Plant protection practices and pesticide exposure levels of Northern Benin cotton producers

In Benin, terrestrial ecosystems are polluted by a widespread presence of pesticide residues released by an intensive use of plant protection products in agriculture, mainly those sprayed on cotton crops. In order to assess the exposure of producers to pesticides and predict the potential impact on human health, field observation of local practices coupled with semi-structured surveys were conducted among 150 cotton growers in Gogounou, Kandi and Banikoara in Northern Benin, the main cotton production area of the country. Seventy-five percent of producers never received an education nor instructions of use, while only 5% have been trained in the safe use of pesticides on cotton crops. Among pesticides used by farmers, only 19% belong to the approved list of plant protection products in Benin. The most frequently used active substances are insecticides such as acetamiprid, lambda-cyhalothrin, chlorpyrifos-ethyl, emamectin benzoate, profenofos or cypermethrin. All are known to be more or less toxic and may have detrimental effects on health after exposure. Seventy-five percent of producers use higher amounts of insecticides than recommended on the labels and 80% do not wear personal protective equipment during mixing, loading and spraying. Empty pesticide containers are often left in cotton fields (73% of observations) or sometimes used for domestic purposes (25% of observations). Field observations were translated into reliable scenarios to estimate the exposure levels of producers, using the UK-POEM predictive model. Total exposures without personal protective equipment vary from 0.099 to 0.546 mg/kg body weight/day. Exposure values far exceed the Acceptable Operator Exposure Levels, indicating a potential risk.