DATE: Thursday, 17 February 2005

SPEAKER: Dr. Heather Stapleton

TOPIC: Brominated Flame Retardants: Environmental Trends and Analytical Uncertainties

TIME: Informal Dinner at 6 pm, Talk to begin at 7 pm

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ABSTRACT:

Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) are two types of brominated flame retardants (BFRs) that are now being measured in many environmental samples. Over the past twenty five years brominated compounds have been increasingly used as flame retardants on many different types of polymers, resins and textiles. These materials are then used in consumer products such as furniture, carpets, mattresses, and TVs which are found in almost all homes. Studies have shown that concentrations of PBDEs are increasing temporally in Arctic seals, sea birds and human breast milk with doubling times ranging from 3 to 9 years and a recent study has shown that concentrations of HBCD have been increasing in California sea lion blubber with a doubling time of 1.7 years. These studies have demonstrated that the increased use of these chemicals in consumer products has led to increased levels in the environment and in people. Questions are now being raised as to how these BFRs are accumulating in people, particularly since levels of PBDEs in the United States population are on average 20 times higher than levels in people from Europe. Dietary intake estimates for PBDEs do not seem to explain the elevated levels of PBDEs in people and suggest alternate PBDE exposure routes are present. Investigations into levels of PBDEs in indoor air and house dust have suggested that the home environment may be the leading route of exposure to these compounds. While many laboratories are beginning to invest a lot of time and money in measuring PBDEs, there are still some difficulties in accurately measuring some mixtures of PBDEs. This presentation will focus on some of the analytical difficulties in measuring PBDEs using gas chromatography/mass spectrometry (GC/MS) and the current understanding on the environmental transport, fate and human exposure of PBDEs.

BIOGRAPHICAL SKETCH

Heather Stapleton earned a B.S. from Long Island University’s Southampton College in 1997 where she had a double major in marine biology and marine chemistry. After receiving her bachelor’s degree she moved on to the University of Maryland where she entered the M.E.E.S. (Marine Estuarine Environmental Science) program and received her Ph.D. in Environmental Chemistry in 2003 under the direction of Dr. Joel Baker. She is currently an NRC Postdoctoral Research Associate at NIST and works on developing analytical methods for measuring brominated flame retardants in environmental samples. Her research interests include the environmental fate, transport and metabolism of halogenated organic contaminants.