Nai Yun Hsu

Predicted risk of childhood allergy, asthma, and reported symptoms using measured phthalate exposure in dust and urine

UNLABELLED   The associated risk of phthalate exposure, both parent compounds in the home and their metabolites in urine, to childhood allergic and respiratory morbidity, after adjusting for exposures of indoor pollutants, especially bioaerosols, was comprehensively assessed. Levels of five phthalates in settled dust from the homes of 101 children (3-9 years old) were measured, along with their corresponding urinary metabolites. Other environmental risk factors, including indoor CO2, PM2.5, formaldehyde, 1,3-β-D-glucan, endotoxin, allergen and fungal levels, were concomitantly examined. Subjects health status was verified by pediatricians, and parents recorded observed daily symptoms of their children for the week that the home investigation visit took place. Significantly increased level of benzylbutyl phthalate, in settled dust, was associated with test case subjects (allergic or asthmatic children). Higher levels of dibutyl phthalate and its metabolites, mono-n-butyl phthalate, and mono-2-ethylhexyl phthalate were found to be the potential risk factors for the health outcomes of interest. Similarly, indoor fungal exposure remained a significant risk factor, especially for reported respiratory symptoms. The relative contribution from exposure to phthalates and indoor biocontaminants in childhood allergic and respiratory morbidity is, for the first time, quantitatively assessed and characterized. PRACTICAL IMPLICATIONS For asthmatic and allergic children living in subtropical and highly developed environments like homes in Taiwan, controlling environmental exposure of phthalates may be viewed as equally important as avoiding indoor microbial burdens, for the management of allergy-related diseases. It is also recognized that multidisciplinary efforts will be critical in realizing the true underlying mechanisms associated with these observations.

Changes in profiles of airborne fungi in flooded homes in southern Taiwan after Typhoon Morakot.

In August 2009, the historic Typhoon Morakot brought extreme rainfall and resulted in flooding which spread throughout southern Taiwan. This study compared the difference between fungal concentrations before and after the disaster in selected homes of the Tainan metropolitan area, which were hit hardest by the catastrophe. A group of 83 households available from a prior cohort established with random sampling out of a regional population in southern Taiwan was contacted successfully by telephone. Twenty-five of these reported to have suffered from floods of various degrees at this time. Around 2 weeks after the event, at which time most of the remedial process had been completed by self-efforts and public health endeavours, 14 of these 25 (56%) agreed to participate in measurements of the airborne microbial concentrations. The averages (standard deviation) of the total culturable fungal concentrations in childrens bedrooms and flooded rooms were 18,181 (25,854) colony-forming units per cubic metre (CFU/m(3)) and 13,440 (11,033) CFU/m(3), respectively. The airborne fungal spore levels in the 2 above-mentioned indoor sites were 221,536 (169,640) spores/m(3) and 201,582 (137,091) spores/m(3), respectively. The average indoor/outdoor ratios in the childrens bedrooms were 4.2 for culturable fungi and 1.4 for fungal spores. These values were higher than the respective values measured in the same homes during the previous year: 1.1 and 0.6. In terms of the specific fungal profile, the percentages of Aspergillus spp. increased significantly in both the indoor and outdoor environments after the event. To this date, this study is among the limited research that has been conducted to quantitatively demonstrate that fungal manifestation is likely to persist in flooded homes even after seemingly robust remedial measures have been put into place. Studies to examine the potential health implications and effectiveness of better remedial technology remain much needed.

Feeding Bottles Usage and the Prevalence of Childhood Allergy and Asthma

This study aimed to examine the association between the length of use of feeding bottles or pacifiers during childhood and the prevalence of respiratory and allergic morbidities. A large-scale questionnaire survey was performed in day care centers and kindergartens (with childrens ages ranging from 2 to 7 years) in southern Taiwan, and a total of 14,862 questionnaires completed by parents were finally recruited for data analysis. Effects of using feeding bottles on childrens wheezing/asthma (adjusted OR: 1.05, 95% CI 1.00–1.09), allergic rhinitis (adjusted OR: 1.04, 95% CI 1.00–1.08), and eczema (adjusted OR: 1.07, 95% CI 1.01–1.2) were found. Moreover, significant dose-dependent relationships were further established after an adjustment for confounders was performed that included childrens ages, gender, gestational age, birth weight, length of breastfeeding, the age when first given infant formula or complementary foods, family history, parental educational levels, and smoking status, as well as the problem of indoor water damage. This study was the first to reveal the potential risk of using plastic consumer products such as feeding bottles on the reported health status of preschool children in Asian countries.

