September 15, 2000

Public Information and Records
Integrity Branch
Information Resources and Services Division (7502C)
Office of Pesticide Programs
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460

Re. Docket Control Number: OPP-00658A
Comments on the Proposed Guidance on Cumulative Risk Assessment of Pesticide Chemicals That Have a Common Mechanism of Toxicity.

Dear Madam/Sir:

Thank you for the opportunity to comment on the Proposed Guidance on Cumulative Risk Assessment of Pesticide Chemicals That Have a Common Mechanism of Toxicity (Guidance on Cumulative Risk). These comments are submitted on behalf of Beyond Pesticides/National Coalition Against the Misuse of Pesticides (Beyond Pesticides), a national membership organization that promotes protection from pesticide hazards and less reliance on chemical dependent pest management, and the Farmworker Justice Fund, Inc., a nonprofit, national advocacy organization that is dedicated to improving the living and working conditions of migrant and seasonal farmworkers and their families.

The passage of the Food Quality Protection Act of 1996 (FQPA) ushered in a new set of responsibilities for the Environmental Protection Agency (EPA). One of the most important of those new responsibilities is the requirement that EPA assess the risks associated with exposure to multiple chemicals from multiple pathways. The Guidance on Cumulative Risk is a significant first step towards that goal.

EPA has wisely determined that the outcome of a cumulative risk assessment usually will not be a single estimate of risk. Rather, it will contain a series of estimates, some represented as ranges reflecting risk values of differing proportions of populations and subpopulations exposed to the possibility of adverse health effects resulting from different time scales of exposure. However, risk assessment is not simply a set of numbers on a page. First and foremost, EPA must keep in mind that its policy affects real people, people whose health has been negatively impacted as a result of exposure to pesticides and other substances.

Beyond Pesticides is regularly contacted by people who have been exposed to pesticides. They share their stories with us through our Pesticide Incident Reporting program. For example, Mr. Johnny Shelton, of Cullman, Alabama worked for a year in a wood treatment plant in Electric Mills, Mississippi applying pentachlorophenol (penta) to wood utility poles. As Mr. Shelton puts it, "I was waist deep in the stuff," and his employers never adequately explained to him the hazards associated with his exposure to penta. Sadly, Mr. Shelton's young son, Taylor, was born with a severe birth defect, the bones in his leg are not hardening properly and he has swapped digits on that foot. Doctors have informed Mr. Shelton that his 18-month-old son will lose his leg if the condition does not improve by year's end. Mr. Shelton is convinced that his son's condition is a direct result of his exposure to penta and its contaminants dioxins, furans, and hexachlorobenzene.

Cheryl Banister of Chalfont, Pennsylvania was exposed to multiple chemicals and was harmed by their cumulative effect. She was poisoned by diazinon (Diazinon 2DTM), bendiocarb (Ficam WTM), and fenvalerate (ConquerTM) in 1998 while at work. The pesticides were applied by a commercial applicator using spot treatments inside her office building. She began showing signs of the exposure immediately. Her symptoms included: diarrhea, coughing, blurry vision, problems wetting her pants, memory loss, depression, anxiety, ear pains, sleeping problems, and hair loss. She eventually found a specialist who ran the appropriate medical tests and linked her health problems with exposure to organophosphate pesticides. She continues to have health problems today and is unable to work because of the exposure.

Beyond Pesticides also receives numerous reports on poisoning and deaths associated with normal pesticide use in and around homes, schools, parks and recreation areas. In August, it was widely reported that an 11-year old girl with a five-year history of asthma died after bathing her dog with a pesticide shampoo.

These are only three tragic stories of people whose lives have been horribly impacted by pesticides. It is interesting to note that under the Guidance on Cumulative Risk, Mr. Shelton's occupational exposure to pesticide would not be factored into a cumulative risk assessment. Although FQPA does not affirmatively require that EPA include occupational exposures it does not prohibit EPA to factor occupational exposure into its cumulative risk assessment. In order for a cumulative risk assessment to reflect real world situations EPA must factor in occupational exposures.

There are additional shortcomings in the Guidance on Cumulative Risk that move the risk assessment away from real world situations. EPA should place most emphasis on the common toxic effect of a group of pesticides and other substances, using the common mechanism of toxicity as a guide to help assign chemicals to a given Cumulative Assessment Group (CAG). EPA must make a paradigm shift and look at numerous endpoints and the interaction between those endpoints when assessing cumulative risk. The universe of chemicals that is included in the definition of "other substances" along with pesticides must be broad. And, finally, EPA must assume that exposure to pesticides and other substances are at tolerance.

