Environmental Factor, March 2010, National Institute of Environmental Health Sciences
Birnbaum Revisits TSCA in Senate Testimony
By Eddy Ball
When Senator Frank Lautenberg (D-NJ) convened hearings on chemical safety Feb. 4, NIEHS/NTP Director Linda Birnbaum, Ph.D., was one of the expert witnesses testifying (watch archived webcast(http://epw.senate.gov/public/index.cfm?FuseAction=Hearings.Choose&Hearing_id=8a722315-802a-23ad-4e9a-b8477139e63f) ). Birnbaum spoke on the use of next-generation personal exposure monitoring, answered several questions about chemical exposures and vulnerable populations, and submitted more detailed written testimony(http://www.niehs.nih.gov/about/assets/docs/testimonybirnbaumfeb042010_508.pdf.pdf) into the record.
Birnbaum spoke before a U.S. Senate Subcommittee on Superfund, Toxics and Environmental Health hearing on "Current Science on Public Exposures to Toxic Chemicals," as part of a panel of government experts (see text box) testifying on the need to update the Toxic Substances Control Act (TSCA). Subcommittee Chairman Lautenberg(http://lautenberg.senate.gov/) is the Senate sponsor of the Kid Safe Chemical Act(http://lautenberg.senate.gov/newsroom/record.cfm?id=298072) , which "would ensure for the first time that all the chemicals used in baby bottles, children's toys and other products are proven to be safe before they are put on the market," according to a press release from his office.
Cutting-edge personal monitoring
Describing recent advances in biomonitoring technology, Birnbaum pointed to several examples of the way this "critical information" can lead to groundbreaking studies of carcinogens, such as the NTP studies on tungsten. She noted that positive health outcomes resulted when exposures to pesticides were reduced because of biomonitoring data, demonstrating the effectiveness of regulatory controls.
Birnbaum noted that NIEHS is the lead on the trans-NIH Genes and the Environment Initiative to support the development of increasingly smaller and more powerful personal monitoring micro- and nano-biosensors. These devices, she said, are capable of more accurately evaluating the biological effects of chemical exposures, diet, and psychosocial stress.
Looking at complex exposures
"While our technical capacity for measuring exposure continues to grow, we still have a way to go in our general understanding of exposure in the United States," she explained. More research is needed so scientists can better understand the effects of mixtures, cumulative low-level exposures, and the synergistic effects of exposure to different chemicals that act in the same way, such as those that target thyroid hormone homeostasis.
"In summary, we are committed to advancing the science of exposure assessment to meet emerging public health challenges," Birnbaum said. "We look forward to the increased contributions of exposure scientists, as we work to understand the role of the environment in the etiology of disease."
Joining Birnbaum at the hearing were NIEHS Bethesda staff members Senior Advisor for Public Health John Balbus, M.D., and Program Analyst Mary Gant. Along with Lautenberg, Senators Barbara Boxer (D-Calif.), Mark Udall (D-Colo), Amy Klobuchar (D-Minn.), and Sheldon Whitehouse (D-RI) made majority statements during the hearing, while Senators James Inhofe (R-Okla.) and David Vitter (R-La.) offered statements reflecting the minority perspective.
Witnesses Tackle TSCA
Three other government experts joined Birnbaum on the hearing's first panel:
- Steve Owens, assistant administrator of the Office of Prevention, Pesticides and Toxic Substances, at the U.S. Environmental Protection Agency (EPA)
- Henry Falk M.D., acting director of the National Center for Environmental Health/Agency for Toxic Substances and Disease Registry at the Centers for Disease Control and Prevention (CDC)
- John Stephenson, director of Natural Resources and Environment at the U.S. Government Accountability Office (GAO)
A second panel of witnesses from the private sector included a patient, a practitioner, a researcher, and a representative of an environmental advocacy group:
- Molly Jones Gray, a mother and a participant in a biomonitoring study
- Charles McKay, M.D., of the Division of Toxicology, Department of Emergency Medicine, Hartford Hospital
- Tracey Woodruff, Ph.D., associate professor and director of the Program on Reproductive Health and the Environment in the Department of Obstetrics, Gynecology, and Reproductive Sciences at the University of California, San Francisco
- Ken Cook, president of the Environmental Working Group