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SPATIAL ASSOCIATION BETWEEN SPECIATED FINE PARTICLES AND MORTALITY
Citation:
Fuentes, M., H. Song, S. Ghosh, D M. Holland, AND J. Davis. SPATIAL ASSOCIATION BETWEEN SPECIATED FINE PARTICLES AND MORTALITY. BIOMETRICS DOI: 10,1111/j.(1541-0420..0052):1-9, (2006).
Impact/Purpose:
Our main objective is to assess the exposure of selected ecosystems to specific atmospheric stressors. More precisely, we will analyze and interpret environmental quality (primarily atmospheric) data to document observable changes in environmental stressors that may be associated with legislatively-mandated emissions reductions.
Description:
Particulate matter (PM) has been linked to a range of serious cardiovascular and respiratory health problems. Some of the recent epidemiologic studies suggest that exposures to PM may result in tens of thousands of excess deaths per year and many more cases of illness among the US population. The main objective of our research is to quantify uncertainties about the impacts of fine PM exposure on mortality. We develop a mutivariate spatial regression model for estimation of the risk of mortality associated to fine PM and its components across all counties the conterminous US. Our approach adjust for meteorology and other confounding influences, such as socioeconomic factors, age, gender and ethnicity, characterizes different sources of uncertainty of the data, and models the spatial structure of several components of fine PM. We consider a flexible Bayesian hierarchical model for a space-time series of counts (mortality) by constructing a likelihood based version of a generalized Poisson regression model. The model has the advantage of incorporating both over and under dispersion in addition to correlations that occur in space and time. We apply these methods to monthly mortality county counts and measurements of total and several components of fine PM from: national monitoring networks in the U.S.
Our results seem to suggest an increase by a factor of 2 in the risk of mortality due to fine particles with respect to coarse particles. Our study also shows that in the Western U.S., the nitrate and crustal components of the speciated fine PM seem to have more impact on mortality that the other components. On the other hand, in the Eastern U.S. sulfate and ammonium explain most of the PM fine effect.