Executive Summary

"Environmental Exposures and Racial Disparities" is a racial analysis of the most comprehensive report to date documenting the environmental chemicals found in people living in the United States, the Centers for Disease Control and Prevention's "Second National Report on Human Exposure to Environmental Chemicals" (National Report). The National Report includes information on the concentration of 116 chemicals in Mexican Americans, Non-Hispanic Blacks and Non-Hispanic Whites. It also establishes a national baseline for 89 chemicals and updates the national baseline for 27 chemicals.

If all socioeconomic factors were equal, one might expect the concentration of environmental chemicals to be evenly distributed across a U.S. population that is approximately three-quarters White and one-quarter people of color. "Environmental Exposures and Racial Disparities" finds that the three categories where such a distribution is most closely paralleled are for naturally-occurring environmental chemicals (metals, phytoestrogens, and PAHs) people touch, eat, or breathe. However, synthetic chemicals that people touch, eat, or breathe (such as dioxins, PCBs, phthalates, pesticides, herbicides, pest repellants, and disinfectants) pose a greater burden to people of color.

Key findings for each racial group are as follows:

1. non-Hispanic Blacks are much more likely to be exposed to dioxins and polychlorinated biphenyls (PCBs) and are more likely to be exposed at higher levels;



2. Mexican-Americans are much more likely to be exposed to pesticides, herbicides, and pest repellants and are more likely to be exposed at higher levels;



3. non-Hispanic Whites are much more likely to be exposed to polycyclic aromatic hydrocarbons (PAHs) and phytoestrogens and are more likely to be exposed to phthalates at higher levels;



4. non-Hispanic Blacks and Mexican-Americans are much more likely to have higher levels of less common chemicals; and
   
   
5. non-Hispanic Blacks are exposed to the greatest number of chemicals in the study.

The CDC report is released every two years and will include findings from studies of people living in special-exposure situations (e.g., pesticide applicators, people living near hazardous waste sites, people working in lead smelters).

Summary of findings from "Environmental Exposures and Racial Disparities"

Other findings: Of the 37 chemicals that are widely found in all groups, 21 are found in highest concentrations in Non-Hispanic Whites, 11 are found in highest concentrations in Mexican Americans, and 5 are found in highest concentrations in Non-Hispanic Blacks.

There are 6 chemicals that are widely found with a geometric mean difference between groups exceeding 100%.

Of the 44 chemicals that are not widely found, 25 are found in highest concentrations in Non-Hispanic Blacks, 11 are found in highest concentrations in Mexican-Americans, and 8 are found in highest concentrations in Non-Hispanic Whites.

DDT is 1 of 7 chemicals only found Mexican Americans and/or Non-Hispanic Blacks. No chemical is only found in Whites.

35 of the 116 chemicals are not detected.

Methodology: The data is drawn from the CDC reports' results for blood and urine samples collected as part of the National Health and Nutrition Examination Survey from 1999 - 2000. For the purposes of the "Environmental Exposures and Racial Disparities" assessment, lipid-adjusted blood results and creatinine-adjusted urine results are used. Such adjustments compensate for individual variation in blood serum and urine and are considered more accurate than data that is not subject to such adjustment. Tobacco smoke is included even though adjusted data is not presented in the CDC report. "Environmental Exposures and Racial Disparities" used two sets of adjusted results from the CDC report: the geometric mean if the chemical was widely found or, if it was not, the result for the small portion of the population that showed some exposure.