1. Division of Field Studies and Engineering National Institute for Occupational Safety and Health Cincinnati Ohio USA
2. Center for Fire, Rescue, and EMS Health Research NDRI‐USA, Inc Leawood Kansas USA
3. Division of Birth Defects and Infant Disorders National Center on Birth Defects and Developmental Disabilities, CDC Atlanta Georgia USA
4. Department of Epidemiology, Gillings School of Global Public Health University of North Carolina at Chapel Hill Chapel Hill North Carolina USA