1. Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, 130 DeSoto Street, Pittsburgh, PA 15261, USA
2. University of Pittsburgh Academic Partner of Excellence in Public Health Tracking, USA
3. Department of Behavioral and Community Health Sciences, University of Pittsburgh Graduate School of Public Health, 130 DeSoto Street, Pittsburgh, PA 15261, USA
4. Department of Biostatistics, University of Pittsburgh Graduate School of Public Health, 130 DeSoto Street, Pittsburgh, PA 15261, USA
5. Center for Occupational Biostatistics and Epidemiology, University of Pittsburgh, USA
6. Division of Environmental Hazards and Health Effects, Centers for Disease Control and Prevention, Environmental Health Tracking Branch, 1600 Clifton Road, Atlanta, GA 30333, USA