1. Department of Environmental and Occupational Health, Texas A&M School of Public Health, College Station, Texas, USA.
2. Department of Epidemiology and Biostatistics, Texas A&M School of Public Health, College Station, Texas, USA
3. Interdisciplinary Faculty of Toxicology, Texas A&M University, College Station, Texas, USA
4. Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas, USA
5. Department of Chemistry, North Carolina State University, Raleigh, North Carolina, USA
6. Epidemiology Program, University of Delaware, Newark, Delaware, USA