of cases 4. Add across the age groups to get the total number of expected cases (E)

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5. We then obtained the number of observed (and confirmed) breast cancer cases among female staff members (O)

6. The SIR is then calculated as SIR = O / E, and we also calculate a 95% confidence interval for the SIR, which is a measure of the statistical uncertainty we have about the estimate (the narrower the interval, the more confident we are about the estimate).

7. Values of SIR greater than 1.0 indicate an increased risk of breast cancer among the female staff compared to the Queensland female population. If the lower bound of the confidence interval is also above 1, then we say the increased risk is statistically significant.

Details 1. Calculate the age-specific incidence of female breast cancer in Queensland (A).

1.1. Data on invasive breast cancer incidence among females in Queensland

was obtained from the Registrar, Queensland Cancer Registry. 1.2. This incidence data was provided for the period 1994 to 2003 (the latest

year for which published data is currently available) in aggregated format. 1.3. Incidence data were also provided separately for DCIS (in situ breast

cancer). 1.4. Data was reported by 5-year age group (0-4 years, 5-9 years, ..., 80-84

years, 85 years and over). 1.5. Incidence data was provided for “Major City” (South-east Queensland,

based on the standard ARIA+ geographical classification (AIHW 2004)) and for “Rest of Queensland”. Data for “Total Queensland” was the simply the sum of the counts in these two categories.

1.6. Population data was sourced from the Australian Bureau of Statistics

(estimated resident population) for the period 1994 to 2003.(ABS 2004) 1.7. Age-specific incidence rates were calculated by dividing the total number

of breast cancer cases in each age group (between 1994 and 2003) by the total population in that age group (summed over 1994-2003).

1.8. These age specific incidence rates (1994-2003) were used as the expected

incidence rates. 2. Calculate the age-specific population at risk among the female staff at ABC studios (B)

2.1. All data regarding the female workforce at ABC Toowong Studios was provided by Deb Beel, who also provided ongoing advice regarding queries about specific data items.

44

2.2. Edits and corrections to the databases were made in consultation with Deb

Beel. All changes are noted in the statistical programs used for this analysis.

2.3. The workforce at the ABC was not constant over the study period.

Therefore rather than calculating the population at risk in terms of people, we calculated it in terms of “person years at risk” (PYAR). This means that if a staff member worked for 3.5 years during the study period, they would contribute 3.5 years of person years at risk.

2.4. It also means that if a staff member was diagnosed with breast cancer

while still employed at the ABC, they stopped contributing to the person years at risk at the time of diagnosis of the cancer.

2.5. The study period had been previously defined 1st January 1994 through to

30th June 2006. Only staff time between these dates contributed to the person years at risk calculations. Any staff who commenced work at the ABC studios after 30th June 2006 were not included in the analysis. Any staff who commenced work prior to 1st January 1994 only contributed to staff years from that date onwards.

2.6. The ABC used two staff payroll/workforce systems during that time –

TIACS and SAP. The change over date between the two systems was 27th August 2001. These two datasets were combined.

2.7. Due to the large number of categories for “Work Area”, it was decided to

collapse the categories into “Newsroom” versus “Other”. Newsroom included both Television and Radio news staff. The categories were consistent with the background documentation that expressed particular concern about the newsroom workforce. See “Limitations” below for a discussion of the limitations of this data.

2.8. Of the 371 women who were on the workforce during the second period

(2001-2006), 43% were listed as Casual, 45% were full-time, and 12% were part-time.

2.9. During the study period, the youngest age of a female staff member was 18

years, and the oldest was 73. Therefore we have limited the analysis to consider only those women aged 15 to 74 years.

2.10. We have calculated PYARs based on start and end dates of work at the

ABC studios, regardless of work status (Full time, part time or casual). 2.11. There were a total of 550 female staff members at ABC Toowong studios

who were eligible for the study cohort.

a. On average, these women worked at the studios for 3.3 years. Forty women had worked at the studios for the total study period (12.5

45

years), while 16 women had worked there for less than one month (30 days).

b. Over half of the cohort (59%, or 324 women) had worked at the studios between 1st January 1994 and 27th August 2001. Over two-thirds of the cohort (67%, 371 women) had worked between 27th August 2001 and 30th June 2006. About a quarter of the women had worked there in both time periods (26%, n=144).

c. In the first time period, 30% of women staff were recorded as working in the Newsroom. This increased to 41% in the second time period.

d. In terms of their age at entry into the cohort (either 1 January 1994 or commencement date), 18 women (3%) were aged 18-19, 258 women (47%) were aged in their 20s, 153 women (28%) were aged in their 30s, 83 women (15%) were aged in their 40s, and the remainder (38 or 7%) were aged 50 years and over.

