Friday, November 20, 2009

Eric Sampson Testimony at Congressional Hearing on Chemical Control

Yesterday I gave a summary of the testimony of EPA Assistant Administrator Steve Owens from the November 17, 2009 Congressional hearings on "Prioritizing Chemicals for Safety Determination." Earlier I gave an overall summary. Today I continue with the series as I take a closer look at the testimony of Eric Sampson, who is Director of the Division of Laboratory Sciences in the National Center for Environmental Health with the Centers for Disease Control and Prevention, which we all know as the CDC.

Sampson emphasized the value of biomonitoring in prioritization efforts. He described the current CDC biomonitoring programs and how they may be expanded. For those who don't know, biomonitoring refers to the taking of samples from humans, usually blood and urine samples, and analyzing them for a variety of chemicals. Sampson notes that biomonitoring, unlike measures of environmental samples like air, soil, water and food, tells the actual amount of chemical from all sources that gets into people. He did say that biomonitoring is pretty far ahead of the science of interpreting what they see, but is still valuable for a variety of human health purposes such as "identifying relative levels of exposure in the population, particularly in children and other vulnerable groups," as well as "setting priorities for research into the health effects of chemicals."

He gave an overview of several ongoing biomonitoring efforts, including the National Health and Nutrition Examination Survey (NHANES), which is a snapshot study repeated several times since the 1970s and then every two years since 1999. The Fourth National Exposure Report is due out by the end of this year. CDC also does targeted biomonitoring surveys in partnership with states, other federal agencies, academic institutions, and international organizations. One important collaboration is the National Children's Study, which is "designed to follow 100,000 children from conception to ae 21.

They key point of Dr. Sampson's testimony is that biomonitoring data by the CDC and other organizations can be an important tool in prioritizing chemicals for further review. Several studies have already shown that hundreds of chemicals are routinely found in the blood (including cord blood), breast milk, and urine, and that these findings can help identify those chemicals of greatest concern for review. He also notes that past biomonitoring has helped regulators "monitor the effectiveness of interventions designed to reduce exposures," as was demonstrated by tracking lead concentrations in blood as lead-based gasoline additives were phased out.

It should be noted that the Kid Safe Chemical Act of 2008, some version of which is expected to be reintroduced in this session of Congress, included a greater emphasis on biomonitoring. Whether it is in the new version remains to be seen as California's attempt to institute a biomonitoring program have been stymied by the economic downturn.

Tomorrow I'll take a closer look at the testimony of Daryl Ditz, Senior Policy Adviser at the Center for International Law, who urged Congress to focus first on "the worst of the worst" chemicals.

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