3.4 Pesticide Poisoning Symptoms, First Aid & Emergency Response

3.4 Pesticide Poisoning Symptoms, First Aid & Emergency Response

Prompt identification of pesticide poisoning symptoms and immediate execution of first aid protocols can mean the difference between rapid recovery and permanent injury or fatality. Applicators must understand clinical signs across chemical classes, master exposure-specific first aid, and know how to coordinate emergency medical care.

Signs vs. Symptoms of Poisoning

• Symptoms: Subjective evidence of illness reported by the victim (e.g., nausea, headache, dizziness, abdominal cramps, blurred vision).
• Signs: Objective evidence of poisoning observed by bystanders or medical personnel (e.g., vomiting, muscle tremors, pinpoint pupils, drooling, cyanosis).

---

Chemical Class Specific Poisoning Symptoms

Different pesticide classes attack human biological systems through specific mechanisms of action:

1. Organophosphates & Carbamates (Cholinesterase Inhibitors)

Organophosphates (e.g., malathion, chlorpyrifos) and carbamates (e.g., carbaryl, methomyl) inhibit the essential enzyme acetylcholinesterase (AChE). This inhibition causes an overaccumulation of the neurotransmitter acetylcholine at nerve synapses, leading to continuous nerve firing.

• Classic SLUDGE Symptoms:
  • Salivation (excessive drooling)
  • Lacrimation (excessive tearing of eyes)
  • Urination (involuntary loss of bladder control)
  • Defecation (involuntary bowel movement)
  • Gastrointestinal distress (severe abdominal cramps, nausea)
  • Emesis (vomiting)
• Key Clinical Sign: Pinpoint Pupils (Miosis). The pupils constrict to tiny dots and do not respond to light.
• Severe Stage: Muscle fasciculations (twitching), bronchial pulmonary fluid buildup, convulsions, loss of consciousness, and respiratory failure.
• Medical Antidotes: Atropine sulfate (blocks acetylcholine receptors) and 2-PAM / pralidoxime (reactivates the cholinesterase enzyme in organophosphate poisoning; it is not used for carbamates).
• Cholinesterase Monitoring: Applicators who handle organophosphates or carbamates regularly should ask a physician about cholinesterase monitoring. A baseline blood test is taken during a period of no exposure, and periodic tests during the use season are compared against that baseline. A meaningful drop from baseline is a warning to remove the applicator from exposure before symptoms appear — but the test is only interpretable if the baseline was established first.

2. Synthetic Pyrethroids (e.g., Permethrin, Bifenthrin)

Synthetic pyrethroids disrupt nerve sodium channels. They possess low systemic mammalian toxicity but cause localized skin sensations known as paresthesia (tingling, stinging, numbness, or burning sensations on cheekbones and forearms), skin rash, sneezing, and eye irritation.

3. Bipyridyliums (e.g., Paraquat, Diquat)

Paraquat is an extremely dangerous, restricted-use herbicide. Ingestion of even a single teaspoonful causes severe mucosal lining burns, acute kidney failure, and progressive delayed pulmonary fibrosis (scarring of lung tissue), leading to fatal asphyxiation within days.

4. Chlorinated Hydrocarbons (Organochlorines)

Chlorinated hydrocarbons stimulate the central nervous system, causing restlessness, dizziness, muscle tremors, hyperexcitability, and generalized seizures.

5. Fumigants (e.g., Aluminum Phosphide, Methyl Bromide)

Fumigants cause severe pulmonary edema (liquid filling the lungs), shortness of breath, chemical pneumonia, brain edema, confusion, and sudden cardiac arrest.

---

Exposure-Specific First Aid Procedures

Speed is critical when administering first aid. Treat the victim immediately while calling for medical assistance.

