Roundup Overdose – A Focus on Glyphosate

• Lawn care and gardening each year use distributes one hundred million pounds of pesticides each year onto the grass and soil. The U.S. Centers for Disease Control and Prevention (CDC), found in a study of 9,282 people nationwide, that 100% of the individuals had pesticides in both their blood and urine. 
• The Environmental Protection Agency (EPA) has reviewed and reassessed its safety and continues to assure that no human health risks or concerns exist. But what are the potential outcomes of glyphosate when used for self-harm? 
• Let’s examine a case study on glyphosate poisoning it’s seriousness when used for self-harm. 

Glyphosate Poisoning

Pesticides and herbicides have been a mainstay of U.S. lawn care since for over 90 years, becoming widespread after World War II when farmers depended on synthetic pesticides to control insects in their crops.  

Roundup® is one of the most recognizable retail products containing glyphosate in both agricultural and non-agricultural settings. 

Lawn care and gardening each year use distributes one hundred million pounds of pesticides each year onto the grass and soil. The U.S. Centers for Disease Control and Prevention (CDC), found in a study of 9,282 people nationwide, that 100% of the individuals had pesticides in both their blood and urine.  

In developing countries, agricultural pesticides cause more deaths than infectious diseases and are one of the most common substances used for self-poisoning.  

Today, glyphosate (a general-purpose and nonselective organophosphorus compound) is the most common broad-spectrum, non-selective herbicide in the world that controls broadleaf weeds and grasses.  

Since 1974, glyphosate, when used per labeling, has been a registered pesticide. The Environmental Protection Agency (EPA) has reviewed and reassessed its safety and continues to assure that no human health risks or concerns exist. But what are the potential outcomes of glyphosate poisoning when used for self-harm?  

Pervasive and Insidious

Acute pesticide poisoning is a significant global public health issue and contributes to a substantial number of emergency department visits. In low and middle income countries, acute pesticide self-poisoning hospitalizes over 2 million people every year and kills around 200,000.

There are two primary reasons that support these numbers: the accessibility of toxic pesticides in the rural homes of farming communities and the extensive use of pesticides that expose the community to both long-term and acute occupational health problems.  

The fundamental components of Roundup® are the active ingredient, salts of glyphosate, and a surfactant structure (polyethoxylated alkyl amine) and water as the inert ingredients to help plant uptake. If consumed in significant quantities, the surfactant molecules in Roundup® disrupt the underlying structure and function of cell membranes, leading to irritation of the skin, mucous membranes of the respiratory and GI tract.

With direct eye exposure, irritation, conjunctivitis, corneal injury can occur. Rapid decontamination via eye washing can mitigate significant eye injuries. Dermal exposure can cause dermatitis and mucosal dose, irritation. Accidental exposures to glyphosate formulations often result in mild, transient, gastrointestinal effects.

Case Study on Glyphosate Poisoning

A 25-year-old female patient (62kg) arrives at your emergency department after an intentional ingestion of one cup (250ml) of glyphosate (herbicide). The family observed the overdose, contacted emergency medical services (EMS), and paramedics transported the patient to the hospital. Having arrived at the emergency within +/- 20 minutes of consumption, the patient received gastric lavage and activated charcoal.  

Physical exam notes the patient as alert and oriented. The patients’ vital signs: afebrile, pulse rate 125, blood pressure (BP): 88/58 mm Hg, SpO2-97% on room air and Glasgow coma scale of fifteen. The nurse administered intravenous fluids and antiemetics per physician orders. 

The emergency room physician noted during the exam that her cardiovascular, respiratory, and gastrointestinal systems were within normal limits. After the lavage, the patient experienced multiple episodes of continued vomiting. Sixty-five minutes after the patient’s emergency room arrival, she became hypoxic, leading to respiratory failure and intubation. Resuscitation efforts required vasopressor support for hypotension.  

The patient’s arterial blood gas (ABG) showed severe metabolic acidosis and elevated lactate level. The treatment team transferred to the intensive care unit (ICU) where she developed hypokalemia, hypernatremia, and aspiration pneumonia. 

After a two-week hospital stay, physicians discharged the patient from the hospital. Prior to discharge, there was no evidence of renal or hepatic damage.  

Glyphosate Poisoning Decontamination

With any chemical exposure, decontamination is key to make sure the staff is safe and remove the potential irritant from the patient.  

After removal of contaminated clothing, hand and skin washing with soap and water will remove up to 94% of the polluting dermal dose of glyphosate.   

Toxicology and Pathology of Glyphosate Poisioning

The surfactant polyoxyethylene amine (POEA) facilitates the toxicity of glyphosate, and its capacity to erode the mucous membranes and linings of the pulmonary and gastrointestinal tract.  

The clinical manifestations of herbicide poisoning vary from gastrointestinal disturbances, oral ulcerations, esophagitis, lactic acidosis, gastrointestinal hemorrhage, renal failure, hypotension, pulmonary edema, acute respiratory distress syndrome (ARDS), arrhythmias, cardiac arrest, and death. Glyphosate has no current antidote and treatment is reliant on aggressive supportive therapy.  

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