Since May 2018, ANSES has been responsible for conducting scientific expert appraisals prior to the creation or amendment of occupational disease lists or the issuing of recommendations to the regional committees for the recognition of occupational diseases (CRRMPs). As part of this new mission, the Agency received a first request for an expert appraisal on pesticides and prostate cancer with a focus on chlordecone. The pesticides covered by the expert appraisal include plant protection products, biocides and external antiparasitics for veterinary and human use.
In France, prostate cancer is the most common cancer affecting men, mainly from the age of 50 onwards. It is a multifactorial disease, with the main risk factors known so far being age, family history and ethnicity. Other factors – especially environmental ones – are also suspected, including exposure to pesticides in particular.
Excess risk of prostate cancer in workers exposed to pesticides
The expert appraisal examined the causal relationship between pesticide exposure and the occurrence of prostate cancer. To do this, the Agency based its work on the INSERM collective expert appraisal of 2013 and its update of 2019, as well as on the latest scientific publications, particularly in epidemiology and toxicology. Several studies show an excess risk in workers exposed to pesticides and that pesticides play a role in prostate carcinogenesis. Although some mainly methodological limitations were identified, partly related to the difficulty of measuring pesticide exposure, they do not call into question the findings of these studies. On the basis of this analysis, ANSES's expert appraisal concluded that there was a probable link between pesticide exposure and the occurrence of prostate cancer.
A wide variety of occupational exposures, not only in the agricultural sector
The experts carried out a review of exposure to pesticides in the agricultural and non-agricultural sectors in metropolitan France and the overseas territories, with a specific focus on chlordecone in the overseas territories. This identified a large number of sectors, occupations and jobs such as agricultural activities involving all crops and types of animal husbandry; the pest control, wood protection, gardening and landscaping sectors; and occupations related to animal care, road maintenance, the waste industry, water treatment, etc. In general, workers are exposed to numerous different pesticides at the same time as well as throughout their working lives. However, little is known about the impact of this multiple exposure. Moreover, some workers who are indirectly exposed to pesticides are as much or even more at risk than those who actually handle them. Indeed, besides pesticide manufacture or use, workers may come into contact with articles, surfaces or animals treated with these products. It is therefore necessary to take into account situations of both direct and indirect exposure to pesticides.
Prostate cancer, an under-recognised occupational disease
Regarding occupational exposure to pesticides, there are lists for Parkinson's disease and haematological malignancies in the agricultural regime. For prostate cancer associated with pesticides, the number of applications for recognition is particularly low (only 12 between 2011 and 2018), and there is currently no list for this disease. To obtain recognition of their illness, individuals are obliged to turn to the complementary system (via the CRRMPs). However, under this system, the presumption of occupational origin of a disease does not apply, unlike the system of recognition by lists. The individual must then prove that there is a direct and/or essential link between their illness and the usual exercise of their work.
Recommendations for the creation of an occupational disease list
On completion of its expert appraisal, ANSES underlined the fact that all the scientific evidence developed provides grounds for the creation of an occupational disease list for prostate cancer associated with pesticides, in the agricultural and general social security schemes. This expert appraisal enabled the occupational disease committees to take account of other considerations – particularly socio-economic ones – when discussing whether or not to create an occupational disease list and the conditions for recognition for the general and agricultural schemes. It is then ultimately up to the State to make a decision on the basis of the committees' opinions.
The particular case of chlordecone in the French Caribbean
Chlordecone is a substance that was used in the French Caribbean as an insecticide in banana plantations until it was prohibited in 1993. It is the focus of public attention because of its health effects, particularly for banana workers, as well as its environmental impact. Following a request from the government, the latest assessment of the national chlordecone plan recommended finalising "procedures for the inclusion of prostate cancer in the list of occupational diseases". In this context, a particular focus on chlordecone in the overseas territories was included in the ANSES expert appraisal on prostate cancer associated with pesticides. It concluded that there was a probable causal relationship between chlordecone and the risk of prostate cancer. This conclusion was mainly based on the findings of the Karuprostate study, and on toxicological and mechanistic data demonstrating a plausible role for chlordecone in the process of prostate carcinogenesis.