Asthma and the indoor environment: the significance of emission of formaldehyde and volatile organic compounds from newly painted indoor surfaces

 As a part of the worldwide European Community Respiratory Health Survey, possible relations between asthma and emissions from newly painted indoor surfaces were studied. The participants (n= 562) answered a self-administered questionnaire, with questions on symptoms and indoor exposures, including indoor painting, during the last 12 months. The participants also underwent a structured interview, spirometry, peak flow measurements at home (PEF), methacholine provocation test for bronchial hyper- responsiveness (BHR), and skin prick tests. In addition, serum concentration of eosinophilic cationic protein (S-ECP), blood eosinophil count (B-EOS), and total immunoglobulin E (S-IgE) were measured. Current asthma was defined as a combination of BHR and at least one asthma-related symptom (wheezing and attacks of breathlessness). The information gathered on indoor painting was compared with exposure measurements of formaldehyde and volatile organic compounds (VOC) performed in a selected sample of the dwellings (n=62). Relations between exposures, asthma and clinical signs were calculated by multiple linear or logistic regression, adjusting for possible influence of age, gender and tobacco smoking. The prevalence of asthma was increased among subjects with domestic exposure to newly painted surfaces (OR=1.5; 95% CI 1.0–2.4), particularly newly painted wood details (OR=2.3; 95% CI 1.2–4.5) and kitchen painting (OR=2.2; 95% CI 1.1–4.5). Moreover, blood eosinophil concentrations were significantly elevated among subjects living in newly painted dwellings. A significantly increased prevalence of symptoms related to asthma, but not BHR, was observed in relation to workplace expo- sure to newly painted surfaces. The indoor concentration of aliphatic compounds (C₈–C₁₁), butanols, and 2,2,4-trimethyl 1,3-pentanediol diisobutyrate (TXIB) was significantly elevated in newly painted dwellings. The total indoor VOC was about 100 μg/m³ higher in dwellings painted in the last year. A significant increase in formaldehyde concentration was observed in dwellings with newly painted wood details. Our results indicate that exposure to chemical emissions from indoor paint is related to asthma, and that some VOCs may cause inflammatory reactions in the airways. To improve asthma management, and to counteract the increasing frequency of asthma, the significance of the indoor environment should not be neglected. Our study suggests that the contri- bution of emissions from paint to indoor concentrations of formaldehyde and VOCs should be as low as possible. Received: 6 November 1995/Accepted: 2 April 1996     

Relationship between sick building syndrome and indoor environmental factors in newly built Japanese dwellings

Objectives  Indoor air contaminants and dampness in dwellings have become important environmental health issues. The aim of this study is to clarify which factors are related to sick building syndrome (SBS) in newly built dwellings at Hokkaido, Japan, through a comprehensive evaluation of the indoor environment and validated sick building symptom questionnaires. Methods  The symptoms of 343 residents in 104 detached houses were surveyed by standardized questionnaires, and the concentrations of formaldehyde, acetaldehyde, volatile organic compounds (VOCs), airborne fungi, and dust mite allergen in their living rooms were measured. By summing the presence or absence of the five dampness indicators (condensations, mold growth, moldy odor, high air humidity of the bathroom, water leakage), a dampness index was calculated. Results  SBS symptoms were found in 21.6% of surveyed individuals. In a fully adjusted multivariate logistic regression analysis, the dampness index [odds ratio (OR) = 1.50; 95% confidence interval (CI): 1.06–1.11], log formaldehyde (OR = 23.79, 95% CI: 2.49–277.65), and log alpha-pinene (OR = 2.87, 95% CI: 1.36–6.03) had significantly higher ORs for SBS symptoms. However, other VOCs, airborne fungi, and dust mite allergen did not have significantly higher ORs. Conclusion  Dampness, formaldehyde, and alpha-pinene were significantly related to SBS symptoms in newly built dwellings. We should, therefore, take measures to reduce the chemicals and dampness in dwellings.     

