Testimony at the Maine Legislature
by Jon Hinck, NRCM toxics project director
Senator Martin, Representative Koffman and members of the Natural Resources Committee. My name is Jon Hinck. I am Staff Attorney and Toxics Project Director with the Natural Resources Council of Maine. The Council will support LD 1790 with the amendments recommended by the bill sponsor. LD 1790 is an important environmental and public health measure that would start to redress problems caused by the overuse of polybrominated diphenyl ethers, or PBDEs as flame retardants. PBDEs are persistent, bioaccumulative and toxic and can be replaced with safer alternatives.
PBDEs are a class of synthetic bromine-based chemicals used as fire retardant additives to plastics and in other applications. They went into wide-scale commercial production three decades ago. Good performance and relatively low cost, along with successful marketing, resulted in PBDEs being added to a wide variety of consumer products, such as computer monitors, televisions, textiles, and plastic foams. Unfortunately, because PBDEs are merely mixed into plastics and do not bind to them, these chemicals leave the plastic and enter the workplace, our homes and the environment. Though not originally found in nature, PBDEs are now nearly ubiquitous, both free in the environment and in life forms, most particularly in animals, like humans, that feed at the top of the food chain. (Alae and Wenning 2002a, Chemosphere 46: 579-82.)
Consistent with an unfortunate pattern of the last half-century, the introduction and use of PBDEs preceded systematic study of their health and environmental effects. As is still the case with other “miracle” chemicals in widespread use, toxicological data on PBDEs are incomplete. Available data, however, raise serious concerns that have only increased as more studies are completed. Since PBDEs have a molecular structure similar to the now infamous PCBs, the appropriate public policy approach, would have been to keep them off the market and out of wide-scale commercial use until rigorous scientific study had determined the extent of the risk to human and environmental health. As we now know, the prudent course was not followed here, just as it was not followed when PCBs were introduced two decades before and also became ubiquitous.
Human exposure to PBDEs comes from eating contaminated foods and breathing the air, particularly indoor air in rooms with electronic equipment such as computers and TVs. PBDEs remain in the body for many years where they are stored in body fat. PBDEs have an affinity for and will concentrate in breast milk fat. As a result, PBDEs enter the bodies of children through breastfeeding. It has also been shown that PBDEs stored elsewhere in a mother’s body can be released during pregnancy, cross the placenta, and enter fetal tissues.
A growing body of research now links PBDE exposure to a range of adverse health effects including nervous system damage, learning and memory impairment, behavioral changes and fetal malformations. Health effects of exposure to PBDEs apparently include disruption of the body’s thyroid hormone balance. PBDEs have been shown to depress levels of what is known as the T3 and T4 hormones that play an important role in metabolism. The resulting condition known as hypothyroidism causes fatigue, depression, anxiety in adults. Depressed thyroid hormone levels in developing fetuses and infants can lead to much more serious consequences. (Porterfield, S.P. 1994 Environ. Health Perspect. 102 Suppl 2: 125-30.) Women who in the first trimester of pregnancy with depressed levels of T4 are much more likely to give birth to a child with low IQ less or even mild retardation.. (Pop, V.J. et al. Clin. Endocrinol. 50: 149-155.)
To understand issues that arise with PBDE use it is important to know that there are more than 200 structural forms, or congeners, of PBDEs. These are classified by the number of bromine atoms in each molecule of each cogener. Hence, each molecule of Penta-BDEs has five bromine atoms, octa-BDEs have eight, and deca-BDEs have 10. For practical purposes, regulation of PBDEs should focus on these three cogeners, referred to as Penta, Octa and Deca. Penta, Octa and Deca account for most of the PBDE production in the U.S. After decades of increasing use, it now appears that Penta and Octa will be phased out, unfortunately less rapidly in the United States than elsewhere. The European Union has already banned these two chemicals. And just last year, EPA successfully negotiated a voluntary phase-out with the leading manufacturer. While the case for continued manufacture and use of Penta and Octa has collapsed, the manufacturers are still trying to preserve the market for Deca against mounting evidence that Deca poses the same kinds of risks. As reported in the January 1, 2004 of the publication of the American Chemical Society, “there is a growing body of data, that Deca can be both toxic and bioaccumulative.” For example, according to research published at the same time, Deca is metabolized by fish and converted “into lighter brominated compounds associated with Penta and Octa” and “could also be breaking down into compounds much more toxic.” (Stapleton, H.; Baker. J, 2004 Env. Sci. & Tech. 1. 112-19.). This research adds more to earlier studies showing the Deca, when exposed to sunlight, breaks down into the more toxic and bioaccumulative cogeners. (e.g. Sellstrom, U. et al. 1998. Organohalogen Compounds 35: 447-450.)
