Estimation of pesticide exposure to greenhouse applicators using video imaging and other assessment techniques

Pesticide exposure in greenhouse applicators was measured using the video imaging technique to assess exposure (VITAE) along with dermal patches, air monitoring, and biological assessment techniques. The exposure of five males to pesticides during high- and low-volume application methods in commercial greenhouse operations was evaluated. Failure to use precautionary handling methods when using low-volume applications resulted in the highest level of dermal tracer deposition. Results demonstrated nonuniform deposition of tracer/pesticide mixtures on various body regions, supporting earlier work that questioned the assumption of uniform deposition when assessing exposure with the dermal patch technique. By combining the tracer with an oil-based concentrate, it remained uniformly suspended in the spray solution, and deposition ratios remained constant. Estimates of pirimicarb exposure using the VITAE method were highly correlated with excretion of urinary metabolites (r2 = 0.93). The immediate visual results provided by the VITAE system to applicators proved to be a powerful educational tool in helping them adopt precautionary application techniques. The need to employ protective operating procedures when handling pesticides was demonstrated, no matter how brief the exposure period.