Identifying Chemical Groups for Biomonitoring

Introduction Environmental health researchers and government scientists in the United States typically encounter a paucity of information on both toxicity and exposure for most chemicals in commerce (Judson et al. 2009; Egeghy et al. 2012; Neltner et al. 2013; Silbergeld et al. 2015). Even if data are available, federal and state agencies have limited capacity for assessing health risks (GAO 2013). The recent legislative reform to the Toxic Substances Control Act (TSCA) includes provisions that aim to increase data availability for chemicals in commerce and expand safety reviews by the U.S. Environmental Protection Agency (EPA) (Frank R. Lautenberg Chemical Safety for the 21st Century Act 2016; McCarthy 2016). Many chemicals have been widely used and then later detected in environmental or biological samples and recognized as hazards to human health (Soto et al. 1991; Rubin 2011; Grandjean and Clapp 2015). A well-known example is the discovery of widespread human exposure and environmental contamination by polybrominated diphenyl ether (PBDE) flame retardants. Swedish researchers characterized the time trend of PBDEs in analyses of breast milk samples (Meironyté et al. 1999), prompting investigations across the globe (Law et al. 2014). PBDEs are structurally similar to polybrominated biphenyl (PBB) flame retardants. PBB flame retardants have been recognized as potentially harmful to human health since the 1970s, after they were inadvertently added to livestock feed in Michigan. In the San Francisco Bay Area, PBDE concentrations approximately 40-fold higher than the Swedish levels were found in marine mammals and human breast adipose tissue samples (She et al. 2002). These unexpected findings prompted policy actions on PBDEs in California and the United States. In response to the recognition that Californians carried a significant body burden of PBDEs and other toxicants, and the concern that additional exposures to as yet unrecognized chemical hazards were occurring, the California Environmental Contaminant Biomonitoring Program (CECBP)—referred to in this article as Biomonitoring California or the Program—was established by legislation in 2006 (State of California 2006). Biomonitoring California was modeled on the National Biomonitoring Program, which is being implemented by the Centers for Disease Control and Prevention (CDC; http://www.cdc.gov/biomonitoring/ about.html). CDC has strongly supported state biomonitoring efforts, providing grants to develop laboratory capability, promote community involvement, and support other aspects of state programs (https://www.cdc.gov/biomonitoring/state_grants.html). Biomonitoring studies at the state level can reveal regional differences in chemical exposures, driven by factors such as product use, types of industry, demographics, and geography. The primary goals of Biomonitoring California are to determine levels of potentially harmful environmental chemicals in the general state population, as well as in sensitive subpopulations (e.g., pregnant women and highly exposed disadvantaged communities); examine time trends in chemical levels; and help assess the effectiveness of public health and regulatory efforts to decrease exposures. Biomonitoring California is implemented by three California departments: the California Department of Public Health (lead for the overall Program), the Department of Toxic Substances Control, and the Office of Environmental Health Hazard Assessment (OEHHA). The enabling legislation also created the Scientific Guidance Panel (SGP), a body of experts appointed by the Governor and the California State Legislature. The expertise of SGP members encompasses a wide range of disciplines that include epidemiology, toxicology, biostatistics, exposure assessment, laboratory sciences, environmental medicine, public health, maternal and child health, and bioethics. The SGP provides scientific oversight for the design and implementation of Biomonitoring California and formally recommends chemicals to biomonitor. OEHHA convenes the SGP meetings and provides scientific support for the Panel’s chemical selection activities. For a chemical to be measured in a Biomonitoring California study, it must be on the list of designated chemicals. This list includes all chemicals measured by CDC’s National Biomonitoring Program, as well as chemicals added by a formal vote of the SGP. To inform the SGP’s deliberations, OEHHA researches possible candidate chemicals and develops detailed technical documents on chemicals chosen for consideration. OEHHA’s documents summarize information relevant to the legally mandated criteria for designated chemicals (State of California 2006) that were based on CDC’s selection criteria (CDC 2002) and address the following areas: exposure or potential exposure; known or suspected health effects; analytical factors, such as the availability of a biomonitoring laboratory method; and the need to assess the efficacy of public health actions to reduce exposure. Lack of data on one or more of these criteria does not preclude addition of a chemical to the designated list. The law also specifies criteria that the SGP must follow in identifying priority chemicals, which are chosen from the list of designated chemicals, for biomonitoring. The Program determines which designated or priority chemicals are ultimately biomonitored in specific studies. In initial efforts to identify chemicals for biomonitoring, the Program invited input from the public via workshops (http:// www.biomonitoring.ca.gov/events/workshop-chemical-selectionjune-2008), teleconferences, and surveys (CECBP 2009a, 2009b). OEHHA interviewed scientists from a wide range of California agencies, such as those responsible for occupational and public health A Section 508–conformant HTML version of this article is available at http://dx.doi.org/10.1289/EHP537.