2.12. Of the 144 women who had worked at the ABC Toowong studios in both

time periods (see above), 22 of these women were recorded as having changed from “Other” in 1994-2001 to “Newsroom” in 2001-2006. Seven women moved the other direction (see “Limitations” for a discussion of the limitations of this data).

2.13. We calculated the person years at risk that each staff member contributed

in each age group. For example, if a woman was exactly 34 years at entry to the cohort, and exactly 43 years at the end of the study period, then she would contribute 1 year to the 30-34 year age group, 5 years to the 35-39 year age group, and 3 years to the 40-44 year age group.

2.14. The total person years at risk in each age group was then added up across

all the staff members.

3. Multiply Queensland rates by person years at risk to get the age-specific expected number of cases (A * B) 3.1. The age-specific Queensland breast cancer incidence rates (A) were

multiplied by the age-specific person years at risk (B). This gave the expected number of breast cancer cases in each 5-year age group (15-74 years).

4. Add across the age groups to get the total number of expected cases (E) 4.1. These age-specific expected numbers of invasive breast cancer at the ABC

Toowong studios were then added up across the age groups to get the total number of expected cases.

5. Obtain the number of observed breast cancer cases among female staff members

(O).

46

5.1. This was limited to those cancers among women who were diagnosed between 1st January 1994 and 30th June 2006 while still working at the ABC studios.

5.2. There were a total of 13 women who were believed to have had breast

cancer. Histopathology reports were able to be obtained for all cases. Twelve women had invasive breast cancer and 1 had in-situ breast cancer.

5.3. The expert panel advised that since this current investigation was primarily

focused on the more common invasive breast cancers, the single in-situ breast cancer case should not be included in this component of the study.

5.4. One woman identified as having invasive breast cancer was not actually

employed by the ABC (she was a regular radio interviewee only). Since she was not included in the denominator (ie. person years at risk) she was also excluded from the list of cancer cases, for the purpose of this analysis. One other woman left the ABC 34 years prior to her diagnosis of breast cancer. Since this woman was not employed at the ABC during the study period (and therefore was not included in the denominator) she was also excluded from the list of cancer cases (numerator) for the purpose of this analysis.

5.5. This left us with 10 confirmed, eligible breast cancer cases among the

study cohort.

6. Calculate the standardised incidence ratio (SIR)

6.1. The SIR is calculated as SIR = O / E. 6.2. A 95% confidence interval for the SIR was also calculated, which is a

measure of the statistical uncertainty we have about the estimate (the narrower the interval, the more confident we are about the estimate).

6.3. The confidence interval was estimated using the method specifically

recommended for the estimation of standardised incidence ratios with small numbers of observed cases (WSDH 2002). This method is based on the assumption that the observed number of cases follows the Poisson distribution. It implicitly accounts for the fact that the observed (and expected) numbers are summed-up across the age categories (since the variance of the sum of the age-specific independent Poisson variables equals the variance of the total observed number). Exact confidence limits were calculated for the total observed count, and then these confidence limits were divided by the expected count.

6.4. We also calculated the probability that, given the expected number of

cases, the observed number of cases occurred by chance (again assuming a Poisson distribution).

47

7. Presentation of results

7.1. Values of SIR greater than 1 indicate an increased risk of breast cancer among the female staff compared to the Queensland female population. If the lower bound of the confidence interval is also above 1, then we say the increased risk is statistically significant. [Some analyses may report SIR values as a percent—this is simply the SIR*100]

7.2. SIRs are presented for all work areas at the Toowong site combined. Initially we tried to calculate SIR for separate work areas, however, as noted in the “Limitations” section below, this level of detail was not possible.

8. Assumptions

8.1. The reported SIR does not account for any potential differences in characteristics related to breast cancer incidence risk between the women working at the ABC Toowong studios and the general Queensland female population, except the difference in age distribution which was accounted for by calculating age-specific expected numbers of cases.

9. Results

9.1. Based on the methodology and assumptions provided above, the expected number of invasive breast cancer cases among female staff working at the ABC Toowong Studios over the study period (1st January 1994 - 30th June 2006) was 1.60 cases (or 1.66 cases if we use the Brisbane incidence rates as the reference population).

9.2. The SIR for 10 observed cases was 6.25 [95% confidence interval: 3.0 –

11.5]. If we use the Brisbane incidence rates as the reference population, then the SIR changes only slightly (6.02 [2.9 – 11.1]).

