Protecting the Public

Q & A with NRDC's Jennifer Sass & Gina Solomon

NRDC's Jennifer Sass and Gina Solomon are two of the country's leading experts on the impact of toxic chemicals on public health. OnEarth asked them about the policy implications of the studies discussed in Robin Marantz Henig's article.

OnEarth: There's never going to be a final smoking gun in proving cause-and-effect with this kind of chemical exposure, but how much more definitive does the evidence have to be before we can talk about banning or further restricting the use of common chemicals like Paraquat, Maneb, Dieldrin, and Rotenone?

Sass: The Environmental Protection Agency (EPA) has the legal obligation to suspend or cancel a pesticide if information shows that use would pose "unreasonable risks" to humans or wildlife. (http://www.epa.gov/opp00001/regulating/laws.htm). Multiple well-conducted studies have reported an association between certain pesticides and Parkinson's disease (PD), particularly when exposure takes place during early life and when combinations of pesticides are involved. Does this amount to evidence of an "unreasonable risk?" It is essential that EPA consider this question, and if it finds evidence is lacking then it has the authority to require the manufacturer to conduct any additional studies that may be necessary. While the science may be uncertain, the law is not.

OE: If the law is so clear, why hasn't EPA acted on this issue?

Solomon: PD is tricky because the animal models are imperfect, and the standard laboratory tests that are used to assess pesticides for chronic toxicity are unlikely to detect this type of effect. Yet EPA currently bases almost all of its decisions about pesticide safety on these limited lab animal tests. To date, EPA has had difficulty integrating human epidemiologic studies into regulatory decisions. That's mostly because the people in these studies are exposed to numerous pesticides and other chemicals, and it is difficult to tease the effects apart. Since EPA regulates in a chemical-by-chemical framework, the combined effect of a mixture of pesticides is hard for them to address, so they usually don't. In other words, although the research studies strongly suggest a link between pesticide exposure and PD, it's hard to pin it to a specific chemical, so EPA has taken no action.

OE: Is there any way around this problem, so that government regulators in the future can use this information to protect people?

Solomon: EPA is aware that it is falling behind the state of the science. For that reason, the agency commissioned a report from the National Academy of Sciences (NAS) on ways to improve toxicity testing, and assessment of environmental agents. I served on the committee, and our report: "Toxicity Testing in the 21st Century" came out a little over a year ago. The committee recommended investigation into so-called "toxicity pathways." These include things like oxidative stress in the brain, and defects in proteasomes (which degrade proteins), both of which are thought to contribute to PD. It is possible to develop rapid screening assays, in animals or in test tubes, that allow many chemicals to be screened to see if they cause oxidative stress or inhibit proteosomes. This type of rapid screening of many chemicals, looking for the flags that suggest they may be linked to a problem, could allow EPA to focus more quickly on the hazardous chemicals and take action on them. This type of approach would be especially valuable with the industrial chemicals because, unlike pesticides, industrial chemicals have largely not been studied at all for their toxic effects.

OE: What do you mean that industrial chemicals have not been studied for their toxic effects?

Solomon: Pesticides are regulated under one set of laws, and industrial chemicals are regulated under a different law. The law that governs industrial chemicals, called the Toxic Substances Control Act (TSCA), is more than 30 years old, and is deeply flawed. The law puts the burden of proof on EPA to demonstrate that a chemical poses an unreasonable risk to public heath or the environment before any measures can be taken to restrict it (or even compel a company to conduct additional testing). The burdens of proof make meaningful use of the law almost impossible. As a result, of the approximately 62,000 chemicals that were in commerce at the time of TSCA's passage in 1976, EPA has used its authority to require testing for fewer than 200. In the 32 years since TSCA's passage, only eight chemicals (or classes of chemicals) have been banned for any uses. This means that most of the chemicals that are being released as pollutants into our air, water, or soil, and even many chemicals in food and consumer products, have not been tested for even the most basic toxic effects.

OE: What can be done to get chemicals tested for toxicity?

Solomon: NRDC is working with a broad coalition of health, environmental, labor, and environmental justice groups to win passage of legislation that would completely overhaul TSCA. The new law, known as the Kid-Safe Chemicals Act, would require testing of all chemicals, and would allow EPA to take action when there is evidence of a problem. Most importantly, the new law would shift the burden of proof to industry to show that their chemicals are safe, rather than on EPA and the public to prove them harmful. The bill was introduced in Congress in late-May and we will be working hard to get it passed within the coming year.

