Biomonitoring and whole body cotton dosimetry to estimate potential human dermal exposure to semivolatile chemicals

Abstract

Current methods of estimating absorbed dosage ( AD ) of chemicals were evaluated to determine residue transfer from a carpet treated with chlorpyrifos (CP) to humans who performed a structured exercise routine. To determine the dislodgeability of residue, a California Department of Food and Agriculture ( CDFA ) roller was applied to a flat cotton cloth upon a treated carpet. Levels ranged from 0.06 to 0.99 g CP/cm 2 . Cotton whole body dosimeters ( WBD ) were also used to assess residue transfer. The dosimeters retained 1.5 to 38 mg CP / person. Urine biomonitoring ( 3 days ) for 3,5,6 -trichloro -2 -pyridinol ( TCP ) of persons who wore only swimsuits revealed a mean AD of 176 g CP equivalents / person. The results show that the AD depends on the extent of contact transfer and dermal absorption of the residue. Default exposure assessments based upon environmental levels of chemicals and hypothetical transport pathways predict excessive exposure. The cotton WBD retains chemical residues and may be effectively used to predict dermal dose under experimental conditions.

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

“…SAP is a set of 20-min, high surface contact, low-impact Jazzercise s exercises and stretches (Ross et al, 1990;Krieger et al, 2000). Seven males were recruited by word of mouth from the university community for the SAP using a protocol approved by the university Human Subjects Review Committee.…”

“…Previous chemical applications for use with the human SAP were made with indoor foggers (Ross et al, 1990;Krieger et al, 2000) that produced variable amounts of surface residue at the study site. Uniform applications are important to reduce variability and increase the reliability of measurements of chemical persistence, transferability, and potential human exposure.…”

“…The sock and shorts worn as personal dosimeters provided an additional measure of chemical transferability during the SAP and allow comparisons of transfer with previous studies (Ross et al, 1990;Krieger et al, 2000). Personal dosimeters transferred a small fraction of the total cyfluthrin residue.…”

“…Under normal circumstances, clothing would act as a protective barrier that would likely retain 90% or more of the available chemical residue (Krieger, 1995;Thongsinthusak et al, 1993). Even though the SAP is a low impact, high-contact program, humans could not sustain that level of activity for 16 h. Previous SAP studies with chlorpyrifos resulted in a urinary biomarker excretion of 14 ppb trichloropyridinol (0.58 mg chlorpyrifos equivalents/kg day; Krieger et al, 2000). This urinary biomarker excretion was similar to the nationwide aggregate exposure estimate of 4.5 ppb (0.19 mg chlorpyrifos equivalents/kg/day; Hill et al, 1995), taken at a time when chlorpyrifos was the most-used residential pesticide.…”

“…Indoor TSRs have been used to estimate human exposure potential during structured activity studies (SAP; Jazzercise s ; Ross et al, 1990) that included measurements of carpet residues transferred to cotton clothing worn as a dosimeter (Ross et al, 1991;Krieger et al, 2000). The extensive surface contact during the Jazzercise s SAP is intended to represent day long, indoor contact with treated surfaces following pesticide use.…”