Dermal Exposure Protocol (Skin Contact)

1. Act Immediately: Remove contaminated clothing and footwear right away.
2. Flush Skin: Drench skin with large volumes of clean water. Wash gently with mild soap and water for at least 15 minutes.
3. Do NOT Scrub: Avoid harsh scrubbing with stiff brushes, which creates microscopic skin scratches that accelerate dermal penetration.
4. Cover Gently: Dry skin with a clean towel and cover loosely with clean cloth.

Ocular Exposure Protocol (Eye Contact)

1. Flush Open Eyes: Hold eyelids open gently with fingers and flush eyes continuously with clean running water or an eyewash station for 15 to 20 minutes.
2. No Chemicals: NEVER add neutralizing chemicals, vinegar, or eye drops to the flushing water, as chemical reactions cause severe secondary corneal burns.
3. Medical Evaluation: Seek immediate ophthalmological examination.

Inhalation Exposure Protocol (Breathing Vapors/Mists)

1. Rescuer Protection: Ensure the rescuer puts on an appropriate respirator before entering an unventilated area to retrieve a victim.
2. Move to Fresh Air: Carry or lead the victim into clean outdoor air immediately.
3. Loosen Clothing: Unbutton tight collars, belts, and waistbands.
4. Artificial Respiration: If breathing has stopped, begin CPR immediately. Use a pocket mask with a one-way valve to prevent the rescuer from inhaling toxic pesticide vapors from the victim's lungs.

Oral Ingestion Protocol (Swallowing)

1. Read Label Statements: Check the pesticide label or Safety Data Sheet (SDS) immediately for specific first aid directions.
2. Vomiting Rules:
   • DO NOT induce vomiting if: The product contains petroleum distillates (hydrocarbons), as aspiration of solvent vapors into lungs causes fatal chemical pneumonia.
   • DO NOT induce vomiting if: The product is a corrosive acid or alkali, as vomiting causes a second severe burn to the esophagus and mouth.
   • DO NOT induce vomiting if: The victim is unconscious or convulsing.
3. Positioning: If vomiting occurs naturally, lean the victim forward or place them on their left side (recovery position) to prevent vomit from entering the lungs.

---

Differential Diagnosis: Heat Exhaustion vs. Organophosphate Poisoning

Working outdoors in full PPE during hot summer months creates significant risk for heat-related illnesses. Applicators must accurately distinguish heat stress from pesticide poisoning:

---

Heat Stress: The Hazard PPE Creates

Chemical-resistant PPE is designed not to breathe, which is exactly what makes it dangerous on a hot day. Heat illness is one of the most common injuries in this trade and is frequently mistaken for pesticide poisoning.

Prevention

• Adjust the schedule. Work in the early morning or evening during heat waves; take the heaviest work when it is coolest.
• Drink before you are thirsty. Thirst lags dehydration. Water in small, frequent amounts beats large volumes taken occasionally; avoid alcohol and limit caffeine.
• Build in rest and shade. Scheduled breaks in shade or air conditioning, with PPE opened or removed in a clean area, let the body shed accumulated heat.
• Acclimatize. It takes roughly one to two weeks of graduated exposure to adapt to working in heat. New employees and anyone returning from time off are at the highest risk.
• Use cooling measures. Cooling vests, wetting the outside of a suit where the label allows, and choosing the lightest PPE the label permits all help. Never substitute lighter PPE than the label requires.
• Watch each other. Confusion and poor judgment are early signs, and the affected person is the least likely to notice them.

Recognizing the Progression

---

Emergency Response & Call Protocols

• Poison Control Center Hotline: Call 1-800-222-1222 anywhere in the United States to connect directly with medical toxicologists.
• 911 Medical Emergencies: Call 911 immediately if a victim is unconscious, experiencing seizures, or suffering respiratory arrest.
• Providing Info to Physicians: Supply emergency personnel with the exact Product Name, EPA Registration Number, Active Ingredient Name, and the Safety Data Sheet (SDS). Never transport unrinsed pesticide containers inside the passenger cabin of an emergency transport vehicle.