Modelling human health risks from pesticide use in innovative legume-cereal intercropping systems in Mediterranean conditions

Background: The adoption of innovative cropping systems with low pesticide inputs would reduce environmental degradation and dependency on the use of plant protection products. Evaluating the pesticide risk to human health is a growing concern in the assessment of the sustainability of cropping practices. The assessment of human health risks linked to pesticide use in either conventional or innovative cropping systems is poorly documented in the literature. Objectives: This study focused on the assessment of pesticide exposure and human health risks from pesticide use in arable cropping systems (two monoculture and one intercropping system) associated with the use of various tillage practices (conventional tillage, reduced tillage, and no tillage). Methods: Human exposure (operators and residents) and health risks from pesticide use were assessed and compared between three conventional and six innovative cropping systems. We used the previously published BROWSE (Bystanders, Residents, Operators, and WorkerS Exposure) model based on data collected from interviews with the farmers and expert knowledge to compare the human health risk from pesticide use in the Setif area. Environmental conditions and the physical characteristics of the farmers were collected on three different farms from 2019 to 2021. Results: The modelling results demonstrate that human exposure to pesticides was systematically high under conservation tillage (no or reduced tillage) and monoculture cropping (pea and barley) conditions. It was also confirmed that operators experienced the highest cumulated exposure to pesticides (56 mg kg−1 bw day−1), followed by resident children seven days after pesticide application (0.66 mg kg−1 bw day−1). BROWSE simulations showed that dermal absorption was the most dominant route and represented more than 98% of the total amount of pesticides applied in all cropping × tillage system combinations. Regarding the overall results of the simulated human health risk, barley-pea intercropping was the most interesting system to reduce the risks for both operators and residents for all tillage practices. In addition, intercropping combined with conventional tillage was the most sustainable cropping system in terms of both agronomic performance (crop yield, Land Equivalent Ratio) and human health risk. Furthermore, the availability of advanced crop protection equipment was associated with a significant decrease in exposure and human health risk for both operators and residents. Conclusions: The prediction of human health risks using BROWSE could help farmers to make the decision to adopt conventional barley-pea intercropping as a good alternative to barley monocultures and pea monocultures under conservation tillage. © 2022 The Authors