Respiratory Effects of Ozone and Acidic Aerosol for Children in an Urban Community

摘要

Background: Ozone is one of the six criteria air pollutants, which can cause various adverse respiratory effects. There are discrepancies between the findings from controlled human exposure studies and environmental epidemiologic studies. Adverse respiratory effects have been reported at lower ozone concentrations in epidemiologic studies than in controlled human exposure studies. Different exposure conditions can cause the inconsistent findings in controlled human studies and environmental epidemiological studies. Ozone health effects can be modified by co-exposure to other air pollutants and meteorological conditions. Aims: We will study 1) the impacts of aerosol acidity on the associations between ozone exposure and FEV1 and FENO, and 2) the impacts of ambient temperature and humidity on the associations between ozone exposure and FEV1 and FENO. Methods: Twenty children (9-14 years old) with asthma, living in downtown Newark, NJ participated in this study. Each child was followed for 10 consecutive days. On each day, real-time 5-min average personal ozone concentration, ambient 24-hr integrated aerosol acidity, and 5-min average ambient temperature and relative humidity were measured. FEV1 measured three times per day for each child, and FENO measured once per day for each child. Linear mixed models were used to find the associations between ozone exposure and FEV1 or FENO. The effect modification of aerosol acidity and ambient meteorological conditions were also examined. Results: Preliminary analyses show that ozone concentrations in the study area ranged from 20 to 60 ppb. Personal exposure to ozone was not well correlated with ambient ozone concentrations. Ambient aerosol acidity was less than 80 nmol/m3 of H+. Negative association between ozone exposure and lung function change was observed. Conclusions: The study first reported the associations between asthma exacerbation and lung function change, modified by copollutant exposures and meteorological parameters.