What is Paraquat?
Paraquat Dichloride is an active ingredient in herbicide Paraquat; commonly sold under the trade name GramOxone. Primarily, Paraquat is used for weeds and grasses that are resistant to Roundup, and is also used for post-harvest dehydration of soybean, corn, and cotton. The substance is sold in a concentrate and must be mixed with water, to then form a spray, which is disseminated onto the plants. Paraquat is acutely toxic to humans, thereby requiring that product users complete an EPA approved training every three years, receive application certification, and wear full personal protective equipment (PPE) while applying Paraquat. “Use” includes the act of mixing and loading; application; transportation or storage of opened containers, equipment cleaning, and disposal of excess product, spray mix, equipment washers, containers and other Paraquat containing materials. Paraquat is 28 times more toxic than RoundUp and long-time exposure has been scientifically proven to cause Parkinson’s Disease. The illnesses connected to Paraquat have led to there being a mass tort lawsuit.
According to Mark Davis, the Senior Officer for Pesticide Management at the Food and Agriculture Organization of the United Nations, “It’s terribly toxic. . . Once it is in your body there is no antidote.” Because of the acute toxicity, 32 countries have banned the use of Paraquat.
In Florida, there are over 47,000 farms encompassing nearly 9.7 million acres of land. Paraquat is not banned in the United States, therefore, the substance may be applied on these farmlands. This use causes farmworkers to be exposed to Paraquat through ingestion, inhalation, or skin contact. Additionally, the toxic spray may be picked up by the wind or air particles and drift into surrounding residential areas or contaminate water. According to research published by the American Journal of Epidemiology, residential areas within 1600 feet of Paraquat application may not be affected by the spray.
History of Paraquat
| 1961 | Paraquat produced for commercial purposes |
| 1970 | Mexican drug enforcement authorities, with funding from the U.S. government, sprayed the chemical on marijuana that later crossed the border. |
| 1997 | EPA acknowledges Paraquat might be linked to Parkinson’s disease. |
| 2009 | Scientific research shows that exposure within 1600 feet increased risk of Parkinson’s Disease up to 75% |
| 2011 | Paraquat labelled a “significant concern” by the EPA |
| 2013 | California Poison Control System and American Association of Poison Control Centers sent letters of concern to the EPA regarding Paraquat exposure after an accidental ingestion in San Joaquin Valley of California. |
| 2016 | EPA’s Paraquat Human Health Mitigation Decision |
| 2017 | EPA says applicators must be certified and licensed |
| 2021 | EPA releases new guidelines regarding Paraquat. |
How can Paraquat harm me?
Absorption Through Short Term Exposure
Research separates Paraquat dangers into two categories: 1) short term exposure and 2) long-term exposure. Within these two categories, there are three ways Paraquat is known to enter the human body: ingestion, inhalation, and skin contact. Scientist have not reported an exact numerical time Paraquat takes to absorb into the human body. However, research is emphatic that “ONE SIP [of Paraquat] CAN KILL”. The product containers bare similar warnings, such as, “NEVER PUT INTO FOOD OR DRINK OR OTHER CONTAINERS”. According to the Center for Disease Control and Prevention (CDC), short term exposure to small amounts of Paraquat through ingestion will result in: contact damage, pain and swelling of the mouth and throat, nausea, vomiting, abdominal pain, and bloody diarrhea. Within several days, the CDC warns that symptoms can progress to heart failure, kidney failure, liver failure, and lung scarring.
When larger amounts of Paraquat are ingested, you may experience acute kidney failure, confusion, coma, fast heart rate, injury to the heart, liver failure, lung scarring (evolves more quickly than when small to medium amounts have been ingested), muscle weakness, pulmonary edema (fluid in the lungs), respiratory failure, and seizure. These results are the same when Paraquat enters the body though inhalation and skin contact.
Absorption Through Long Term Exposure
Absorption through long term exposure primarily focuses on inhalation and skin contact. Long term exposure through inhalation can be directly by a Certified Applicator or by spray drift from living near farms that apply Paraquat on their crops. Long term Paraquat exposure results in signature changes to the brain that is associated only with Parkinson’s disease. The substance works on the human body by crossing the blood-brain barrier once absorbed into the system via inhalation or skin. From there, Paraquat enters the Midbrain. The Midbrain is the section of our brain that controls motor function through the production of dopamine. Paraquat chemically alters the area by destroying the neurons that create dopamine and thus, decreasing the ability to control motor function.
Important to note that Parkinson’s disease is not a diagnosis of elimination. The markers of Parkinson’s disease are very specific and can only be diagnosed by a neurologist after taking several MRI scans of the brain. Further evidence of specific Parkinson’s disease markers in the brain was shown in rats exposed to Paraquat by Parkinson’s Disease researchers.
Government Regulations
A. EPA
The EPA claims that the research is insufficient to directly link Paraquat to Parkinson’s Disease. However, the agency does acknowledge that Paraquat is dangerous and must only be applied by certified applicators. Certified applicators are required to wear full PPE. Still, that protective gear is not 100% effective against the risk of Paraquat exposure as many epidemiological studies found a two-to-five-fold or greater increase in the risk of Parkinson’s disease in people exposed to paraquat on the job. The agency insists that Paraquat can be safe through proper use of the substance. Thus, the EPA released a safety awareness campaign, as well as mandatory changes to labels and product packaging. Periodically, the EPA releases guidelines for Paraquat use and safety measures to reduce the risk of exposure to humans. Recently released guidelines include:
- A ban on aerial application except cotton desiccation
- A ban on pressurized handgun and backpack sprayer application methods
- Adding label language for mandatory spray drift management
- Putting a limit on the maximum application rate for alfalfa
- Requiring a 48-hour restricted entry time for all uses and crops except cotton desiccation
- Requiring a drift buffer for residential areas and seven-day restricted entry interval for cotton desiccation
- Requiring PF10 respirators or closed cabs if the area treated in a 24-hour period is 80 acres or less
B. CDC
The CDC outlines that the current form of Paraquat marketed in the United States has a blue dye to keep it from being mistaken with beverages such as coffee, a sharp odor to serve as a warning, and an added agent to cause vomiting when ingested. As well, the CDC provides an emergency pocket guide to Paraquat that includes first aid, and respirator recommendations[1].
C. World Health Organization
The World Health Organization provides an international chemical safety card. This safety care provides specifics on disposal, storage, packing[2].
[1] https://www.cdc.gov/niosh/npg/npgd0478.html
[2] https://www.ilo.org/dyn/icsc/showcard.display?p_lang=en&p_card_id=0005&p_version=2
