Friday, December 18, 2009
For the past 10 months I have been following the ongoing developments as Congress considers how to "reform," "modernize" or otherwise change the Toxic Substances Control Act (TSCA). Originally passed in 1976 and largely unchanged since then, there seems to be wide agreement across all stakeholders that it is time for TSCA to be updated.
The questions are how, and when?
While there is agreement on the "general principles" level, there is still quite a bit of difference in how to get there. Industry largely favors an government-centric prioritization step in which EPA would do some preliminary review based on the available data and then identify chemicals for which industry would agree to provide additional information. The health and environmental advocacy community, while recognizing that resource limitations will require some sort of prioritization, is in favor of something closer to what the REACH program stipulates in the EU. They want to have industry provide at least a base set of data on all chemicals that are currently produced. Otherwise, they say, EPA will have the same problem it has now, i.e., how do you prioritize when you don't have the data needed for prioritization.
Rumor now has it that Senator Lautenberg wants to make sure the bill he will likely reintroduce gets some attention, and that there are likely to be some additional Congressional hearings before introduction. Given that and the approaching holidays, as well as the current focus on the climate change meetings in Copenhagen, it will likely be January before we see hearings and February or March before a bill is introduced.
I suspect it will be done pretty early in the year since members in the House (and 1/3 of the Senate) will be in reelection campaign mode by late spring and summer. I think there will be interest in being able to tout a major legislative victory (depending, of course, on which members would think of TSCA reform passage as "victory").
Wednesday, December 16, 2009
As promised by Steve Owens at the November 17, 2009 hearing on TSCA chemical control in the House, the USEPA has now sent for White House review the first six of its “action plans” for addressing chemicals of concern under the authority of the existing toxic chemical law. This is the first of a series of steps taken by USEPA as it more aggressively uses its current authority while waiting for a new law to be enacted by Congress.
As is the standard procedure, USEPA first sends the action plans to the White House Office of Management & Budget (OMB), which it did on December 14th. As Owens previously noted, the action plans are designed to "outline the risks that use of these chemicals may present and what steps we may take to address those concerns."
According to USEPA's web site, the initial six chemicals being evaluated are:
* Benzidine dyes and pigments
* Bisphenol A (BPA)
* Penta, octa, and decabromodiphenyl ethers (PBDEs) in products
* Perfluorinated chemicals
* Short-chain chlorinated paraffins
Once the plans are published, USEPA would then engage with stakeholders (both manufacturers, users, and the public) to prioritize additional chemicals for evaluation. The goal is to make new action plans available to the public every four months. The final result of the reviews could lead to labeling requirements, restrictions and bans under section 6 of TSCA, and other actions as appropriate.
Needless to say, industry is less than thrilled about USEPA exerting their existing TSCA authority and, in fact, there is the possibility that industry could argue USEPA has overreached that authority. However, industry must be careful if they choose to fight the USEPA's actions, as it may have the reverse effect of demonstrating to US lawmakers the urgency of a need to modernize TSCA into something that puts much more of the onus for proving chemical safety onto the companies that manufacture the chemicals.
Tuesday, December 15, 2009
Continuing my series of the statements of key participants in the recent Senate EPW Committee hearings on TSCA chemical control reform, today is a report from John Stephenson. Earlier statements can be found here, and also at the committee web site. Today is actually not his specific testimony, which is rather long, but the summary of the GAO report on which his testimony is based. Stephenson is the Director, Natural Resources and Environment group at the General Accountability Office, which periodically researches and issues reports at the request of Congress. They have done several reports evaluating TSCA and its deficiencies over the years. The following is the executive summary from the report "Observations on Improving the Toxic Substances Control Act." His full testimony is at the link.
