15
Sep
A Very Slow EPA Settlement Process Keeps a Harmful Herbicide on the Market
(Beyond Pesticides, September 15, 2023) The U.S. Environmental Protection Agency suspended the registration of the herbicide dimethyl tetrachloroterephthalate (DCPA) (also widely known as Dacthal), effective August 22, 2023 and leaves existing stocks (products containing DCPA manufactured before August 22) available on the market. The decision is one of a series of EPA attempts dating to 2013 to get more data from the manufacturer as the agency considers reregistration of DCPA. The suspension is toothless, however, since EPA did not totally close the book on this chemical. Six days before the suspension, EPA signed a settlement agreement with the sole manufacturer, AMVAC Corporation, to reinstate the registration upon receipt of the complete toxicological data—that is, animal and laboratory tests— needed to determine the chemical’s safety and how and where it can be used. DCPA is currently classified by EPA as a possible human carcinogen and has also been shown to be a thyroid hormone disrupter.
DCPA is regulated under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Pesticides are supposed to undergo reregistration every 15 years to take new science into consideration, but this process is glacial. Congress amended FIFRA in 1988 to speed up reregistration of products registered before 1984, and the EPA issued a DCPA reregistration document in 1995. Originally registered only for crabgrass and other weeds in turf, by 1995 there were 83 registrations for products made with DCPA. EPA had issued three calls for additional data on DCPA between 1987 and 1992, including one in 1987 because of concerns about dioxin and furan contamination. The 1995 reregistration allowed all uses of DCPA except the original turf application. The agency could not decide on approval for turf because, “The risks of concern include carcinogenic risk to children playing on lawns post-treatment, carcinogenic risk through contaminated drinking water, chronic risks to wild mammalian species, including endangered species, and acute risks to freshwater and estuarine mollusks, including endangered species.”
When the DCPA review came before an administrative law judge last year, an EPA specialist in the Office of Pesticide Programs testified that by October 2020, “AMVAC had not satisfied approximately 41 [data call-in] requirements.”
AMVAC’s attitude has been particularly egregious. The EPA expert further testified, “AMVAC’s actions as to the [Data Call-In] are abnormally dilatory and repetitive. Following EPA’s denial of AMVAC’s requests to waive certain data requirements, AMVAC followed up with additional waiver requests, which usually provided rationales similar to the originals, often with only minor or insignificant changes. In some cases, AMVAC simply opposed the Agency’s denials and did not offer any additional, substantive rationale. During this cycle of waiver requests and denials, AMVAC did not initiate attempts to satisfy the subject data requirements.”
In its suspension notice, EPA recites its enforcement efforts only since 2013. But EPA’s tolerance for industry malfeasance goes much farther back than that. DCPA was first registered under the 1947 FIFRA law in 1958—65 years ago. The EPA did not exist. Since then, manufacturers of DCPA have undergone several mergers and acquisitions, but they have all disregarded their obligations to provide toxicology data. By the time the first EPA Registration Standard was issued in 1988, only one test had been submitted by the then-manufacturer, Fermenta Plant Protection Company.
The most recent EPA action is emblematic of the agency’s timid capitulation to industry pressure by allowing manufacturers to procrastinate on required testing, which enables EPA to delay decision-making. This pattern prevents protection of public health. EPA discourse uses terms like “partners” to describe pesticide companies whose products are collapsing the planet’s biosphere. Time and time again, instead of regulating under clear standards of protection, EPA negotiates settlements with the regulated industry. This is a troubling and deadly pattern that has plagued the agency since its creation, and certainly since the adoption of the 1972 amendments to the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Beyond Pesticides has argued since its founding in 1981 that EPA should regulate and litigate against chemical manufacturers as it is charged with doing under FIFRA and should let the industry know that it will not compromise with the public’s health and the protection of the environment.
The U.S. General Accountability Office (formerly known as the U.S. General Accounting Office) has issued two documents critical of EPA’s handling of registrations. In 1993, GAO reported to Congress regarding delays in reregistrations of lawn and turf pesticides, which includes DCPA. This report cites repeated slippage in deadlines for reregistration because the pesticide companies failed to provide the required studies. GAO noted that EPA did not even have testing and assessment guidelines for human exposure occurring after lawn and turf pesticides were applied. The 2013 GAO analysis took EPA to task for issuing inappropriate conditional registrations and for sloppy recordkeeping. “Specifically, EPA does not have a reliable system, such as an automated data system, to track key information related to conditional registrations, including whether companies have submitted additional data within required time frames. As a result, pesticides with conditional registrations could be marketed for years without EPA’s receipt and review of these data,” the report stated.
The 1993 GAO analysis also noted that EPA had likely underestimated children’s exposures to lawn and turf pesticides while playing on grass. Exposures to DCPA are of critical importance for children, pregnant women, and people who work in agriculture or live near fields treated with DCPA. A recent study by a scientists at the University of California, Berkeley, and Oregon State University gave 100 Latina teenagers in the Salinas Valley silicon wristbands to wear over the summer in 2016. Such wristbands absorb chemicals their wearers are exposed to, and laboratory processing can reveal a wearer’s exposome. The agricultural pesticide found most frequently was DCPA, and a breakdown product of the flea treatment pesticide fipronil had the overall highest occurrence. There was a distinct difference in pesticide exposures between city and country, with rural girls having higher exposures than those who lived in Salinas. Proximity to a field or orchard was also a very large factor in exposures.
These results are consistent with many other studies showing agricultural workers bear the brunt of toxic pesticide exposures and suffer the worst health consequences. This makes EPA’s delays unconscionable, and the agency’s commitment to environmental justice lukewarm.
