December 05, 2005
PBDEs: Another Nail
Some cheery news for Monday: The Olympian, Washington's capital city newspaper, reports that the state departments of ecology and health are proposing further steps to eliminate PBDEs, a toxic flame retardant, from commerce. And I imagine that some state legislators are paying close attention to those recommendations as they gear up for the legislative session next January.
Just to recap -- PBDEs are flame retardants used in furniture foams and plastics, but have some disturbing similarities to their chemical cousins, the PCBs. Both classes of compounds have been found to affect neurological development in lab animals, and PCBs are known to cause developmental delays and deficits in children. Scientists routinely find PBDEs in samples of food, housedust, and human breastmilk and body fat -- and levels in North America, where the use of the most troublesome forms of the compound has been concentrated, are the highest in the world.
Last year the Washington legislature funded a PBDE action plan for the state, but delayed action on a bill to actually remove compounds out of commerce. Meanwhile, the manufacturer of the kinds of PBDEs most often found in people's bodies has stopped manufacturing the compounds, under an agreement with the US EPA. Still, one type of PBDEs are still used widely in commercial electronics and other applications (though, apparently, many manufacturers have managed to remove all PBDEs from their supply chain).
Today's news means, in essence, that departments of health and ecology are leaning towards a more comprehensive ban of PBDEs. As summarized by the Olympian:
The two agencies recommend that the Legislature:
• Ban the manufacture, distribution or sale of new products containing Penta or Octa [which are the most problematic forms of the compounds].
• Ban the use of Deca [the PBDEs that are still in widespread use] in electronic components, as long as safer fire retardants are available or if additional studies show that Deca harms human health.
• Consider a ban on Deca in products that don’t already contain it, but could in the future, including textiles and mattresses.
• Continue research on PBDE alternatives and monitor the levels of PBDE in the environment.
These are all good steps. Of course, it would have been nice if the same level of caution had been exercised before PBDE contamination became so widespread.
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Almost as brilliant as when Peru discontinued chlorination.
Someday, people who devastate an industry on Sunday Supplement Science will be brought into court and made to pay.
Silly Science kills a million a year in Africa.
Posted by: Walter E. Wallis | Dec 6, 2005 7:55:10 PM
The DDT myth lives on. Anyway,
Can you, Walter, point out exactly where the science is 'silly' wrt PDBEs?
Don't use phrases, don't use talking points, don't cut/paste from Reason Mag website, but show us empirical papers that have robust conclusions that differ from the evidence DOE used to make their recommendations.
Thank you so much for providing evidence for your assertion, Walter.
Posted by: Dan Staley | Dec 7, 2005 9:00:58 AM
Thanks for playing "Wheel of Intellect." We have some lovely parting gifts for you.
Posted by: Clark Williams-Derry | Dec 8, 2005 8:50:51 AM
How about the almost total lack of any demographic evidence of the toxicity of PDBEs, just as the evidence against DDT, softening of bird's aggs, was finally attributed to nest disturbances by "scientists" and all the studies of the toxicity of dioxines and PCBs have never come up with anything more deadly than chloracne? Electricians were up to their elbows in Askarel for 30 years and there are no demographics that they were harmed. So some substances concentrate in fatty tissue? Big duckin' feel. Que malo?
Posted by: Walter E. Wallis | Dec 8, 2005 9:37:58 AM
P.S. I guess I missed the charts, graphs and papers you used to rationalize your condemnation of PDBEs and your implied assertion that manufacturers are incorporating a demonstrably toxic material in their products. Your attacks on me are pretty much par for this site's inability to discuss anything that runs contrary to your programming. Pay attention, kiddies, you might just learn something more that bumper sticker chants for once.
Posted by: Walter E. Wallis | Dec 8, 2005 9:44:01 AM
"just as the evidence against DDT, softening of bird's aggs, was finally attributed to nest disturbances by "scientists" and all the studies of the toxicity of dioxines and PCBs have never come up with anything more deadly than chloracne? "
Walter, I asked if you could provide some empirical evidence, not a cut-paste from junkscience.com.
Do you have a reference, website with empirical evidence, quote, .avi, link, something other than hearsay to back your unattributed assertions?
That is: I'm asking you to back your unattributed assertion.
Posted by: Dan Staley | Dec 8, 2005 10:57:19 AM
My comment above was rude, and I apologize.
I know next to nothing about DDT, really. This article strikes me as reasonable, though.
As to PBDEs toxicity: no human epi evidence, thank goodness. There's plenty of animal evidence -- some forms of PBDE were found to have the same general effect as PCBs. PBDEs and PCBs share a similar chemical structure & makeup; and for PCBs there's evidence of developmental and IQ deficits that persist through early adolescence, at least. And there's additional evidence that they can work synergistically with PCBs -- that is, PCBs + PBDEs together may be cause more neurological aberrations than either one separately.
If you seriously want some citations, I can point you to a bunch. Google can help, too.
If that sort of thing isn't convincing to you, I'm sure you can find more entertaining reading elsewhere on the web. Good luck!
Posted by: Clark Williams-Derry | Dec 8, 2005 5:16:13 PM
Everything I cite is from my own observations over years of engineering practice and general interest in opposition to junk science.
Posted by: Walter E. Wallis | Dec 8, 2005 5:50:44 PM
>>Everything I cite is from my own observations over years of engineering practice and general interest in opposition to junk science. <<
Well, you haven't cited anything Walter.