Prevalence of bronchial hyperresponsiveness in children: the relationship between asthma and skin reactivity to allergens in two communities

A coastal population mainly reactive to house dust mite was compared with an inland population mainly reactive to other allergens to investigate whether exposure to house dust mite plays a part in initiating childhood asthma. Respiratory symptoms, asthma, bronchial hyperresponsiveness, hay fever and atopy were all more common in the dry inland area than in the humid coastal area. In both areas 38% of children were atopic. Coastal children had more skin reactivity to house dust mites and inland children were more reactive to grass pollen extracts. The findings suggest that the clinical presentation of asthma may be related more to the total burden of aeroallergens than to exposure to a particular allergen.     

Volatile organic compounds, respirable dust, and personal factors related to prevalence and incidence of sick building syndrome in primary schools

Possible relations between incidence and prevalence of sick building syndrome (SBS), indoor exposures, and personal factors were studied in a four year longitudinal study among personnel (n = 129) in six primary schools. The mean concentration of carbon dioxide was above the recommended value of 0.08 microliter/l (800 ppm) in all schools, indicating a poor outdoor air supply. Indoor concentration of volatile hydrocarbon (VOC) was enhanced at high room temperatures. Respirable dust, but not concentration of VOC was enhanced at lower ventilation rates and high air humidity. Chronic SBS was related to VOC, previous wall to wall carpeting in the schools, hyper-reactivity, and psychosocial factors. Incidence of new SBS was related to concentration of respirable dust, current smoking, and the psychosocial climate. Remission of hyperreactivity, decrease in sick leave owing to airway illness, removal of carpeting in the schools, and moving from new to old dwellings resulted in a decrease in SBS score. It is concluded that SBS is of multifactorial origin, related to a variety of factors and exposures. The total concentration of hydrocarbons is a simple and convenient measure of exposure, which also seems to be a predictor of chronic symptoms. Further investigations on the effect of temperature, ventilation, and air humidity on SBS should consider how these factors may influence the chemical composition of the air. Because poor air quality in schools could also affect the children, it may have implications for the state of health of a large proportion of the population.     

Volatile organic compounds, respirable dust, and personal factors related to prevalence and incidence of sick building syndrome in primary schools.

Possible relations between incidence and prevalence of sick building syndrome (SBS), indoor exposures, and personal factors were studied in a four year longitudinal study among personnel (n = 129) in six primary schools. The mean concentration of carbon dioxide was above the recommended value of 0.08 microliter/l (800 ppm) in all schools, indicating a poor outdoor air supply. Indoor concentration of volatile hydrocarbon (VOC) was enhanced at high room temperatures. Respirable dust, but not concentration of VOC was enhanced at lower ventilation rates and high air humidity. Chronic SBS was related to VOC, previous wall to wall carpeting in the schools, hyper-reactivity, and psychosocial factors. Incidence of new SBS was related to concentration of respirable dust, current smoking, and the psychosocial climate. Remission of hyperreactivity, decrease in sick leave owing to airway illness, removal of carpeting in the schools, and moving from new to old dwellings resulted in a decrease in SBS score. It is concluded that SBS is of multifactorial origin, related to a variety of factors and exposures. The total concentration of hydrocarbons is a simple and convenient measure of exposure, which also seems to be a predictor of chronic symptoms. Further investigations on the effect of temperature, ventilation, and air humidity on SBS should consider how these factors may influence the chemical composition of the air. Because poor air quality in schools could also affect the children, it may have implications for the state of health of a large proportion of the population.     