Focus on Common Toxic Effect

The current Guidance on Cumulative Risk requires that chemicals share both a common toxic effect and a common mechanism of toxicity to be considered in a CAG. In the real world, a liver cannot tell the difference between two cancer causing chemicals because of the biochemical route each chemical takes to cause that cancer. In other words, if a number of pesticides and other substances cause liver cancer via a number of different pathways the end result is the same, a diseased liver. EPA should not use common mechanisms of toxicity as a filter to decrease the number of chemicals it considers in a given CAG.

Atrazine, and other chemicals that are endocrine disruptors provide an excellent example. It has been established that exposure to atrazine causes the body to increase the production of estrogen. Different pesticides and other substances, for example, organochlorines such as pentachlorophenol (penta), mimic estrogen in the body. An individual exposed to both atrazine and penta would experience elevated levels of estrogen as a result of the cumulative effects of this exposure. The current Guidance on Cumulative Risk would not consider atrazine and penta in the same CAG because of their differing mechanisms of toxicity.

Another important example are the organophosphates (OPs) and carbamates. Both of these families of chemicals have been shown to inhibit acetylcholine (ACh) function. Although these two sets of pesticides inhibit ACh in different ways, the effect is the same, a body exposed to both an OP and a carbamate would experience inhibition of ACh as the result of the cumulative effect of exposure to these pesticides. EPA must think "outside the box" and develop a protocol that will consider these types of cumulative effects.

Interactions Between Multiple Endpoints

The development of a protocol for cumulative risk assessment calls for a paradigm shift on the part of EPA in order to calculate the real world risks to people exposed to multiple pesticides via multiple pathways. The current Guidance on Cumulative Risk follows EPA's standard procedure of selecting endpoints and considering them in isolation from other toxic effects.

Different endpoints have been shown to influence one another. For example, if a chemical causes a suppression of the immune system this could cause an increase in the risk of cancer. Historically, EPA has assessed the risks associated with one chemical at a time, focusing on a small number of endpoints, without consideration of either exposure to additional toxins or the interaction between endpoints. FQPA requires EPA to consider the cumulative effect of exposure to multiple chemicals EPA should also move to consider the effects of interactions of multiple endpoints.

Looking at each endpoint individually ignores the complicated set of interactions that occur within a body exposed to a variety of toxic chemicals. There are a huge number of variables in the real world. EPA must recognize this fact and exercise its authority to protect human health through the reduction of exposure to pesticides and other substances.

Exposure to Pesticides and "Other Substances"

People are exposed to a large number of environmental toxins as they go about their lives. In order for EPA to accurately assess the risks of exposure to multiple pesticides the agency must factor in as wide a range of pesticides and other substances as possible. The agency must include in its definition of "other substances" the inert ingredients in pesticide formulations as well as all contaminants and metabolites of pesticides. It is also very important that EPA factor in the effects of those pharmaceuticals that have toxic effects in common with pesticides. It is also important that EPA factor in environmental contaminants such as dioxins, PCBs and other byproducts of the chemical industry when assessing cumulative risk.

Assume Exposure at Tolerance

EPA has stated that it will not consider the worst-case scenario in its calculation of cumulative risk. The agency's "hypothetical person" must include a worst-case scenario because it encompasses the widest range of people, i.e. if the worst case is protected then we all are protected. There are also important environmental justice issues associated with consideration of a worst-case scenario.

President Clinton's Executive Order 12898, signed on February 11, 1994 states that "each Federal agency shall make achieving environmental justice part of its mission by identifying and addressing, as appropriate, disproportionately high and adverse human health or environmental effects of its programs, policies, and activities on minority populations and low-income populations."

Farmworkers and their children represent an important low-income population that experience disproportionately high, adverse human health impacts from exposure to pesticides. Farmworker children represent the hypothetical worst-case scenario. The landmark National Academy of Sciences report, Pesticides In the Diets of Infants and Children (1993) found that EPA has failed to adopt standards necessary to protect children. Children, due to their small size, greater intake of air and food relative to body weight, developing organ systems and other unique characteristics, are at higher risk than adults to pesticides. This is particularly true for the children of farmworkers whose parents come back from the field wearing contaminated clothing that is then washed with the family's clothes.

Farmworkers are regularly exposed to pesticides on the job. In fact, occupational exposure to pesticides is the single most important source of exposure to pesticides. The proposed Guidance on Cumulative Risk does not consider occupational exposure to pesticides in its cumulative risk. In the past the agency has argued that FQPA does not provide them authority to consider occupational exposure in their cumulative risk assessment. I disagree, and feel that EPA must factor occupational exposure into its cumulative risk assessment.

