[Pharmwaste] Glut of data on "new" flame retardant documents its presence all over the world

[DeBiasi,Deborah]

So the alternative to PBDE (deca) is causing problems too...


http://pubs.acs.org/doi/full/10.1021/es8032154


Glut of data on "new" flame retardant documents its presence all over
the world

Kellyn Betts

Environ. Sci. Technol., Article ASAP

Publication Date (Web): December 3, 2008

Copyright (c) 2008 American Chemical Society

Three recent articles published in ES&T provide some of the first
evidence that a flame retardant previously believed to be minimally
biologically available is bioaccumulating in North American seagulls, a
variety of Chinese waterbirds, and two kinds of pandas. Other recent
papers suggest that the retardant, known as decabromodiphenyl ethane and
abbreviated as DBDPE or DeBDethane, is widely dispersed in the
environment and that people may be exposed to it in their homes.
However, industry scientists are questioning some of the findings.

A steadily increasing stream of research about DBDPE's presence in the
environment has been published since 2004, especially in the past few
months. The compound has been detected in wastewater destined for sewage
treatment as well as in treated effluent, sewage sludge, sediments,
household dust, indoor air, tree bark, and ambient air. One of the most
comprehensive assessments identifies DBDPE in sewage sludge from 12
countries on 3 continents (Chemosphere 2008, 73, 1799?1804). The
authors, from Stockholm University's Institute of Applied Environmental
Research, say their findings suggest that DBDPE may be "a worldwide
concern."

DBDPE is used in applications ranging from consumer electronics to wire
and cable to insulation foams, according to Albemarle Corp., one of
three companies known to commercially produce DBDPE. Albemarle sells the
retardant as SAYTEX 8010, and a company press release says production of
this compound was significantly expanded twice in the past 2 years. In
some products, such as TVs, DBDPE can be used in place of the widely
used flame retardant decabromodiphenyl ether (Deca-BDE), which has been
banned in the EU and some U.S. states.
"Albemarle Corporation is . . . participating vigorously in the industry
Voluntary Emissions Control Action Programme (VECAP) to ensure that our
products are handled in an environmentally safe manner and that any
releases to the environment: air, water or land, do not occur,"
according to a written statement from Marcia Hardy, Albemarle's senior
toxicology adviser. VECAP focuses on minimizing the release of flame
retardants to the environment during all phases of their use, "with
particular emphasis on the processes which have the greatest risk of
emitting material to the environment," she wrote.

However, at least 10 articles in peer-reviewed journals now suggest that
detectable amounts of DBDPE?up to the low parts-per-million level?are
somehow escaping into the environment. The compound was first reported
in animals in 2006 by a team of researchers led by Gregg Tomy of
Fisheries and Oceans Canada, who documented uptake of up to 3.30
nanograms per gram of tissue (ng/g, lipid weight) in fish from Lake
Winnipeg.
The new papers published in ES&T document concentrations of DBDPE that
are orders of magnitude higher. To date, the highest concentrations are
documented in Environment Canada's Great Lakes herring gull egg archive,
which dates back to 1971. Both the occurrence and concentrations of
DBDPE increased in the herring gull eggs collected in 2004, 2005, and
2006 (the last year analyzed), according to the paper.

The findings are presented in terms of wet weight, which results in
concentrations that are approximately 10 times lower than those obtained
by normalizing on lipids (as the Chinese findings do), says
corresponding author Rob Letcher of Environment Canada's National
Wildlife Research Centre. From 2004 to 2006, most of the eggs contained
concentrations of DBDPE ranging from 13 to about 200 ng/g, lipid weight.
These findings are consistent with concentrations reported in giant and
red pandas (up to 863 ng/g, lipid weight) and the slightly lower
accumulation in the five species of waterbirds discussed in the other
new ES&T paper.

In 2005, however, the concentrations of DBDPE in herring gull eggs were
significantly higher (up to 2880 ng/g, lipid weight) at two locations,
Letcher says. Reaching this level?the parts-per-million range?must "be
viewed with substantial concern," Letcher contends. In contrast, Hardy
characterizes the concentrations reported in the eggs as "de minimis"
and says that the papers published in ES&T thus far present "no
identifiable trends."
Other scientists take a different view. Letcher's group's findings that
"the concentrations of DBDPE are greater than those of BDE-209 [the main
component of Deca-BDE] in several samples after a comparatively short
period of usage suggest that DBDPE may be more persistent and/or
bioaccumulative than BDE-209," says Michael McLachlan, deputy head of
Stockholm University's department of applied environmental science.