室内装修后空气中挥发性有机物污染状况调查分析

目的了解居室装修后室内空气中主要挥发性有机物污染状况。方法对居室装潢后不同时间的居室室内空气中甲醛、苯、甲苯、二甲苯、空气耗氧量进行测定,并与室外空气标准进行对比。结果装修后居室空气中甲醛、苯、二甲苯及空气耗氧量均严重超标,12个月后浓度虽明显下降,但甲醛和空气耗氧量超过室外空气标准。结论装修后相当长一段时间内居室空气中挥发性有机物污染严重,装修后1年内入住可能至少导致为期1~2年的免疫伤害。     

某居民楼使用不合格建筑材料的卫生学调查

目的 了解不合格建筑材料对居民楼室内空气卫生质量的影响。方法 对采用碱渣代替石灰用于内墙的某居民楼进行调查，调查设使用碱渣的受影响单元组、未使用碱渣的未受影响单元组和室外对照组，检测指标为CO、CO2、 NO2、SO2、甲醛、可吸入颗粒物（IP）、氯化氢、氨和空气细菌总数，现场检测1天，上、下午各1次，同时对居民进行健康询问。结果 受影响单元组室内空气HCl、CO2明显较未受影响单元经且及室外对照组高，差异有非常显著性，受影响单元组55％监测点空气中HCl超出国家居住区在气中有害物质的最高容许浓度，受影响单元钢窗与墙壁交界处被腐蚀。受影响单元组及未受影响单元组甲醛、NO2、NH3均较室个对照组高，差异有非常显著性。室外对照组的IP和细菌总数均显著高于受影响单元组和未受影响单元组，各组的CO、SO2差异不显著。居民易感冒并有头痛、头晕、胸闷、上呼吸道炎症等症状。结论 使用不合格建筑材料影响建筑体本身质量，同时引起室内空气质量恶化，影响居住者身心健康，呼吁国家 应尽快制订有关法规。     

装修材料销售场所室内空气污染状况调查

目的了解装修材料销售场所室内空气中有害物质污染状况,为制订防治对策提供依据。方法检测30家装修材料销售店,分别对其室内空气中甲醛、挥发性有机物（VOCs）进检测。结果各类装修材料销售店室内空气中甲醛、VOCs浓度均高于室外对照（P〈0.05）;甲醛最高值约为室外对照的70倍,VOCs最高值为室外对照的20倍。通风状态甲醛、挥发性有机物低于不通风状态（P〈0.05）,尤其是甲醛相差悬殊。面积50 m2以下的销售店甲醛、挥发性有机物的超标率高于面积50 m2以上的销售店（P〈0.05）。结论装修材料销售场所室内空气中甲醛、挥发性有机物污染严重,其污染的程度与销售装修材料的类型、店面大小、通风状况等有关。     

Levels of volatile organic compounds in homes in Dalian,China

This paper measured selected individual volatile organic compounds (VOCs), including formaldehyde, in residences in Dalian, evaluated the association between the apartment characteristics and VOC concentrations, and explored the associations between chemicals and sick building syndrome (SBS). Higher VOC concentrations were measured indoors than outdoors in summer (August to September) and winter (January to March) in Dalian, and there were no strong correlations between the indoor and outdoor concentrations of most VOCs. This indicates the dominance of indoor sources as compared to outdoor sources. Formaldehyde was the most abundant compound in this study, followed by toluene, benzene, xylene, and styrene. These pollutants increase the occurrence of SBS. Thus, the VOC levels in dwellings in Dalian should be regulated, in view of SBS risks.     

Variation in indoor air pollutant concentrations with time in a newly constructed private house

