Perspiration increased human pesticide absorption following surface contact during an indoor scripted activity program

Homeowners and professional applicators frequently use chemicals to control insect pests in urban environments. The identification and evaluation of determinants of human exposure are critical to conduct reliable and responsible human exposure assessments following indoor residential chemical applications. The effect of sweat on absorbed dose in humans was evaluated with human volunteers who participated in a structured activity program ( SAP). Participants ( n = 20) performed a warm-up exercise to induce light sweating prior to an SAP on chlorpyrifos(cp)-treated nylon carpet. Absorbed daily dosages (ADDs) were calculated using urinary biomonitoring of trichloropyridinol. In two separate exposures, participation in the warm-up exercise prior to the exposure SAP resulted in an increased ADD of CP equivalents by approximately 50%. Measured ADDs averaged 2.8 ( SAP 1) and 2.0 (SAP 2) mug CP equivalents/kg/day in volunteers who participated in the warm-up exercise. In participants who rested prior to the exposures, ADDs were significantly lower at 1.9 (SAP 1) and 1.3 (SAP 2) mug CP equivalents/ kg/day. Perspiration may also be a determinant of exposure in active children and field workers. Measured ADDs were less than estimates of ADD made from environmental measurements including CP deposition, the California roller, and clothing dosimeters worn by participants.