Paraquat

J. William Langston was working as the head of neurology in July of 1982 at the Santa Clara Valley Medical Center, in California, where a 42-year-old heroin addict was brought from the county jail after suddenly becoming unable to move or speak Admitted for possible catatonic schizophrenia, Langston found that the patient appeared to be cognitive but unable to control his motor skills. The symptoms, he said, resembled those typically displayed by older patients during the advanced stages of Parkinson's disease. Stiff, rigid and in a frozen state, five more zombie-like addicts began arriving at San Francisco Bay Area emergency rooms. "A group of heroin addicts in the 1980s all developed full-blown Parkinson's disease overnight," Langston said, recounting the episode that ultimately led to a scientific breakthrough in the research of Parkinson's disease and linked its risk to a number of herbicides. "It looked identical to advanced Parkinson's. It was called 'the walking dead' on the street. Nobody had ever seen anything like it. Eventually, we found out what was going on." The connection, so to speak, was a clandestine chemist who had cooked a bad batch of MPPP, a painkiller similar to Demerol first created in 1947 as an alternative to morphine. In 1976, the formula resurfaced when a 23-year-old chemistry student used the recipe to create an uncontrolled designer drug to be used as a synthetic heroin. The student, by no small coincidence, developed the same Parkinsonian symptoms as the addicts seen by Langston in 1982. Working with law enforcement, Langston was able to find the source of the drug, analyze its chemical compound and identify an unintentional impurity called MPTP, which is created during the manufacture of MPPP when its temperature gets too high. "They not only got high, but they became stiff and rigid," Langston said. "The drug they injected isn't toxic at all. But (MPTP) is a compound that can get in the brain, and once it gets there, it's converted to MPP+, and that's the toxin. It gets into the brain and wipes it out like a Nike missile. It's unbelievable how incredibly toxic it is." Because Parkinson's disease isn't known to naturally occur in any species other than humans, researchers had no way to replicate the disease in animals prior to Langston's discovery. Within months of the finding, they were able to induce Parkinsonian symptoms in monkeys by using MPTP. In 1988, Langston founded the Parkinson's Institute and Clinical Center in Sunnyvale, California, where he now serves as Chief Scientific Officer. The non-profit, independent institute provides basic and clinical research, clinical trials and patient care for Parkinson's disease and related neurological movement disorders. Research developed from the discovery of MPTP allowed for a better understanding of Parkinson's disease, including ways to treat it and potential causes. Studies began focusing on pesticides when scientists discovered MPP+ was introduced by Gulf Oil Chemicals as an herbicide in the 1970s under the name Cyperquat. "It was almost marketed in the U.S. as an herbicide," Langston said. "I'm not sure why it never made it to market." The revelation that a chemical shown to cause Parkinson's-like symptoms was developed as an herbicide led to dozens of subsequent studies investigating whether exposure to pesticides may increase the risk of Parkinson's disease. Perhaps the most studied pesticide has been paraquat dichloride, or simply "paraquat," which is one of the most widely used herbicides on earth. While not identical to cyperquat, Langston said MPP+ and paraquat are structurally similar. "There are probably over 40 or 50 studies, from a variety of pesticides to other environmental neurotoxins, into Parkinson's that all came out of this little molecule that froze the addicts, which surged this whole thing," Langston said. "There is a huge amount of research on paraquat." Paraquat dichloride, or paraquat, is a non-selective herbicide that controls a range of weeds, grasses and other green plants in which it comes in contact. Paraquat is used in the farming of more than 100 types of crops, including row crops, orchards, fruits and vegetables. It's also used as a desiccant, which is applied to some crops prior to harvest to kill off green material and aid in harvesting. Outside of farming use, paraquat may be used in right of ways, pastures or fallow land, around commercial buildings or storage yards. "It's a very effective herbicide, and it's been out there for a long time," said Christy Sprague, a crop and soil research scientist with Michigan State University's research and extension program. "In general, it works a little differently. It's a contact herbicide, so it works differently than glyphosate (Round Up) that moves throughout the plant. Pretty much, whatever it comes in contact with, it will control. And it will control most plant species, so the one that is being controlled has to be above the ground at the time of application. It pretty much burns the plant tissues." Paraquat was first registered for use in the United States in 1964. Due to it's high toxicity, the United States Environmental Protection Agency (EPA) in 1978 categorized paraquat as a "restricted use" pesticide. The designation requires those working with paraquat to attain a special certification. Likewise, the sale, transport, storage and application of paraquat is heavily regulated by the EPA, which prohibits its storage or use in residential areas, near schools, playgrounds, golf courses, parks and home