9.3. These results suggest that the incidence of breast cancer among female

staff working at the ABC Toowong Studios may be about 6 times higher than what could be expected based on the age-specific breast cancer incidence rates of the Queensland female population. Taking the statistical uncertainty into account, we have high confidence that the breast cancer rates among female staff at ABC Toowong studios are at least 2.9 times higher than expected.

9.4. Given the expected number of breast cancer cases was 1.60, and assuming

that the cases follow a Poisson distribution, then the probability of observing at least 10 cases is p=0.000001025. So there is less than a 1 in 900,000 probability that the observed number of cases occurred purely by chance.

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9.5. Of the study cohort, the average time worked at the ABC (including time worked at the ABC prior to 1994) among the 10 cases prior to diagnosis was 12.3 years (range 6-18 years), while the average for the 540 non-cases was 4.4 years (range 0-39 years).

9.6. The average time worked at the ABC Toowong Studios during the study

period (excluding time worked prior to 1994) among the 10 cases was 6.5 years (range 1-11 years), while the average for the 540 non-cases was 3.2 years (range 0-12.5 years).

9.7. We calculated women’s age at either the start of the study period

(01/01/1994) or when they started work after that date. 9 out of the 10 (90%) cases were aged in their 20s or 30s. In comparison, 74% of female staff were aged in their 20s or 30s.

9.8. Seven out of the 10 cases (70%) had worked long term (>5 years) in the

newsroom. However, for the reasons mentioned above, it is not possible to make a direct comparison of this percentage with the overall female workforce.

9.9. Of those women (n=371) who worked at the ABC studios between 2001-

2006, 8 were cases and 363 were non-cases. About 63% of cases worked full time compared to 45% of non-cases.

9.10. To assess if the risk of breast cancer was associated with duration of

previous work at ABC Toowong studios, we used a Cox proportional hazards regression model with age (in single years) as the “time axis” and past work duration (including time worked prior to 1994) as a time-dependent covariate, updated over follow-up time.

9.11. Note that time worked prior to 1st January 1994 may not have been at the

ABC Toowong studios (see 10.6 below). 9.12. This model indicated a trend toward increasing risk of invasive breast

cancer with increasing duration of past work at the ABC. Adjusting for the woman’s age, the risk of invasive breast cancer increased significantly by about 12% for one year increase in the duration of past work at the ABC Toowong studios (Hazard Ratio: +1.120; 95% CI: 1.02-1.23; p=0.022).

9.13. Further miscellaneous results are provided in Appendix A.

10. Limitations

10.1. The results may be influenced by small numbers and the fairly transient/dynamic nature of the workforce at the Toowong site of the ABC (in contrast to a closed defined cohort that is followed over time).

10.2. No consideration has been given to time lag from possible exposure to

cancer diagnosis. However it is worth noting that all 10 cases have worked

49

at the ABC for at least 5 years before the diagnosis, and most (7) for more than 10 years.

10.3. In this analysis we have not considered any other factors (apart from age)

that could explain the difference in breast cancer risk between the ABC staff and the Queensland female population. Medical research suggests there are a range of factors that contribute to female breast cancer risk, and it is possible that the presence or absence of these factors among the ABC staff have contributed to the increased risk.

10.4. The administrative data on area of work (ie. “Newsroom” vs “Other”)

within the Toowong site was not complete or detailed enough for a more in depth analysis by work area. Such work data usually reflects an administrative structure rather than the true work location for the people involved. In addition, many staff at the Toowong site are known to often change work roles and locations and even in a particular job they may work in 2-3 different work areas. These limitations in the provided work data were clearly apparent as, for example, the only occasion when staff were recorded as changing work areas was when the payroll system changed in August 2001.

10.5. Any major sources of bias in these results are not immediately evident.

One source could have been ascertainment bias. However by establishing case definitions based on pathology reports the possibility of over-ascertainment is excluded. If there was under-ascertainment (ie. we missed some true cases), then our estimated SIR would be lower than the “true” SIR, so we would be under-estimating the real observed effect.

10.6. Time worked at the ABC prior to 1st January 1994 may have been at sites

other than the ABC Toowong studios. Specific details regarding this were not available at the time of analysis. This does not impact on any of the SIR estimates, since these calculations are based on time worked at the ABC Toowong studios since 1st January 1994.

11. Other considerations

11.1. Most of the cancer cases were diagnosed among longer term workers at the

ABC. If we restricted the analysis to longer term workers, then assuming the numbers of cases would remain the same, we would increase the calculated SIR.

