About the Authors

Sharine Wittkopp

Affiliation Occupational and Environmental Medicine Division, Department of Medicine, School of Medicine, University of California Irvine, Irvine, California, United States of America

Norbert Staimer

Affiliation Department of Epidemiology, School of Medicine, University of California Irvine, Irvine, California, United States of America

Thomas Tjoa

Affiliation Department of Epidemiology, School of Medicine, University of California Irvine, Irvine, California, United States of America

Daniel Gillen

Affiliation Department of Statistics, School of Information and Computer Sciences, University of California Irvine, Irvine, California, United States of America

Nancy Daher

Affiliation Department of Civil and Environmental Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, California, United States of America

Martin Shafer

Affiliation University of Wisconsin-Madison, Environmental Chemistry and Technology Program, Madison, Wisconsin, United States of America

James J. Schauer

Affiliation University of Wisconsin-Madison, Environmental Chemistry and Technology Program, Madison, Wisconsin, United States of America

Constantinos Sioutas

Affiliation Department of Civil and Environmental Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, California, United States of America

Ralph J. Delfino

rdelfino@uci.edu

Affiliation Department of Epidemiology, School of Medicine, University of California Irvine, Irvine, California, United States of America

Competing Interests

C.S. receives royalties from SKC Inc. for the air sampling device (Sioutas Personal Cascade Impactor Sampler) used in this research. The remaining authors declare they have no actual or potential competing financial interests.This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: SW RD NS DG CS. Performed the experiments: SW RD NS ND MS JJS CS. Analyzed the data: SW RD TT DG. Wrote the paper: SW RD.