About the Authors

Alison P. Sanders

Affiliation Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, United States of America

Kaye Flood

Affiliation State Laboratory of Public Health, North Carolina Department of Health and Human Services, Raleigh, North Carolina, United States of America

Shu Chiang

Affiliation State Laboratory of Public Health, North Carolina Department of Health and Human Services, Raleigh, North Carolina, United States of America

Amy H. Herring

Affiliation Department of Biostatistics, Gillings School of Global Public Health, and Carolina Population Center, University of North Carolina, Chapel Hill, North Carolina, United States of America

Leslie Wolf

Affiliation State Laboratory of Public Health, North Carolina Department of Health and Human Services, Raleigh, North Carolina, United States of America

Rebecca C. Fry

rfry@email.unc.edu

Affiliation Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, United States of America

Competing Interests

The authors have read the journal's policy and have the following conflicts: This research was funded in part by a commercial funder (Pfizer, Inc). This does not alter the authors' adherence to all the PLoS ONE policies on sharing data and materials. The authors have declared that no other competing interests exist.

Author Contributions

Conceived and designed the experiments: RCF. Performed the experiments: KF SC. Analyzed the data: APS AHH. Contributed reagents/materials/analysis tools: LW. Wrote the paper: APS RCF.