[graffis-l] THE DANGER OF PDBE'S

December 27, 2007

The Danger of PBDEs

Posted by: " Mark Graffis "

mgraffis

Wed Dec 26, 2007 9:32 am (PST)

http://www.enn.com/wildlife/article/28141

UC Riverside Published December 25, 2007 10:34 PM The Danger of PBDEs

Riverside, California - Polybrominated diphenyl ethers (PBDEs),

chemicals used as fire retardants, can be found in numerous items in the

home, such as the television, computer, toaster and the sofa.

Now, they are being found in alarming concentrations, in human blood

and breast milk - a potentially major concern for human health. In

addition, these industrial chemicals have been associated with cases of

feline hyperthyroidism, a potentially fatal condition in cats.

UC Riverside scientists interviewed for the KNBC story have done

research using rat tissue that shows that PBDEs disrupt mechanisms that

are responsible for releasing hormones in the body. Moreover, their work

has shown that like polychlorinated biphenyls (PCBs), whose manufacture

in the U.S. was discontinued in 1977, PBDEs alter calcium signaling in

the brain - a critical mechanism for transmitting information between and

within brain cells, for learning and memory, and for regulating the

release of hormones in the body. " Long-term exposures to PBDEs may

pose a human health risk, especially to infants and toddlers who are more

likely to ingest household dust or acquire these chemicals through

mother's milk, " said Margarita Curras-Collazo, an associate

professor of cell biology and neuroscience and one of the scientists

interviewed for the KNBC story.

" How much PBDE in the body is considered safe is yet to be

determined and will require further federal and state research

funding. " PBDEs, which have different forms based on the number and

location of bromine atoms they contain, closely resemble the molecular

structure of PCBs.

Because they can slow the spread of a fire, PBDEs currently are being

produced for use as flame-retarding compounds in a variety of consumer

goods, including electrical appliances, building materials, some foams

and upholstery furnishings. Because they are used as flame retardants,

the volume of PBDEs in household goods is higher in states, such as

California, that have enacted stringent flammability regulations for

these products.

PBDEs mobilize into the indoor air and household dust from household

goods, resulting in humans and pets getting exposed continuously to these

toxicants. Over time, PBDEs, PCBs and similar organic toxicants leach

into the environment when household wastes decompose in landfills or are

incompletely incinerated.

They are now found in air, water and soil as well as in wildlife and

supermarket foods. When people ingest food contaminated with PBDEs, it

adds to their body burden over their lifetime. Some forms of PBDEs are

subject to a ban that will become effective in California in January

2008.

The form that is most commonly used in plastics such as computer

casings is not subject to the ban, however, but may deteriorate to the

more detrimental forms (including those that are banned) over time.

" It is clear that the environmental levels of PBDEs are

increasing, " said Cary Coburn, a student in the Environmental

Toxicology Graduate Program and a member of Curras-Collazo's laboratory,

who also was interviewed for the KNBC story. " The extent of their

toxicity is currently being investigated by the U.S. Environmental

Protection Agency as well as internationally by other

toxicologists. "

In a paper to be published in a forthcoming issue of Neurochemical

Research (the paper is available online), Curras-Collazo and Coburn, in

collaboration with Prasada Rao S. Kodavanti, a senior research

toxicologist at the U.S. Environmental Protection Agency, show that the

regulation of calcium in neurons can be compromised by PBDEs and PCBs.

This summer, the three researchers reported in Toxicological Sciences

that PBDEs, like PCBs, can disrupt the neuroendocrine system, which

regulates the secretion of hormones such as those responsible for body

water regulation and cardiovascular function. " At present, one more

mass-produced chemical is finding its way into our bodies - one with

features similar to a banned substance, " Coburn said. " This in

itself should be cause for concern, given that low level concentrations

of hundreds of man-made compounds have been found in the human body and

may act cooperatively to produce harmful health effects. "

Curras-Collazo is urging more research funding into the short- and

long-term toxicity of PBDEs. " Due in part to our lifestyles -

electronic equipment, car and airplane travel, computers - PBDEs

bioaccumulate, increasing their concentration in human and animal tissues

over time, " she said. " They are difficult to get rid of,

persisting in the environment and in our bodies. "

