1. Asthma and Community Health Branch, Division of Environmental Health Science and Practice, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
2. Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
3. Division of Health Informatics and Surveillance, Center for Surveillance, Epidemiology, and Laboratory Services, Centers for Disease Control and Prevention, Atlanta, GA, USA
4. Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
5. U.S. Public Health Service Commissioned Corps, Rockville, MD, USA