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References ABS (2004). 3201.0 Population by Age and Sex, Australian States and Territories.

Canberra, Australian Bureau of Statistics (Catalogue number 3201.0) (www.abs.gov.au).

AIHW (2004). Rural, regional and remote health: A guide to remoteness classifications. Canberra, Australian Institute of Health and Welfare AIHW Cat. No. PHE 53.

WSDH (2002). Guidelines for using confidence intervals for public health assessment., Washington State Department of Health (http://www.doh.wa.gov/data/guidelines/ConfIntguide.htm).

51

http://www.abs.gov.au)/

http://www.doh.wa.gov/data/guidelines/ConfIntguide.htm)

Appendix 1: Additional data The following information was provided in response to ah-hoc requests from the ABC Expert Review Panel. A.1. Length of time worked at the ABC studios. The figure below shows the total time that each member of the study cohort had worked at the ABC. This includes time worked at the ABC prior to 1st January 1994 (which may or may not have been at the ABC Toowong studios). It shows that each of the cancer cases (n=10) had worked at least 5 years at the ABC studios prior to their cancer diagnosis.

0%10

%20

%30

%P

erce

nt

0 5 10 15 20 25 30 35 40Total number of years worked at ABC Studios

Based on workforce data provided by ABCOnly female staff who worked between 01/01/1994 - 30/06/2006 are includedCases (n=10) indicated by circles

Total time working at ABC Studios up to 30th June 2006,including time worked prior to 1st January 1994

Females only (n=550)

A.2 Expected counts for DCIS (in-situ breast cancer): Although this statistical report focuses on invasive breast cancers, we also obtained population data on DCIS (in-situ breast cancers). Final numbers of DCIS among staff at ABC Toowong studios have not yet been confirmed. However based on total Queensland incidence rates of DCIS, we would expected 0.186 cases among female staff employed at the ABC Toowong studios over the study period. The corresponding estimate based on Brisbane incidence rates was 0.209 cases of DCIS. Further information and interpretation of the DCIS data is beyond the scope of this report.

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A.3. Average age, PYAR and duration of employment among study cohort. Table A.1: Average age, PYAR and duration of employment among study cohort Age (years) 1 PYAR (study) 2 Duration of

employment 3

Cases N 10 10 10 Average (95% CI) 33.5 (29.3, 37.8) 6.5 (4.6, 8.4) 12.3 (9.2, 15.4) Median 32.5 6.2 12.6 Q1 26.9 4.9 6.3 Q3 38.4 8.4 17.5 Non-cases N 540 540 540 Average (95% CI) 32.5 (31.6, 33.3) 3.2 (2.9, 3.5) 4.4 (3.9, 5.0) Median 29.9 1.9 2.0 Q1 24.1 0.9 0.9 Q3 38.5 4.3 5.2

1. based on the women’s age at the start of the study period (01/01/1994), or (if they commenced after 01/01/1994) their age when they commenced employment.

2. Person years at risk for the study cohort over the study period only (01/01/1994 – 30/06/2006)

3. Total years employed by the ABC for the study cohort including time worked before 01/01/1994.

A.4. Sensitivity analyses Some of the breast cancers (n=3) were diagnosed following routine screening mammography, and the diagnosis of one cancer was prompted by knowledge of the other breast cancer cases at the Toowong studios. To investigate the effect of these screen-detected cases on the results, additional analyses were conducted to see what the impact of excluding these cases was. When we removed these four screen-detected cases from the listed of breast cancer cases, we obtained the following results. Expected number of cases = 1.60 Observed number of cases = 6 Standardised incidence ratio (SIR) = 3.75 95% confidence interval = 1.4 – 8.2 Probability of at least 6 cases occurring by chance = 0.001 (about one in 750)

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A.5 Age distribution of cohort members

Table A.2

Age distribution of person years for women in employment with the ABC at Toowong in the period 1st January 1994 to 30th June 2006 1




15-19 years 14.8 (1%) 35-39 years 283.4 (16%) 55-59 years 86.4 (5%) 20-24 years 217.2 (12%) 40-44 years 215.2 (12%) 60-64 years 53.2 (3%) 25-29 years 293.4 (16%) 45-49 years 162.5 (9%) 65-69 years 3.3 (0%) 30-34 years 337.1 (19%) 50-54 years 141.1 (8%) 70-74 years 2.0 (0%) 1. Based on the number of years each of the study cohort spent in each age group. For example if they started work on 1st January 2000 aged exactly 33, then they would contribute 2 years to the 30-34 year age group, and 4.5 years to the 35-39 year age group (assuming they continued working up to 30th June 2006). A.6 SIR estimates by age group. Note that age group was based on the women’s age at the start of the study period (01/01/1994), or (if they commenced after 01/01/1994) their age when they commenced employment. Table A.3 SIR estimates by age group 1

