Relationship Between Sick Building Syndrome and Indoor Environmental Factors in Newly Built Japanese Dwellings

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<ul><li><p>Int Arch Occup Environ Health (2009) 82:583593DOI 10.1007/s00420-009-0395-8ORIGINAL ARTICLE</p><p>Relationship between sick building syndrome and indoor environmental factors in newly built Japanese dwellingsMakoto Takeda Yasuaki Saijo Motoyuki Yuasa Ayako Kanazawa Atsuko Araki Reiko Kishi </p><p>Received: 13 December 2007 / Accepted: 18 January 2009 / Published online: 10 February 2009 Springer-Verlag 2009</p><p>AbstractObjectives Indoor air contaminants and dampness indwellings have become important environmental healthissues. The aim of this study is to clarify which factors arerelated to sick building syndrome (SBS) in newly builtdwellings at Hokkaido, Japan, through a comprehensiveevaluation of the indoor environment and validated sickbuilding symptom questionnaires.Methods The symptoms of 343 residents in 104 detachedhouses were surveyed by standardized questionnaires, andthe concentrations of formaldehyde, acetaldehyde, volatileorganic compounds (VOCs), airborne fungi, and dust miteallergen in their living rooms were measured. By summingthe presence or absence of the Wve dampness indicators(condensations, mold growth, moldy odor, high air humid-ity of the bathroom, water leakage), a dampness index wascalculated.Results SBS symptoms were found in 21.6% of surveyedindividuals. In a fully adjusted multivariate logistic regres-sion analysis, the dampness index [odds ratio (OR) = 1.50;95% conWdence interval (CI): 1.061.11], log formalde-hyde (OR = 23.79, 95% CI: 2.49277.65), and log alpha-pinene (OR = 2.87, 95% CI: 1.366.03) had signiWcantlyhigher ORs for SBS symptoms. However, other VOCs,</p><p>airborne fungi, and dust mite allergen did not have signiW-cantly higher ORs.Conclusion Dampness, formaldehyde, and alpha-pinenewere signiWcantly related to SBS symptoms in newly builtdwellings. We should, therefore, take measures to reducethe chemicals and dampness in dwellings.</p><p>Keywords Sick building syndrome Formaldehyde Alpha-pinene Mold Airborne fungi Mite allergen</p><p>Introduction</p><p>The airtightness of dwellings has been increasing recently,with the result that conditions similar to sick building syn-drome (SBS), which occurred in many countries in the1970s, have reemerged in newly built dwellings in Japansince the early 1990s. In Japan, the problem, called sickhouse syndrome (SHS), and other indoor air problems ofdwellings have attracted broad interest (Torii 2002).</p><p>We have previously reported that condensation on win-dow panes/walls and mold growth were related to SBSsymptoms in newly built dwellings (Saijo et al. 2002; Saijoet al. 2004). Building dampness was also signiWcantly asso-ciated with airway infections in various types of dwellings(Bakke et al. 2007). In old multifamily dwellings, damp-ness and odor were signiWcantly related to asthma and SBSsymptoms (Engvall et al. 2001a, 2002). Dampness andmold were further signiWcantly associated with upper andlower respiratory symptoms in oYce buildings (Park et al.2004). Dampness at home has also been signiWcantlyrelated to allergy symptoms in preschool children (Bornehaget al. 2005).</p><p>Several mechanisms are assumed to account for thedampness eVect. Higher humidity in dwellings facilitates</p><p>M. Takeda Y. Saijo M. Yuasa A. Kanazawa A. Araki R. Kishi (&amp;)Department of Public Health Science, Graduated School of Medicine, Hokkaido University, N15, W7, Kita-ku, Sapporo 060-8638, Japane-mail:</p><p>Y. SaijoDepartment of Health Science, Asahikawa Medical College, Midorigaoka, E2-1-1-1, Asahikawa, Hokkaido 078-8510, Japan123</p></li><li><p>584 Int Arch Occup Environ Health (2009) 82:583593mold growth (Garrett et al. 1998b) and the proliferation ofdust mites (Garrett et al. 1998a; Hirsch et al. 1998; Emeniuset al. 2000; Bemt et al. 2006), both of which can aVect aresidents health. Fungi can produce microbial volatileorganic compound (MVOC) (Elke et al. 1999; Kim et al.2007), endotoxin (Thorn and Rylander 1998; Park et al.2006), and (13)-beta-D-glucan (Beijer et al. 2002; Douwes2005) which may also inXuence a residents health. Struc-tural dampness which may be hidden may cause chemicaldegradation of building materials, leading to the formationand emission of 2-ethyl-1-hexanol from the alkaline degra-dation of di-(2-ethylhexyl) phthalate (DEHP) in poly-vinylchloride materials (Wieslander et al. 1999; Sakai et al.2006). The relationship of odor to SBS may be becausemoldy odor reXects exposure to MVOC and pungent odorreXects exposure to formaldehyde, ammonia and otherstrong chemicals (Engvall et al. 2002).</p><p>Indoor air quality has declined in part because of com-prehensive energy conservation campaigns and high energyprices which have motivated people to tighten their dwell-ings and reduce the rate of ventilation. As a consequence,air exchange in many homes is at a historically low level(Ole Fanger 2006). Furthermore, Japan includes snowyregions, like Hokkaido, whose dwellings seem to havegreater airtightness. Thus, the indoor environment of dwell-ings is important; yet, in Japanese dwellings, there havebeen few SBS studies which have evaluated comprehensiveindoor environments for the presence of aldehydes, VOCs,airborne fungi, dust mite allergen, etc.