1. Western States Pediatric Environmental Health Specialty Unit, University of California San Francisco, San Francisco, California, USA
2. California Environmental Protection Agency, Oakland, California, USA
3. Collaborative on Health and the Environment, Bolinas, California, USA
4. Science and Environmental Health Network, Ames, Iowa, USA
5. Environmental Medicine Branch, Division of Toxicology and Human Health Sciences, Agency for Toxic Substances and Disease Registry, Atlanta, Georgia, USA.