Until a few years ago, most environmental scientists believed that
Deca-BDE's low bioavailability would preclude it from concentrating in
animals to an appreciable extent, but it has since been shown to
bioaccumulate to the parts-per-million level, particularly in birds of
prey. In addition to being used in some of the same industrial
applications, DBDPE and Deca-BDE have very similar physical and chemical
properties. "The difference between both compounds is an ethane instead
of an ether linkage [bridging] the two phenyl rings," Tomy points out.

The publicly available data on DBDPE's toxicology include papers by
Hardy showing that DBDPE which the industry identifies as ethane
1,2-bis(pentabromophenyl)?"is unlikely to have significant biological
availability." This is consistent with the compound's large size and
extreme insolubility, Hardy says. The compound has also undergone a risk
assessment by the U.K.'s Environment Agency, she points out.
Despite the relatively poor bioavailability of Deca-BDE and DBDPE, the
compounds may be entering the food chain because they are present in the
environment in relatively high amounts, Letcher hypothesizes. "If the
exposure load is high enough, . . . any compound in the
environment?depending on stability?may eventually become meaningful," he
says.

Bi-Xian "Nancy" Mai, corresponding author for the papers reporting DBDPE
in pandas and waterbirds, says that she and her colleagues were inspired
to look for the compound in biota after an earlier screening survey
detected it in Chinese air, soil, dust, sediment, and sewage sludge
samples. "We found that most samples contained DBDPE, and its
concentration just followed BDE-209, the predominant PBDE congener,"
says Mai, a professor at the Guangzhou Institute of Geochemistry's State
Key Laboratory of Organic Geochemistry and a member of the Chinese
Academy of Sciences.

Mai's papers report finding DBDPE in 21 of 26 captive giant and red
pandas, and in 28 of 29 wild waterbirds from China's Pearl River Delta,
where there are many e-waste recycling facilities. Hardy contests the
findings in both of those papers, but Mai and her co-workers stand by
their data. Letcher and other scientists interviewed for this story
believe these findings are valid because of their consistency with the
other reports.

This summer, a team of U.S. researchers documented DBDPE's presence in
U.S. house dust, sometimes at relatively high concentrations. This
suggests that people, especially young children, may be exposed to it,
says Heather Stapleton, an environmental chemist at Duke University's
Nicholas School of the Environment. "We know that Deca-BDE has the
potential to be a neurodevelopmental toxicant, and, given the similar
structure of DBDPE, one has to ask if they are going to have similar
toxicological endpoints," she says. "If wildlife are accumulating
Deca-BDE and DBDPE, I don't see why humans wouldn't accumulate it as
well," she says. 
In a comment published in ES&T (DOI 10.1021/es802281d), Hardy noted that
the DBDPE concentrations Stapleton's group reported were below levels
shown to be of concern in a risk assessment. In response (DOI
10.1021/es8026192), Stapleton pointed out that risk assessments don't
consider that people are exposed to mixtures, rather than individual
compounds, and scientists "have no idea if the combined effects are
additive or synergistic."

"The same questions that surround the significance of Deca-BDE in
environmental and indoor dust samples will eventually have to be
addressed with DBDPE?and indeed with other highly brominated additive
[flame retardants] as well," says Derek Muir, a senior research
scientist with Environment Canada's National Water Research Institute.
Muir argues that basic applied research is needed to investigate the
extent to which large, superhydrophobic molecules can be bioaccumulated;
whether they break down, or debrominate, in the environment; and how
flame retardants are released from the plastic polymers they are
intended to protect from conflagration. "This would allow much better
exposure and risk assessment than seems to be possible with presently
available information," he says.

Researchers in China have detected DBDPE in red pandas, as well as giant
pandas and five species of waterbirds.




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
PPCPs, EDCs, and Microconstituents
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Location:  629 E. Main Street, Richmond, VA  23219
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