gardens. There are no paraquat products that are registered for homeowner use, and no products registered for application to residential areas. The Michigan Department of Agriculture and Rural Development (MDARD) is responsible for registering about 15,500 pesticide products in the state, which includes about 600 that are classified as "restricted use" pesticides. Of the those 600, 14 herbicides registered in Michigan contain paraquat as an active ingredient, said Brian Verhougstraete, pesticide registration program specialist with the Michigan Department of Agriculture. "You have to be certified to buy it for use. You have to be certified before you can even buy this stuff," Verhougstraete said. "Certification isn't specific to that herbicide itself. If it's restricted use, certification is for any herbicides that are restricted." The Michigan Department of Agriculture and Rural Development said about 23,600 gallons of paraquat were sold from 2013 to 2016 throughout the state. Of that amount, about 110 gallons were sold in Macomb County and five gallons were sold in Oakland County. No paraquat was sold in St. Clair, Wayne or Livingston counties during that period. "That doesn't mean the applicator is applying it in Oakland County – it just means that's where they bought it," Verhougstraete said. In terms of unique qualities, there are at least a few reasons that paraquat stands out from other herbicides. Its high toxicity and lack of any known antidote if swallowed has led to paraquat becoming a known suicide agent, a dubious distinction that contributes to its heightened regulation and additives to make it harder to ingest. Yet, because paraquat becomes mostly inactive when it makes contact with soil, its use isn't typically connected to agricultural runoff or crop contamination. Paraquat also solidified its place in pop culture when actor Jeff Bridges improvised the term "human paraquat" in the movie "The Big Lebowski." The term is a reference to paraquat's use in drug enforcement efforts to destroy marijuana crops, and implies a person is a "buzzkill," in the parlance of cannabis culture. From 1975 to 1978, the United States did indeed work indirectly with the government of Mexico by funding an aerial spraying program to destroy marijuana fields with paraquat in the Sierra Madre. The United States contributed about $30 million per year to that program and its companion that utilized another herbicide to eradicate poppy plants used in the production of heroin. Because the action of paraquat is largely dependent upon sunlight, Mexican farmers at the time were able to salvage the treated marijuana by quickly harvesting the plants and wrapping them in dark cloths before exporting them across the border. In 1978, following the discovery that marijuana entering the United States from Mexico was contaminated with paraquat, Congress ordered an investigation into whether or not the plants represented a health hazards to marijuana smokers. Epidemiologists at the Centers for Disease Control (CDC) and the National Institute of Environmental Health Services found 13 of 61 samples of marijuana from the southwestern United States to be contaminated with paraquat from the Mexican spraying program in concentrations from 3 to 2,264 parts per million. About 3.6 percent of 910 samples of confiscated marijuana nationwide had "detectable" levels of paraquat. The CDC estimated about .2 percent of paraquat found on contaminated marijuana remains unchanged when smoked and is retained in the lungs. It was estimated about 31.3 percent of all marijuana smokers in the United States would inhale less than 100 micrograms of paraquat in one year, with .1 percent inhaling 100 micrograms or more. In 1985, the government issued an impact statement on the effects of paraquat on marijuana smokers, stating "there is a slight risk that heavy smokers of marijuana could be affected by paraquat-sprayed marijuana.” Whether marijuana smokers exposed to paraquat suffered immediate health impacts is unknown; attempts by epidemiologists to assess them at the time didn't produce any conclusive results. Likewise, there's no existing evidence the spraying program resulted in any additional risk for Parkinson's disease. "Parkinson's is a disease of aging that progresses over time,” said Samuel Goldman, principal investigator of neurology at the San Francisco Veterans Affairs Medical Center. "Whatever process was initiated in the late 1970s, it would only now be coming to fruition. If there were effects, we would start to feel them now." Yet, paraquat isn't the only pesticide that has been named in scientific studies to be a potential environmental factor in the onset of Parkinson's disease. In fact, a 1986 study spurred by Langston's development with MPTP just a few years prior studied Parkinson's patients whose symptoms began at age 40 or earlier, then looked into those patients' childhood environments. The study, conducted by neurologists at the University of Saskatchewan, in Canada, focused on 21 patients. Of the 21, all but two had spent the first 15 years of their life in rural Saskatchewan. Further, all but one of the patients exclusively drank well water for those first 15 years. The researchers concluded that rural environments in the province contributed to early onset of Parkinson's disease, and that well water contamination from pesticides may have contributed to that onset. While the study didn't offer definitive evidence of a specific pesticide with a causal factor to Parkinson's disease, it served as one of the early