Commission 2004; Knudsen 2004, as cited in ECETOC 2005). Research projects typically are hypothesis-driven and geared to the collection of data to link health outcomes causally to exposures (ECETOC 2005).
Selected historical and current U.S. and international large-scale, population-based efforts to monitor environmental toxicants in human tissues are summarized below. Also included is a brief discussion of biomonitoring by private organizations and laboratories. This chapter is meant not to be a comprehensive summary of biomonitoring efforts but to provide context on the history of biomonitoring and on current and planned efforts in the field. This overview illustrates the diversity in current biomonitoring efforts, particularly with respect to study population size and analytes measured. Because of the differences in biomonitoring studies, including the type of studies conducted, when the studies were performed, and the various applications for the biomarkers, the committee explicitly did not address the duration of the biomonitoring studies or their respective costs in this chapter.
Population-based biomonitoring programs in the United States have been in place since the late 1960s and have evolved substantially (see Figure 2-1). Such initial efforts as the National Human Monitoring Program, administered by the U.S. Environmental Protection Agency (EPA), and NHANES, administered by the Centers for Disease Control and Prevention (CDC), monitored for only a few chemicals, primarily pesticides and metals. Later efforts, including the National Human Exposure Assessment Survey (NHEXAS) and NHANES (1999-2000), began monitoring for many more chemicals. In addition to monitoring for a greater variety of chemicals, some studies (NHEXAS and the Agricultural Health Study) began to include environmental sampling to quantify personal exposure better. Although the larger population-based efforts (such as NHANES) have not been able to incorporate environmental monitoring, they have been instrumental in collecting background information on exposure to upwards of 140 chemicals. In the future, the National Children’s Study (NCS), if funded, would have the potential to collect biomonitoring data and link them to environmental monitoring data.
CDC has been a major player in funding both state and national biomonitoring programs. NHANES and the National Reports on Human Exposure to Environmental Chemicals have provided regulators with a comprehensive overview of exposures in the general population to selected chemicals.
Improvements in analytic techniques for sampling, including lower detection limits, will probably change how biomonitoring data are used. It