1. Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
2. Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA
3. Department of Environmental Health, Columbia University, New York, NY, USA
4. Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA
5. Department of Biostatistics, Mailman School of Public Health, Columbia University and New York State Psychiatric Institute, New York, NY, USA
6. Department of Clinical Psychology, Columbia University and New York State Psychiatric Institute, New York, NY, USA
7. Department of Neurology, University of California, San Francisco, CA, USA, and
8. Centers for Disease Control and Prevention/Agency for Toxic Substance and Disease Registry (CDC/ATSDR), Atlanta, GA, USA