Author Contributions: Dr Vesper had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Johnson, Pirkle.
Acquisition of data: Kuiper.
Analysis and interpretation of data: Vesper, Mirel.
Drafting of the manuscript: Vesper, Kuiper.
Critical revision of the manuscript for important intellectual content: Vesper, Mirel, Johnson, Pirkle.
Statistical analysis: Mirel, Johnson.
Obtained funding: Johnson, Pirkle.
Administrative, technical or material support: Vesper, Kuiper, Johnson, Pirkle.
Study supervision: Vesper, Johnson, Pirkle.
Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.
Funding/Support: The Centers for Disease Control and Prevention funded this study.
Role of the Sponsor: The Centers for Disease Control and Prevention had a role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript.
Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention or the Agency for Toxic Substances and Disease Registry.
Additional Contributions: We thank Christina Waters, BS, Judith Heitz, BS, Tunde Meyers, MS, Antoinette Smith, MPH, Ashley Ribera, BS, Marcela Muresan, BS, Ashley Tippins, BS, Cindy Tse, BS, and Monir Clark, BS (all with the National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia) for their support in the laboratory measurements and Brenda Lewis, MPH (National Center for Health Statistics, Centers for Disease Control and Prevention, Atlanta, Georgia) for her support with specimen logistics. No individual received compensation for their contributions beyond their salaries.