New research has identified at least 485 chemicals used in US pesticide products that are linked to breast cancer. This finding, published in the peer-reviewed journal Environmental Health Perspectives, raises questions about the safety of food and other products.
The paper highlights what public health advocates describe as deficiencies in how US pesticides are regulated. The review includes active pesticide ingredients, as well as hundreds of “inert” or inactive ingredients that typically do not undergo a thorough safety review.
According to the research, the Environmental Protection Agency (EPA) considers each pesticide ingredient’s individual health risks but not the entire pesticide formula or exposure to multiple pesticides. These chemicals are found in pesticides used on crops, lice treatments, home lawn fertilisers, and flea and tick treatments.
Jenny Kay, a report co-author with the Silent Spring Institute non-profit, stated, “Adding these exposures up gets pretty consequential and concerning.” She added, “We wanted to bring more attention to the pesticides in different products.”
The American Cancer Society reports that breast cancer incidence rates have increased by 1% per year in the US, with a slightly faster rise in women younger than 50 (1.4%). Federal health data indicates that 84 of these breast cancer-linked chemicals are present in the general population, though scientists suggest this is an undercount.
The Silent Spring Institute's broader effort has also identified about 500 breast cancer-linked chemicals in common consumer goods and 462 in drinking water. Only about 145 of the identified pesticide chemicals were registered with the EPA as active ingredients.
Kay noted that inactive ingredients are often added to make pesticides more toxic to living organisms, stating, “They are not biologically inert, they are just called inert because they do not target the pest.” She added that the body does not distinguish between inert and active ingredients, and inactive substances pose a danger to human health, calling it “a regulatory blind spot.”