Allostatic Load Model Associated with Indoor Environmental Quality and Sick Building Syndrome among Office Workers

This study investigates whether indoor environmental quality (IEQ) influences allostatic load (AL) and whether AL can be a predictor for sick building syndrome (SBS). We also assessed and compared the associations between AL and SBS versus 8-hydroxydeoxyguanosine (8-OHdG) and SBS. A total of 115 office workers from 21 offices completed self-reported SBS questionnaires, and provided 11 biomarkers for their AL. Multiple linear regressions and logistic regression analysis were applied to examine the correlations between IEQ and AL or 8-OHdG and between AL or 8-OHdG and SBS, respectively. Our data revealed that the neuroendocrine system was correlated with CO2, the difference between indoor and outdoor CO2 levels (dCO2), and the indoor-outdoor ratio of CO2 (CO2 I/O). Metabolic system effects were associated with illumination. The relationships between illumination, CO2, dCO2, CO2 I/O and 8-OHdG were consistent with those and AL in specific systems. Furthermore, we found that risks for SBS syndromes were related with neuroendocrine and metabolic system of the AL. 8-OHdG was associated with eye dryness or irritation, eye tiredness and vomiting. We conclude that IEQ significantly influences AL and that AL can be a predictor for reporting SBS with information on system-specific effects.

A dose-dependent relationship between the severity of visible mold growth and IgE levels of pre-school-aged resident children in Taiwan

UNLABELLED To demonstrate a dose-dependent relationship between severity of indoor visible mold growth and serum total IgE levels of resident children. A total of 97 children (4-7 years old) identified from previously established birth-cohort, with information pertaining to indoor environmental conditions after childs birth, were successfully recruited while sera were concurrently collected for total IgE and specific IgE analysis during clinical visits. Severity of visible mold growth at homes was scaled into three levels accordingly. A statistically significant dose-dependent relationship was found between severity of indoor visible mold growth and total serum IgE levels. The trend sustains after the model was adjusted for resident childs age, gender, pet-keeping history, number of siblings, atopic history of parents, presence of incense burning, and environmental tobacco smoking (ETS) at home. Further analysis of specific IgE to commonly examined fungal allergens did not substantiate the correlation. Rather, resident childs specific IgE to mite allergens, although without statistical significance, seemed to better associate with the ranked severity of indoor mold growth in this study. An adjuvant role of fungal exposure to enhance sensitization in indoor environment is therefore suggested in Taiwanese population with high prevalence of building dampness. PRACTICAL IMPLICATIONS The presence of indoor visible mold growth, potentially resulting in fungal exposure, was not associated directly with changing biomarker levels of allergic response in resident children, rather playing an adjuvant role to enhance sensitization. On the other hand, other allergens, such as mite allergen examined in this study, appeared to support a more plausible etiology for directly triggering the ultimate allergic symptoms and diseases of interest. Evidence as such may derive different priority-setting when designing preventive measures for managing indoor air quality.

Paternal Heredity and Housing Characteristics Affect Childhood Asthma and Allergy Morbidity

ABSTRACT A birth cohort was initiated when each pregnant woman was asked for her own and her husbands history of asthma and allergic diseases at the time of recruitment. They were further inquired to verify their housing conditions, and current health status of children 3 to 5 years old at the time of interview. Paternal history was the most significant risk factor associated with reporting childhood morbidities at age of 3 to 5 years. Housing characteristics became meaningful variables only if the fathers were asthmatic or atopic. A 9-fold increase of risk was found if children with paternal history and also exposed to incense burning and water damage at home. This is the first epidemiological evidence of East Asia suggesting paternal heredity, with concurrent indoor hazardous exposures, as a predominant risk on developing childhood asthma and allergy.

Higher moisture content is associated with greater emissions of DEHP from PVC wallpaper

Abstract Water damage and moisture in buildings may become more prevalent due to the increasing frequency of extreme precipitation and flooding events resulting from climate change. However, the effects of moisture levels on phthalate emissions from building materials are still underreported. This study aims to evaluate the effect of moisture content (MC) on the level of di‐(2ethylhexyl) phthalate (DEHP) emitted from plastic wallpaper (0.22 wt% DEHP) within 15 days in a closed chamber. A scenario of short‐term exposure to DEHP in buildings suffering from water damage was simulated. Experiments, controlled at 100% relative humidity (RH) of air and 28 °C, were conducted under the following three conditions: (I) without wallpaper (control chamber), (II) dry wallpaper (MC at 3.57%) and (III) damp wallpaper (MC at 52.31%). Air and dust samples were collected at the elapsed time of 2, 4, 6, 8, 10, 13 and 15 days, and the wipe sample was collected on the last day. Higher DEHP concentrations were found to be emitted into the air and adsorbed on the dust for wallpapers with higher MC%. DEHP levels in the air exhibited an increasing trend with the length of the experiment. Overall, it was found that approximately 35.31% more total DEHP mass was released into the air, dust and wipe samples from damp wallpapers compared to dry wallpapers. It is concluded that DEHP emissions from plastic materials are affected by the inner moisture percentage. HighlightsDEHP emissions from plastic materials are affected by the inner moisture percentage.Damp wallpaper emits 35% more total DEHP mass compared to dry wallpaper.The material should be removed within 4 days once it has experienced water damage.