An indoor air quality research project was conducted in a new private house built in January 1997 to investigate time course changes in formaldehyde concentrations during an 11-month period from April 1997 to February 1998. Indoor and outdoor concentrations of volatile organic compounds (VOCs) and nitrogen dioxide were also measured in August 1997 and February 1998. Indoor formaldehyde concentrations were measured 14 times (48 hrs sampling for each measurement) for 28 days in the living room, a bedroom and the kitchen in April '97. The concentrations exceeded the Japanese Government's guideline value of 0.08 ppm in 34 of the 42 (81.0%). Day to day variation in the formaldehyde concentration was found to be substantial, the range being between 0.073 and 0.232 ppm for the bedroom, for example. In June and August '97, values for 20 of 21 measurements exceeded the guideline, the results suggesting that indoor formaldehyde concentrations remain high until 7 months after the completion of construction. There were positive correlations between the formaldehyde concentrations in the living room and the kitchen and personal exposure levels to formaldehyde, the result indicating a direct influence of the home environment. The formaldehyde concentration in the living room also exhibited a positive correlation with the room temperature. Natural ventilation by opening windows was found to be effective for decreasing the concentration of formaldehyde in the indoor air. Indoor VOC concentrations decreased rapidly after the completion of construction except for that of toluene, which was higher than the outdoor concentration even after 7 months. Indoor concentrations of all of the VOCs were, however, found to be almost the same as those outdoor at the 13 month time point. Indoor nitrogen dioxide concentrations measured in the bedroom in winter (February '98) exceeded the Environmental Air Quality Standard in Japan, this result being considered due to use of an oil fan heater. These data suggest that personal exposure levels to formaldehyde and nitrogen dioxide are high in newly constructed private homes in Japan. In order to avoid prolonged exposure to high concentrations of indoor air pollutants, it is considered very important to take measures such as of use building materials with low formaldehyde emissions and to discontinue the use of oil fan heaters.     

吸烟和交通废气污染联合作用对交通警察健康影响的研究

目的 调查唐山市交通废气污染现状，探讨吸烟和交通废气污染联合作用对交通警察的健康影响。方法 选择三个有代表性路口进行环境监测，包括可吸入性颗粒物(IP)、氮氧化物(NOx)、一氧化碳(CO)、总烃(CmHn)和铅尘(Pb)浓度。采用现况研究的方法，以唐山市196名男性外勤交通警察(外勤警)和148名男性内勤交通警察(内勤警)为研究对象，进行问卷调查和各种症状的体检，并测定了血碳氧血红蛋白饱和度(HbCO%)、肺最大呼气流速(PEF)，抽样测定部分调查对象血铅含量。结果各监测点的CO、NOx的浓度明显超标，Pb尘差异无显著性。外勤警的各种症状出现率、HbCO％显著高于内勤警，PET低于内勤警，血Pb差异无显著性。按是否吸烟分层后，内、外勤警中吸烟者的各症状出现率、HbCO％均高于不吸烟者，PET低于不吸烟者；吸烟内勤警的神经衰弱及心血管系统症状出现率、血铅甚至高于不吸烟的外勤警。结论交通废气污染是引起外勤警症状出现率升高、HbCO％升高、PET下降的一个重要因素，吸烟可使神经衰弱、心血管系统症状出现率、血铅增高更明显。吸烟和交通废气污染联合作用加重了对吸烟外勤警的健康损害。     

Occupational therapy adaptation of the home environment in Sweden for people with asthma

The purpose of this study was to evaluate changes of lung function, respiratory symptoms and indoor air quality after reducing allergens and indoor pollutants in the home environment of people with asthma (n = 21). A quasi-experimental pre-/post-test design with one group of participants was implemented. The interventions included removal of wall-to-wall carpets (n = 14) or improvement of indoor air exchange (n = 7). Participants' lung function, symptoms, medication and type-1 allergy were recorded before and after the intervention. The indoor environment was monitored at house calls by an occupational therapist using conventional physical, biological and chemical methods. There was an improvement of lung function evidenced by an increased mean Forced Expiratory Volume (FEV(1) %) and a reduction of airway obstruction (reversibility, % of baseline value), which indicate an improved asthmatic condition. Lung function assessed by vital capacity, bronchial hyper-responsiveness, mean of Peak Expiratory Flow, symptom score and medicine consumption did not change significantly. There was a tendency that the amount of airborne dust (p=0.06) was reduced in the indoor environment. Relative humidity, carbon dioxide, formaldehyde and house dust mite levels had decreased after the intervention, but not significantly. Asthma symptoms related to the home environment are probably caused by several factors. When people with asthma suffer from increased symptoms in the home, house calls should be performed routinely. Dust samples from beds and carpets for analysis of allergens give information about exposure, and environmental assessments should be performed before interventions. Occupational therapists can make a valuable contribution in evaluating the home environment and suggesting ergonomic adaptations for individuals with asthma.     