OE: What is NRDC doing to protect people from hazardous pesticides, such as those that have already been linked to Parkinson's Disease?

Sass: NRDC and a coalition of advocacy groups supported passage of the Food Quality Protection Act (FQPA), a law passed unanimously by Congress in 1996. It was the first environmental law that required specific protections for the health of infants and children. This law mandated that EPA consider the aggregated exposure to each pesticide from food, drinking water, and home uses. In addition, it forced EPA to evaluate pesticides together if they shared the same toxic action.

Solomon: Since passage of the FQPA, NRDC has been working to force EPA to implement the law correctly and to take action against the most hazardous chemicals. We have had some remarkable successes. For example, use of organophosphate pesticides, which have been linked to PD, have decreased by 30 million pounds annually in less than 10 years.

Sass: The insecticide Chlorpyrifos in particular was banned from being used in or around the home, resulting in a reduction of 6 million pounds annually, and reducing chlorpyrifos-related poisonings by 66 percent since 1995. Similarly the phase-out of over 11 million pounds annually of non-agricultural uses of a related pesticide, diazinon, took three-quarters of all diazinon off the market. This was correlated with a measurable reduction of diazinon in streams of between 20 percent and 40 percent, according to government survey data.

Solomon: We have recently petitioned EPA to remove two more neurotoxic pesticides from flea control products. Tetrachlorvinphos (TCVP) and propoxur are both commonly used in flea collars, and TCVP is also used in various other flea control products. These chemicals are closely related to the ones that have been linked to PD, as well as to early neurodevelopmental damage in children. NRDC's independent testing revealed that flea collars, when used according to the package instructions, create significant concentrations of a toxic pesticide residue on the pet's fur. This residue can be absorbed through people's skin when they touch their pet. More information is available at www.greenpaws.org.

OE: Some of the animal tests with MPTP after the California heroin cases, which Henig discusses in her article, began to suggest new possibilities for finding a cure. Do our latest discoveries about pesticides take us any closer to finding a cure for PD?

Solomon: There's lots of research into finding a cure for PD and other diseases. That research is admirable and very important. However, there is very little funding available to support research into the cause of PD and other diseases. That's a problem. I don't know what the statistics are for PD specifically, but overall less than 1 percent of the NIH research budget goes for research into environmental causes of disease. It's no surprise that we don't know more about the causes of many common diseases, since the funding is so hard to come by. That's starting to change, with a strong new direction emerging at the National Institute of Environmental Health Sciences, and new interest from Congress and the administration in funding much-needed scientific research. NRDC is part of a coalition called the Collaborative on Health and the Environment, which mostly includes health-affected groups. Many of these groups share a common interest in increasing research funding into discovering the causes of many diseases so that we can then prevent them in future generations. Right now, we are pushing for a major increase in funding for the Centers for Disease Control and Prevention to improve their nationwide health tracking network. Much of the funding will go to states, so that they can better track diseases such as asthma, autism, and Parkinson's Disease. Better information on trends over time, differences across geography, and patterns in the population will help a lot. Also, tracking can make it possible to overlay disease rates with other data such as pesticide use, to generate additional research studies.

OE: Pesticide and chemical manufacturers are very powerful, and there are massive amounts of money at stake. So how does industry respond in cases like this, where science is getting closer and closer to understanding the health consequences of exposure to specific chemicals?

Sass: NRDC has documented the efforts by pesticide manufactures to engage in bitter and aggressive defense of their products, by creating data that fails to find an effect, by questioning the certainty of the data that does report a harmful effect, and by creating public advertising campaigns that misleadingly tout the safety of these products. However, when the writing is on the wall and a product is about to get cancelled, the pesticide industry will usually opt for a voluntary cancellation. This allows the industry to negotiate a phase-out that may take several years and allows the manufacture to sell off its existing stocks, and it avoids the public scandal of having a ban associated with its product. Chlorpyrifos, for example, was voluntarily cancelled with a five-year phase-out.

Solomon: Also, a ban in the United States would trigger a requirement under the international treaty on Prior Informed Consent. Under that treaty, when a pesticide is banned in one country, manufacturers must notify other countries about the ban prior to selling or disposing of their products there. Obviously pesticide manufacturers are reluctant to be required to inform their customers worldwide that their product has been banned in the United States.