Human exposure to environmental

Human exposure to environmental contaminants has been investigated through the analysis of adipose tissue, breast milk, blood and the monitoring of faecal and urinary excretion levels. However, while levels of persistent contaminants in human milk, for example, are extensively monitored, very little is known about foetal exposure to xenobiotics because the concentrations of persistent compounds in blood and trans-placental transmission are less well studied. Also, more information is needed in general about the behaviour of endocrine disruptive compounds (and their metabolites) in vivo, for example the way they bind to blood plasma proteins. 

Reduction of Human Exposure to Environmental iV-Nitroso Compounds... 

The complex pattern of human exposure to environmental N-nitroso compounds is summarized. Recent results are given in three areas, where a significant reduction of human exposure has been achieved after elucidation of its causes 1, N-Nitrosodimethylamine in beer. 2, Volatile N-nitrosamines in baby nipples and pacifiers and 3. occupational exposure in the rubber industry. 

Centers for Disease Control and Prevention (2001). National Report on Human Exposure to Environmental Chemicals. Atlanta, Georgia. 

Preussmann, R., Spiegelhalder, B., and Eisenbrand, G. "Reduction of Human Exposure to Environmental N-nitroso compounds. In N-Nitroso Compounds. R. A. Scanlan and S. R. Tannenbaum, eds. ACS Symposium Series No. 174. American Chemical Society, Washington, D. C. 1981, p.217. 

Let us deal with this last issue first, and simply note that the laws listed in Table 11.1 each have their own history and were generally enacted quite independently. Their particular forms were fashioned out of a complex interaction of industry, consumer and environmental activist, and governmental constituencies that each brought its own agenda to the legislative process. It is not the purpose here to try to understand how these differences came about, but rather to explore some of the effects of these differences on the problem of deciding what limits ought to be placed on human exposures to environmental chemicals. 

Centers for Disease Control. (2001) National Report on Human Exposures to Environmental Chemicals. Washington, DC, Department of Health and Human Services. 

Wallace LA. 1995. Human exposure to environmental pollutants A decade of experience. Clinical and... 

Develop more accurate and efficient methods of measuring human exposure to environmental chemicals with potential reproductive toxicity. 

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... 

In 2001, 2003, and 2005, CDC published the First, Second, and Third Reports on Human Exposure to Environmental Chemicals. Those landmark publications reported the concentrations of chemicals and metabolites in blood and urine of a representative sample of the U.S. civilian population from NHANES, with the first report detailing 27 chemicals and the second and third 116 and 148 chemicals, respectively. 

CDC (Centers for Disease Control and Prevention). 2003. Second National Report on Human Exposure to Environmental Chemicals. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, Atlanta, GA [online]. Available http //www.jhsph.edu/ephtcenter/Second%20Report.pdf [accessed Nov. 16, 2005]. 

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. 

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). 

Since the 1960s, NHANES has been monitoring nutritional and clinical factors in the U.S. population chemicals in blood and urine were included recently. In addition, CDC s National Reports on Human Exposure to Environmental Chemicals, based on NHANES data, have been influential in setting priorities for future biomonitoring research (Schober 2005). 

National Reports on Human Exposure to Environmental Chemicals... 

The first National Report on Human Exposure to Environmental Chemicals was initially released in 2001 and is based on analyses of NHANES biomonitoring data on exposure to chemicals. The data have various uses to determine which chemicals people are exposed to and at what concentrations to establish reference ranges for assessing whether an individual or group has an unusually high exposure, including susceptible populations, such as children, the elderly, and women of childbearing age to track exposure trends to assess the effectiveness of public-health efforts to reduce exposure of Americans to specific chemicals and to set priorities for research on human health effects (CDC 2005). 

The criteria for including chemicals in the National Reports on Human Exposure to Environmental Chemicals include the following considerations ... 

CDC is developing formal criteria for delisting chemicals from the National Reports on Human Exposure to Environmental Chemicals, which it plans to publish in the Federal Register. Delisting criteria will consider whether there has been a change in the concentration of a chemical if not, the chemical may be delisted (Pirkle 2005). 

Despite those limitations, the National Reports on Human Exposure to Environmental Chemicals are the most comprehensive available summaries of biomonitoring data on a representative sample of the U.S. population. The data provide reference ranges for numerous chemicals and will include, in future reports, data on chemicals which have recently become available,... 

It can assess risks posed by multiple exposures. Large-scale biomonitoring studies illustrate the need for developing cumulative risk-assessment approaches for biomonitoring data because exposures are typically to mixtures rather than to single toxicants. An examination of the Third National Report on Human Exposure to Environmental Chemicals, for example,... 

One of several examples in this chapter of the balance issue is the study that detects no biomarkers. Nondetection could be ideal for everyone except (perhaps) biomonitoring researchers all else being equal, no one wishes evidence of human exposure to environmental chemicals. Study subjects and wider populations that share their potential external exposures could be told that their exposure is no worse, and perhaps better, than that of the reference-range population. 

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