Age group 1 Observed Expected SIR 95% CI 15-39 years 5 0.27 18.23 [5.9 – 42.5] 40-49 years 4 0.55 7.23 [2.0 – 18.5] 50 years + 1 0.77 1.30 [0.0 – 7.2] Total 10 1.60 6.25 [3.0 – 11.5] 1. Based on the women’s age at diagnosis.

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Appendix 2: Calculation of the expected number of breast cancers in the study cohort. These calculations were provided solely as a rough check to confirm the more detailed calculations described earlier in the report.. Invasive breast (females) cancer incidence data obtained from Kerrie Dennison (QCR) for the period 1994 - 2003 (inclusive); ABC staff data obtained from Deb Beel, ABC.

Age group PYAR Age-specific incidence of

invasive breast cancer Expected countObserved count

/100,000 population 15-19 14.8173 0.1619 0.0000 0 20-24 217.2238 0.9408 0.0020 0 25-29 293.4429 6.7255 0.0197 0 30-34 337.0945 25.2059 0.0850 1 35-39 283.4120 59.1282 0.1676 4 40-44 215.2012 112.1645 0.2414 3 45-49 162.5058 191.9337 0.3119 1 50-54 141.1033 236.2389 0.3333 1 55-59 86.4353 287.4376 0.2484 0 60-64 53.2081 325.4149 0.1731 0 65-69 3.2793 323.0583 0.0106 0 70-74 1.9904 334.7344 0.0067 0 Total 1809.7138 1.5998 10 Crude rates Observed (ABC Staff) annual incidence (15-74 years) / 100,000 PYARs = 552.57 Expected (QLD female population) annual incidence (15-74 years) / 100,000 population = 125.1

There were 550 female staff members. Thus the total of 1809 PYAR equates to an average of about 3.3 PYAR for each staff member over the study period. Published Breast cancer incidence rates in 2003 (QCR report)

Age group

Age-specific incidence of invasive breast

cancer /100,000 population 15-19 0.0 20-24 0.0 25-29 7.7 30-34 27.0 35-39 60.3 40-44 122.3 45-49 197.0 50-54 230.2 55-59 281.4 60-64 325.5 65-69 364.0 70-74 317.8

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Attachment 4

ABC Toowong

Hazards assessment and further monitoring requirements

Geza Benke, PhD

Centre for Occupational and Environmental Health Department of Epidemiology and Preventive Medicine

Monash University Victoria

Brief

This report aims to document the history of the ABC Toowong site with respect to hazards possibly causative of breast cancer. The hazards investigated were in part identified through information from the work histories collected by Professor Malcolm Sim and also in part from a walk through survey undertaken by Dr Benke on Monday 13th November 2006. The information in this report should be used to direct further environmental monitoring where considered necessary and to comparatively assess risk from all possible environmental hazards on the site. 1. Site history: Overview Prior to the construction of the first ABC buildings on the site in 1959, the site spanned two residential premises, Middenbury House and Sydney House. The plans of 1/5/1959 clearly show that the TV building was constructed over a former driveway/car-park to the original residences. This history eliminates the possibility that the TV building was constructed on a former orchard (possible pesticide residues) or an industrial site (unknown radiation source or contaminated site). The TV building was constructed in five stages, with the initial stage in 1959, stage two in 1961, stage three about 1967, stage four in about 1985 and the latest refurbishment over the former car-park in 2000. The current TV building is constructed on a concrete slab and does not have any basement levels. Prior to 1985 the TV News group was broken across a number of locations i.e. under the lower ground and off site. Management of Radio was at Sherwood Road prior to 1985. In 1985 TV News was located in the First Floor of the TV Building. In 2000, following an extension of the ground floor, that involved the inclusion of the former river side car-park, the TV News group was relocated to the ground floor. The current occupiers of the first floor are the Digital group that went “On-line” about 2003, but were formed in 1997. The Digital group formed as a small subunit in 1997 and were part of the Radio News group for the first 5 to 6 years of operation. Radio News has been located on the ground floor since 1985, and was joined by TV News after the 2000 refurbishment.

