Comparison of diverse estimation methods for personal exposure to air pollutants and their associations with allergic symptoms; the Allergy & Gene-Environment Link (ANGEL) study

Abstract

Introduction: Exposure assessment of air pollution is critical in evaluating its effect on public health. We compared diverse estimation methods for the exposure to air pollutants and their associations with allergic diseases. Methods: 177 children with atopic dermatitis (AD) and 70 asthmatic adults living in Seoul Metropolitan Area, Korea, were followed for 17 months between August 2013 and December 2014. Parents or patients recorded symptom scores on a daily basis. Exposure to particulate matter with a diameter less than 10 m (PM10) and nitrogen dioxide (NO2) in each individual was estimated in 4 different ways; measurements from the nearest station of air quality monitoring system (AQMS) to residential houses (AQMS1), measurements modified from AQMS1 with indoor level of air pollutants and time activity of each individual (AQMS2), measurements modified from AQMS1 and AQMS2 with daily inhalation intakes of the air pollutants (AQMS1-DI and AQMS2-DI, respectively). A generalized linear mixed model (GLMM) was used to analyze associations between the exposure metrics and clinical symptoms after controlling for ambient temperature and humidity, age, and sex. Results: We found consistent positive associations between PM10 exposure and allergic symptoms in all exposure metrics. These exposure metrics for PM10 and NO2 showed different distributions, and thus the magnitude of effects of exposure to PM10 and NO2 on allergic symptoms appeared to be different by exposure metric and disease; the effect sizes of PM10 exposure on asthma symptoms were slightly greater in metrics with inhalation capacity (AQMS-DIs) than those without (AQMSs). This pattern was not observed in AD. The GLMM models based on AQMS-DIs showed relatively lower Akaike information criterion (AIC) than AQMSs. Conclusion: Exposure estimates considering individual behaviors and physical status such as inhalation capacity may provide better estimation of the effect of air pollution on allergic disease.