Exposure to house dust phthalates in relation to asthma and allergies in both children and adults.

Although an association between exposure to phthalates in house dust and childhood asthma or allergies has been reported in recent years, there have been no reports of these associations focusing on both adults and children. We aimed to investigate the relationships between phthalate levels in Japanese dwellings and the prevalence of asthma and allergies in both children and adult inhabitants in a cross-sectional study. The levels of seven phthalates in floor dust and multi-surface dust in 156 single-family homes were measured. According to a self-reported questionnaire, the prevalence of bronchial asthma, allergic rhinitis, allergic conjunctivitis, and atopic dermatitis in the 2 years preceding the study was 4.7%, 18.6%, 7.6%, and 10.3%, respectively. After evaluating the interaction effects of age and exposure categories with generalized liner mixed models, interaction effects were obtained for DiNP and bronchial asthma in adults (Pinteraction=0.028) and for DMP and allergic rhinitis in children (Pinteraction=0.015). Although not statistically significant, children had higher ORs of allergic rhinitis for DiNP, allergic conjunctivitis for DEHP, and atopic dermatitis for DiBP and BBzP than adults, and liner associations were observed (Ptrend<0.05). On the other hand, adults had a higher OR for atopic dermatitis and DEHP compared to children. No significant associations were found in phthalates levels collected from multi-surfaces. This study suggests that the levels of DMP, DEHP, DiBP, and BBzP in floor dust were associated with the prevalence of allergic rhinitis, conjunctivitis, and atopic dermatitis in children, and children are more vulnerable to phthalate exposure via household floor dust than are adults. The results from this study were shown by cross-sectional nature of the analyses and elaborate assessments for metabolism of phthalates were not considered. Further studies are needed to advance our understanding of phthalate toxicity.

The relationship between exposure to microbial volatile organic compound and allergy prevalence in single-family homes.

Microbial volatile organic compounds (MVOCs) are a type of VOCs produced by microorganisms. Exposure to 1-octen-3-ol, one of the known MVOCs, has been reported to reduce nasal patency and increase nasal lavage myeloperoxidase, eosinophil cationic proteins, and lysozymes in both experimental and field studies. We reported in a previous paper that 1-octen-3-ol exposure at home is associated with mucosal symptoms. In this study, our aim was to investigate the relationship between asthma and allergies and MVOC exposure in single-family homes. The subjects were 624 inhabitants of 182 detached houses in six regions of Japan. Air samples were collected using diffusive samplers, and the concentrations of eight selected MVOCs were analyzed using gas chromatography/mass spectrometry in selected-ion-monitoring mode. Each inhabitant of each of the dwellings was given a self-administered questionnaire. Among the 609 subjects who answered all of the questions about allergies, history of the medical treatment for asthma, atopic dermatitis, allergic rhinitis, and allergic conjunctivitis within the preceding two years was 4.8%, 9.9%, 18.2%, and 7.1%, respectively. A significant association between 1-octen-3-ol (per log(10) unit) and allergic rhinitis odds ratio (OR): 4.10, 95% confidence interval (CI): 1.71 to 9.80 and conjunctivitis (OR: 3.54, CI: 1.17 to 10.7) was found after adjusting for age, sex, tobacco, wall-to-wall carpeting, signs of dampness, history of treatment for hay fever, and other potentially relevant environmental factors. No relationships were found between any MVOCs and asthma or atopic dermatitis after the adjustment. The levels of MVOCs and airborne fungi were only weakly correlated. These results are consistent with previous studies that have associated higher levels of 1-octen-3-ol exposure with increased irritation of nasal and ocular mucosae. Although the indoor-air concentrations of 1-octen-3-ol found in this study were relatively low, we conclude that exposure to MVOC may be related to rhinitis and conjunctivitis.

A longitudinal study of aldehydes and volatile organic compounds associated with subjective symptoms related to sick building syndrome in new dwellings in Japan.

To determine whether indoor chemicals act as possible environmental risk factors responsible for sick building syndrome (SBS)-related symptoms in new houses (<6 years old) in Japan, we studied 871 people living in 260 single-family houses in 2004 and 2005. We measured the indoor concentrations of aldehydes and volatile organic compounds and longitudinal changes in the living rooms over two consecutive years. Participants answered standardized questionnaires on SBS symptoms and lifestyle habits. Approximately 14% and 12% of subjects were identified as having SBS in the first and second year, respectively. According to analysis adjusted for sex, age, smoking, and allergic diseases, increases in aldehydes and aliphatic hydrocarbons contributed to the occurrence of SBS. Elevated levels of indoor aldehydes and aliphatic hydrocarbons increased the possible risk of SBS in residents living in new houses, indicating that source controls against indoor chemicals are needed to counter SBS.

Nationwide study of sick house syndrome: comparison of indoor environment of newly built dwellings between Sapporo city and Southern areas including those in Honshu and Kyushu.

