By Matt Smith
Editor’s note: This article grants one continuing education unit (CEU) in the Core category toward the renewal of a Florida Department of Agriculture and Consumer Services restricted-use pesticide license when the accompanying test is submitted and approved.
“In retrospect, I would rather have been a poet. Or a farmer.” Instead, British Special Air Services Agent John Patrick Mason is the only person to ever escape Alcatraz and the only man who can lead FBI Agent Stanley Goodspeed to save San Francisco from being destroyed by a chemical weapon attack.
This article will review the symptoms of pesticide exposure, how cholinesterase inhibitors work, and how to render first aid for pesticide emergencies. Along the way, we’ll take lessons from perhaps the greatest movie Michael Bay has ever made, and certainly the one most appropriate for this topic.
SYMPTOMS OF PESTICIDE EXPOSURE
In “The Rock,” a rogue group of U.S. Marines take Alcatraz hostage and ransom San Francisco for reasons that are shockingly nuanced for a Michael Bay film. But the film’s chief villain is arguably the chemical weapon itself, which is a slightly fictionalized version of VX nerve agent. VX is a cholinesterase inhibitor that was the result of a failed pesticide development in the early 1950s and is depicted in the film as a green gas. Its symptoms are incredibly violent and dramatic and include vomiting, convulsions and a truly gnarly skin reaction. For most pesticides used in the field, symptoms are more subtle and can often be confused for something else.
Common symptoms of mild pesticide poisoning include fatigue, headache, dizziness, blurred vision, excessive sweating/salivation, nausea, vomiting, stomach cramps and diarrhea. External irritations, including redness, blisters, rashes and burns, may develop. Victims may also experience swelling and a stinging or burning sensation in their eyes, nose, mouth and throat. These symptoms may be difficult to distinguish from other ailments such as heat stress, illness, reactions to irritating plants like poison ivy, and even hangovers. However, when such symptoms immediately follow handling or working around pesticides, you should seek medical attention.
CHOLINESTERASE INHIBITORS
Whenever you move a muscle, an electrical signal travels from your brain to the muscle via a series of specialized cells called neurons. However, this message does not travel along an unbroken wire. There are gaps between the neurons called synapses that electrical signals can’t cross. Instead, special chemicals called neurotransmitters ferry the message across the gaps. Eventually, the message reaches the muscle cell and tells it to contract.
One very common neurotransmitter for this task is called acetylcholine. When acetylcholine reaches a muscle cell, it has one job: It tells the muscle to contract. Acetylcholine has no “release” instruction; it must be destroyed to allow the muscle cell to stop contracting. That is where an enzyme called cholinesterase comes into play.
Cholinesterase is an enzyme that breaks up acetylcholine. If something were to inhibit cholinesterase from doing its job, the muscle cells would remain contracted. On a large enough scale, whole parts of the central nervous system begin to shut down. In incredibly small doses, VX nerve agent does this on a massive scale, leading to suffocation as the victim’s chest muscles remain contracted. Certain chemical families of pesticides, such as organophosphates and carbamates, primarily kill target insect pests by inhibiting cholinesterase. While humans are quite different from insects, we are similar enough that these pesticides can affect us.
Mild organophosphate and carbamate poisoning can cause any of the common poisoning symptoms described above. Moderate and severe organophosphate and carbamate poisoning symptoms are more obvious. Signs of moderate poisoning include weakness, inability to walk, discomfort in the chest and constricted pupils. Severe symptoms include difficulty breathing, muscle twitching, runny nose, drooling, unconsciousness, coma and even death.
Cholinesterase inhibitor poisoning in humans may present itself immediately following a significant exposure, but it may also present itself gradually over a long period of small exposures. Catching long-term exposure early is achievable by enrolling pesticide applicators in a cholinesterase-monitoring program. A physician will take two blood samples over a couple of weeks to establish a baseline cholinesterase level. Regular checkup tests, or testing after a suspected exposure, can spot a significant drop in cholinesterase levels from the baseline if the person has been exposed. If exposure has occurred, the applicator should be removed from spraying cholinesterase inhibitors until the body has had sufficient time to build new cholinesterase.
RESPONDING TO A PESTICIDE EMERGENCY
First aid is the first course of action when responding to a pesticide emergency, but it is not a substitute for proper medical care. Before rendering first aid, remove yourself or the victim from the source of the exposure. This may require you to first don the proper personal protective equipment.
Check to see if the victim is breathing or unconscious. An unconscious person should always be treated as a medical emergency. Hollywood action movies treat unconsciousness like a snooze button that is easily recovered from. But in reality, being rendered unconscious means something has gone seriously wrong, and long-term damage may result.
If you have the opportunity to flag down a passing first responder helicopter by waving green flares over your head while screaming, always do that. However, if you are not living in a Nicholas Cage film, call 911 instead. Designate someone to collect copies of the labels and safety data sheets for the pesticides the injured person was in contact with and give them to first responders. Under the Worker Protection Standard, agricultural employers are required to provide medical personnel with the names and labels of any pesticides the injured worker may have been exposed to if requested. If the injury was the result of chronic, long-term pesticide exposure, a history of proper recordkeeping becomes vital to determine what may be the cause.
