%0 Journal Article %K Indoor environment department %K Ozone %K Exposure and health effects %K Diesel particulate matter %K Environmental justice %K Exposure analysis %K Geographic information system (gis) %K Mobility %K Environmental Chemistry, Exposure and Risk Group %A Julian D Marshall %A Patrick W Granvold %A Abigail S Hoats %A Thomas E McKone %A Elizabeth Deakin %A William W Nazaroff %B Atmospheric Environment %D 2006 %G eng %N 23 %P 4381-4392 %R 10.1016/j.atmosenv.2006.03.034 %T Inhalation intake of ambient air pollution in California's South Coast Air Basin %V 40 %1

7.1

%8 07/2006 %X

Reliable estimates of inhalation intake of air pollution and its distribution among a specified population are important for environmental epidemiology, health risk assessment, urban planning, and environmental policy. We computed distributional characteristics of the inhalation intake of five pollutants for a group of ~25,000 people (~29,000 person-days) living in California's South Coast Air Basin. Our approach incorporates four main inputs: temporally resolved information about people's location (latitude and longitude), microenvironment, and activity level; temporally and spatially explicit model determinations of ambient concentrations; stochastically determined microenvironmental adjustment factors relating the exposure concentration to the ambient concentration; and, age-, gender-, and activity-specific breathing rates. Our study is restricted to pollutants of outdoor origin, i.e. it does not incorporate intake in a microenvironment from direct emissions into that microenvironment. Median estimated inhalation intake rates (μg d-1) are 53 for benzene, 5.1 for 1,3-butadiene, 8.7 10-4 for hexavalent chromium in fine particulate matter (Cr-PM2.5), 30 for diesel fine particulate matter (DPM2.5), and 68 for ozone. For the four primary pollutants studied, estimated median intake rates are higher for non-whites and for individuals in low-income households than for the population as a whole. For ozone, a secondary pollutant, the reverse is true. Accounting for microenvironmental adjustment factors, population mobility, and temporal correlations between pollutant concentrations and breathing rates affects the estimated inhalation intake by 40% on average. The approach presented here could be extended to quantify the impact on intakes and intake distributions of proposed changes in emissions, air quality, and urban infrastructure.