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2. Physical Hazards 2.1 Ionizing radiations There is no documented history of the use of ionizing radiation on the site. Given the nature of the operation of the ABC at Toowong it is also unlikely any irradiating apparatus i.e. X-ray or industrial radiography machines, or radioisotopes, have been ever used/operated on the site. Radiation contamination could only be possible on-site if the original (or subsequent) construction material had been inadvertently contaminated (an extremely unlikely occurrence) prior to it arriving on-site. Radon gas exposure is unlikely, but possible. Radon gas and it’s progeny usually builds-up in cellars and well sealed buildings and a survey undertaken by ARPANSA about 20 years ago found that exposure inside Australian buildings and dwellings to radon is negligible. 2.2 Non-Ionizing radiations 2.2.1 Radiofrequency (RF) Since this has been a TV and radio broadcasting and receiving site for over 40 years it has numerous RF communications devices located within its perimeter. The current RF sources are described in both the THL Australia report of 16th February 2004 and the EMC Technologies report B050401, 2nd May 2005. A history of the equipment on site prior to 1980 was not forthcoming. However, it appears that most of the equipment on site was added in the past twenty years due to advances in technology, with little replacement of older receivers and transmitters. It can be assumed that the current RF exposure levels are probably higher than at any time during the operation of the site, due to the incremental addition of RF sources. The THL RF Hazard control document of 16th February 2004 indicates that the most prominent RF source on site is the 7 meter satellite dish on the TV Building rooftop, operating at 14 Ghz. The three VHF Comms, 3 metre antennae have high maximum power and operate between 168 and 172 MHz. Overall the RF sources on site cover a wide range of frequencies and power outputs. In these circumstances it is advisable to check the broadband exposures in the offices below. The EMC RF survey clearly indicated that broadband exposure levels were well below the ARPANSA reference levels, as outlined in the 2002 ARPANSA standard for exposure to RF radiation between frequencies of 3kHz and 300GHz. In all the office work areas in the TV building the levels were below the detection limit of the survey meter (<2 V/m). This is not surprising in view of the RF sources currently in place and the known high directionality of these sources. Additionally, since the broadband measurements do not indicate any excess exposure to RF it is most unlikely any future narrow band measurements will result in excessive exposure results in the office areas. The security card readers operate at only 125kHz , significantly lower than the other RF sources on site. The card readers can be categorized as low frequency (LF) sources compared to the other sources on site. The concern from staff was that if the hands were engaged in carrying books, bags or equipment, the employee would simply bring

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their chest in close proximity to the card reader and perhaps be exposed to intermittent high levels of RF radiation. The EMC report indicated that at 5 centimetre distance from the card reader the levels were only about a quarter the reference levels. In addition, given the brief exposure periods over the course of a work-shift i.e. perhaps 1 to 2 minutes at most per day, the time-weighted average exposure should be extremely low. 2.2.2 ELF-EMF The ELF-EMF (50/60 Hz) exposure has not been measured in the TV building. Given the high concentration of communications equipment in many of the workstations in this building, exposure is expected to be higher than in a normal office environment e.g. computers and Decart audio systems are located at many workstations, there are also large number of editing rooms with electronic equipment etc. The power requirement to the ABC Toowong site is clearly significant, given the site has its own substation. This indicates that there exists many potential power intensive sources and that power frequency currents, required for high ELF-EMF exposures are present. 3. Chemical Hazards 3.1 Asbestos The construction of the TV building involved the use of materials containing asbestos. These were primarily the use of AC sheeting, asbestos vinyl tiles and millboard. Significant removal was undertaken in the late 1980s with a few small batches removed about 2000 (at the time of refurbishment of the ground floor and renovation of the air-conditioning system). Asbestos in the heater banks and asbestos containing millboard were also involved in the latter removals. All removal was undertaken by an approved asbestos removalist and all documentation required under Queensland OHS regulations are kept on site. Generally, the removal of AC sheeting does not present a high risk for asbestos exposure, if the removal is undertaken by a competent removalist. It is also unlikely exposure to friable asbestos would be present in the office areas of the TV building at the times during removal given the requirement for containment in the Queensland regulations dating back to the mid-1980s. 3.2 Environmental Tobacco Smoke (ETS) Smoking was banned inside buildings at the Toowong ABC site in March 1989. It is now impossible to assess the extent of passive smoke exposure in the work areas of the TV building in the 1980s. Recall of persons that may have worked in this environment would be unreliable and could not be compared with other office environments. Population smoking rates were higher in the 1980s and so an estimate of exposure based on the current number of smokers in the employ of the ABC today would probably be an underestimate. 3.3 Pesticides Since the site was a residential premise prior to construction of the ABC buildings it is unlikely any pesticide contamination was present at the site pre-1960. Arrest-a-Pest has been the pest control contractor since at least the early 1980s. The pesticides of most concern are the organochlorines (OCs) comprising chemicals such as DDT, Lindane and Chlordane. This group of insecticides has a relatively long residual time

