Rubber Latex Gloves as a Direct Dosimeter for Measuring Dermal Harvester Pesticide Exposure Particularly With Malathion
- Author(s): Lopez, Terry Enriquez
- Advisor(s): Krieger, Robert
- Eastmond, David
- et al.
Hands are an important route of dermal exposure to agricultural pesticides during strawberry harvesting. Direct dosimeters that trap pesticide residues as they contact workers during harvesting may be valuable sources for estimates of exposure. Latex gloves as hand dosimeters have been evaluated in two settings: 1) commercial strawberry farms, and, 2) controlled studies using a surrogate contact transfer device and malathion-treated turf.
With the assistance of field operators from a commercial strawberry farm, harvester glove samples were collected and obtained via overnight shipping for extraction and analysis of pesticide residues. Harvester gloves accumulated multiple pesticide residues during normal work periods (2 to 2.5 h). Thirteen different pesticide active ingredients were found on harvester gloves at different times. Pesticide residues can accumulate on rubber latex gloves up to ~20 mg/pair by intermittent contact during normal work.
To evaluate the accumulation of surface pesticide residues on light rubber latex gloves, a surrogate model system, the Brinkman Contact Transfer Unit (BCTU), was developed. The BCTU consisted of latex gloves fitted on mannequin hands mounted in a wheeled chassis that could be pushed across a grid of treated turf. Using the BCTU on malathion-treated turf (2 lbs/A), residues accumulated on gloves (0.14-398 µg/glove) over a 13 d study period. Turf residues dissipated biphasically over 13 d and the malathion first-order half-life was 1.4 d. The percent transferred and recovered residue from treated turf to a gloved mannequin hand (assuming 420 cm2 surface area) ranged from <1% to 10% based on measurements of deposition applied to turf. Concurrent applications of malathion and fenpropathrin (data not shown) to turf showed that gloves can accumulate multiple pesticide residues.
Transferable turf residues (TTRs) were also measured using the CDFA (California) roller and cotton cloth dosimeters. Residues accumulated on cotton cloths ranged from 0.002-0.117 µg /cm2 for days 1 through 13. When PGRs (µg/glove) were plotted as a function of TTRs (µg/cm2), a strong linear regression correlation was observed (R2= 0.5-1.0) and an empirical transfer factor of 1548 cm2/glove was derived from the slope.