What GAO found
EPA lacks adequate scientific information on the toxicity of many chemicals. One major reason is that TSCA generally places the burden of obtaining data about existing chemicals on EPA rather than on chemical companies. For example, the act requires EPA to demonstrate certain health or environmental risks before it can require companies to further test their chemicals. As a result, EPA does not routinely assess the risks of the over 83,000 chemicals already in use. Moreover, TSCA does not require chemical companies to test the approximately 700 new chemicals introduced into commerce each year for toxicity, and companies generally do not voluntarily perform such testing. Furthermore, the procedures EPA must follow to obtain test data from companies can take years. Regarding IRIS, in 2008, GAO reported that this significant chemical assessment program—which provides EPA’s scientific position on the potential human health effects of exposure to more than 540 chemicals—is at serious risk of becoming obsolete because the agency has
not been able to complete timely, credible assessments. In May 2009, EPA announced reforms to its IRIS assessment process, citing GAO’s past recommendations and its high-risk designation. Overall, GAO believes that, if the reforms are effectively implemented, they will address GAO’s recommendations and provide a sound framework for conducting IRIS assessments. However, given the number of obstacles that can impede the progress of IRIS assessments, the viability of this program will depend on effective and sustained management.
While TSCA authorizes EPA to ban, limit, or otherwise regulate existing toxic chemicals, EPA must meet a high legal threshold, which has proven difficult. For example, EPA must demonstrate “unreasonable risk” to ban or limit chemical production, which EPA believes requires it to conduct extensive cost-benefit analyses that can take many years to complete. Since 1976, EPA has issued regulations to control only five existing chemicals. Furthermore, its 1989 regulation phasing out most uses of asbestos was largely vacated by a federal appeals court in 1991 because it was not based on “substantial evidence.” In contrast, the European Union and a number of other countries have largely banned asbestos, a known human carcinogen that can cause lung cancer and other diseases. GAO previously suggested that Congress amend TSCA to reduce the evidentiary burden EPA must meet to control toxic substances and continues to believe such change warrants consideration.
Because of TSCA’s prohibitions on the disclosure of confidential business information, EPA has limited ability to share information on chemical production and risk. According to EPA officials, about 95 percent of the notices companies have provided to EPA on new chemicals contain some information claimed as confidential. Evaluating the appropriateness of confidentiality claims is time- and resource-intensive, and EPA does not challenge most claims. GAO previously suggested that Congress, among other things, consider amending TSCA to authorize EPA to share the confidential business information that chemical companies provide to EPA with states.
More analysis to follow in ensuing days.
Sunday, December 13, 2009
I have been posting the statements of key participants in the recent Senate EPW Committee hearings on TSCA chemical control reform. Previously I posted the Chairwoman's opening statement, the Ranking member's opening statement, and the statement of the EPA Administrator. Today is the opening statement of Linda Birnbaum, Director of the National Institutes of Health and the National Toxicology Program.
Mr. Chairman and distinguished members of the Subcommittee—I am pleased to appear before you today to present testimony on our current understanding regarding chemical hazards. My name is Linda Birnbaum; I am the Director of the National Institute of Environmental Health Sciences (NIEHS) of the National Institutes of Health, as well as of the National Toxicology Program (NTP).
Environmental health science has made tremendous strides since the original passage of the Toxic Substances Control Act, or TSCA. Our understanding of chemical toxicity has been challenged by the new science of epigenetics, which is the study of changes to the packaging of the DNA molecules that influence the expression of genes, and hence the risks of diseases and altered development. Studies indicate that exposures that cause epigenetic changes can affect several generations. This new understanding heightens the need to protect people at critical times in their development when they are most vulnerable to this kind of toxicity.
The concept of “windows of susceptibility” is an important area. Research has revealed the heightened vulnerability of fetal, infant and child developmental processes to disruption from relatively low doses of certain chemicals. Established first for neurodevelopmental toxicants like PCBs, and lead and other metals, this concept also applies to hormonally active agents (endocrine disrupting chemicals). In our NIEHS Breast Cancer and Environment Research Program, co-funded with the National Cancer Institute, researchers are investigating whether periods of susceptibility exist in the development of the mammary gland, when exposures to environmental agents may impact the breast and endocrine systems that can influence breast cancer risk in adulthood.