Comparisons of seasonal fungal prevalence in indoor and outdoor air and in house dusts of dwellings in one Northeast American county

Fungi cause allergies and many other adverse health effects. In this study, we characterized the nature and seasonal variation of fungi inside and outside homes in the Greater New Haven, Connecticut area. Three indoor air samples (in the living room, bedroom, and basement) and one outdoor sample were collected by the Burkard portable air sampler. House dust samples were collected in the living room by a vacuum cleaner. The mold concentrations varied widely from house to house in both indoor and outdoor air. No significant difference (p>0.05) in concentration and type of fungi between living room and bedroom or by season was observed. Both concentration and type of fungi were significantly higher (p<0.05) in the basement than other indoor areas and outdoor air in winter. The type of fungi in living room, bedroom, and outdoor air were found to have significant changes among seasons, but there was no significant difference for the basement among seasons. Cladosporium spp. was dominant in both indoor and outdoor air in summer. Penicillium and Aspergillus were dominant in indoor air in winter, but neither was dominant in any season in outdoor air. The type of fungi and their concentrations in house dust samples were not representative of those isolated in indoor air. In dust samples, more Mucor, Wallemia, and Alternaria species, but less Aspergillus, Cladosporium, and Penicillium species were found in all seasons. Air sampling in spring or fall in every suspected house is suggested for year-round fungal exposure assessment.     

Indoor air quality and personal factors related to the sick building syndrome

The "sick building syndrome" involves symptoms such as eye, skin and upper airway irritation, headache, and fatigue. A multifactorial study was performed among personnel in consecutive cases of sick buildings to investigate relationships between such symptoms, exposure to environmental factors, and personal factors. The total indoor hydrocarbon concentration was significantly related to symptoms. Other indoor exposures such as room temperature, air humidity, and formaldehyde or carbon dioxide concentration did not correlate with the symptoms. Personal factors such as reported hyperreactivity and sick leave due to airway diseases were strongly related to the sick building syndrome. Other factors associated with the sick building syndrome were smoking, psychosocial factors, and experience of static electricity at work. Neither atopy, age, sex, nor outdoor exposures correlated significantly with the number of symptoms. It was concluded that the sick building syndrome is of multifactorial origin and related to both indoor hydrocarbon exposure and individual factors.     

Symptoms in relation to chemicals and dampness in newly built dwellings

Objectives: As the airtightness of dwellings has recently increased, problems associated with indoor air pollution and dampness have become important environmental health issues. The aim of this study was to clarify whether symptoms in residents living in newly built dwellings were related to chemicals and dampness. Methods: Symptoms of 317 residents were surveyed by standardized questionnaires, and the concentrations of formaldehyde, acetaldehyde, and 17 volatile organic compounds (VOCs) in their homes were measured. Dampness (condensation on window panes and/or walls, and mold growth) was identified by questionnaires given to the householders or their partners. Results: Some VOCs (toluene, butyl acetate, ethylbenzene, alpha-pinene, p-dichlorobenzene, nonanal, and xylene) were significantly related to the symptoms, and the sum of all VOCs (all identified VOCs) was significantly related to throat and respiratory symptoms [odds ratio (OR) for eye symptoms =2.4; 95% confidence interval (CI) 1.0–5.5], although the concentrations of VOCs were relatively low. As for the dampness index, condensation on window panes and/or walls was related to all symptoms, and mold growth was related to all symptoms except skin, throat and respiratory and general symptoms. As the number of dampness signs increased, the ORs increased for the symptoms except general symptoms (OR for nose symptoms = 4.4, 95% CI 1.6–11.9). Conclusion: Both VOCs and dampness were significantly related to symptoms. We should take measures to reduce the concentrations of VOCs, dampness and microbial growth in dwellings.     

