Environmental residues and biomonitoring estimates of human insecticide exposure from treated residential turf

Intentional and unavoidable human exposure is a consequence of using pestic ides to nurture and protect residential turf. Limited exposure studies have been conducted for assessing potential human exposure of turf residues. Ex posure was measured in persons who performed a 20-minute structured activit y (Jazzercise(R)) on chlorpyrifos (CP)-treated Kentucky bluegrass (12 +/- 4 mug CP/cm(2)). 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 su its (shorts and a sports top or one-piece suit with similar amounts of expo sed skin). An average of 1.6 mg CP/person was extracted from whole body dos imeters worn by study participants. The measured residue transfer was well below the 35 mg CP/person estimated using the US EPA standard operating pro cedures. Biomonitoring based on urine clearance of TCP indicated that an av erage of 1.3 mug CP/kg was absorbed. Absorbed dosages (0.5 to 2 mug 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 lim ited amount of CP applied to turf is available for transfer and absorption during intensive human contact.