epidemiological studies that looked at the incidence and distribution of Parkinson's with other factors based on Langston and other's findings with MPTP. Later epidemiological studies on the subject included better data on specific herbicides and more accurate exposure incidents. More recent studies, including one by Goldman that was published in 2012, have focused on the association of paraquat and Parkinson's disease in context with genetic factors. It is the combination of both genetic and environmental factors that is believed to be the cause of Parkinson's disease, rather than any specific influence. "It hasn't been easy to find the causes. If it were just one thing, it would be easy. We would have found it," Langston said. "It's probably a combination of genetic risk factors and environmental factors." Working with Langston and other researchers, Goldman's 2012 study, "Genetic Modification of the Association of Paraquat and Parkinson's Disease," investigated Parkinson's disease risk associated with paraquat use in individuals with certain genetic influencers known to be associated with higher rates of Parkinson's disease. Goldman said researchers already know that people with Parkinson's disease have lower levels of glutathione S-transferase T1, an enzyme that acts as an antioxidant by removing free radicals from the body. Some studies with lab rodents have shown that paraquat produces Parkinson's symptoms through the imbalance of free radicals and antioxidants. Goldman said nearly 20 percent of people have a genetic variation that inhibits the production of glutahione. "We think this is the model for what is going on with most Parkinson's," Goldman said. "There are a lot of these environmental factors out there, and in many people they don't result in disease. But, if you're one of the people with this genetic predisposition, it does. In this case, it is a genetic variation that is very common. A 20 percent variation is high; most genetic variations are about 5 percent." Researchers genotyped individuals who had participated in the Agricultural Health Study (AHS), which is a high quality epidemiology study evaluating the link between pesticide use and various health concerns, including cancer. The AHS includes more than 89,000 pesticide applicators and their spouses in Iowa and North Carolina, who have participated in the study since 1993. The Goldman study examined those applicators exposed to paraquat in relation to whether or not they had the genetic mutation affecting glutathione. They found those applicators exposed to paraquat unable to produce the enzyme were 11 times more likely to have Parkinson's disease than those who aren't exposed to paraquat and are able to produce the enzyme. "It's the largest risk association ever recorded for Parkinson's disease," Goldman said of the correlation. "Clearly, based on this – although in epidemiology we like to see replications to make sure it's not random – it's pretty compelling based on the magnitude and biological plausibility. It makes sense scientifically that it would be a combined effect." Outside of being associated with Parkinson's disease, paraquat is highly toxic. The herbicide works by disrupting the photosynthesis process when it comes into contact with green plants. Much of the toxicity of paraquat is lost when the active ingredient hits the soil and binds to clay particles. Those factors suit themselves to some specific situations, such as treating weeds between rows of crops, as well as a herbicide that can be used in no-till farming to knock down weeds prior to planting without having to disturb the soil. Further, paraquat is commonly used to treat weeds that have become resistant to other herbicides, such as glyphosate, known commercially as Round Up, which is a more widely-used herbicide. Paraquat's toxicity and lack of antidote when ingested; it's track record for what the EPA has deemed high risk for harm from exposure; and the possible link as an environmental factor in the development of Parkinson's disease, have resulted in the herbicide being banned from use in at least 32 countries, including China and those in the European Union. Switzerland, where the largest producer of paraquat, Syngenta, is located, has also banned its use. In 2015, Canada's Pest Management Regulatory Agency issued a Special Review Decision on paraquat, making it a "restricted class" pesticide in that country, based on ingestion and occupational exposure incidents that have posed a risk to human health. Further, the country imposed limits on paraquat's active ingredient concentration levels, as well as other safety measures. The use of paraquat in the European Union was initially authorized in December of 2003 by the Commission of the European Communities. At the time, the herbicide had been banned in 13 countries within the EU, including Sweden, Denmark, Austria and Finland. In February of 2004, Sweden, supported by Denmark, Austria and Finland, took legal action against the commission to annul the decision. In its claim against the commission, Sweden alleged the commission failed to protect the environment and human and animal health, as well as procedural shortcomings. The European Court of First Instance, which in July of 2007 overturned the commission's decision in favor of Sweden's request, found a number of producers of paraquat led by Zeneca, never addressed existing studies on the link between paraquat and Parkinson's disease, nor did the commission's report include any assessment of such literature. The court also found the commission