SURVEILLANCE AND MONITORING: CDC Releases Updated Biomonitoring Report

Biomonitoring—the science of measuring environmental chemicals in human blood, urine, and other tissues—made another modest advance with the 10 December 2009 release of the Fourth National Report on Human Exposure to Environmental Chemicals by the Centers for Disease Control and Prevention (CDC). The report includes data on 75 substances not in the preceding report, for a total of 212 reported chemicals. Data for more than 45 additional pesticides and metabolites are expected to begin appearing on the CDC website (http://www.cdc. gov/exposurereport/) by spring 2010. This is almost a 10-fold increase over the 27 substances covered in the initial report in 2001, greatly expanding the data researchers can use in their continuing efforts to take the next step—determining what the reported concentrations mean from a health risk perspective. " Interpretation is key to making biomonitoring data more meaningful , " says Sarah Brozena, senior director for regulatory and technical affairs with the American Chemistry Council. Yet such understanding is extremely limited so far for most chemicals. But the science of biomonitoring may be nearing a short-term zenith for the number of substances assessed in the general population , and future CDC reports " will probably grow less than [they] have recently, " says John Osterloh, chief medical officer and toxi-cologist with the CDC Division of Laboratory Sciences. That's due to technological limitations as well as capacity and budget constraints. As a result, in the foreseeable future it's likely that data for only a tiny fraction of the 239,000 toxic substances listed by the Chemical Abstract Service as regulated or included in inventories worldwide would be included in biomonitoring efforts. The report draws on data from the National Health and Nutrition Examination Survey, an ongoing survey that every 2 years samples a small number of people intended to represent the U.S. general population. Chemicals included in the fourth report have been selected on the basis of likelihood of exposure in the U.S. population, seriousness of known or suspected health effects resulting from exposure, and availability of appropriate ways to measure the chemical, among other factors. Of the samples assessed, 90–100% had detectable levels of substances such as perchlorate, mercury, bisphenol A, acrylamide, multiple perfluorinated chemicals , and the flame retardant BDE-47. Osterloh knows of no breakthrough technologies that can substantially expand the CDC biomonitoring program. One option could be to have industries generating chemicals conduct such testing—a suggestion that could be presented …