Potential dermal exposure and ergonomic assessment in greenhouse spraying

Greenhouses are space-efficient structures used in the production of produce. However, occupational health issues like exposure to chemicals, and physiological and postural stresses are experienced by operators while performing farm activities due to the enclosed environment of the greenhouse. This study assesses chemical exposure and physiological and postural parameters of operators during spraying with two different types of sprayers (Battery-powered knapsack sprayer [Battery sprayer] and AC-powered stationary sprayer [Stationary sprayer]) with two different application techniques (continuous and alternate row). The mean Potential Dermal Exposure (PDE) for a continuous row of spraying was 54 and 70 mL h^-1 with battery and stationary sprayers, respectively. However, PDE in alternate row spraying was approximately 16 and 25% less in battery and stationary sprayers than in a continuous row. The upper and left portions of the body had higher exposure compared to the lower and right half portions in all treatments. The ergonomic parameters (physiological and postural assessment) in continuous and alternate row spraying techniques did not differ but varied with the type of sprayer used. Mean values of energy expenditure rate, body part discomfort score, overall discomfort score, and risk index were 210 ± 35 W, 27 ± 2.0, 6.1 ± 0.4, and 1.0, respectively, in the battery sprayer compared to 290 ± 80 W, 35 ± 4.1, 8.3 ± 1.0, and 2.0 in the stationary sprayer. This study concluded that the use of a battery sprayer with an alternate row spraying technique resulted in lower dermal exposure (45 mL h^-1) and was ergonomically less demanding.