FQPA section 405 (b)(2)(D) requires EPA to consider from among a number of relevant factors when regulating pesticides. The law provides the Administrator to also consider "other relevant factors" and, therefore, the subsequent list of factors in not exclusive. Subsection (D)(v) establishes the authority of EPA to consider "available information concerning the cumulative effects of such residues and other substances that have a common mechanism of toxicity," thus giving rise for the need to develop this Guidance on Cumulative Risk. This section does not exclude any type of exposure, whether occupational or non-occupational, from being factored into the cumulative risk assessment. Although the following subsection, (D)(vi) does specifically require EPA to consider non-occupational exposure, without mentioning occupational exposure, that is in the context of "information concerning the aggregate exposure levels of consumers" to the pesticide chemical residues. Even so, as mentioned above it is clear that the list of factors cannot be an exclusive list because "the Administrator [of EPA] shall consider, among other relevant factors."

In addition, the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) requires that EPA develop a risk assessment for each registered pesticide that includes risks from occupational exposure. Given that occupational exposure is the most significant type of exposure as reflected in EPA's own risk assessment documents, the agency cannot justify ignoring occupational exposure in its cumulative risk assessment.

EPA must also consider that segment of society that obtains a significant portion of their protein from catching fish and hunting game. Like farmworkers, these people represent an important low-income population that experience disproportionately high, adverse human health impacts from exposure to pesticides. It is well known that some pesticides and other substances bioaccumulate in fish and game. EPA has listed some of the sources of data that can be used to assess exposure to pesticides in food, including market basket data. This type of data would not account for exposure to pesticides from eating wild fish and game.

The EPA must also consider the homeless population across the country and other segments of society that are particularly susceptible to pesticide exposure. This includes people that suffer from Multiple Chemical Sensitivity and those communities with Superfund sites. In this context, EPA must consider background levels of pesticides and other substances in communities across the country, the existing body burden and potential risks caused by the aggregate effect of these chemicals.

Finally, EPA must consider unintentional exposure to pesticides through misapplications and drift. EPA cannot assume that household users of pesticides will follow the label to the letter 100% of the time. In fact, our Pesticide Incident Report program, mentioned above, demonstrates that people are exposed to pesticides as the result of misapplications by homeowners and professional applicators. Studies have shown that farmworkers and their families living within one half mile of fields are exposed to significant amounts of drift from pesticide applications. The EPA cannot ignore these segments of the population by failing to include a worst-case hypothetical person in its cumulative risk protocol.

EPA Should Adopt Precautionary Principle and Err on the Side of Safety

EPA has adopted the notion that risk concerns of ARIs close to the unacceptable level can be moderated by risk mitigation techniques, such as personal protective equipment (PPE), label restrictions or voluntary measures adopted by registrants. Much of the risk mitigation that EPA suggests is not evaluated for efficacy or usability. EPA does not assess the degree to which it can enforce PPE and therefore ensure that the exposure assumptions in its risk assessment are valid. Similarly with agricultural use, since the label rate is the enforcement level, EPA must assume in all cases that

applications to food crops and other uses will occur at maximum label rates, otherwise the agency has no basis for protecting people who are exposed above the rate assumed in the risk assessment. In the case of wood preservatives, EPA accepted a voluntary consumer information sheet program in the mid-1980s that was intended to warn consumers about proper handling of pressure treated wood but failed to insure compliance with the agreement. This program according to all parties has never been adequately carried out, and as a result EPA's exposure and risk assumptions have been flawed for over a decade. If EPA cannot enforce under law the levels of exposure that it utilizes in its risk assessments, then it should not be using those exposure assumptions in its risk assessment.

Ensure Open Meetings on Risk Assessments

EPA should open the meeting process on chemical reviews to the public. No meetings with the chemical industry on risk assessments presented to EPA should be considered confidential unless EPA has determined in advance that the meetings are subject to the confidentiality protections of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), Section 10. Under this process, EPA must make a determination that any and all confidentiality claims are valid. If the agency were to determine at the front end of the process which information being discussed qualified as confidential, then the public should be excluded from only discussion involving that information.


It is of tantamount importance that EPA focuses on the fact that their policy on cumulative risks posed by exposure to pesticide and other substances affect real people. The goal of EPA must be to establish a protocol that captures the real world situation. EPA must look at the complete spectrum of chemicals that a person is exposed to throughout the day and over their lifetime.


Gregory S. Kidd, J.D., Science and Legal Policy Director
Beyond Pesticide/NCAMP

Shelly Davis, Co-executive Director
Farmworker Justice Fun

Terry Shistar, Ph.D.,
Beyond Pesticides Board of Directors