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in the environment (5 years) and they are weak estrogens which may increase breast cancer risk by mimicking endogenous estradiol. The pesticides of less concern are the organophosphates, carbamates and synthetic pyrethrins, which have relatively short environmental residual times (days to a month at most) and do not accumulate in body tissue over prolonged time periods. The use of OCs was discontinued in Queensland about 1995. Between 1985 and 1995 OCs were used in very limited quantity for termite control around the exterior of buildings and under slabs prior to construction. The use of OCs inside buildings and homes was discontinued in Queensland in the early 1980s. Synthetic pyrethrins have been predominantly used for termite control in the past 10 years. Following contact with Mr Chris Hill of Arrest-a-Pest it was confirmed that no significant quantities of OCs were used at the ABC Toowong site (Mr Hill has been in the employ of Arrest-a-Pest since 1989). Mr Hill could not comment on the use of OCs at the site pre-1980s. 3.4 Water The water supply to the site is from the Brisbane community water supply and most unlikely to be contaminated. There has been no water testing undertaken from water taps at the site. Heavy metal contamination, such as arsenic, cadmium, chromium, lead, mercury or nickel is possible if the water piping has been contaminated by some outside source or there has been significant corrosion of old piping. Testing of the drinking water in accordance with the NHMRC Australian Drinking Water Guidelines 2004, could reveal if heavy metal contamination is present. Although we believe these measurements are unlikely to identify any heavy metal concentrations above the guideline standards, they should eliminate this as a potential source of toxic intake. It must also be emphasised that measurements undertaken in 2006 are unlikely to have much bearing upon the water quality of earlier years e.g. 1995 or 1985, since concentrations to some metals could change due to corrosion in the metal pipes etc. 3.5 Other chemicals, hydrocarbons and solvents Concerns were raised that there may have been exposure to other chemicals, hydrocarbons and solvents via: (i) Tanks removed from the car-park area in 2000

Two former petrol tanks were removed from the car-park in 2000. These tanks were disused since 1996 and remained in-situ for four years. This time period would have enabled any volatile hydrocarbons trapped in the tanks or soil to have successfully evaporated. There would only have been high-carbon hydrocarbons remaining at the time of removal, with little if any volatile hydrocarbons present. Soil measurements were taken at the time of the removal with the results showing no contamination found.

(ii) Cleaning of the air-conditioning system

Concerns had been raised about chemicals used for the cleaning of the air-conditioning system for the TV building. Contact was made with Mr Bruce Clayton of Haden, the air-conditioning contractors for the site. Mr Clayton confirmed that the condensate trays were cleaned with a common detergent to remove slime on an infrequent basis. This is a soap-based detergent and therefore not considered toxic. There is also routine maintenance undertaken on the ductwork that involves vacuuming also on an infrequent basis. The

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filters are not cleaned but replaced once the pressure drop exceeds 150 pascals, and this is normally required about once a year. The heat exchangers are cleaned of grime on an infrequent basis by a chemical named “Coil and Filter cleaner AK’ manufactured by Sterile-Care Pty Ltd. The Material Safety Data Sheet (MSDS) was obtained for this product and indicated that the active ingredient was a Quaternary ammonium compound and that it also contained alkaline salts at a concentration of 90 grams per litre. Neither of these compounds are considered carcinogens or suspected carcinogens in the literature. Ammonium compounds have been linked with respiratory disease such as occupational asthma, and alkaline salts are considered skin irritants.

(iii) Ceiling tiles

The ceiling tiles in the ground floor of the TV building were installed during the refurbishment undertaken in 2000. These are Armstrong RH90 tiles manufactured in the USA in December 1997 with batch no. S3570B, recorded on them. Access to the MSDS of this product can be obtained via the Armstrong website: www.armstrong.com/home/us/en/. Prior to the refurbishment in 2000, Gyprock with vinyl coating ceiling tiles were fitted throughout the building since the 1970s. These products are unlikely to have any off-gassing of volatile organic compounds (VOCs) such as n-hexane, n-pentane, xylenes, toluene or 2-mthyl butane. Formaldehyde off-gassing has been a hazard in commercial office buildings using older style ceiling tiles, but this is almost certainly not the case in the TV building.