failed to satisfy procedural requirements and disregarded procedural provisions in its assessment report of paraquat's potential risks by stating there are no indications of neurotoxicity associated with paraquat, as well as the commission's omission of a French study on paraquat operators' exposure levels. The court also found at least one instance where an operator's exposure to paraquat was above the acceptable exposure levels despite prescribed use, and that it ignored another study's safety recommendations. Further, the court found the commission failed to properly assess paraquat's risk to animal health. In the United States, the EPA recently increased restrictions on paraquat in an attempt to mitigate human health risks. In December of 2016, the EPA issued an "Interim Mitigation Decision" on paraquat that phases in a series of additional restrictions intended to prevent accidental ingestions and reduce exposure to workers who mix, load and apply the herbicide. Specific changes announced by the EPA in December include: label changes emphasizing paraquat's toxicity and supplemental warning materials; targeted training materials for paraquat users; closed system packaging for all non-bulk (less than 120 gallon) end use product containers of paraquat; and restricting the use of all paraquat products to certified applicators only, thus prohibiting use by uncertified persons working under the supervision of a certified applicator. Closed-system packaging requires the herbicide application equipment used to connect to the container and transfer the product through a series of hoses, pipes and couplings so that the closed system is the only feasible way to remove paraquat from the container without destroying the container. Packaging can't contain any screw caps that can be removed or allow paraquat to be poured from the container. The new restrictions and requirements will be phased in, beginning in March of 2017 through September 30, 2020, which is the last day for the sale of paraquat products that don't comply with new labeling and closed system requirements. The EPA also is undertaking a Health Risk Assessment for paraquat, which is scheduled to be released in late 2017. That assessment will include a review of studies that purport a link between the herbicide and Parkinson's disease, as well as other health risks. The EPA stated in its proposed interim decision released in March of 2016 that "there is a large body of epidemiology data on paraquat dichloride use and Parkinson's disease," and that "animal studies and other epidemiological evaluations have suggested that paraquat (and also the pesticide rotenone) may be causative agents (or contributors) in the etiology of Parkinson's disease. Still the agency said in documentation that the interim restrictions were based only on acute exposure to paraquat dichloride. "However, as part of the comprehensive human health risk assessment scheduled for 2017, chronic effects will be reviewed," the agency said it its decision. The risk assessment may recommend additional mitigation measures prior to the completion of the registration review, and may be incorporated into the final registration review's decision. In addition to the recent mitigation decision, paraquat is undergoing the EPA's Registration Review process, in which the agency re-evaluates the herbicide to determine whether it continues to meet the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) standards to protect applicators, consumers and the environment. All pesticides registered under the federal act must undergo the re-evaluation process on a 15-year cycle. An initial draft and recommendations of the registration review is expected to be issued in late 2017, with a final version due in 2018. Medical professionals Downtown Publications spoke with who have studied paraquat and the potential increased risk for Parkinson's disease say they believe the EPA should join some of the other countries that have banned the herbicide and deny its re-registration. "I think it is totally appropriate to take it off the market," Langston said. Goldman also said he believes paraquat use should be halted. "To me, it's crazy that this stuff is on the market," Goldman said of paraquat. "If you give it to a rat, if you give it to them once, nothing happens. If you give it to them twice, spaced apart in low doses, they develop something that looks exactly like Parkinson's disease." While the EPA has worked to increase protections for those handling and using paraquat, Goldman said those measures don't appear to be adequate. In looking at the rates of Parkinson's disease among applicators in the Agricultural Health Study, he said it's apparent farmers are at an increased risk. "Presumably, because they were the professionals, they were using the appropriate protective measures, like gloves and respirators, but nonetheless, they absorbed this," Goldman said. The Pesticide Action Network (PAN) of North America, a non-profit organization with five regional centers worldwide and more than 125,000 members nationally, has asked the EPA to impose a ban on paraquat. "Pesticide Action Network is encouraged by the EPA's proposed interim mitigation measures for paraquat dichloride, but finds that while these may be useful in the short-term, the only way to effectively end poisonings and human health impacts from paraquat exposure in the US is to ban all uses of paraquat dichloride," the organization said in a statement to the EPA in May. Additional short-term mitigation measures that PAN recommended