室内装修致空气污染的研究

目的 了解装修所致室内空气污染状况。方法 以装修3个月的住宅为短时间组，以装修1年的住宅为长时间组，以装修10年以上的住宅为对照组。分别测定空气中的一氧化碳、二氧化碳、甲醛、COD含量。结果 4项指标中，一氧化碳、二氧化碳浓度在3个组中无显差异。装修3个月的住宅，甲醛和COD的浓度超标率均为100％；装修1年的住宅，甲醛和COD浓度超标率分别为72％和100％；装修10年以上的住宅，甲醛和COD的浓度超标率分别为8％和0。短时间组的甲醛和COD浓度明显高于长时间组；长时间组甲醛和COD浓度明显高于对照组。通风前后甲醛浓度差异具有显性。结论 在新装修住宅中甲醛和COD污染较严重，随着装修时间的延长，甲醛和COD浓度明显下降，通风后甲醛浓度低于通风前。     

Quantification of house dust mite allergens in ambient air

The house dust mites Dermatophagoides pteronyssinus and Dermatophagoides farinae are important sources of indoor allergens. In sensitized patients, house dust mites induce and exacerbate diseases like asthma bronchiale, rhinitis, and conjunctivitis. The most significant exposure of persons occurs overnight in bed and to a lesser extent, during the daytime while performing activities like vacuum cleaning or bed making. In general, house dust mite antigens are quantified in samples of reservoir dust of carpets or beds. Yet, assessing allergens in ambient air would better represent human exposures because inhalation is the main route of uptake, and a close correlation between levels of floor and air antigens has not yet been proved. Unfortunately, because of extremely low airborne particle concentrations, analyses are difficult to perform and depend on sophisticated sampling strategies, as well as on sensitive immunometric detection assays. Using monoclonal immunoassays, house dust mite antigens, quantified in undisturbed conditions in ambient air, are found at pg/m3 levels. The disturbance of reservoir dust by vacuum cleaning or bed making increases the airborne allergen levels up to ng/m3 concentrations. In this review, we discuss the current knowledge regarding the analysis of airborne house dust mites in both undisturbed and disturbed ambient air. The advantages and disadvantages of different sampling strategies are outlined.     

Comparisons of the allergenic mite prevalence in dwellings and certain outdoor environments of the Upper Silesia (southwest Poland)

The occurrence of allergenic mites (pyroglyphid house-dust mites, acarid and glycyphagid storage mites and others) in dwellings and in synanthropic outdoor sites in a densely populated urban area was investigated. A total of 335 house dust samples were collected from dwellings at 7 different locations in Upper Silesia (Poland), including 84 samples from dwellings of Katowice. Mites were found in 188 of the samples examined (56.1%). A total of 4410 mite specimens were isolated and identified, including 4212 members of the family Pyroglyphidae (95.51%). Among them, Dermatophagoides farinae was predominant (75.3%), followed by D. pteronyssinus (18.6%) and Euroglyphus maynei (1.5%). Moreover, litter soiled with communal wastes was sampled. All 86 samples contained mites. A total of 7547 mite specimens were isolated including 6050 mites known as allergenic (80.5%). Among the astigmatid mites two acarids were dominant: Tyrophagus silvester and T. longior (28.7% and 25.1% of all mites). It should be stressed that 6 of the acarid mite species or genera found in outdoor environments are typical domestic mites (T. putrescentiae), or they have been collected from house dust samples (T. longior, Tyrolichus casei, Thyreophagus entomophagus, Mycetoglyphus fungivorus and Rhizoglyphus robini). The litter of synanthropic sites can therefore form a substantial source of infestation.