Abstract
Lead is widely recognized as one of the most pervasive environmental health threats in the United States, and there is increased concern over adverse health impacts at levels of exposure once considered safe. Lead contamination of tap water was once a major cause of lead exposure in the United States and, as other sources have been addressed, the relative contribution of lead in water to lead in blood is expected to become increasingly important. Moreover, prior research suggests that lead in water may be more important as a source than is presently believed. The authors describe sources of lead in tap water, chemical forms of the lead, and relevant U.S. regulations/guidelines, while considering their implications for human exposure. Research that examined associations between water lead levels and blood lead levels is critically reviewed, and some of the challenges in making such associations, even if lead in water is the dominant source of lead in blood, are highlighted. Better protecting populations at risk from this and from other lead sources is necessary, if the United States is to achieve its goal of eliminating elevated blood lead levels in children by 2020.
ACKNOWLEDGMENTS
The authors acknowledge the financial support of the National Science Foundation under grant CBET-0933246. Opinions and findings expressed herein are those of the authors and do not necessarily reflect the views of the National Science Foundation. The authors would also like to thank Dr. Yanna Lambrinidou for her useful suggestions, as well as the anonymous reviewers for their valuable comments. Portions of sections VI and VII were presented at the Yale University Drinking Water Symposium in April 2009 and appeared as a supplemental paper of that symposium.