Operator dermal exposure to pesticides in tomato and strawberry greenhouses from hand-held sprayers

Abstract

Protection of greenhouse crops in southern Italy usually requires 15-20 phytosanitary treatments per year, with volume rates in the range of 1000-2000 L ha-1, depending on the plant growth stage. The most widespread sprayers are hand-held, high-pressure devices, which may expose operators to high levels of pesticides. This paper, also with the aim to lead toward a more sustainable use of greenhouses in agricultural productions, including some aspects of workers' safety, reports the results of experimental tests aimed at measuring the amount of the mixture deposited on the worker's body (potential dermal exposure, PDE) during pesticide applications to tomato and strawberry plants in a protected environment. Experimental tests on tomatoes were carried out taking into account two plant growth stages (flowering and senescence), two types of spray lance, two working pressures (1 and 2 MPa), and two walking directions (forwards and backwards). Those on the strawberries were carried out at the maturity of the fruit growth stage, comparing two hand-held sprayers (a standard spray gun and a short hand-held spray boom equipped with two nozzles) and working according to the common practice: forwards movement of the operator and high pressure (2 MPa). The results showed that with the tomato plants, the most important factor in reducing the deposit on the operator was the walking direction: on average, the PDE was 718 mL per 1000 L of the sprayed mixture (0.72h) while walking forwards and 133 mL (0.13h) while walking backwards. The reduction factor ranged from 3.0 at the flowering growth stage to 7.2 at the senescence growth stage. With respect to the strawberry plants, the PDE was significantly higher when the operator used the short hand-held spray boom (887 mL per 1000 L of the sprayed mixture, equivalent to 0.89h), rather than the spray gun (344 mL, 0.34h). In both cases, the most exposed body parts were the lower limbs, which accounted for 89-94% of the total PDE.