A study published in The Lancet Planetary Health says smallholder farmers in Costa Rica and Uganda are experiencing widespread exposure to toxic pesticides, with chemical traces found in nearly every participant tested.
The research, led by a team of international scientists including Anouk Petitpierre and Samuel Fuhrimann, highlights a global health crisis where even those attempting to follow safety protocols are falling victim to chemical contamination.
“All pesticide biomarkers were detected in nearly all participants, confirming widespread exposure,” the authors wrote.
The study focused on 601 smallholder farmers located in two distinct tropical regions: Zarcero County in Costa Rica and the Wakiso District in Uganda. The group included a mix of “conventional” farmers, who rely on synthetic chemicals, and “organic” or “mixed” farmers, who aim to reduce or eliminate chemical use. By comparing these two groups across two different continents, researchers sought to understand how geography and farming philosophy impact human health.
Researchers collected urine samples on two separate occasions during the primary spraying seasons to measure “biomarkers”the chemical fingerprints left in the body after exposure. They specifically tracked six of the world’s most common agricultural chemicals, including the fungicide mancozeb, the herbicides 2,4-D and glyphosate, and various insecticides.
The exposure occurs through the daily handling, mixing, and spraying of crops. However, the study found that the methods of exposure are often counterintuitive. While pesticide application within the previous week caused massive spikes in chemical levels, the use of personal protective equipment (PPE) like gloves did not always help.
In a surprising find, the researchers noted that “unlike previous self-reported studies, we found no protective effect of PPE use, incorrect glove use was even associated with elevated biomarker levels.” This suggests that without proper training, safety gear can actually trap chemicals against the skin, worsening the dose.
The goal of the study was to identify specific habits or policies that can be changed to save lives. The team found that education is an important tool, noting that “lower biomarker concentrations were significantly associated with organic and mixed farming practices and with previous training on pesticide safety.”
The research findings point to significant gaps in international agricultural policy, suggesting that simply distributing equipment is insufficient. The researchers called for tailored interventions and systemic support to help farmers transition toward organic practices.
Photo from CABI