What is measured?
This first edition of the Report presents levels of 27 environmental chemicals measured in the U.S. population. These chemicals include metals (e.g., lead, mercury, and uranium), cotinine (a marker of tobacco smoke exposure), organophosphate pesticide metabolites, and phthalate metabolites.
 
The first release of the Report presents data for the general U.S. population for 1999 from CDC’s National Health and Nutrition Examination Survey (NHANES). Because the sample size in any one year of NHANES is relatively small and for 1999 the survey was conducted in only 12 locations across the country, and because most analyses were conducted in subsamples of the population, more data will be needed to confirm these findings and to allow more detailed analysis to describe exposure levels in population subgroups.

What is next?
The Report will be updated with new data each year. Next year, CDC will combine the 1999 and 2000 data from NHANES to provide updated national estimates. In the future, the Report will also include data from other large exposure studies and studies of exposure of special-population groups within the United States. 

For more information about the National Report on Human Exposure to Environmental Chemicals please see:

• The Press Release 3/21/2001
• The Report Major Findings
• The Report Overview
• The Report Results
• The Report Summary (a PDF file)
• The Frequently asked Questions (FAQs)
• Related Links