1. Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA;
2. Carolina Population Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
3. School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
4. Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
5. Institute of Environmental Health Solutions, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
6. Center for Public Health and Environmental Assessment, US Environmental Protection Agency, Chapel Hill, North Carolina, USA