In the United States, 80-90 percent of industrial chemicals destined

for use in commercial products are sold without any legally required

premarket testing. " We need a different legal strategy, " said

Carl Cranor, a professor of philosophy at UCR who researches legal

philosophy, regulatory policy and philosophic issues in science and the

law. " Unauthorized chemical invasions usurp important decisions over

which, at a minimum, citizens should have considerable collective

control. Invasions that also pose risks or harm are additional

wrongs. " With the help of funding from the University of California

Toxic Substances Research and Teaching Program and the University of

California Institute for Mexico and the United States (UC MEXUS),

Curras-Collazo and Coburn now are studying other mechanisms, such as

nitric oxide signaling, through which PBDEs act to cause neurotoxic

effects.

They also are researching the potential effect of the chemicals on

blood pressure regulation, especially as a consequence of perinatal

exposure such as that experienced by infants and children. " While we

plan to increase and continue our focus on the mechanisms of PBDE

toxicity, our long-term goal is to investigate the neurodevelopmental

effects of PBDEs, " Curras-Collazo said. rm At 08:06 AM 12/27/07, you wrote:

The Danger of PBDEs

Posted by: " Mark Graffis " mgraffis

mgraffis

Wed Dec 26, 2007 9:32 am (PST)

http://www.enn.com/wildlife/article/28141

UC Riverside

Published December 25, 2007 10:34 PM

The Danger of PBDEs

Riverside, California - Polybrominated diphenyl ethers (PBDEs), chemicals

used as fire retardants, can be found in numerous items in the home, such

as the television, computer, toaster and the sofa.

Now, they are being found in alarming concentrations, in human blood and

breast milk - a potentially major concern for human health. In addition,

these industrial chemicals have been associated with cases of feline

hyperthyroidism, a potentially fatal condition in cats.

UC Riverside scientists interviewed for the KNBC story have done research

using rat tissue that shows that PBDEs disrupt mechanisms that are

responsible for releasing hormones in the body. Moreover, their work has

shown that like polychlorinated biphenyls (PCBs), whose manufacture in

the U.S. was discontinued in 1977, PBDEs alter calcium signaling in the

brain - a critical mechanism for transmitting information between and

within brain cells, for learning and memory, and for regulating the

release of hormones in the body. " Long-term exposures to PBDEs may

pose a human health risk, especially to infants and toddlers who are more

likely to ingest household dust or acquire these chemicals through

mother's milk, " said Margarita Curras-Collazo, an associate

professor of cell biology and neuroscience and one of the scientists

interviewed for the KNBC story.

" How much PBDE in the body is considered safe is yet to be

determined and will require further federal and state research

funding. " PBDEs, which have different forms based on the number and

location of bromine atoms they contain, closely resemble the molecular

structure of PCBs.

Because they can slow the spread of a fire, PBDEs currently are being

produced for use as flame-retarding compounds in a variety of consumer

goods, including electrical appliances, building materials, some foams

and upholstery furnishings. Because they are used as flame retardants,

the volume of PBDEs in household goods is higher in states, such as

California, that have enacted stringent flammability regulations for

these products.

PBDEs mobilize into the indoor air and household dust from household

goods, resulting in humans and pets getting exposed continuously to these

toxicants. Over time, PBDEs, PCBs and similar organic toxicants leach

into the environment when household wastes decompose in landfills or are

incompletely incinerated.

They are now found in air, water and soil as well as in wildlife and

supermarket foods. When people ingest food contaminated with PBDEs, it

adds to their body burden over their lifetime. Some forms of PBDEs are

subject to a ban that will become effective in California in January

2008.

The form that is most commonly used in plastics such as computer casings

is not subject to the ban, however, but may deteriorate to the more

detrimental forms (including those that are banned) over time. " It

is clear that the environmental levels of PBDEs are increasing, "

said Cary Coburn, a student in the Environmental Toxicology Graduate

Program and a member of Curras-Collazo's laboratory, who also was

interviewed for the KNBC story. " The extent of their toxicity is

currently being investigated by the U.S. Environmental Protection Agency

as well as internationally by other toxicologists. "