was a request for the EPA to lower the concentration of paraquat in its formulation, such as a measure that Japan took in 1986 when it lowered the solution from a 24-percent solution to about 5 percent. Solutions in the United States are about 30 percent paraquat dichloride. The American Association of Poison Control Centers, which represents 56 regional poison control centers in the country also requested the EPA require a reformulation of paraquat to a 5 percent solution. "The best way to treat an illness, including poisoning, is to prevent it," the association's president, Marsha Ford, said in its statement to the EPA. "In exposures to toxicants, what often determines illness from non-illness and death from non-death is the dose." But not all scientists agree. Many in the agricultural fields say paraquat's effectiveness and relatively inexpensive costs make it hugely beneficial to domestic farmers, as well as third-word countries that have struggled with food production. Michigan State University's Sprague said she doesn't feel it's necessary to ban paraquat's use, as there are already protective measures in place. "Personally, I don't think it needs to be banned," Sprague said. "I think there's been very responsible use of that herbicide. I don't see it going away." Domestically, the EPA estimates an average of four million pounds of paraquat were applied annually to over seven million acres between 2011 and 2013. Bernard Zandstra, a research and extension professor at Michigan State University's Department of Horticulture, said paraquat in Michigan is widely used for tree crops, such as apples, as well as specialty crops. "Its use has been pretty constant," Zandstra said. "When it first came out in the 1960s, it was the only contact desiccant type herbicide people had. Until that time, they were using things like 2,4-D for that, but that drifts and has a lot of problems. Then glyphosate came out in the 1970s, and in many cases it's used in it's place for a couple reasons. It's not nearly as toxic. Paraquat has human toxicity problems. With that said, there's a fair amount of use because little resistance has developed to it." Zandstra said the most recent discussions about paraquat at the EPA level have focused on the dangers associated with the ingestion of the herbicide. He said he wasn't familiar with much research connecting paraquat to increased risk for Parkinsons disease. "I'm aware that it's widely used in third world countries in Africa and Asia because it's widely inexpensive," he said. "The poisonous part to humans is what the discussion is about at the EPA. It's still widely used. I've talked to a number of growers since the discussion came up in the past couple of months, and there is a lot of concern." Syngenta, the largest manufacturer of paraquat, thus far has taken the view that paraquat doesn't cause Parkinson's disease, stating that there is an absence of evidence that paraquat is causally related with the disease in humans. A spokesperson for the company declined to comment for this story, instead referring to official statements made to the EPA. "Syngenta is undertaking a major research program in the animal model to investigate the alleged link between paraquat and Parkinson's disease. The research has been or will be published and the results communicated to relevant regulatory agencies," the company said in its statement. "The key finding is that paraquat, even at the maximum tolerated dose, does not cause dopaminergic neuronal cell loss in the SNpc, the area of the brain associated with Parkinson's disease, as claimed in certain external publications." The company further stated­ that many epidemiology studies investigating the alleged association "are characterized by weakness in their study design, particularly the assessment of past exposure, and provide an inconsistent picture." The Michigan Farm Bureau has stated that paraquat is an important herbicide for farmers in the state. While the EPA in March of 2016 said it was proposing prohibiting the use of backpack sprayers for the application of paraquat, the agency reversed the proposal to allow continued use. The Farm Bureau and others strongly opposed the proposed measure. "Paraquat dichloride is a restricted use herbicide that our state's growers depend on for weed control. Many of our grower members tell us that they utilize this herbicide in site specific areas, often applying with small batch mixes for handheld or backpack sprayers. In EPA's recommendations, they would like to prohibit this type of application. This would be devastating for our state's growers, and we urge the EPA to reconsider, and re-register the use of paraquat dichloride, by following the strict label requirements." Across the state, Michigan has more than 36,000 acres of cherries, 36,500 acres of apples, 21,000 acres of blueberries, 48,000 acres of potatoes, 112,000 acres of specialty crops, and a large amount of alfalfa, corn, dry beans and soybeans, with row crops accounting for more than 4.7 million acres of agricultural production in Michigan. Beth Nelson, president of the National Alfalfa and Forage Alliance, said paraquat's use in alfalfa is important as both an herbicide and a desiccant. "Paraquat dichloride is used both as a winter annual weed management treatment and as a harvest aide in alfalfa grown for seed throughout the United States," Nelson said. “Depending on the region in which it is grown and the variety, most alfalfa goes dormant during the winter months, and paraquat can be applied during the dormant