For the current reregistration cycle, the Endocrine Society, a global group of more than 18,000 endocrine clinicians and researchers, submitted a letter to the EPA saying its members are “extremely concerned about the results of the DCPA thyroid toxicity studies, which showed decreased levels of T3 and T4 [forms of thyroid hormone] in fetal rats at very low, biologically relevant levels, indicating that this chemical is an [endocrine disrupting chemical].” The society also urged adoption of the Precautionary Principle and called for restriction measures, “including cancelling the registration of all products containing DCPA.”
DCPA is a high concentration technical grade product used in the formulation of other commercial herbicide products with an alarming mechanism of action: It affects plants’ ability to reproduce by interfering with the formation of microtubules, a major structural element in every cell on the planet (with slightly different structures in multicellular organisms than in most bacteria and archaea). It is used widely in the cultivation of cabbage, broccoli, cilantro, strawberries, cotton, garlic, and onions, as well as on golf courses and athletic fields. The Yuma, Arizona area is a major DCPA hotspot which grows at least 80 percent of the nation’s winter vegetables and leafy greens, according to Raymond Griffin of Griffin Family Farms, in a comment to EPA protesting EPA’s threat of cancellation. DCPA use is also ubiquitous in California.
The DCPA toxicological results that are available from EPA archives contain disturbing contradictions that the manufacturer and the EPA both disregarded. An EPA analysis in 1994 shows unambiguous thyroid and liver tumors in both sexes of rats tested. Other EPA reports indicate effects on test animals that should have been red flagged. One in 1967 reviewing various dosages in rats, dogs and rabbits, noted significant effects in some dosage groups, such as “depression” in rats and low lactation in rat mothers, and included a remark that, “Data seems to indicate the animals are in poor physical condition. Reproductive indices are low.” Dogs were observed to lose their appetites, lose weight, and become lethargic, yet the various examinations of their internal organs found “no observable gross pathology.” Thus obvious health effects were disregarded in favor of registration.
In 1982, despite numerous detailed criticisms of the test methodologies, such as “[I]t is questionable that the integrity of test cultures was properly maintained in performing the assay,” the EPA’s deference to the DCPA manufacturer was obvious when it proposed to “discontinue establishing potable water tolerances…as an uncessary [sic] burden on applicants for registration of products which may be used in potable water supplies.”
All of this illustrates that EPA knew most of the major ecosystem and human health hazards associated with DCPA almost from the chemical’s first registration. As with the registrations for glyphosate, which disregarded early EPA scientists’ concerns in favor of allowing Roundup (glyphosate) to spread around the world, EPA has ignored DCPA’s clear hazards for decades. It is questionable whether EPA would even require reregistrations of many pesticides if it were not required by law to do so. As it is, EPA drags its feet at every opportunity.
Nathan Donley, PhD of the Center for Biological Diversity observes in a Brookings Institution article that as the U.S. shies away from rational regulation of pesticides, other parts of the world have moved far ahead. For example, in 2019 the U.S. used 322 million pounds of 70 agricultural pesticides that are banned in the European Union. Similarly, the U.S. uses 40 million pounds of pesticides banned or phased out in Brazil. Other countries are making similar decisions. Donley also points out that much of the time when EPA cancels a registration, it is because the company requests it; over the last 20 years, pesticide companies have voluntarily taken 60 pesticides off the market, but EPA has only removed five on its own authority.
Dr. Donley points out that pesticide users are shooting themselves in the foot economically by continuing to treat their products with chemicals banned in their overseas target markets. The U.S. is already losing about $17 million in revenue from the European Union annually. Thailand has banned chlorpyrifos and paraquat, costing U.S. producers $1.8 billion annually; France rejected cherries treated with dimethoate, costing U.S. growers about $5 million over four years; and Mexico is phasing out glyphosate. The failure to even apply enlightened self-interest to the pesticide issue, let alone altruism, is costly in lives, dollars and jobs.
One of the most egregious failings of EPA’s pesticide regulations—indeed, of all its chemical oversight—is its reliance on piecemeal and outdated toxicological concepts while ignoring a vast body of academic health effects research. One result of this is that EPA ignores the commonalities among various parts of the biosphere, such as between vertebrates and invertebrates, animals and plants, microbes and metazoans. DCPA is an outstanding example of this blindness.
DCPA’s interference with microtubules makes it an effective weed suppressor, but as with most pesticides, collateral damage is at least as dramatic. Importantly, DCPA is a phthalate, one of the most notorious reproductive hormone disrupters in the world. DCPA’s microtubular mechanism of action is common to about a quarter of all herbicides that have reached the market, and is not confined to members of the same chemical family. For example, carbendazim, a fungicide used on turf, fruits, and nuts, prevents mouse ova from maturing and damages male sperm production. Oryzalin, a dinitroaniline pesticide commonly used on soybeans, almonds, grapes, and other crops to control weed growth, suppresses microtubule synthesis in a complex process involving oxidative stress that prevents embryos from implanting.
It does not appear that the pesticide industry is able to make the obvious connection between biological interference in one type of organism with the same in other organisms, given that all life stems from a common ancestor and shares a great deal of DNA in common—humans and cabbages have about half their genes in common. It is not surprising that something that kills a cabbage or a dandelion might also injure a human.
The EPA should adopt the Precautionary Principle by assuming that it should not grant approval of groups of chemicals with similar structures if one member is already known to be harmful to humans and ecosystems; and by doing the same thing with chemicals with a common and harmful mechanism of action regardless of their structural families. As the DCPA saga proves, the EPA needs to apply balanced science in a timely manner to the registration of pesticides and stop treating the pesticide industry with kid gloves.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: EPA Issues Notice of Intent to Suspend the Herbicide DCPA