OBJECTIVES: The aims of this study are to evaluate the associations between residential factors and sick house syndrome (SHS) in a cold region and in a temperate region in Japan. METHODS: A questionnaire survey was conducted on dwellings aged within 7 years from 2003 to 2004 in Sapporo and 'Honshu and northern Kyushu' including Fukushima, Aichi, Osaka, Okayama, and Kitakyushu. The questionnaire consisted of questions about the characteristics of dwellings, manner of living, and health problems of occupants. SHS was identified from the 'yes' responses to the questions on the five items on nasal, throat and respiratory, eyes, skin, and general symptoms that appeared frequently or sometimes at home and improved upon leaving the home. RESULTS: The dwellings with the SHS problem, where at least one inhabitant reported any symptoms of SHS, were 4.7% in Sapporo City and 3.3% in Honshu and northern Kyushu. Regarding ventilation, the principal method was the enforced ventilation in Sapporo and ventilation from open windows in Honshu and northern Kyushu. The sums of five signs of dampness were 0.8 +/- 1.0 in Sapporo and 1.3 +/- 1.0 in Honshu and northern Kyushu. The elevated scores were accompanied by the increased percentage of SHS in both groups. Condensation on both window panes and walls was strongly associated with SHS. CONCLUSIONS: Differences were found in the ventilation method and in the dampness state between Sapporo and Honshu and northern Kyushu. In both groups, the dampness state was associated with SHS.

Relationship between selected indoor volatile organic compounds, so-called microbial VOC, and the prevalence of mucous membrane symptoms in single family homes.

Microorganisms are known to produce a range of volatile organic compounds, so-called microbial VOC (MVOC). Chamber studies where humans were exposed to MVOC addressed the acute effects of objective and/or subjective signs of mucosal irritation. However, the effect of MVOC on inhabitants due to household exposure is still unclear. The purpose of this epidemiological study was to measure indoor MVOC levels in single family homes and to evaluate the relationship between exposure to them and sick building syndrome (SBS). All inhabitants of the dwellings were given a self-administered questionnaire with standardized questions to assess their symptoms. Air samples were collected and the concentrations of eight selected compounds in indoor air were analyzed by gas chromatography/mass spectrometry - selective ion monitoring mode (GC/MS-SIM). The most frequently detected MVOC was 1-pentanol at a detection rate of 78.6% and geometric mean of 0.60 microg/m(3). Among 620 participants, 120 (19.4%) reported one or more mucous symptoms; irritation of the eyes, nose, airway, or coughing every week (weekly symptoms), and 30 (4.8%) reported that the symptoms were home-related (home-related symptoms). Weekly symptoms were not associated with any of MVOC, whereas significant associations between home-related mucous symptoms and 1-octen-3-ol (per log(10)-unit: odds ratio (OR) 5.6, 95% confidence interval (CI): 2.1 to 14.8) and 2-pentanol (per log(10)-unit: OR 2.3, 95% CI: 1.0 to 4.9) were obtained after adjustment for gender, age, and smoking. Associations between home-related symptoms and 1-octen-3-ol remained after mutual adjustment. However, concentrations of the selected compounds in indoors were lower than the estimated safety level in animal studies. Thus, the statistically significant association between 1-octen-3-ol may be due to a direct effect of the compounds or the associations may be being associated with other offending compounds. Additional studies are needed to evaluate these possibilities.

Relationship between indoor chemical concentrations and subjective symptoms associated with sick building syndrome in newly built houses in Japan.

OBJECTIVES: This study explored possible associations between chemical substances and sick building syndrome (SBS)-type symptoms of residents living in new houses in Japan. METHODS: We randomly sampled 5,709 newly built conventional homes. In the end, 1,479 residents in 425 households completed a questionnaire survey and agreed to environmental monitoring for indoor aldehydes and volatile organic compounds (VOCs) to be conducted in their homes. If the residents had complained about at least one SBS-related symptom, they were classified as suffering from SBS. Multiple logistic regression analysis was used to select predictive chemical factors of SBS symptoms. RESULTS: About 14% of the subjects suffered from SBS. Many aldehydes and VOCs were associated factors of optical, nasal, and gular symptoms in univariate analysis. After adjustment for other possible risk factors, formaldehyde dose-dependently showed to be a significant risk factor for SBS. Several chemicals had tendency to be associated with SBS symptoms. CONCLUSIONS: Chemicals detected in Japanese newly built houses tend to increase the risk of subjective symptoms in residents suffering from SBS.

[Indoor air pollution of volatile organic compounds: indoor/outdoor concentrations, sources and exposures].

In this review, we discussed about volatile organic compounds (VOC) concentrations, sources of VOC, exposures, and effects of VOC in indoor air on health in Japan. Because the ratios of indoor concentration (I) to outdoor concentration (O) (I/O ratios) were larger than 1 for nearly all compounds, it is clear that indoor contaminations occur in Japan. However, the concentrations of basic compounds such as formaldehyde and toluene were decreased by regulation of guideline indoor values. Moreover, when the sources of indoor contaminations were investigated, we found that the sources were strongly affected by to outdoor air pollutions such as automobile exhaust gas. Since people live different lifestyles, individual exposures have been investigated in several studies. Individual exposures strongly depended on indoor concentrations in houses. However, outdoor air pollution cannot be disregarded as the sources of VOC. As an example of the effect of VOC on health, it has been indicated that there is a possibility of exceeding a permissible cancer risk level owing to exposure to VOC over a lifetime.