About the Authors

Jay P. Graham

Affiliation Department of Environmental and Occupational Health and Department of Global Health, Milken Institute School of Public Health at George Washington University, Washington, DC, United States of America

Mitsuaki Hirai

Affiliation Department of Global Health, Milken Institute School of Public Health at George Washington University, Washington, DC, United States of America

Seung-Sup Kim

ssk3@korea.ac.kr

Affiliation Department of Public Health Sciences, Korea University, Seoul, South Korea

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Performed the experiments: SSK MH JG. Analyzed the data: JG SSK. Wrote the paper: JG MH SSK.