Several documents describe the risks of harmful effects of pesticides on the health of workers in the greenhouse environment. Frequent indoor pesticide use and the rapid return to regular activities in locations that have been treated increase these risks. To respond to concerns raised by workers at the City of Montréal's Botanical Gardens and Louis Dupire greenhouses, scientists from the Institut national de santé publique du Québec initiated this study on the potential risks of pesticide exposure in a closed environment. To document this question, researchers analyzed the evolution of the behaviour of dislodgeable foliar residues between the application of pesticides and the return to work, the risks of skin exposure, and finally, the results of biological monitoring of the total exposure of workers to pesticides. The information collected allowed a better documentation of the pesticide exposure levels of the workers involved, identified certain deficiencies in the technical organization of the work, and allowed corrective measures to be proposed for limiting the exposure of these workers to pesticides. Although the exposure levels measured in greenhouses seem to be relatively low, possibly due to the short direct-exposure times, the data relating to the persistence of the dislodgeable residues suggest a significant exposure in intensive production greenhouses.