</p><p>The aim of this study is to clarify which factors arerelated to sick building symptoms in newly built dwellingsin Hokkaido, Japan through a comprehensive evaluation ofthe indoor environment and validated sick building symp-tom questionnaires.</p><p>Methods</p><p>Study population</p><p>During the period of 2003 through 2004, a questionnairesurvey of the indoor air quality and presence of SBS innewly built dwellings was performed in six regions ofJapan (Kish et al. submitted). In Sapporo city (Hokkaidoprefecture) in November 2003, the questionnaires were dis-tributed to the occupants of 1,240 dwellings, which were alldetached houses that had been newly built within 7 years intwo new residential areas. The dwellings were chosen froma list of building plan approval applications. The question-naires included queries about the building structure andcharacteristics, the residents habits in the home, and sub-jective symptoms. We asked, Has any one in your dwell-ing experienced any symptoms such as tiredness, headache,</p><p>dermal and mucosal irritation, eczema, or allergic dis-eases? We requested that the one resident with the mostsevere symptoms in the dwelling answer the questionnaireabout symptoms. The residents of 252 dwellings agreed toparticipate in the symptom questionnaire and have mea-surements of the concentrations of aldehydes, VOCs, airborne fungi, and house dust mite allergens performed intheir dwellings. We randomly selected 53 of 100 dwellingsin which at least one inhabitant complained of one or moresymptoms, and we also randomly selected 51 of 151 dwell-ings in which none of the inhabitants complained of symp-toms. The following year, we performed a comprehensiveindoor environment evaluation, and all residents of these104 dwellings completed the symptom questionnaire inSeptember through October of 2004. Average outdoor tem-perature and relative humidity in September 2004 were18.4C and 68%, respectively, and in October 2004 theywere 12.5C and 63%, respectively. During this timeperiod, windows are sometimes opened.</p><p>Questionnaire survey</p><p>We used two types of questionnaires: one for all residentsand the other for the head of the household or his/her part-ner. The questionnaire for all residents queried for informa-tion on personal characteristics and lifestyle, such as age,gender, current smoking, time spent in the dwelling, work-ing hours, stress level, etc. The questionnaire also containedquestions about the history of any previous treatment by aphysician for asthma or allergies. The questionnaire con-tained the symptoms query part of the Japanese version ofMM040EA, a validated questionnaire designed for epide-miologic assessment of SBS symptoms (Mizoue et al.2001). Symptoms surveyed for over the previous 3 monthsincluded the following: general symptoms (fatigue, feelingheavy-headed, headache, nausea/dizziness, diYculty con-centrating); eye symptoms (itching, burning or irritation ofthe eye); nasal symptoms (irritated, stuVy or runny nose);throat and respiratory symptoms (hoarse, dry throat,cough); and skin symptoms (dry or Xushed facial skin, scal-ing/itching of the scalp or ears, dry, itching or red-skinnedhands). For each symptom, the following answers werepossible: Yes, often (every week); Yes, sometimes;and No, never. An additional question concerning theattribution of a symptom to the home environment wasincluded in the questionnaire. SBS symptoms were scoredas positive if at least one sub-symptom was found to occuroften (every week)/sometimes and was thought to be attrib-uted to the home environment. In this paper, generalsymptoms, eye symptoms, nasal symptoms, throatand respiratory symptoms, and skin symptoms refer tothe above mentioned MM040 SBS symptoms. Further-more, any symptom was deWned as at least one positive123</p></li><li><p>Int Arch Occup Environ Health (2009) 82:583593 585SBS symptom. The questionnaire for children who couldnot read and/or write was answered by a parent.</p><p>The other questionnaire for the head of the household orhis/her partner contained questions about dwelling charac-teristics, such as renovation over the past 2 years, Xooringand wall materials in the living room, dampness (condensa-tion on window panes or walls, mold growth, moldy odor,slow drying of wet towels in the bathroom, water leakageduring past 5 years or since you have lived in the dwelling,if 5 years has not passed), pets in the dwelling, the presenceof a smoker in the dwelling, the use of room fragrance, andthe use of insect repellent. By summing the presence orabsence of the Wve dampness indicators, an overall damp-ness index (05) was calculated. Data on the structure andage of the dwelling were obtained from a previous surveydone in 2003.