WASHINGTONNational exposure data for 27 contaminants are detailed in the first National Report on Human Exposure to Environmental Chemicals, assembled and released by the Centers for Disease Control and Prevention (CDC). Unlike studies that estimate population exposures by measuring air, water, and soil samples, the new data represent direct measurements of chemicals in blood and urine samples. The samples were collected in 1999 as part of CDC’s periodic National Health and Nutrition Examination Survey.
CDC had previously assessed the population exposure of only three of the substances listed in the new reportlead, cadmium, and cotinine. Cotinine, a byproduct of the breakdown of nicotine(Drug information on nicotine) after it enters the body, serves as a marker for a person’s exposure to tobacco smoke, either primary or secondary.
The report showed a 75% decrease in serum cotinine levels of nonsmokers in the United States, documenting "a dramatic reduction in exposure of the US population to environmental tobacco smoke since 1991," said Richard Jackson, MD, director of CDC’s National Center for Environmental Health.
Other metals covered in the report include mercury, cobalt, antimony, barium, beryllium, cesium, molybdenum, platinum, thallium, tungsten, and uranium. The pesticide data include six metabolites of organophosphate pesticides, which represent exposure to 28 pesticides. Also included are data on seven phthalate metabolites, found in many plastics.