Definition and validation of exposure and risk profiles for pesticide risk prevention in agricolture

Due to the variability of the meteorological conditions, different application modalities, and intermittent use of several plant protection products, often composed by more than a single active ingredient, measuring the levels of exposure to pesticides in agriculture is a very complicated task, and measures are only very seldom performed. Fort this reason, we have realized, in the frame of a project addressed at Occupational Health and Safety in Agriculture in the Region of Lombardy, a simple model for the estimation of pesticide exposure and related health risk (“Pesticide Exposure and Risk Profile”). The general algorithm of the model is: Risk = [(MIX %t + APP %t + REPAIR %t + RE-ENTRY %t) x FREQ x PPE x Skills X M. Conditions] x Toxicity (MIX = mixing and loading, APP = application; REPAIR = maintenance; FREQ = frequency; PPE = Personal protective equipment; Skills= operator skills; M. conditions: machinery conditions). This study has been carried out with the aim of validating the model, through the definition of the levels of concordance between the risk estimates produced by the profile and the levels of exposure measured in typical agricultural activities. To this aim, a group of six greenhouse workers, engaged in mixing and loading (2), application (2), re-entry (2), has been selected, exposed to chlorpiryfos-methyl. Exposure was assessed through determination of environmental and biological parameters, that is, respectively, chlorpiryfos-methyl in the air and in the workers skin, and 3,5,6-trichloro-2-pyridinol collected in 24-hr urine samples. The study pointed out, for each of the jobs taken into account, exposure levels largely below those able to bring about an health risk. These finding were in total agreement with the model estimates. Despite some limits (small number of subjects considered; only very low exposure levels detected) the study suggest that exposure and risk profile are promising tools for pesticide risk prevention in agriculture