title: Concurrent 2,4-D and triclopyr biomonitoring of backpack applicators, mixer/loader and field supervisor in forestry.
abstract: Two herbicides, 2,4-D and triclopyr esters (application ratio 1.6:1 acid equivalents) were applied as a tank mix by a crew of 8 backpack sprayer applicators, a mixer/loader, and a field supervisor. The crew was employed in a conifer release program in northern California during the summer of 2002. Biomonitoring (urine, 24 h) utilized 2,4-D and triclopyr (a.e.) as rapidly excreted exposure biomarkers. The absorbed dosages of 2,4-D and triclopyr were calculated based upon cotton whole body suits and biomonitoring. Dosages based upon accumulation of the herbicides on body suits averaged 42.6 μg (a.e.) 2,4-D/kg-d and 8.0 μg (a.e.) triclopyr/kg-d. Six consecutive days of concurrent urine collections showed that backpack applicators excreted an average of 11.0 μg (a.e.) 2,4-D/kg-d and 18.9 μg (a.e.) triclopyr/kg-d. Estimates based upon curve fitting were 17.1 and 29.3 μg (a.e.)/kg-d, respectively. Results suggest that passive dosimetry for 2,4-D consistently overestimated the dosage measured using biomonitoring by a factor of 2-3 fold, while for triclopyr, passive dosimetry underestimated the absorbed dose based on biomonitoring by a factor of 2-4 fold.
authors.affiliation: Personal Chemical Exposure Program, University of California, Riverside, California, USA.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Zhang
authors.forename: Sandra
authors.initials: S
authors.lastname: Acevedo
authors.forename: Yingfu
authors.initials: Y
authors.lastname: Chao
authors.forename: Zhenshan
authors.initials: Z
authors.lastname: Chen
authors.forename: Travis
authors.initials: T
authors.lastname: Dinoff
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Driver
authors.forename: John
authors.initials: J
authors.lastname: Ross
authors.forename: Ryan
authors.initials: R
authors.lastname: Williams
authors.forename: Robert
authors.initials: R
authors.lastname: Krieger
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000032:analysis / Q000493:pharmacokinetics / Q000652:urine*; D000042:Absorption; D000328:Adult; D015415:Biomarkers / Q000652:urine; D002140:California; D004784:Environmental Monitoring / Q000379:methods*; D016468:Forestry; D006016:Glycolates / Q000032:analysis / Q000493:pharmacokinetics / Q000652:urine*; D006540:Herbicides / Q000032:analysis / Q000493:pharmacokinetics / Q000652:urine*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis / Q000493:pharmacokinetics / Q000652:urine*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D006016:Glycolates; D006540:Herbicides; D010573:Pesticide Residues; D015084:2,4-Dichlorophenoxyacetic Acid; C032742:triclopyr