selikoff & nicholson, electric boat groton connecticut cohort 1984

7/28/2019 Selikoff & Nicholson, Electric Boat Groton Connecticut Cohort 1984

1/11

Mortality Experience of 1,918 Employeesof the Electric Boat Company,Groton, Connecticut

January 1, 1967 -.June 3D, 1978

January 27, 1984


2/11

During 1975 and 1976 clinical examinations were conducted of 2,000employees of the Electric Boat Company in Groton, Connecticut. Theresults of th e eza.in.tioD showed that about SOl of tOe workers inthe ?ard had X-ra? abnormalities characteristic of asbestosexposure. The abnormalities were found not onlyused asbestos, but in a l l . production trades.

in insulators whoAlbeltos was a. .

ubiquitous contaminant in the yard with .. y workmen exposed.In order to .ore fully understand the extent of the effects ofa.bestos exposure, a .or tal i ty study was undertaken of theproduction workforce of the ElectriC Boat Shipyard. The atudy groupconsisted of 1,918 males who were employed on January I , 1967 andwho were f i rs t employed hefore January 11 , 1957. Employment wasascertained using seniority l is ts available in various unions of theMetal Trades COWlcil. In addition to the 1,918 .ell, 42 wo.en, 39 ofwhom were office employees with 10 years of seniority, also werel isted. Because of the small number and few deaths (4) no analysiswas undertaken of this group and the remainder of the report will beconcerned with the male employees. Tables 1 and 2 l i s t thedistributions of the entire cohort by age and time lince onset ofemployment and years of employment. Asgroup was employed for less than 20 years.

caD be leen, .os t of theBarely 20l had worked in the


3/11

2

excess is stat ist ically significant at the level. Cancer of a ll siteswas also increased by 1 3 ~ (79.5 deaths expected, 90 observed).The .. or l i tes of cancer increase were of th e lung and .a . t ro-intestinal t ract , l i tes that in other Itudies have been a t t r i -butable to a.bestos exposure. l 'he' .trend in the r l t io of oblServed toexpected deaths, by year from onlet of exp05ure, ahows an increasingrelationship until 25 . years from onset, af ter which d a b l i t t ledifferent from those expected in the general population are leen.The increasing risk with years from onlet of exposure Cand abo withincreasing years of exposure) is characteristic of other asbestosgroups, such as insulation workers. The lower values at longertimes from onset of exposure may be the result of s tat is t icaluncertainties associated with few death$. Only leven cancer deathswere seen in relatively few individuals who achieved 25 y e a ~ s fromonset of exposure (373 of the 1,918). However. they might also bedue to the unusual pattern of asbestos usage at Electric Boat.Prior to 1950, the predominant vessds constructed at Electric Boatwere diesel-electric submarines. These ships required l i t t leasbestos because of th e absence of high temperature steam l ines.After 1950, when the yard became a predominantly nuclear lubmarine


4/11

3

Table 5 shows the .ort.ality data for a ll causes, a ll cancer, lungcanClI!r,diseasework) .increasedwhereas

cardiovascular disease and non-infect.ious respiratoryaccording t.o work activity ( p r ~ d u c t i o n , aupport.. or officeAs can be aeen, both production and aupport workers have

.orul i ty over that aspected for a ll of these causes,the .orul i ty e x p e r i e n ~ e of office employees is in accord

with general population atatist ics. Becaule of the relatively Imallnumbers of deaths in each union group, i t i s not possible to .ake adefinitive aUtement about riaks allociated with particular trades.I t would appear, however, that the r i l b of employment in theElectric Boat Shipyard are spread equally across a ll craft unions.

Table 6 shows the dist.ribution of deaths for a ll causes, s l lcancers,respirat.orydefiCit of

lung cancer, cardiovascular disease and non-infectiousdisease according to calendar period of observation. Adeat.hs of a ll causes in t.he early Years of followup is

generally the case in ot.her groups of employed workers ("healthyworker effect") This occurs because the health statuB of employedworkers is better than that of individuals in the general populationand this selection for health leads to deficits of .ort.ality inearly years of follow-up. For cancer, however, where such the"healthy worker" effect is of less importance, ODe aees elevated


5/11

4

,exposure in shipyard employees. This possibility should be further studied,particularly since a very large number of workers were employed in thisshipyard over the years; i f these early experiences will continue (and, indeed, become worse) i t will be important to inst i tute appropriate medicalsurveillance IDeaBures for the early diagnosis and treatment of cancer.

This report provides a brief summary of the results of the investigation ofthe mortality experience of Groton shipyard workers employed at the ElectriCBoat Company January I, 1967 - June 30, 1978. A much fuller and more detailed analysis is being prepared and will be published. The present review is being made available nevertheless, l ince the prinCipal findingsmay provide guidance for public health measures necessary to meet an antiCipated serious increase in cancer ineidenee, as well as of chronic nonmalignant pulmonary disease (asbestosis).