Though PBDEs are found worldwide, evidence shows that Americans have remarkably high exposure. In a 2002 study of the breast tissue of women in California, PBDE concentrations were found to be higher than what had been found in studies conducted elsewhere — three times higher than samples taken from Swedes, 10 times higher than from Germans and 25 times higher than levels found in Spaniards. (She, J.et al. 2002. Chemosphere. 46(5): 697-707.) The high levels of U.S. exposure to PBDEs is perhaps best explained by looking at how the use of PBDEs by American manufacturers differs from use elsewhere. The Environmental Working Group examined records of production and use of PBDEs and found that North America uses 44 percent of global Deca production by weight, 40 percent of Octa and 95 percent of global Penta production. America’s disproportionate share of the market for these compounds will only increase as Europe implements its ban and restrictions on PBDEs.
With respect to environmental fate and effects, research has shown that PBDEs do not dissolve readily in water but generally attach to particles and settle on the bottom. Sediments at the bottom of lakes, rivers and streams have become reservoirs of PBDEs where they will remain for years. PBDEs earlier were shown to concentrate in fish. Recent studies show that PBDEs are also building up in terrestrial species. Both lower and higher cogeners of PBDEs were found in wild peregrine falcons, a species whose numbers have only slowly recovered from near extinction due to exposure to chlorinated compounds, like PCBs and certain pesticides. A study of falcons published this year directly contradicts the argument made by PBDE manufacturers that the Deca molecule is so large that it is not bioavailable and will not accumulate in organisms. “Our study indicates that this is not correct,” the authors write. “Eggs from wild peregrine populations had significantly higher BDE-209 [Deca] concentrations than the captive population feeding on chickens. This is an indication that the congener is present in the environment, is bioavailable, and taken up in falcons and transferred to eggs.” (Lindberg, P. et al. 2004, Env. Sci & Tech. 38 (1) 93 – 96.)
Finally, it is important to understand the separate risks that arise when PBDEs are burned or incinerated. It has been shown that the PBDEs will form polybrominated dioxins and furans (PBDD/Fs), for example in, when burned in a solid waste incinerator. (Soderstrom, G. and Marklund, S. 2002. Env. Science and Tech. 36: 1959-1964.). Of course, this is of particular concern to Mainers where a high proportion of our refuse is incinerated. This unfortunate circumstance supports a rapid phase-out of PBDEs and also the implementation of a system to collect and recycle such things as consumer electronics, including computers and TVs at the end of life.
Fortunately, neither PBDEs nor other hazardous halogenated materials are needed to achieve adequate flame retardancy and meet stringent flammability standards. For example, substitute flame retardants are already use on printed circuit boards and the plastic housings used in computers and other electronics. One substitute is halogen-free epoxy resins that have been developed for use on printed circuit boards. (Gentzkow et al. (1997). Fire retardancy is achieved in these epoxies by the use of nitrogen and phosphorus constituents. Different substitutes for the BFRs are used in computers’ plastic housings. Phosphorus-containing flame retardants such as triaryl phosphates, Triphenyl phosphates and resorcinol bis(diphenylphosphate) are all effectively used as flame retardants in these applications (ABS). Some inorganic materials, such as antimony, aluminum trioxide and magnesium hydroxide, are also available and in use as flame retardants. In addition, ceramic laminates have also been shown to work and may become more cost-effective in the future.
LD 1790, with proposed amendments, will institute a needed phase-out of a dangerous and unnecessary class of persistent, bioaccumulative toxic chemicals. It deserves the support of members of this Committee. I thank you for the opportunity to testify in favor of this bill.