Toxic Chemicals

Three main barriers limit federal and state agencies' ability to make more progress in measuring internal doses of exposure to toxic chemicals--actual levels of chemicals or their metabolites in human tissues--which can be a more useful measure of exposure for some purposes than the historical estimates of human exposure based on the concentration of these chemicals in environmental media, such as air, water, and food. First, federal and state laboratories often lack the capacity to conduct measurements needed to collect human exposure data; no laboratory method has been developed for measuring the levels of many chemicals in human tissues. Second, information is lacking to help set test results in context; public health officials need more information on typical exposures in the general population in order to compare this information with people's levels at specific sites or with specific populations within states. Third, coordinated, long-term planning among federal agencies is lacking, partly because of sporadic agency commitments to human exposure measurement and monitoring. GAO recommends that the Secretary of the Department of Health and Human Services and the Administrator of the Environmental Protection Agency develop a coordinated federal strategy for short-term and long-term monitoring and reporting of human exposures to potentially toxic chemicals.

GAO noted that: (1) federal and state efforts to collect human exposure data are limited, despite some recent expansions; (2) HHS and EPA have been able to take advantage of improved technology to measure exposures for more people and for a broader range of chemicals; (3) still, with existing resources, HHS and EPA surveys together measure in the general population only about 6 percent of the more than 1,400 toxic chemicals in GAO's review; (4) for those toxic chemicals that GAO reviewed, the portion measured ranged from 2 percent of chemicals prioritized for safety testing to about 23 percent of those chemicals most often found at Superfund sites and considered to pose a significant threat to human health; (5) even for those chemicals that are measured, information is often insufficient to identify smaller population groups at high risk, such as children in inner cities and people living in polluted locations who may have particularly high exposures; (6) at the state level, efforts are similarly limited; (7) almost all state officials said they highly valued human exposure data for populations within their borders, and many provided specific examples of how such data have provided useful information for interpreting citizens' health risks and guiding public health actions; (8) three main barriers limit federal and state agencies' abilities to make more progress; (9) first, federal and state laboratories often lack the capacity to conduct measurements needed to collect human exposure data--additionally, for most of the chemicals on GAO's list, no laboratory method has been developed for measuring the chemical levels in human tissues; (10) the second barrier, particularly voiced by state officials, relates to the lack of information to help set test results in context; (11) public health officials said they need more information on typical exposures in the general population so that they can compare this information with people's levels at specific sites or with specific populations in their states; (12) they also said they needed more research to relate exposure levels to health effects for the chemicals of concern in their states; (13) the third barrier, of particular concern at the federal level, is that coordinated, long-term planning among federal agencies has been lacking, partly because of sporadic agency commitments to human exposure measurement and monitoring; and (14) HHS and EPA officials indicated that they have been discussing the merits of establishing a coordinated interagency human exposure program, but they have not yet formalized or agreed upon a long-term strategy.

Recommendations

Our recommendations from this work are listed below with a Contact for more information. Status will change from "In process" to "Open," "Closed - implemented," or "Closed - not implemented" based on our follow up work.

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