Blood Lead Concentrations in Children and Method of Water Fluoridation in the United States, 1988-1994 Mark D. Macek,1,2 Thomas D. Matte,3 Thomas Sinks,3,4 and Dolores M. Malvitz2 1Department of Health Promotion and Policy, Baltimore College of Dental Surgery, Dental School, University of Maryland, Baltimore, Maryland, USA; 2Division of Oral Health, National Center for Chronic Disease Prevention and Health Promotion, 3National Center for Environmental Health, and 4Agency for Toxic Substances and Disease Registry, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
Abstract Some have hypothesized that community water containing sodium silicofluoride and hydrofluosilicic acid may increase blood lead (PbB) concentrations in children by leaching of lead from water conduits and by increasing absorption of lead from water. Our analysis aimed to evaluate the relation between water fluoridation method and PbB concentrations in children. We used PbB concentration data (n = 9,477) from the Third National Health and Nutrition Examination Survey (1988-1994) for children 1-16 years of age, merged with water fluoridation data from the 1992 Fluoridation Census. The main outcome measure was geometric mean PbB concentration, and covariates included age, sex, race/ethnicity, poverty status, urbanicity, and length of time living in residence. Geometric mean PbB concentrations for each water fluoridation method were 2.40 µg/dL (sodium silicofluoride) , 2.34 µg/dL (hydrofluosilicic acid) , 1.78 µg/dL (sodium fluoride) , 2.24 µg/dL (natural fluoride and no fluoride) , and 2.14 µg/dL (unknown/mixed status) . In multiple linear and logistic regression, there was a statistical interaction between water fluoridation method and year in which dwelling was built. Controlling for covariates, water fluoridation method was significant only in the models that included dwellings built before 1946 and dwellings of unknown age. Across stratum-specific models for dwellings of known age, neither hydrofluosilicic acid nor sodium silicofluoride were associated with higher geometric mean PbB concentrations or prevalence values. Given these findings, our analyses, though not definitive, do not support concerns that silicofluorides in community water systems cause higher PbB concentrations in children. Current evidence does not provide a basis for changing water fluoridation practices, which have a clear public health benefit. Key words: adolescents, children, fluoridation, nutrition surveys, lead, United States. Environ Health Perspect 114: 130-134 (2006) . doi:10.1289/ehp.8319 available via http://dx.doi.org/ [Online 17 August 2005] Address correspondence to M.D. Macek, Baltimore College of Dental Surgery, Dental School, University of Maryland, 666 West Baltimore St., Room 3-E-02, Baltimore, MD 21201-1586 USA. Telephone: (410) 706-4218. Fax: (410) 706-3028. E-mail: mmacek@umaryland.edu We gratefully acknowledge the technical assistance and guidance of L. Barker, A. Dannenberg, R. Hirsch, and J. Madans. This investigation was supported by the Centers for Disease Control and Prevention (CDC) , which funded the design and conduct of the study ; collection, management, analysis, and interpretation of the data ; and preparation, review, or approval of the manuscript. The findings and conclusions in this report are those of the authors and do not necessarily represent views of the CDC. The authors declare they have no competing financial interests. Received 13 May 2005 ; accepted 17 August 2005. The full version of this article is available for free in HTML or PDF formats. |