</p><p>Assessment of indoor environmental factors</p><p>Indoor air monitoring of aldehydes, acetone and VOCswere carried out in the living room of each dwelling. Airsamples were collected with a DSD-DNPH diVusion sam-pler (Supelco, Japan) for aldehydes and acetone, and aVOC-SD diVusion sampler (Supelco, Japan) for VOCs at100150 cm above the Xoor for 24 h. Eleven aldehydes andacetone were quantiWed by HPLC and 27 VOCs were quan-tiWed by GC-MS, using a previously described method(Takigawa et al. 2004). The limit of quantiWcation of eachof the chemicals was 1.0 g/m3. Total VOC (TVOC) wascalculated as the sum of all VOCs. To calculate TVOC,VOC values under the lower limits of quantiWcation wereconsidered to be half of the lower limit of quantiWcation.</p><p>Indoor airborne fungi were collected on dichloran 18%glycerol agar (DG-18) as cultural medium using a SAS airsampler (AINEX BIO-SAS, International Pbi, Italy) for a0.1 m3 air volume at a height of 150 cm above the Xoor inthe living room. The DG-18 medium was incubated at27C, fungal colonies were counted and species were iden-tiWed morphologically at the Mitsubishi Chemical MedienceCorporation (Tokyo, Japan). The fungal levels wereexpressed as colony forming units per cubic meter of air(CFU/m3).</p><p>Dust samples on the Xoor of the living room were col-lected with a hand vacuum cleaner (HC-V15, National,Japan) equipped with a paper Wlter for 0.5 m2/min. Der p1and Der f1 levels of the dust samples were quantiWed byELISA at the LCD Allergic Center (Osaka, Japan); thelimit of quantiWcation of both mite allergens was 0.1 g/g-Wne dust. Der 1 levels were calculated as the sum of quanti-Wed Der p1 and Der f1. To calculate Der 1, Der p1 and Derf1 values under the lower limit of quantiWcation were con-sidered to be half of the lower limit of quantiWcation.</p><p>The temperature and relative humidity in the living roomwere monitored by a Thermo Recorder TR-72U (T&amp;D Cor-poration, Japan) for 24 h, and the average temperature andrelative humidity were calculated. Average indoor tempera-ture and relative humidity were 23.5C and 56.1%, respec-tively.</p><p>Statistical analysis</p><p>Statistical analysis was performed by multiple logisticregression, and crude and adjusted odds ratios with 95%conWdence intervals (OR, 95% CI) were calculated. For allstatistical analyses, a 5% level of signiWcance was applied.To obtain adjusted ORs for SBS symptoms, we controlledfor age, gender, current smoking and time spent in thedwelling, which were introduced separately in the model.</p><p>To determine whether indoor environmental factors suchas aldehydes, VOCs, fungi and mite allergen were associ-ated with SBS symptoms, MannWhitney U tests wereconducted. Next, logarithmic values of aldehydes, VOCs,and fungi and mite allergens which were found to be sig-niWcantly associated with SBS symptom in the MannWhitney U tests were applied in the multiple logisticregression models. We controlled for age, gender, historyof allergy, current smoking, time spent in the dwelling andage of dwelling, and each selected variable was introducedseparately in the model. To transfer to their logarithmic val-ues, aldehyde and VOC values under the lower limits ofquantiWcation were considered as half of the lower limit ofquantiWcation, and 0 CFU/m3 for fungus was changed to0.5 CFU/m3.</p><p>Finally, the variables which were signiWcantly associ-ated with SBS symptoms in the previous logistic regressionanalyses and basic personal and building factors, such asage, gender, history of allergy, current smoking, time spentin the dwelling, age of the dwelling, dampness index, totalCFU and Der 1, were introduced in the multiple logisticregression model.</p><p>All analyses were conducted with SPSS software forWindows version 13.0 (SPSS Inc., Chicago, USA).</p><p>Results</p><p>Table 1 shows the characteristics of 104 dwellings. Most ofthe dwellings were wooden structures: 43.3% of those builtwithin 3 years and 56.7% of those built within the previous38 years.</p><p>Table 2 shows the characteristics of the study partici-pants. Among the 343 participants, the proportion offemales was 50.4%, 25.1% were under 10 years old, and11.1% were over 60 years old.123</p></li><li><p>586 Int Arch Occup Environ Health (2009) 82:583593Table 1 Characteristics of the dwellings Number of dwellings (n = 104)</p><p>n %</p><p>Structure of dwellingWooden 102 98.1Reinforced concrete or steel-reinforced concrete 1 1.0Others 1 1.0</p><p>Age of dwelling1 </p></li><li><p>Int Arch Occup Environ Health (2009) 82:583593 587Table 3 shows the prevalence of SBS symptoms in thissurvey. Throat and respiratory symptoms, nose symptoms,skin symptoms, eye symptoms, and general symptoms werefound in 13.1, 10.2, 6.4, 3.8, and 2.9% of participants,respectively. Any symptom (throat and respiratory, nose,skin, eye, and general symptom) was found in 21.6% ofparticipants. All symptoms, except for general symptoms,were found at a higher prevalence in females than in males.</p><p>Table 4 shows the crude and adjusted ORs of dampness andother variables. Dampness indicators, such as mold growth,moldy odor and water leakage, had signiWcantly higher ORsfor SBS symptoms. Time spent in the dwelling (20 h) alsohad a signiWcantly higher OR for SBS...</p></li></ul>