1. The significant increase in cancer deaths that was found Was somewhat unexpected. We did not antiCipate that this would be seen.s early as i t has been (four-fifths of the men were less than 20years from onset of their shipyard work in 1967, When the studybegan; the major burden of asbestos-anociated cancer tends to


6/11

Table 1

Distribution of 1.918 Electric Boat employeesas of January 1. 1967 .by age ant!. yUTS sinceonset of yard employment

Years since onset of Electric Boat em210vmentAge 10-14 15-19 20-24 25-29 30+ Totals % of Total

25-29 15 1 16 0.830-34 110 9 119 6.235-39 165 51 7 1 224 11. 740-44 139 95 34 18 286 14.945-49 151 89 20 45 2 307 16.050-54 173 82 49 62 16 382 19.955-59 122 91 43 35 18 309 16.1


7/11

Table 2Distribution of 1,918 Electric Boat employeesas of January 1, 1967 by age and years ofyard employment

Years of Zleetrie Boat employmentAile (10 10-14 15-19 20-24 25-29 30+ Total %of Total

25-29 1 14 1 16 0.830-34 3 109 7 119 6.235-39 1 167 48 7 1 224 11.740-44 1 148 107 22 8 1 286 14.945-49 3 155 101 34 13 10 307 16.050-54 2 177 103 56 34 15 382 19.955-59 1 122 101 45 25 18 309 16.160-64 78 67 38 25 9 226 11.865-69 14 14 5 7 49 2.6


8/11

Tabl. :t

StiltU," of 1,918 Electric Boat emp10yeeaas of January I , 1967 and June 30 , 1978Status 6-30-78

Status 1-1-67 Working a t Working DlIIabledUnion aff i l ia t ion Electric Boat Elsewhere Retired Deceased Or I I I TotalProduction Unions 705 139 495 )1 1 19 1669Pipefi t ters 53 14 44 22 2 135Boilermakers 279 57 117 116 9 638Painters 47 1 36 23 3 116Carpentera 71 14 56 34 1 176Electricians 76 19 50 23 2 170Machinist!! 156 26 111 70 2 365I.aborera 13 1 14 17 0 45Fo,,';dry workers 10 1 7 6 0 24.

Support Unions 32 6 28 19 0 85Teamsters 15 4 11 8 0 38Guards 12 2 16 10 0 40Pattern ... k.ers 5 0 1 1 0 7

Office Workers 71 17 50 4 0 164


9/11

Cause of deathAll causes

All cancerLung

~ Colon-rectumStomachBuccal, pharynx,Inrynx, esophagua

Other cancerCardtovascu1ar

HeartCerebral and other"trcuilltory

RespiratoryPneumonia, influenzaNon-infectf.oua

Other causes---------------------

Tll t -J . _

OhSt-lrvt'd nnd PXllccted .Jp;,tl.8 t by couse . (rom 1-1-1;7to 6-JO-197f! " m o , , ~ 1.?18 "]ectrtc Ront employees

Years from onset of employmentTotal ]0 - 14 15 - 19 20 - 24

Obs. Exp.a Obs. Exp. Obs. Exp. Oba. Exp.]56 315.9 19 19.1 93 74.4 120 94.690 79.5 6 4.] 23 17.7 29 24.435 25.9 4 1.3 9 5.7 15 8. 113 10.5 0 .5 2 2.] 4 ] . ]6 4. 2 1 . ] 2 1. 0 2 1 .]6 7.] 0 .5 4 1.7 1 2. 2

30 31.6 1 1.8 6 7. 0 7 9.7200 164.9 9 9. 7 54 ]8.4 70 49.1166 136.0 8 8. 1 45 ]1.9 60 40.7

]4 28.9 1 1. 6


10/11

Unlon HembershipAU unionsProduction unionsSupport unionsOffice union

Table 5

The observed and expected deaths fo r selected causeefrom 1-1-1967 to 6-30-78 among 1,918 Electric Boatemployees by union memberahipC a u s 'e o f d eat h

Cardio-vascularAl l cauaea Al l cancer Lung cancer diaeaseObs. Exp. Obs. Exp. Obs. Exp. Obs. Exp;356 315.9 90 79.5 35 28.9 200 164.9311 272.1 76 68.6 28 22.4 117 142.219 15.4 2 3.9 5 1.3 8 8.126 27.8 1 7.0 2 2. 3 15 14.6

Non-infectiousrespiratorydiseaseDba. Exp.

,-17 11.316 9. 11 0. 60 ' 1.0


11/11

Calendar pedod1967-681969-131974-78

Al l years

Table 6The observed and expected deatha for selected c_useaamong 1,918 Electric Doat employees in differentcalendar periods of time

C a u a e o f d eat h

All causes All cancer Lung ~ a n c e r diaeasaObs. Exp. Oba. Exp. Obs. Exp. .Obs. Exp.39 44.1 13 9.9 7 3. 0 22 23.0

132.3 32 31.6 11 10.3 74 69.7186 139.5 45 37.9 17 12.6 104 72.2356 315.9 90 79.5 35 25.9 200 164.9

No_infectiousrespiratorydiaeaae .abs . Exp.

0 1.46 4. 3

11 5. 617 11.3

selikoff & nicholson, electric boat groton connecticut cohort 1984

Documents