Skin cancer has increased significantly over the past 50 years and now a new study is raising suspicion that weed killers may play a factor.

(Beyond Pesticides) Herbicide use is associated with an increased risk of developing cutaneous melanoma, a skin cancer, according to a meta-analysis published last month in the Journal of the European Academy of Dermatology and Venereology. For those working on farms and in other occupations with frequent exposure to herbicides, the risk is another in a long list of pesticide-induced diseases. Ultimately, researchers suggest, “A precautionary public health safety policy that includes preventive individual counselling and surveillance to workers exposed to pesticides may be advisable.”

Authors of the study conducted a systematic review of the peer-reviewed literature on pesticide exposure and skin cancer, finding nine acceptable studies for analysis. These studies represent nearly 185,000 individuals, and included enough data to make a risk estimate and determine 95% confidence intervals. Although pesticides and insecticides in general were not associated with increased risk of skin cancer, general use of herbicides was (relative risk 1.85; 95% confidence interval, 1.01-3.36). Spouses whose partners work as pesticide applicators are also found to be at higher risk of developing cutaneous melanoma.

As skin cancer has increased significantly over the past 50 years, many appropriately point to the link between sun exposure and development of the disease. However, this research indicates that contact exposure to herbicides may be affecting risk. The authors point to studies finding links between skin adsorption of pesticides and exposure to UV radiation, as well as research that finds sunscreen itself may facilitate skin adsorption of pesticide residue.

A precautionary approach to this data would include a response from regulatory agencies that limits herbicide exposure to high risk populations like farmworkers and their families, or in the least increase monitoring of these individuals for skin cancer development. However, as recently as this month, the Trump Administration’s Environmental Protection Agency (EPA) has moved to roll back protections for farmworkers health. EPA is significantly shrinking Application Exclusion Zones (AEZs), buffer areas where individuals are not supposed to enter during a pesticide application.

Under the agency’s new rules, on-farm family members would be exempt from all aspects of the AEZ. EPA says this will allow farmers and their family “to decide whether to stay in their homes or …on their property during certain pesticide applications, rather than compelling them to leave even when they feel safe remaining.”

Critics argue that it is the role of health and environmental regulatory agencies to promote precautionary actions among at risk individuals. In this sense, asking individuals without medical training or expertise to determine whether exposure to a toxic chemical is safe for them is a dereliction of EPA’s duty to protect public health.

Herbicide exposure is linked to a long list of health effects, which are documented in Beyond Pesticides Pesticide- Induced Diseases Database. The peer-reviewed research cited in the database reveals elevated rates of chronic diseases among individuals exposed to pesticides, with increasing numbers of studies associated with both specific illnesses and a range of illnesses. Some of these diseases are at very high and, perhaps, epidemic proportions, indicating an urgent need for public policy at all levels–local, state, and national—to end dependency on toxic pesticides and replace their use with sustainable, organic practices.

All unattributed positions and opinions in this piece are those of Beyond Pesticides.