Evaluation of Biomonitoring Data from the CDC National Exposure Report in a Risk Assessment Context: Perspectives across Chemicals

Lesa L. Aylward,¹ Christopher R. Kirman,² Rita Schoeny,³ Christopher J. Portier,⁴ and Sean M. Hays⁵

¹Summit Toxicology LLP, Falls Church, Virginia, USA; ²Summit Toxicology LLP, Orange Village, Ohio, USA; ³Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC, USA; ⁴National Center for Environmental Health/Agency for Toxic Substances and Disease Registry, Atlanta, Georgia, USA; ⁵Summit Toxicology LLP, Lyons, Colorado, USA

Abstract

Background: Biomonitoring data reported in the National Report on Human Exposure to Environmental Chemicals [NER; Centers for Disease Control and Prevention (2012)] provide information on the presence and concentrations of > 400 chemicals in human blood and urine. Biomonitoring Equivalents (BEs) and other risk assessment–based values now allow interpretation of these biomonitoring data in a public health risk context.

Objectives: We compared the measured biomarker concentrations in the NER with BEs and similar risk assessment values to provide an across-chemical risk assessment perspective on the measured levels for approximately 130 analytes in the NER.

Methods: We identified available risk assessment–based biomarker screening values, including BEs and Human Biomonitoring-I (HBM-I) values from the German Human Biomonitoring Commission. Geometric mean and 95th percentile population biomarker concentrations from the NER were compared to the available screening values to generate chemical-specific hazard quotients (HQs) or cancer risk estimates.

Conclusions: Most analytes in the NER show HQ values of < 1; however, some (including acrylamide, dioxin-like chemicals, benzene, xylene, several metals, di-2(ethylhexyl)phthalate, and some legacy organochlorine pesticides) approach or exceed HQ values of 1 or cancer risks of > 1 × 10^–4 at the geometric mean or 95th percentile, suggesting exposure levels may exceed published human health benchmarks. This analysis provides for the first time a means for examining population biomonitoring data for multiple environmental chemicals in the context of the risk assessments for those chemicals. The results of these comparisons can be used to focus more detailed chemical-specific examination of the data and inform priorities for chemical risk management and research.

Key words: biomonitoring, Biomonitoring Equivalents, blood, cancer risk, CDC National Exposure Report, hazard quotient, NHANES, risk assessment, urine.

Environ Health Perspect 121:287–294 (2013). http://dx.doi.org/10.1289/ehp.1205740 [Online 11 December 2012]

Address correspondence to L.L. Aylward, Summit Toxicology LLP, 6343 Carolyn Dr., Falls Church, VA 22044 USA. Telephone: (703) 349-3515. E-mail: laylward@summittoxicology.com

L.L.A., S.M.H., and C.R.K. received funding to support the preparation of this review from the American Chemistry Council.

The authors had complete control over the design, conduct, interpretation, and reporting of the analyses included in this manuscript. The contents of this manuscript are solely the responsibility of the authors and do not necessarily reflect the views or policies of the U.S. Environmental Protection Agency or the National Center for Environmental Health/Agency for Toxic Substances and Disease Registry.

L.L.A., S.M.H., and C.R.K. are independent partners in Summit Toxicology LLP, a toxicology, risk assessment, and pharmaceutical consulting firm, and have worked on risk assessment issues related to many of the chemicals addressed in this review for a wide variety of governmental, trade association, and industry clients. R.S. and C.P. declare they have no actual or potential competing financial interests.

Received 10 July 2012; Accepted 4 December 2012; Online 11 December 2012.