
Biomonitoring makes the issue of toxic chemicals very personal: we are all contaminated. Whether the data comes from large-scale national testing or a sample size of 8, evidence of toxins coursing through the human body is powerful. Particularly sobering are the studies of amniotic fluid, cord blood and breastmilk that prove beyond a shadow of a doubt that infants come into the world pre-polluted, and that nature's first, best food is compromised.
Small studies give a human face to chemical body burden data.
Biomonitoring studies fall into two general categories: large-scale, long-term studies conducted by government agencies, and smaller studies focused in specific communities or targeted groups. Both types of studies are valuable, providing very different types of information.
The largest U.S. biomonitoring study is a national survey conducted every few years by researchers at the Centers for Disease Control and Prevention (CDC). CDC released it's fourth National Report on Human Exposure to Environmental Chemicals in 2009, reporting the results of blood and urine tests on 2,400 people throughout the United States for 212 chemicals (including 48 pesticides).
While CDC's researchers look for only a fraction of the estimated 700 chemicals we each carry in our bodies, the study provides the most comprehensive body burden data set available. CDC expands the list of chemicals they look for in each of their studies; the next report is expected in 2011.
A few examples of other large-scale studies looking at chemicals in our bodies:
California is in the process of launching the first statewide biomonitoring program, designed to monitor chemical exposure levels, identify specific chemicals and communities of concern, assess the effectiveness of efforts to decrease exposure to specific chemicals.
My levels are amont the highest of all the participants. I worry most about my children who, like all children, are especially vulnerable to damage from pesticides. - Luz Medellin Rodriguez, Lindsay biomonitoring project participant.

New York's Mount Sinai School of Medicine conducted a small biomonitoring study in 2003, in collaboration with the Environmental Working Group and Commonweal. The resulting report, Body Burden: The Pollution in People documented 167 industrial chemicals and pesticides in the blood and urine of the nine people tested. Though the sample size for The Pollution in People was not statistically significant, the study was unique in providing individual profiles and personal reactions to test results, giving a human face to the chemical body burden data.
Many similar studies followed. Some have focused on communities at high risk of chemical contamination, others on groups sharing common health effects. Here we highlight just a few of the dozens of powerful biomonitoring projects conducted in recent years.
Commonweal's Biomonitoring Resource Center includes many resources and information on recent studies, as does the Environmental Working Group's Human Toxome Project.