4. Recommendations for further monitoring Recommendation 1: Given that ionizing radiation is the only known environmental exposure that increases breast cancer risk, it would be prudent to undertake radiation dose rates, contamination monitoring and radon gas concentration measurements in the TV building. This should confirm whether radiation levels are at normal background or whether there has possibly been some contamination present from an as yet unknown source. Recommendation 2: An ELF-EMF measurement survey should be undertaken on the ground and first floor of the TV building. This should involve dosimetry to workers in various workstations on both floors. Recommendation 3: Water testing be undertaken in accordance with the NHMRC Australian Drinking Water guidelines 2004. 5. References Hansen J. Breast cancer risk among relatively young women employed in solvent–using Industries. Am J Ind Med 1999;36:43-47 McElroy J, Shafer M, Trentham-Dietz A et al. Cadmium exposure and breast cancer risk. J Natl Cancer Inst 2006;98:869-73

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Tokunaga M, Land C, Tokuoka S et al. Incidence of female breast cancer among atomic bomb survivors 1950-1985. Radiat Res 1994;138:209-223 Weiderpass E, Pukkala E, Kauppinen T et al. Breast cancer and occupational exposures in women in Finland. Am J Ind Med 1999;36:48-53 Wells A. Breast cancer, cigarette smoking, and passive smoking. Am J Epidemiol 1991;133:208-210 APPENDIX 1. Specifications for measurements according to recommendations: Ionizing Radiation Surface contamination should be checked in the office areas of the ground floor and first floor of the TV Building with a Portable Contamination Meter fitted with an alpha/beta radiation probe. Dose rates are to be measured in the office areas with a calibrated dose-rate meter. Radon concentrations should be measured by use of a real-time radon monitor. In addition, dose-rate measurements should be measured at the air-conditioner filters to the building, as these are most likely to trap natural radioactivity from the air. Results are to be compared with the backgrounds in the Brisbane area. Power Frequency EMF For a survey of ELF-EMF exposure we suggest the use of EMDEX-II dosimeters to assess the time-weighted daily exposure of about four or five workers on the ground floor and a similar number on the first floor of the TV Building. It is important that personal measurements are ascertained as spot measurements alone will not be sufficient. A handful of measurements should also be undertaken with workers in the Woodhouse building and the Riverside Block (to act as controls). The results may then be compared with industry norms published in the Australian and international literature. Spot magnetic field measurements should also be undertaken in the TV Building, particularly in the vicinity of the workstations where the personal dosimetry is undertaken. These measurements should indicate the main sources of ELF exposure. Water Testing The water testing should be undertaken according to the National Health and Medical Research Council- Australian Drinking Water Guidelines 2004. We suggest that samples be taken on the ground floor and first floor of the TV Building. The samples should be analysed for concentrations of arsenic, cadmium, chromium, lead, mercury, barium and nickel and compared with the health standards in Table 10.10 in section 10.8 of the Guidelines. We do not see any need to analyse the samples for organochlorine pesticides listed in Table 10.11 of the guidelines.

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APPENDIX 2: Summary of Known and Suspected Occupational & Environmental Breast Cancer Risk Factors and Exposures Assessed

Breast Cancer Risk Factor (known=K, suspected=S)

Source Exposure levels at ABC_Toowong plausible?

Exposure Assessed?

Assessment of Current Exposure adequate?

Current Exposure at Level of concern?

Ionizing Radiation (K)

Tokunaga et al, 1994

No. There have never been any known sources on site.

No. No. Unknown.

ELF (S)

Laden and Hunter, 1998

Yes. Many sources present.

No. No. Unknown.

RF Broadband (S)

Nil Yes. Many sources present.

Yes. Yes. Not of concern.

Pesticides for Termites (S)

Laden and Hunter, 1998

Possible exposure to OCs in the 1970s and 1980s.

No Not necessary.

Not of concern.

Asbestos (S)

Weiderpass et al, 1999

Yes. Yes, by clearance monitoring

Not necessary.

Not of concern.

ETS (S)

Wells, 1991

Yes. No. Not possible.

Not of concern.

Water (Metals?) (S)

McElroy et al, 2006

Possible. No. No. Unknown.

Solvents/Cleaning agents for AC system (S)

Hansen, 1999

Possible. No. Not necessary.

Not of concern.

Soil, hydrocarbons (around underground tank) (S)

Weiderpass et al, 1999

No. Hydrocarbons and contaminated soil not likely to be airborne.

Yes, soil testing in 2000

Not necessary.

Not of concern.

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third progress report from the independent review...

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