So you have no empirical evidence and cannot back the assertions. Thank you for that, Walter.
It surely is a relief to know there is no evidence that shows the sudden disappearance of tens of thousands of birds for years is due to a bunch of scientists feeling eggs. Talk about what a cock-up that would be!
Posted by: Dan Staley | Dec 8, 2005 6:57:36 PM
Thank you for having validated my main assertion, that the toxicity of DDT, PCBs and PDBEs has never been demonstrated.
I suppose you won't take my word that much of the reported deformaties in amphibians was traced to investigaters carrying the infection on their shoes from pond to pond, either.
I am going to wipe this site off my feet and go elsewhere.
Posted by: Walter E. Wallis | Dec 8, 2005 8:30:51 PM
>>Thank you for having validated my main assertion, that the toxicity of DDT, PCBs and PDBEs has never been demonstrated. <<
I haven't validated anything. You made the claim, I asked for evidence, you have none. It's your burden of proof, not mine.
Bye bye, Walter.
Posted by: Dan Staley | Dec 9, 2005 8:27:22 AM
Walter - Here's a sampling of some of the main papers on PBDE toxicity. The main area that's been investigated has been neonatal neurological development, but there appear to be other effects as well.
Per Eriksson et al., "Brominated Flame Retardants: A Novel Class of Developmental Neurotoxicants in Our Environment?" Environmental Health Perspectives, 109(9): 903–907 (2001).
Per Eriksson et al., "A Brominated Flame Retardant, 2,2’,4,4’,5-Pentabromodiphenyl Ether: Uptake, Retention, and Induction of Neurobehavioral Alterations in Mice during a Critical Phase of Neonatal Brain Development," Toxicological Sciences, 67: 98–103 (2002).
Tong Zhou et al., "Developmental Exposure to Brominated Diphenyl Ethers Results in Thyroid Hormone Disruption," Toxicological Sciences, 66(1): 105–116 (2002).
Thomas A. McDonald, "A Perspective on the Potential Health Risks of PBDEs," Chemosphere, 46(5): 745–755 (2002).
Prasada Rao S. Kodavanti and Ethel C. Derr-Yellin, "Differential Effects of Polybrominated Diphenyl Ethers and Polychlorinated Biphenyls on [3H]Arachidonic Acid Release in Rat Cerebellar Granule Neurons," Toxicological Sciences, 68(2): 451–457 (2002).
Henrik Viberg et al., "Neonatal Exposure to the Brominated Flame Retardant 2,2’,4,4’,5-Pentabromodiphenyl Ether Causes Altered Susceptibility in the Cholinergic Transmitter System in the Adult Mouse," Toxicological Sciences, 67(1): 104–107 (2002).
P. Eriksson, C. Fischer, and A. Fredriksson, "Co-exposure to a Polybrominated Diphenyl Ether (PBDE 99) and an Ortho-substituted PCB (PCB 52) Enhances Developmental Neurotoxic Effects," Organohalogen Compounds, 61: 81–83 (2003).
Here's just a bit about the human epidemiological evidence on PCBs -- there's a lot of literature out there. Schantz's review is a good place to start. The most troubling findings are from the Jacobsen's, who looked at childhood IQ -- they found that kids who had relatively high background exposure (not through industrial accidents or anything, just the high end of dietary exposure) had IQ deficits that persisted through age 11. The effects were subtle -- high exposure is linked with a 6 point IQ drop, which probably isn't as much as my IQ changes after my first cup of coffee. But on a population basis, it's a pretty startling result -- and clearly places the burden of proof on people who claim that PCBs are completely safe. See:
Susan L. Schantz et al., "Effects of PCB Exposure on Neuropsychological Function in Children," Environmental Health Perspectives, 111(3): 357–376 (2003).
Joseph L. Jacobson and Sandra W. Jacobson, "Association of Prenatal Exposure to an Environmental Contaminant with Intellectual Function in Childhood," Clinical Toxicology, 40(4): 467–475 (2002).
From the Jacobson abstract...
Polychlorinated biphenyls are a family of synthetic hydrocarbon compounds that
were used historically for a broad range of industrial purposes. Although banned in
the 1970s, they continue to be ubiquitous in landfills, sediments, and wildlife.
Prenatal polychlorinated biphenyl exposure was evaluated in a sample of children
born to women who had eaten relatively large quantities of polychlorinated
biphenyl-contaminated Lake Michigan fish. This exposure was found to be
associated with poorer intellectual function after controlling statistically for a
broad range of potential confounding variables. Deficits included poorer
recognition memory in infancy, lower scores on a preschool IQ test, and poorer
verbal IQ and reading comprehension at 11 years of age. Although breast-fed
children were exposed postnatally to elevated levels of polychlorinated biphenyls
from maternal milk, the adverse effects associated with prenatal exposure were
markedly stronger in the children who were not breast-fed. It is not clear whether
the adverse effects were attenuated in the breast-fed children due to certain
nutrients in the breast milk or due to better quality of intellectual stimulation
provided by the breast-feeding mothers. Virtually no adverse effects were found in
relation to postnatal exposure to polychlorinated biphenyls from breast-feeding,
indicating that the fetus is particularly vulnerable to this exposure.
Posted by: Clark Williams-Derry | Dec 9, 2005 9:35:11 AM