Operator safety and plant deposits when using pesticides in greenhouses

Operator exposure and plant deposits have been measured while spraying in greenhouses using handheld spraying equipment. Suction samplers and static samplers (rods and pads) were used. Rubidium Chloride (RbCl) was added to the spray as a tracer. Spray application was carried out with a knapsack sprayer (CP-20), a knapsack mist blower (Solo Master), a high pressure spray gun (Wanjet 200 spray gun with four nozzles), and a hot aerosol fogger (Igeba TF-30). Average dermal exposure was over ten times higher than respiratory exposure. Both dermal and respiratory exposure were reduced when the operator walked backwards away from the spray. When using a knapsack mist blower, the dermal exposure of the operator working forwards was 20 times higher than when he worked backwards. Respiratory exposure was also greater. Working forwards using a knapsack sprayer gave a dermal exposure almost four times greater than when working backwards. A high pressure spray gun used while working backwards gave the lowest dermal exposure. A hot aerosol fogger also gave a low dermal exposure, but the respiratory exposure was very high. Pesticide deposit on the operators face and hands after 8 h spraying was in the worst case more than 2500 times greater than the plant deposit. When applying the same dose, a hot aerosol fogger and knapsack mistblower gave lower plant deposits than a high pressure spray gun and knapsack sprayer. (C) 1996 Silsoe Research Institute