Mercury Levels in Mothers

Abstract

Vol. 112, No. 17 PerspectivesOpen AccessMercury Levels in Mothers Katherine M. Shea Katherine M. Shea Search for more papers by this author Published:1 December 2004https://doi.org/10.1289/ehp.112-a978aAboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit I read with great interest the excellent article by Mahaffey et al. (2004), which further describes the characteristics of the 1,709 women from the National Health and Nutrition Examination Survey (NHANES) 1999–2000 who were sampled for total and organic mercury levels in blood. It adds valuable detail to the initial report published last year (Schober et al. 2003). I would appreciate clarification on one important point: in the “Discussion,” the authors cited a new analysis which indicates that the cord blood:maternal blood ratio is not 1:1 as assumed by the National Research Council (NRC) in 2000 (Committee on the Toxicological Effects of Methylmercury 2000), but rather 1.7:1. Using the same benchmark dose lower limit and uncertainty factor used by the NRC, Mahaffey et al. (2004) calculated that blood total mercury levels > 3.5 μg/L in mothers could be associated with increased risk to the developing fetal nervous system. I am very interested in the details of this analysis and particularly in understanding why the uncertainty factor applied by the NRC to account in part for toxicokinetic variability does not compensate for uncertainty related to the cord blood:maternal blood mercury ratio. This is a critical concept because it has a dramatic impact on how many women may carry mercury levels in excess of what is believed to be safe for a fetus.ReferencesCommittee on the Toxicological Effects of Methylmercury, Board on Environmental Studies and Toxicology, Commission on Life Sciences, National Research Council 2000. Toxicological Effects of Methylmercury. Washington, DC:National Academy Press. Available: http://www.nap.edu/books/0309071402/html/ [accessed 28 October 2004]. Google ScholarMahaffey KR, Clickner RP, Bodurow CC. 2004. Blood organic mercury and dietary mercury intake: National Health and Nutrition Examination Survey, 1999 and 2000. Environ Health Perspect 112:562-57015064162. Link, Google ScholarSchober SE, Sinks TH, Jones RL, Bolger PM, McDowell M, Osterloh Jet al.. 2003. Blood mercury levels in U.S. children and women of childbearing age, 1999–2000. JAMA 289:1667-167412672735. Crossref, Medline, Google ScholarFiguresReferencesRelatedDetails Vol. 112, No. 17 December 2004Metrics About Article Metrics Publication History Originally published1 December 2004Published in print1 December 2004 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.