Risk assessment of pesticide spray drift damage in Belgium

A risk assessment of pesticide spray drift damage for the major crops in Flanders, Belgium, was set up. The assessment was done according to the principles of Directive 91/414/EC. In the directive, 10 modules reflect the risk for persons arising from occupational, non-dietary exposure and the risk to the environment. For each module the risk is expressed as a risk index, which is the quotient of the estimated human exposure or predicted environmental concentration to a toxicological reference. The Ganzelmeier curves and the IMAG drift calculator were used to predict drift values. Knowing the applied dose of pesticide and the percentage of drift, the predicted environmental concentrations and the human exposures were calculated. The corresponding risks were estimated for the major growths for three of the ten modules: aquatic organisms, human bystanders and earthworms. Coherent with these calculations, the reducing effects of buffer zones were considered. The assessed buffer zone lengths were compared to the buffer zones, legislated by the Belgian government.