Air pollution and lung function growth among schoolchildren

• Main Authors: Ya-Hui Chen, 陳雅惠
• Other Authors: 黃彬芳
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/31026648021290908560

碩士 === 中國醫藥大學 === 職業安全與衛生學系碩士班 === 99 === There were limited studies concerning ambient air pollution exposure on development of lung function among children. They provided suggestive but inconclusive results. The study objectives were to assess the relation between exposure to ambient air pollutants and lung function growth among Taiwanese school children. The specific aims were 1) to assess the relation between exposure to ozone (O3), particles with an aerodynamic diameter of 2.5 μm or less (PM2.5), nitrogen dioxides (NO2), sulfur dioxide (SO2) and carbon monoxide (CO) and lung function growth; 2) to evaluate the relation between traffic density and lung function growth; 3) to assess the effects of factors on lung function growth among schoolchildren; 4) to elaborate the possible effect modification of gender in the relation between air pollution and lung function growth; 5) to determine whether asthmatic children are more susceptible than non-asthmatic children on the effect of air pollution on lung function growth . We conducted a prospective cohort study. The source of population was 7th grade children from 14 communities around Taiwan. We carried out baseline survey to collect personal and relevant information and performed the first lung function test between October and December, 2007. We conducted follow-up survey and performed the second lung function test between July and November, 2009. The spirometers recorded forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), maximal mid-expiratory flow (MMEF), forced expiratory flow rate at 75% of expired FVC (FEF75) and peak expiratory flow rate (PEFR) of each blew. We calculated the differences between the second and the first pulmonary function indices to assess the lung function growth. We used two-stage hierarchical model and multiple regression model to investigate the impact of air pollution and traffic density on lung function growth and performed stratified analysis to elaborate the potential role of effect modification between boys and girls as well as asthmatic and non-asthmatic children. Exposure to 8hr-O3, PM2.5 and traffic density was associated with statistically significant deficits in the FVC, FEV1 and PEFR attained at the age of 15 years. The estimated value for subjects in the most polluted of the communities as compared with the least polluted was predicted to results in a cumulative reduction of 1.8% for 8hr-O3 and 2.2% for PM2.5 in FVC, 3% for 8hr-O3 and 2.6% for PM2.5 in FEV1, and 10% for 8hr-O3 and 4.5% for PM2.5 in PEFR, respectively. We compared the deficis of lung function growth in three traffic-related exposure categories on the basis of high (≧20001 PCE/day), and medium (3701-20000 PCE/day), with low traffic density (≦3700 PCE/day) as reference. The deficis of FVC was significantly decreased with an exposure-response pattern, yielding of 0.5% for medium and 1.2% for high exposure category. Similar trend was found for FEV1. The observed joint effects of air pollutants (8hr-O3 or PM2.5) and traffic density were similar with expected joint effects on lung function growth in the multiplicative scale (p for interaction > 0.05) per se. We further performed a stratified analysis for gender and asthma. We found that greater effects of air pollutants, such as 8hr-O3 or PM2.5 on lung function growth for boys than girls, but there was no significant difference between asthmatic and non-asthmatic children. Our finding suggests that ambient 8hr-O3, PM2.5 and traffic density had adverse effects on lung function growth among Taiwanese school children, especially for boys.