| Integrating Biomonitoring Exposure Data into the Risk Assessment Process: Phthalates [Diethyl Phthalate and Di(2-ethylhexyl) Phthalate] as a Case Study Antonia M. Calafat1 and Richard H. McKee2 1Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA; 2Toxicology Research Task Group, Phthalate Esters Panel, American Chemistry Council, Arlington, Virginia, USA Abstract
The probability of nonoccupational exposure to phthalates is high given their use in a vast range of consumables, including personal care products (e.g., perfumes, lotions, cosmetics) , paints, industrial plastics, and certain medical devices and pharmaceuticals. Phthalates are of high interest because of their potential for human exposure and because animal toxicity studies suggest that some phthalates affect male reproductive development apparently via inhibition of androgen biosynthesis. In humans, phthalates are rapidly metabolized to their monoesters, which can be further transformed to oxidative products, conjugated, and eliminated. Phthalate metabolites have been used as biomarkers of exposure. Using urinary phthalate metabolite concentrations allows accurate assessments of human exposure because these concentrations represent an integrative measure of exposure to phthalates from multiple sources and routes. However, the health significance of this exposure is unknown. To link biomarker measurements to exposure, internal dose, or health outcome, additional information (e.g., toxicokinetics, inter- and intraindividual differences) is needed. We present a case study using diethyl phthalate and di(2-ethylhexyl) phthalate as examples to illustrate scientific approaches and their limitations, identify data gaps, and outline research needs for using biomonitoring data in the context of human health risk assessment, with an emphasis on exposure and dose. Although the vast and growing literature on phthalates research could not be covered comprehensively in this article, we made every attempt to include the most relevant publications as of the end of 2005. Key words: biomarkers, biomonitoring, DEHP, DEP, exposure, human, phthalate, urine. Environ Health Perspect 114:1783–1789 (2006) . [Online 12 June 2006]
This article is part of the mini-monograph "Use of Biomonitoring Data in Exposure and Human Health Risk Assessments." Address correspondence to A.M. Calafat, Centers for Disease Control and Prevention, 4770 Buford Highway, Mailstop F17, Atlanta, GA 30341 USA. Telephone: (770) 488-7891. Fax: (770) 488-4371. E-mail: acalafat@cdc.gov The findings and conclusions in this article are those of the authors and do not necessarily represent the views of the CDC. R.H.M. is member of the American Chemistry Council, a trade association that represents chemical manufacturers, and contributed to this article in his capacity as Chairman of the Toxicology Research Task Group of the Phthalates Ester Panel. A.M.C. declares she has no competing financial interests.
The full version of this article is available for free in HTML or PDF formats. |