There are unanticipated effects of exposure to toxic chemicals, and our research must extend to health endpoints beyond cancer and birth defects. NIEHS is supporting research on the developmental origins of obesity and the theory that environmental exposures during development play an important role in the current epidemic of obesity, diabetes, and metabolic syndrome. There are data showing weight gain in rats and mice after developmental exposure to a number of different substances. Thus we need to start thinking about obesity not just in terms of genetics and lifestyle but also in terms of exposures. These kinds of outcomes will need to be considered in assessment of toxicity.
There are other susceptibilities to consider. For some types of chemicals and health effects, there may be excess risk from specific genes or chronic diseases. For example, the level of a person’s risk of bladder cancer from smoking has been shown to depend in part on whether or not that individual’s genome contains variants in specific detoxification enzymes. The existence of these subtle variations in susceptibility must be factored into overall toxicity assessments.
Furthermore, exposures do not occur singly, the way they are usually tested in the lab. All of us are exposed to many different chemicals at the same time. Scientists have labored to come up with ways to estimate risk from combinations of exposures. One example was the method used for dioxin and related compounds. Dioxin is an environmental contaminant and known human carcinogen. Scientists believe that other chemicals such as some PCBs and furans may cause cancer in a similar manner. The question for public health officials was how health standards could be adjusted to take into account the fact that people are always exposed to mixtures of dioxin-like compounds, not just one at a time.
To address this problem, a large body of work led to the development of a method to estimate toxicity of mixtures of dioxin-like compounds based upon toxic equivalency factors, or TEFs. To estimate the overall toxicity of a mixture, the contaminants’ weighted contributions are added together, adjusting for the fact that some compounds are more toxic than others. The additive methodology has been tested and confirmed by studies done by the NTP, EPA, and others. TEF methodology has also been extended to other health endpoints, including reproductive and developmental, immune, and neurological.
Differences in routes of exposure must also be considered. For example, hexavalent chromium compounds have been shown to cause lung cancer in humans when inhaled, but it was not known how these compounds behaved when ingested. Hexavalent chromium was tested by the NTP because of concerns over its presence in drinking water. The NTP studies showed that a compound containing hexavalent chromium causes cancer in laboratory animals following oral administration in drinking water, confirming the need to protect people from oral routes of exposure.
The impact of new scientific information we have on effects of environmental chemicals can be seen in the EPA’s arsenic standards for drinking water implemented in 2006. The NIEHS Superfund Research Program, which is authorized by this Committee, funded scientists who played a vital role in the process through research on health effects of arsenic in drinking water. This research included studies of arsenic metabolism, mechanistic research on disease pathogenesis by arsenic, and both molecular and traditional epidemiology with detailed exposure assessment. These studies provided the scientific underpinnings for a standard that protects the health of Americans against long-term effects of arsenic exposure such as cancer, diabetes, neurological and cardiovascular disease.
We are poised to move forward into an era of a new kind of toxicological testing that is less expensive and also gives us an improved understanding of the actual effects on humans. Toxicology is advancing from a mostly observational science using disease-specific models to a better predictive science focused upon a broad inclusion of target-specific, mechanism-based, biological observations. This means using alternative assays targeting the key pathways, molecular events, or processes linked to disease or injury, and incorporating them into a research and testing framework. The NTP is laying the foundation for this testing paradigm in partnership with the National Human Genome Research Institute and the EPA. They are using quantitative high throughput screening assays to test a large number of chemicals. The resulting data are being deposited into publicly accessible relational databases. Analyses of these results will set the stage for a new framework for toxicity testing.
Reform of TSCA needs to account for the ways in which our understanding of the effects of chemical exposures has deepened and improved over the past 33 years. We must have the ability to harness new technologies and a growing knowledge base of underlying biology, receptor and other host pathways, variations in susceptibility, and routes and timing of exposure, to obtain a clearer and more accurate picture of the risks posed by these chemicals. Our new tools under TSCA must provide for research and development to create the comprehensive testing envisioned.
Thank you. I would be happy to answer questions.