Author Contributions J. T. Nigg and K. H. Friderici developed the study concept and design. Data collection, including genotyping of samples analyzing blood lead levels, was overseen by J. T. Nigg, K. H. Friderici, and M. A. Nikolas. M. A. Nikolas, A. L. Elmore, and N. Natarajan performed the data analysis with supervision and guidance by J. T. Nigg. J. T. Nigg, A. L. Elmore, and M. A. Nikolas drafted the manuscript, and all authors provided critical revisions. All authors approved the final manuscript before submission.
