Human exposure to indoor residential cyfluthrin residues during a structured activity program.

Estimations of absorbed daily dosage (ADD) of chemicals following contact with treated surfaces may be required for risk assessment and risk management. Measurements of ADD based upon biomonitoring are a more reliable data than estimates of ADD from environmental measurements since they require fewer default assumptions. Study participants performed a structured activity program (SAP) 24-h after an application of Tempo((R)) 20 WP (cyfluthrin; 3-(2,2-dichloroethenyl)-2,2-dimethyl-cyclopropanecarboxylic acid cyano(4-fluoro-3-phenoxy-phenyl)-methyl ester) on a medium pile, plush nylon carpet. Measurements of total cyfluthrin residue and transferable cyfluthrin residue (cotton cloth and CDFA roller; personal sock and short dosimetry) were made at 3, 7, 12, 23, 47.5, and 407.5 h. Total cyfluthrin residue extracted from (Soxhlet extraction) carpet was 11.1+/-2.7 microg/cm(2) 1 h prior to the SAP. Transferable cyfluthrin residue obtained through analysis of cotton cloths rolled with a weighted 30-pound cylinder was 0.11 microg/cm(2). Cyfluthrin residues from socks and shorts were 0.74+/-0.23 and 0.15+/-0.03 microg/cm(2), respectively. Urine was collected at 12-h intervals during a 72-h period following the SAP and was analyzed for the cyfluthrin biomarker, 4-fluoro-3-phenoxybenzoic acid (FPBA). The mean cyfluthrin equivalents excreted were 8.4+/-5.7 microg/person (yielding an absorbed dosage of 0.10 microg/kg; n=7). The elimination half-life was 16+/-5 h. All predicted ADDs based upon environmental measurements overestimated the ADDs measured by urinary excretion.