Environmental biomonitoring exposure

Marked, B., Oehlmann, J., Roth, M 1997b. General aspects of heavy metal monitoring by plants and animals. In Subramanian, K.S., Iyengar, G.V. (Eds.), Environmental Biomonitoring - Exposure Assessment and Specimen Banking. ACS Symp Ser 654, American Chemical Society, Washington, DC, pp. 18-29. 

Centers for Disease Control and Prevention—National Health and Nutrition Examination Surveys (NHANES) National Reports on Human Exposure to Environmental Chemicals Provides continuing assessment of U.S. population s exposure to environmental chemicals using biomonitoring data from NHANES. First National Report on Human Exposure to Environmental Chemicals (First Report) was issued in March 2001. Second Report, released in January 2003, presents biomonitoring exposure data on 116 environmental chemicals for noninstitutionalized, civilian U.S. population in 1999-2000. Third report was released in July 2005 and includes data on 148 chemicals (CDC 2005). 

Conceptually, SPMD data fills a gap between exposure assessments based on direct analytical measurement of total residues in water and air, and the analysis of residues present in biomonitoring organisms. SPMDs provide a biomimetic approach (i.e., processes in simple media that mimic more complex biological processes) for determining ambient HOC concentrations, sources, and gradients. Residues accumulated in SPMDs are representative of their environmental bioavailability (see Section 1.1.) in water and air and the encounter-volume rate as defined by Landrum et al. (1994) is expected to be proportional to the uptake rate. SPMD-based estimates of water concentrations can be readily compared to aquatic toxicity data (generally based on dissolved phase concentrations) and SPMD extracts can be used to screen for toxic concentrations of HOCs using bioassays or biomarker tests. 

Bernard, C. E., et al. (2001). Environmental residues and biomonitoring estimates of human insecticide exposure from treated residential turf. Archives of Environmental Contamination and Toxicology 41(2) 237-240. 

Dekant W, VoUcel W (2008) Human exposure to bisphenol A by biomonitoring methods, results and assessment of environmental exposures. Toxicol Appl Pharmacol 228 114—134... 

Prerequisites are (1) a biological test system that is capable of registering the observed effect in an environmental system and (2) an applied concentration technique that acts as an interface between the environment and the test system. If biomonitoring indicates an unwanted exposure to chemicals, it must be translated in chemical terms. This chemical information can be used for control purposes to eliminate the exposure, preferably to a real no-effect level, so that no risk evaluation has to be made. This method requires a bioassay that is specific for an effect in an environmental system and a concentration technique that is specific for the collection and transition of compounds causing the effect. 

The ability to generate new biomonitoring data often exceeds the ability to evaluate whether and how a chemical measured in an individual or population may cause a health risk or to evaluate its sources and pathways for exposure. As CDC states in its National Reports on Human Exposure to Environmental Chemicals, the presence of a chemical in a blood or urine specimen does not mean that the chemical causes a health risk or disease. The challenge for public-health officials is to understand the health implications of the biomonitoring data, to provide the public with appropriate information, and to craft appropriate public-health policy responses. 

The National Report on Human Exposure to Environmental Chemicals, produced by CDC, is based on a representative sample of the population and a large number of chemicals, and uses well-documented analytic techniques. However, not all biomonitoring studies are conducted with the... 

Biomonitoring data are more challenging to interpret than other exposure measures, such as personal air sampling or exposure diaries, in that they provide information on internal doses that are integrated across environmental pathways and routes of exposure and directly reflect the amount of chemicals that are absorbed into the blood and are distributed, stored, metabolized, and excreted. Therefore, not only must the complexities of the biologic system be considered, but also the properties of the chemicals or their metabolites. 

The most important question for biomonitoring efforts to address is whether exposure to a chemical causes health effects. Few data are available on most of the chemicals measured in population studies, such as NHANES, to address that question (Metcalf and Orloff 2004). For example, the Government Accountability Office (GAO 2005) reports that EPA has limited data on the health and environmental risks posed by chemicals now used in commerce. A survey of risk-assessment practitioners on the extent to which biomarkers are used in risk assessment concluded that the absence of chemical-specific data (for example, toxicologic and epidemiologic data) was the primary limitation in using exposure biomarkers in risk assessment (Maier et al. 2004). 

The committee acknowledges that there has been substantial research developing biomarkers further along the exposure-effect continuum, including prominent work by Gan et al. (2004) Hecht (2003) Joseph et al. (2005) Kensler et al. (2005) Qian et al. (1994) Rappaport et al. (2005) and Yu et al. (1995). The ultimate objective of the biomonitoring research is to link biomarkers of exposure to biomarkers of effect and susceptibility to understand the public-health implications of exposure to environmental chemicals. 

Sexton, K., L.L. Needham, and J.L. Pirkle. 2004. Human biomonitoring of environmental chemicals Measuring chemicals in human tissue is the gold standard for assessing the people s exposure to pollution. Am. Sci. 92(l) 38-45. 

Current biomonitoring efforts can be categorized as survey projects and research projects. The objective of survey projects typically is to advance public health by producing information about the prevalence of exposure to environmental toxicants based on periodic monitoring (European... 

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. 

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