While awaiting emergency medical services, start administering first aid. The pesticide label should always be consulted for product-specific first aid treatment. That said, there are some general rules of thumb you can consider.
SKIN EXPOSURE
If skin is exposed to pesticides, first remove any clothing that has been exposed. Wash affected skin with water and soap and rinse well. A shower is ideal but jumping into the nearest irrigation ditch will work in a pinch. Avoid harsh scrubbing. If the skin has chemical burns, cover them lightly with clean, soft cloth and do not apply any medicine unless instructed to by a medical professional.
If exposure occurs due to normal, legal application, clothing contaminated by chemicals designated as solid waste or as hazardous waste can be disposed of in the trash. If pesticides regulated as hazardous waste contaminate clothing as the result of a leak or spill, that clothing must be disposed of as hazardous waste.
EYE EXPOSURE
If pesticides get into your eyes, timing is critical. If you don’t have access to an eyewash dispenser, start with applying gentle drops across the eye with whatever clean water source is available. Direct the stream of water from your nose to the side of your head so you do not splash pesticide from one eye into another. Rinse for 15 minutes, being sure to rinse under your eyelids.
If you are wearing contact lenses, rinse with the lenses in for five minutes before removing the lenses. Applicators who wear contact lenses should consider wearing daily disposable contacts or glasses during spray days because weekly or monthly lenses may accumulate pesticide residues.
RESPIRATORY EXPOSURE
The first priority when treating someone suffering from pesticide inhalation is to get them into fresh air, but the first step is protecting yourself from the source. This is especially true if you find an applicator unconscious in an area where there is little air movement, such as an enclosed greenhouse. Unconscious people are heavier than you think, and you are not going to be able to drag them out without taking a deep breath.
If the victim is conscious, have them lie down as soon as they are in a safe place. Loosen any tight clothing. Keep them comfortably warm and have them refrain from speaking. From this point to when paramedics arrive, your job is to keep the person breathing. Tilting the chin back will keep the airway open and make for easier breathing. If the person begins to convulse, protect their head and make sure they are still breathing. If breathing stops at any time, begin artificial respiration.
ORAL EXPOSURE
If you get a pesticide in your mouth but haven’t swallowed it, grab your water bottle and rinse your mouth out thoroughly. Once rinsed, drink up to a quart of water or milk, then get medical attention.
If you or someone else swallows a pesticide, your gut reaction may be to induce vomiting. This is often a very bad idea. The first reason is the possibility of additional tissue damage. Your stomach is designed to handle some very caustic chemicals; your throat is not. A caustic chemical has already done damage on the way down, and it will do further damage on the way back up. The second reason is that vomiting carries a chance that some of the materials being expelled could find their way into the lungs. This can lead to death, particularly with emulsifiable concentrates and oil solutions. For these reasons, never induce vomiting unless specifically instructed to do so by the pesticide label or medical personnel.
If the label states to induce vomiting, first make sure that the victim is neither unconscious nor convulsing, as either of these could lead to choking. Have the victim kneel forward. If they can’t stand, roll them onto their side with their upper leg bent outward so their knee is touching the ground. This will prevent them from accidentally rolling onto their stomach. Give the victim two full glasses of still water. Then, use your finger or something long with a blunt end to touch the back of the victim’s throat to stimulate vomiting. You’ll know when the reaction has started. Collect some of the vomit to give to the doctor for analysis.
YOU’RE THE ROCKET MAN
In “The Rock,” the only way to deactivate the deadly VX nerve gas is with thermite plasma rockets that aren’t yet operational. The audience likely knows they’re going to be operational by the end of the movie, but the characters don’t. If you’re going to stockpile potentially dangerous chemicals, having a detailed safety plan with countermeasures already in place is the best practice. Pesticide emergencies aren’t fixed with high explosives; they’re fixed by the positive safety environment that you develop. Learning to recognize the symptoms of pesticide exposure, knowing proper first aid treatments, stocking necessary medical supplies and taking proactive steps like enrolling in a cholinesterase-monitoring program can be the difference between life and death.
Sources:
- “Applying Pesticides Correctly, 7th Edition” by F. Fishel (ifasbooks.ifas.ufl.edu/p-104-applying-pesticides-correctly-a-guide-for-pesticide-applicators-core.aspx)
- “Recognition and Management of Pesticide Poisonings: 6th Edition” from the U.S. Environmental Protection Agency (epa.gov/pesticide-worker-safety/recognition-and-management-pesticide-poisonings)
- “VX: Nerve Agent” by the National Institute for Occupational Safety and Health (cdc.gov/niosh/ershdb/emergencyresponsecard_29750005.html)
Matt Smith is a University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Extension sustainable agriculture and food systems agent in Bushnell.
To request a hard copy of the article and test, or if you have questions regarding this article, test or CEUs, email Matt Smith at smith197@ufl.edu or call 352-569-6862. Please allow two weeks to process your CEU request.
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