stage to control emerged winter and annual weeds without injuring the crop... few weed species have developed resistance to it, and it is an excellent desiccant harvest aide... There are no alternative herbicides currently available that can function similarly in all of these rolls." Chip Bowling, president of the National Corn Growers Association, said paraquat is one of the herbicides that makes it possible for no-tillage farming, which reduces soil erosion and water runoff from crop fields. "The use of herbicides, including paraquat, has made the revolutionary practice of conservation tillage possible. To remove grower access to these important tools threatens to undermine the water quality progress, progress and reductions in pesticide runoff that have been achieved through the incorporation of such practices." Richard Wilkins, president of the American Soybean Association, said about 173 million acres, or about 62 percent of all tillable acres in the United States, practice no-tillage farming. "The non-selective herbicides, including paraquat, used in conservation-tillage scenarios save precious topsoil every year in the United States,” he said. In considering the benefits and drawbacks of pesticides, it's not abnormal for the agriculture and medical communities to not come to the same conclusions. Further, those hoping for stronger restrictions or an all-out ban on paraquat know they are facing an uphill challenge as President Donald Trump has vowed to take down regulations that may hamper business. As Trump works to get his cabinet appointments approved, the EPA, both on a regional and national level, is adhering to the administration's blackout order on the media. Multiple calls and emails to the EPA's national and regional spokespeople requesting comment for this story were not returned. Out-of-office email responses and voicemail messages suggest journalists email all questions to press@epa.gov. No responses to emails to that address were made. "We have seen this in other areas as well," said Carrolee Barlow, CEO of the Parkinson's Institute. "We have work done by high-quality technicians where we can show how compounds are causing connections, and the industry is able to squelch data to keep things on the market. "The pesticide industry is one that really needs to be regulated. We know how these compounds kill areas of the brain... if that information is regularly denied or squashed, that is really where the problem starts." Organizations and lobbyists representing farmers and the pesticide industry say they will be working with the Trump administration to pull back on regulations pushed by the previous president that they see as too restrictive. CropLife America, a Washington D.C.-based trade organization representing the pesticide industry, said one of its main objectives under the new administration will be to seek a reset of the Federal Insecticide, Fungicide, and Rodentcide Act (FIFRA), which is the federal law that guides pesticide regulations that are intended to protect applicators, consumes and the environment. Under the act, the EPA is responsible for enforcement of pesticide regulations. However, many in the industry accuse the EPA of shifting enforcement policies from those based on science to those based on public perception. "We believe there was a policy shift in regard to pesticide regulation over the past few years. The goal is to reset pesticide regulations back within the four corners, or boundaries, of FIFRA. That includes re-establishing sound science, stakeholder engagement, transparency and due process," Beau Greenwood, executive vice president of governmental relations and public affairs for CropLife America, said. "Whether we are reaching out to new members of the Trump administration as those positions are filled, or working with congressional Democrats and Republicans alike, we believe that policy shift isn't going to course correct itself. Our number one goal is to correct that shift." Greenwood said the EPA has imposed several restrictions on pesticides without a need being necessary or proven, many of which he said appear to be based on politics rather than sound science. Likewise, he said members desire improved stakeholder engagement on decisions, including input from other government agencies. For instance, Greenwood pointed to the EPA's recent decision to place additional restrictions on paraquat when the United States Department of Agriculture offered suggestions during the EPA's comment period, rather than being ensured a seat at the table. "We are also looking for sufficient funding levels for the EPA," Greenwood said. "The trend has been to spend less. It's critical to have a regulator that is sufficiently funded, and we will be working to make our case. They are the licensing agent, and it's in our interest to have them fully staffed." Syngenta, which is the largest manufacturer of paraquat, is among the companies represented by CropLife America. Others include major pesticide manufacturers, such as Monsanto, Dow AgroSciences, DuPont, and others. Another goal of the association is the reauthorization of the Pesticide Registration Improvement Act, which sets out the registration service fee system. "It's still early. We would love to have people confirmed at the EPA and USDA, but those confirmations haven't occurred, yet. We are looking for those opportunities once they are confirmed," Greenwood said. "There was a growing list of agency actions we thought went beyond the four corners of FIFRA, and that is what we are trying to correct." ­