Modeling the Effect of Temperature on Ozone-Related Mortality

• Activity Number: 592
• Type: Topic Contributed
• Date/Time: Wednesday, August 7, 2013 : 2:00 PM to 3:50 PM
• Sponsor: Section on Statistics and the Environment
• Author(s): Ander Wilson*+ and Ana Rappold and Neas Lucas and Brian J. Reich
• Companies: North Carolina State University and U.S. Environmental Protection Agency and U.S. Environmental Protection Agency and North Carolina State University
• Keywords: Bayesian semiparametric method ; Bivariate surface ; Monotonicity ; Mortality ; Temperature ; Ozone

Abstract

Studies show ozone and temperature are associated with increased mortality; however, the joint effects are not well characterized. Understanding this relationship is important for estimating the potential effects of climate change on ozone-related mortality. We extend the ozone risk model from National Morbidity, Mortality, and Air Pollution Study (NMMAPS) to include an ozone-temperature risk surface. At the second stage we use a spatial process on the spline coefficients and introduce a monotonicity constraint in the ozone direction. The proposed model allows for a different number of basis functions to be used in each city, enabling smoothing over cities with different ozone and temperature ranges while avoiding overparameterizing the first-stage models. Our method is computationally simple and provides closed form statistical summaries of the risk surface. By spatially smoothing, our model improves estimation of the high-temperature-high-ozone risk surface. Using the NMMAPS data we estimate the risk surfaces for 95 US urban centers and explore the potential effect of changes in temperature on ozone-related mortality. This abstract does not necessarily reflect U.S. EPA policy.