Chronic occupational and household pesticide exposure is linked to a more aggressive breast cancer with higher rates of recurrence metastasis and chemoresistance
Brazil is the country with the third highest use of agricultural pesticides in the world. Many of the people spraying the pesticides are rural women (writes Oxford University Biochemist, Chris Woollams).
In a new peer reviewed study (1) which compared women who used pesticides against those who did not, users had higher levels of more aggressive breast cancer. This was found whether the use was occupational or household.
Exposed patients had a prevalence of the aggressive subtype Luminal B (32.83%), while unexposed patients had a prevalence of the less aggressive molecular subtype Luminal A (37.78%).
Exposed patients also had higher disease recurrence (10.19%) and chemoresistance (21.26%), than unexposed patients.
And Breast cancer patients exposed to pesticides were also more likely to have distant metastases (1.4 times) and lymph node invasion (1.3 times) compared to patients not exposed.
Pesticides harm the world
For the record, pesticides are linked to increased climate change in a vicious circle, but Governments aren’t imposing extra fines and 15 minute lockdowns on the company owners. Apparently pesticide production, not just use, causes significant greenhouse gas emissions, and changing weather and temperature patterns increase pest pressures, driving up pesticide use. Pesticide use also reduces soil biodiversity.
Organic pollutants and pesticides have also been found in Antarctica's snow, ice and ecosystems. As most people with a rudimentary knowledge of science would know, dissolved chemicals can cause the melting and loss of ice caps and the loss of animal and fish life.
And all along you thought that the problem was carbon emissions!
The top four pesticide companies are - Syngenta, Bayer, BASF, and Corteva. Some companies, such as Bayer, also make cancer drugs.
Cause it, cure it.
Reference
1. Hidden risks associated with occupational pesticide exposure in women with breast cancer: High frequency of the Luminal B molecular subtype and occurrence of poor prognostic features; Isabella C. Cazagranda et al, PLOS one, February 5, 2026