Inhalation intake of ambient air pollution in California's South Coast Air Basin

TitleInhalation intake of ambient air pollution in California's South Coast Air Basin
Publication TypeJournal Article
Year of Publication2006
AuthorsJulian D Marshall, Patrick W Granvold, Abigail S Hoats, Thomas E McKone, Elizabeth Deakin, William W Nazaroff
JournalAtmospheric Environment
Volume40
4381
Issue23
Pagination4381-4392
Date Published07/2006
Keywordsdiesel particulate matter, Environmental Chemistry, Exposure and Risk Group, environmental justice, exposure analysis, exposure and health effects, geographic information system (gis), indoor environment department, mobility, ozone
Abstract

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.

DOI10.1016/j.atmosenv.2006.03.034