Air Pollution and Pre-Term Pregnancy: Identifying Critical Windows of Exposure

• Activity Number: 99
• Type: Invited
• Date/Time: Monday, August 1, 2011 : 8:30 AM to 10:20 AM
• Sponsor: ENAR
• Author(s): Montse Fuentes*+ and Joshua Warren and Amy Herring and Peter Langlois
• Companies: North Carolina State University and North Carolina State University and University of North Carolina at Chapel Hill and Texas Department of State Health Services
• Keywords: multivariate statistics ; spatial statistics ; particulate matter ; ozone ; pregnancy outcomes ; probit spatial models

Abstract

A major methodological challenge in the study of environmental exposures and birth outcomes is the identification of a critical window of exposure. The developing organ systems of the fetus may be more vulnerable to exposures to environmental toxicants during these critical windows because of a variety of factors, including higher rates of cell proliferation or changes in metabolism. We introduce new Bayesian spatial shrinkage methods to control potential multicollinearity of exposure due to multi-pollutants exposure and multiple lags. This framework facilitates the search for susceptible periods of exposure during fetal development, and sheds additional light on exposures previously examined in isolation or under strict assumptions about the nature of the association. We apply our methods to geo-coded birth outcome data from the state of Texas (1997-2004) to identify the critical windows of the pregnancy where increased exposure to fine particulate matter and ozone is particularly harmful. Our results indicate the susceptible window for higher preterm probabilities is mid-first trimester for the fine PM and beginning of the first trimester for the ozone.