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
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 after it enters the body,
serves as a marker for a person’s exposure to tobacco smoke, either primary
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
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.