Pesticide exposure linked to 150% higher cancer risk – Study

A new study has found that exposure to pesticide-heavy environments may raise cancer risk by up to 150 per cent, even when the chemicals involved are individually considered safe.

According to ScienceDaily on Monday, citing the study, living in areas with high levels of mixed pesticide exposure could “raise cancer risk by up to 150%,” adding that such mixtures may “silently damage cells years before cancer appears.”

The study found a strong connection between environmental exposure to agricultural pesticides and an increased risk of cancer. It combined environmental monitoring, national cancer registry data and biological research by scientists from the French National Research Institute for Sustainable Development, Institut Pasteur, University of Toulouse, and the National Institute of Neoplastic Diseases in Peru.

The report noted that pesticides are commonly found in food, water and the surrounding environment, often as complex mixtures rather than single substances, making their health effects difficult to measure. It added that most previous research has focused on individual chemicals in controlled settings, which does not reflect how people are exposed in real-life conditions.

The study identified Peru as a unique setting for the research due to intensive agriculture, diverse climates and ecosystems, and social and geographic inequalities, noting that cancer is an increasing public health concern and pesticide exposure levels in some communities are particularly high.

It found that certain populations, especially Indigenous and rural farming communities, face higher exposure, with individuals in these groups exposed to around 12 different pesticides at elevated concentrations at the same time.

The researchers analysed 31 widely used pesticides and “modelled the dispersion of pesticides in the environment over a six-year period, from 2014 to 2019,” which allowed them to “create a high-resolution map and identify areas with the highest risk of exposure,” according to Jorge Honles, a PhD in epidemiology at the University of Toulouse.

The study compared the exposure data with health records from more than 150,000 cancer patients recorded between 2007 and 2020 and found that regions with higher environmental pesticide exposure also recorded higher rates of certain cancers. In those areas, the likelihood of developing cancer was about 150 per cent greater on average.

“This is the first time we have been able to link pesticide exposure, on a national scale, to biological changes suggesting an increased risk of cancer,” said Stéphane Bertani, a researcher in molecular biology at the French National Research Institute for Sustainable Development.

The study also found that pesticide exposure may affect the body long before cancer is diagnosed, noting that molecular research showed pesticides can interfere with processes that maintain normal cell function and identity, with such disruptions occurring early and accumulating over time without obvious symptoms.

The researchers said current approaches to chemical safety, which evaluate one substance at a time and define exposure limits considered safe, may overlook the risks posed by combined exposures under real-world conditions.

They added that environmental factors, including climate events such as El Niño, may influence how pesticides are used and how they move through the environment, calling for updated risk assessment and prevention strategies to reflect these complexities.

While the study focused on Peru, the researchers said the findings have broader global implications, particularly for vulnerable populations exposed to high levels of agricultural chemicals, and noted that further research would focus on the biological mechanisms involved and improved prevention tools.