[Pharmwaste] NIST uses SRMs (Standard Reference Materials) to Track
Fire Retardants in Humans and Environment
dldebiasi at deq.virginia.gov
Tue Aug 21 15:00:27 EDT 2007
SRMs Track Fire Retardants in Humans and Environment
If only the flame retardant chemicals routinely added to consumer
products from carpets to cell phones just did their job and nothing
more. Health officials, however, are concerned that one class of these
chemicals called polybrominated diphenylethers (PBDEs), may be doing
more than reducing fire-related injuries and property damage.
After several decades of use, PBDEs are widely distributed in the
environment as contaminants, and trace levels of these chemicals can be
measured in animal tissues and in the food chain (they can be found, for
example, in bird eggs and human breast milk). To help scientists
evaluate the risks of PBDEs by improving measurements of these
pollutants in the environment, the National Institute of Standards and
Technology (NIST) has re-evaluated several of its environmental
reference materials to report PBDE concentrations in them.
Different commercial PBDE flame retardant formulations have been used,
including pentaBDE in furniture foam; decaBDE in plastics for television
cabinets, consumer electronics, draperies and upholstery; and octaDBE in
plastics for personal computers and small appliances. Although human
data on health effects are limited, the U.S. Environmental Protection
Agency (EPA) cites animal tests as evidence that PBDEs are
neurodevelopmental toxins, disruptors of thyroid functions, and liver
toxins. The doses used in animal studies were slightly higher than PBDE
levels found in some people in the United States.
U.S. production of pentaBDE and octaBDE formulations ended in 2004.
DecaBDE (formulations which do not seem to be easily accumulated in
humans, but can degrade to octaBDEs and pentaBDEs) are not banned.
Pathways by which PBDEs enter the environment and humans are not yet
known. Human exposure might come from food, manufacturing, or even from
use of consumer product such as furniture.
To help investigators get a handle on the source and degree of PBDE
contamination, NIST measured concentrations of selected PBDEs and other
brominated flame retardants including hexabormocyclododecane (HBCD) in
seven of the agency's existing Standard Reference Materials (SRMs) that
are considered benchmarks for measurements of environmental pollutants.
Concentration values for PBDEs are now available for NIST's reference
materials for house dust (SRM 2585), cod liver oil (SRM 1588b) and human
blood serum (SRM 1589a). Newly certified values for PBDE concentrations
in four other SRMs for whale blubber, mussel tissue and two types of
fish tissue are expected to be available soon.
In collaboration with the Centers for Disease Control and Prevention
(CDC), NIST also is developing four new SRMs based on human blood and
milk. Two of these SRMs will have certified values for current PBDE
concentrations to record the level of current human exposure. PBDEs will
be added at higher levels for the other two materials to facilitate
comparability of measurements among laboratories.
For further information, see H.M. Stapleton, J.M. Keller, M.M. Schantz,
J.R.Kucklick, S.D. Leigh and S.A. Wise. Determination of polybrominated
diphenyl ethers (PBDEs) in environmental standard reference materials.
Analytical and Bioanalytical Chemistry. 387, 2365 (2007).
Deborah L. DeBiasi
Email: dldebiasi at deq.virginia.gov
WEB site address: www.deq.virginia.gov
Virginia Department of Environmental Quality
Office of Water Permit Programs
Industrial Pretreatment/Toxics Management Program
Mail: P.O. Box 1105, Richmond, VA 23218 (NEW!)
Location: 629 E. Main Street, Richmond, VA 23219
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