The Centers for Disease Control and Prevention (CDC) has released the Fourth National Report on Human Exposure to Environment Chemicals. The report is a 527-page document that summarizes blood and urine levels for 212 chemicals, including levels for 75 chemicals which have never before been measured in a representative sample of the U.S. population.

TheFourth National Report on Human Exposure to Environmental Chemicals and an executive summary can be downloaded at CDC’s Web site:www.cdc.gov/exposurereport

Report overviewTheFourth Reportis the most extensive assessment to date of the exposure of Americans to environmental chemicals, according to CDC. Chemicals in theFourth Report include metals such as lead, cadmium, uranium, mercury, and speciated forms of arsenic; environmental phenols such as bisphenol-A (BPA); acrylamide; perfluorinated chemicals; polybrominated diphenyl ethers (PBDEs); polychlorinated biphenyls (PCBs); volatile organic compounds such as benzene, styrene and methyl tert-butyl ether; pesticides; phthalates; and dioxins, furans and related chemicals.

The data analyzed in the Fourth Report are based on blood and urine samples that were collected from approximately 2,400 people who participated in CDC's National Health and Nutrition Examination Survey (NHANES) from 2003 through 2004. NHANES is an ongoing national health survey of the non-institutionalized U.S. population that includes collecting and analyzing blood and urine samples to help further research involving exposures and health effects.

The types of exposure information found in the report can help physicians and public health officials determine whether people have been exposed to higher environmental chemicals as well as help scientists plan and conduct research about health effects. Much of the information has been previously published, but this is the first publication of all the data in one place. The report does not provide new health effects information. Research separate from that compiled in the Fourth Report is needed to determine whether higher levels of environmental chemicals in blood or urine are related to health effects.

One example of a finding from the report: Environmental tobacco smoke (ETS) has significant health effects on cardiovascular and respiratory disease. Cotinine is a metabolite of nicotine, and for nonsmokers, levels of cotinine in people’s blood tracks exposure to ETS. In the past 15 years, data show that blood cotinine levels for nonsmokers in the U.S. population have decreased about 70%, indicating that public health interventions to reduce second-hand tobacco smoke exposure are achieving success.