Environmental Residues and Biomonitoring Estimates of Human Insecticide Exposure from Treated Residential Turf

Abstract

Intentional and unavoidable human exposure is a consequence of using pesticides to nurture and protect residential turf. Limited exposure studies have been conducted for assessing potential human exposure of turf residues. Exposure was measured in persons who performed a 20-minute structured activity (Jazzercise®) on chlorpyrifos (CP)-treated Kentucky bluegrass (12 ± 4 μg CP/cm²). CP exposure was measured by determining urine clearance of the 3,5,6-trichloro-2-pyridinol (TCP). Study participants wore either 100% cotton whole body dosimeters (union suit, gloves, and socks) or exercise suits (shorts and a sports top or one-piece suit with similar amounts of exposed skin). An average of 1.6 mg CP/person was extracted from whole body dosimeters worn by study participants. The measured residue transfer was well below the 35 mg CP/person estimated using the US EPA standard operating procedures. Biomonitoring based on urine clearance of TCP indicated that an average of 1.3 μg CP/kg was absorbed. Absorbed dosages (0.5 to 2 μg CP/kg) derived from transferable residue on cotton cloths pressed to the turf with a weighted roller were similar to estimates from biomonitoring. A very limited amount of CP applied to turf is available for transfer and absorption during intensive human contact.