The Association Between Air Pollutants and Birth Weight Using Various Buffer Sizes

• Activity Number: 351
• Type: Contributed
• Date/Time: Tuesday, August 6, 2013 : 10:30 AM to 12:20 PM
• Sponsor: Section on Statistics and the Environment
• Author(s): Keita Ebisu*+ and Kathleen Belanger and Michelle Bell
• Companies: Yale University and Yale University, School of Public Health, Department of Epidemiology and Yale University, School of Forestry and Environmental Studies
• Keywords: Environmental Epidemiology ; Air Pollution ; Birth Weight

Abstract

Spatial heterogeneity and associated exposure misclassification are key challenges in studies of air pollution and health . Few studies explored these issues, particularly for fine particulate matter (PM2.5) chemical components. We investigated associations between birth weight and PM2.5 components and gaseous pollutants considering issues of buffer size (i.e., distance from residence to monitor). We estimated the association between each pollutant and birth weight using seven different buffer sizes from 5 to 50km. Gestational exposure to NO2, SO2, PM10, and PM2.5 were associated with lower birth weight with any buffer size. On the other hand, several pollutants show inconsistent results across different buffer sizes. For instance, PM2.5 sulfate did not show association with 5km buffer, while it showed associations with 50km buffer. Results indicate effect estimates vary with different buffer sizes for some pollutants, implying potential exposure misclassification. Homogeneous pollutant levels within a certain distance is a basic assumption in many environmental epidemiology studies, but our findings suggest that different exposure metrics may be needed for different pollutants.