During the 20th century, the green revolution transformed agriculture, ushering in new technologies that dramatically boosted food production. Among these advancements, pesticides became a staple in modern farming. While they helped create a surplus of food, there are concerns that pesticides have corroded the environment, contaminating the food supply, and harming the neurological health of the very farmers who rely on them. 

A recent article revealed a troubling link between pesticide exposure and depression among Brazilian farmers. Those who worked primarily with glyphosate reported significantly higher rates of depressive symptoms compared to those with less exposure. This study also adds to the growing body of evidence linking pesticide use to a range of health issues, including Parkinson’s disease, birth defects, Alzheimer’s, congenital malformation, cancer, and depression. 

A team of researchers examined the gut-brain connection in relation to pesticide exposure. They proposed that the correlation between pesticide use and mental health disorders could be explained by the disruption of gut health. Conditions like irritable bowel syndrome, for instance, are often associated with higher levels of depression and anxiety, demonstrating the bidirectional communication between the digestive system and the brain.  

The relationship is mediated by the enteric nervous system (ENS), often referred to as ‘the second brain’ which regulates the gastrointestinal tract and relays information to the brain through the vagus nerve. While essential for maintaining both psychological and physiological well-being, this system is vulnerable. Many pesticides are capable of invading and disrupting this equilibrium. 

Even more concerning is the impact on maternal gut health. Chemicals like glyphosate are known to cross the placenta, potentially dysregulating fetal brain development, an effect that may help explain the observed correlation between maternal pesticide exposure and birth defects. Pesticides can also infiltrate the developing brain through breast milk, compounding early-life exposure during critical stages of growth. 

Tristan Bekinschtein, a researcher specializing in neuroscience and neurophysiology, prefaced that children are not the only ones at risk for developing mental health conditions due to pesticide exposure. Adults with chronic exposure have also reported motor dysfunction, mood disorders and depressive symptoms. 

Bekinschtein explains how exposure to pesticides not only harms the processes involved in the development of the brain, such as neurogenesis, but may also disrupt hormone balance, leading to irregularities in brain functioning. Additionally, prolonged exposure can trigger neuroinflammation and chronic stress, contributing to brain degeneration and hindering the brain’s ability to regulate itself.

While many of these observations were found on workers directly exposed to pesticides, nearby residents are not exempt from risk. In rural Chilean communities, individuals living close to pesticide-treated farms reported higher levels of depressive symptoms. Exposure often occurs through the inhalation of airborne chemicals carried by wind during spraying, as well as through contamination of soil and water.

Consumers also face potential dangers. A twin study found that those who consume conventionally grown vegetables, often sold in grocery stores, lead to higher levels of pesticide exposure. Despite growing public concerns, pesticide use is still on the rise. In 2024 alone, Canadians purchased 130 million kilograms of pesticides. Glyphosate usage has surged by 47% over the past decade. In fact, an estimated 70% of Canadians have detectable levels of glyphosate in their system. 

The long-term effects of exposure through contaminated food remain under investigation but ongoing research is increasingly challenged by industry lobbying, with many millions being spent on lobbying efforts by pesticide manufacturers in the U.S. and around the world.  

Alongside the neurological factors, Bekinschtein notes that social factors like education seem to also amplify the risks of pesticide exposure. Workers with lower levels of education tend to be more susceptible to harm, likely due to limited awareness about the dangers they face. 

Even when they are aware, economic hardship and a lack of alternatives force them to continue working under dangerous conditions. Inadequate access to protective gear and safety measures further increase exposure. These risks are often compounded by broader economic and political conditions, which limit resources and enforcement in affected communities. 

Some of the largest buyers of harmful pesticides are developing countries such as Costa Rica, Myanmar, Thailand, Malaysia, Philippines and Brazil. These nations often lack regulations, policies and enforcement that protect workers and citizens. They are also especially vulnerable to lobbying.

In 2024, Mexico attempted to ban glyphosate and genetically modified corn due to concerns about safety, but relentless pressure by industry and the U.S. government delayed the ban, buying more time for pesticide manufacturers to tighten their grip on global agriculture.

Permitting corporate interests to endanger the health of farmers is not only a policy failure, it is a profound ethical one. Compromising the mental and physical health of farmers keeps these groups marginalized and challenges their ability to live healthy lives. 

-Adrian Parham, Contributing Writer

Image Credits: 

Feature Image: Photo by Heather Gill on Unsplash; Creative Commons

Body Image 1:Photo by Chris Ensminger on Unsplash; Creative Commons

Body Image 2:Photo by Jan Kopřiva on Unsplash; Creative Commons