Study finds pesticide residues in breast cancer tissues, raising concerns about exposure risks

Raising concerns about the long-term impact of agricultural chemicals on human health, a recent study by scientists in Bengaluru has found pesticide residues in breast cancer tissues.

The findings point to a possible link between environmental exposures and cancer risk, while highlighting gaps in awareness and safety practices at the local level. However, the study also says it is unlikely to be the sole cause of breast cancer.

The finding comes from a study conducted by researchers at Healthcare Global Enterprises (HCG), Bengaluru and published in the Journal of Clinical Oncology. The study examined breast cancer tissue samples and found traces of several pesticides commonly used in Indian agriculture, prompting calls for stricter monitoring, farmer education and stricter regulation of pesticide use.

30 tissue samples

The research team analyzed 30 breast cancer tissue samples using high-resolution mass spectrometry and detected 49 different pesticide residues. The study found that pesticide concentrations were generally higher in the fatty tissue surrounding the tumors than in the tumors themselves.

According to the researchers, this pattern is consistent with the nature of many pesticides, especially organophosphorus compounds, which tend to accumulate in fatty tissues. These chemicals are also known to act as hormone disruptors and can contribute to chronic inflammation, both of which have been linked to the development of cancer.

Lifestyle and environmental factors

Krithikaa Sekar, consultant radiation oncologist at HCG and lead author of the study, said breast cancer is increasingly linked to a combination of hormonal, lifestyle and environmental factors.

“Obesity is one of the main causes of hormonal imbalance because fat cells produce excess estrogen. This is one of the reasons why breast cancer is the most common cancer among women in many Western countries. India is also starting to see similar trends as sedentary lifestyles and higher body mass index are becoming more common,” she told The Hindu.

Dr. Sekar said the study points to pesticide exposure as a potentially important but less discussed risk factor.

“Some pesticides, especially organophosphorus compounds, can mimic hormones. Many also act as irritants and tend to accumulate in fatty tissues. Repeated exposure to such chemicals can contribute to cancer. Because the breast contains a significant amount of fatty tissue, these compounds have a greater tendency to accumulate there,” she said.

Traces of 47 pesticides

In the study, researchers examined the fatty tissue surrounding breast tumors for nearly 100 pesticides commonly used in India and detected traces of 47 of them.

“Carcinogenic potential is already recognized for three of them. The remaining 44 have not been sufficiently investigated for their cancer-causing effects. Their long-term impact on health remains largely unknown,” said Dr. Cleaver.

Pesticide use practices

To understand potential sources of exposure, the team also interviewed 50 farmers about pesticide use practices. The interactions revealed limited awareness of the health risks associated with pesticide exposure.

“Many farmers told us that pesticide use decisions are often driven by local practice or trader advice rather than scientific advice. Excessive amounts are often used and crops are sometimes harvested before the recommended waiting period to allow pesticide residues to break down,” she said.

The fuse is missing

The researchers noted a stark contrast between produce grown for export and produce for domestic consumption.

“For export-oriented agriculture, soil tests, regulated pesticide application, mandatory waiting periods and residue testing are routine. Such guarantees are often absent for products intended for local markets,” said Dr. Cleaver.

She also pointed out that some pesticides still allowed in India have been banned in several other countries, while the permissible residue limits abroad are often much lower.

“Consumers have a right to know the levels of pesticide residues in the food they consume. More systematic residue monitoring and stronger enforcement of safety standards could make a significant difference,” she said.

Multifactorial disease

Dr. Sekar emphasizes that breast cancer is a multifactorial disease influenced by genetic, hormonal and lifestyle factors, but said the findings suggest that environmental exposure to pesticides may be a significant contributor.

“Our study shows that pesticide residues can accumulate in the fat surrounding breast tumors. They are unlikely to be the sole cause, but unregulated pesticide exposure may be a significant contributing factor in addition to the other identified risks,” she added.

Published – 18 Jun 2026 23:40 IST