The finding, by a team of environmental engineers at the University of California, Berkeley, suggests these transformations could complicate efforts to reduce or eliminate the most problematic polybrominated diphenyl esters (PBDEs) from the environment.
"This study, for the first time, establishes that microbes found in every-day settings can degrade relatively stable forms of PBDEs, making them far less stable and potentially more toxic," says Lisa Alvarez-Cohen, Ph.D., the study’s corresponding author. "It implies that current and planned bans of the most toxic forms of PBDEs may be ineffectual if the less toxic forms are rendered more toxic when released into the environment."
In laboratory animals, high blood levels of PBDE are associated with cancer, lowered immunity, thyroid problems, and learning and memory difficulties. Although PBDE levels in people haven’t reached the levels of laboratory animals, Alvarez-Cohen says scientists are concerned because they are rising in humans at an exponential rate, doubling every two to five years.
In 2004, U.S. manufacturers reached a voluntary agreement with the EPA to stop making and selling penta-BDEs and octa-BDEs, two potent forms of PBDEs linked to health problems in animals. Deca-BDE, the most commonly used form of PBDE, remains on the market because it is considered more stable and less readily absorbed into the body, Alvarez-Cohen says. Laboratory studies, however, have shown that over time, both deca- and octa-BDEs can break down into potentially more harmful forms, including penta- and tetra-BDEs.
This new study supports the notion that this process also could occur in the real world, raising concerns about the continued manufacture and use of deca-BDEs, Alvarez-Cohen says. In their study, Alvarez-Cohen and her colleagues exposed octa-BDE and deca-BDE to five types of anaerobic bacteria commonly found in the soil. Based on previous research with other compounds, they anticipated that the bacteria would break down deca-BDEs into benign components. Instead, the microbes transformed deca-BDEs into octa-BDEs and the octa-BDEs into the more harmful penta- and tetra-BDEs.
"Now that we understand that certain PBDEs found in the environment can be transformed into more toxic forms, we need to make more intelligent policy decisions with respect to how, or even if, we should use these compounds," Alvarez-Cohen says.
PBDEs are used in televisions, computers, wire insulation, upholstery and many other products containing plastic and foam. If these products overheat, PBDEs release atoms called bromines that sap oxygen from the air, preventing a fire. Over time, PBDE’s can leach into the air, soil and sediment, and move up through the food chain. These compounds have been detected in fruits and vegetables, meats, dairy products and even household dust.
The American Chemical Society — the world’s largest scientific society — is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.
Michael Bernstein | EurekAlert!
Research team creates new possibilities for medicine and materials sciences
22.01.2018 | Humboldt-Universität zu Berlin
Saarland University bioinformaticians compute gene sequences inherited from each parent
22.01.2018 | Universität des Saarlandes
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
22.01.2018 | Materials Sciences
22.01.2018 | Earth Sciences
22.01.2018 | Life Sciences