Breanna L Alman1, Jeanette A Stingone2, Mahsa Yazdy3, Lorenzo D Botto4, Tania A Desrosiers5, Shannon Pruitt6, Amy H Herring7, Peter H Langlois8, Wendy N Nembhard9, Gary M Shaw10, Andrew F Olshan5, Thomas J Luben11. 1. Office of Air and Radiation, U.S. Environmental Protection Agency, Research Triangle Park, NC. 2. Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, NY, NY. 3. Massachusetts Department of Public Health, Boston, MA. 4. Department of Pediatrics, University of Utah, Salt Lake City. 5. Department of Epidemiology, Gillings School of Global Public Health, UNC Chapel Hill, NC. 6. National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention (CDC), Atlanta, GA; Oak Ridge Institute for Science and Education, Oak Ridge, TN. 7. Global Health Institute, Duke University, Durham, NC. 8. Birth Defects Epidemiology and Surveillance Branch, Texas Department of State Health Services, Austin, TX. 9. Departments of Pediatrics and Epidemiology, University of Arkansas for Medical Sciences, Little Rock, AR. 10. Department of Pediatrics, Stanford University, Stanford, CA. 11. Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC. Electronic address: luben.tom@epa.gov.
Abstract
PURPOSE: Studies suggest exposure to ambient particulate matter less than 2.5 μg/m3 in aerodynamic diameter (PM2.5) may be associated with preterm birth (PTB), but few have evaluated how this is modified by ambient temperature. We investigated the relationship between PM2.5 exposure during pregnancy and PTB in infants without birth defects (1999-2006) and enrolled in the National Birth Defects Prevention Study and how it is modified by concurrent temperature. METHODS: PTB was defined as spontaneous or iatrogenic delivery before 37 weeks. Exposure was assigned using inverse distance weighting with up to four monitors within 50 kilometers of maternal residence. To account for state-level variations, a Bayesian two-level hierarchal model was developed. RESULTS: PTB was associated with PM2.5 during the third and fourth months of pregnancy (range: (odds ratio (95% confidence interval) = 1.00 (0.35, 2.15) to 1.49 (0.82, 2.68) and 1.31 (0.56, 2.91) to 1.62 (0.7, 3.32), respectively); no week of exposure conveyed greater risk. Temperature may modify this relationship; higher local average temperatures during pregnancy yielded stronger positive relationships between PM2.5 and PTB compared to nonstratified results. CONCLUSIONS: Results add to literature on associations between PM2.5 and PTB, underscoring the importance of considering co-exposures when estimating effects of PM2.5 exposure during pregnancy.
PURPOSE: Studies suggest exposure to ambient particulate matter less than 2.5 μg/m3 in aerodynamic diameter (PM2.5) may be associated with preterm birth (PTB), but few have evaluated how this is modified by ambient temperature. We investigated the relationship between PM2.5 exposure during pregnancy and PTB in infants without birth defects (1999-2006) and enrolled in the National Birth Defects Prevention Study and how it is modified by concurrent temperature. METHODS: PTB was defined as spontaneous or iatrogenic delivery before 37 weeks. Exposure was assigned using inverse distance weighting with up to four monitors within 50 kilometers of maternal residence. To account for state-level variations, a Bayesian two-level hierarchal model was developed. RESULTS: PTB was associated with PM2.5 during the third and fourth months of pregnancy (range: (odds ratio (95% confidence interval) = 1.00 (0.35, 2.15) to 1.49 (0.82, 2.68) and 1.31 (0.56, 2.91) to 1.62 (0.7, 3.32), respectively); no week of exposure conveyed greater risk. Temperature may modify this relationship; higher local average temperatures during pregnancy yielded stronger positive relationships between PM2.5 and PTB compared to nonstratified results. CONCLUSIONS: Results add to literature on associations between PM2.5 and PTB, underscoring the importance of considering co-exposures when estimating effects of PM2.5 exposure during pregnancy.
Authors: Kristen M Rappazzo; Julie L Daniels; Lynne C Messer; Charles Poole; Danelle T Lobdell Journal: Environ Health Perspect Date: 2014-05-30 Impact factor: 9.031