title: Biomonitoring equivalents for deltamethrin.
abstract: Measured concentrations of chemicals in blood or urine in biomonitoring studies provide an integrated reflection of exposures to chemicals via multiple routes and pathways. The potential significance of the measured concentrations of chemicals in the context of existing toxicology data and risk assessments can be assessed if chemical-specific quantitative screening criteria are available. This work presents the derivation of Biomonitoring Equivalents (BEs) for deltamethrin, a synthetic Type II pyrethroid. BEs are estimates of biomarker concentrations that are consistent with risk assessment-based exposure guidance values such as reference doses or acceptable daily intakes. BE values were derived for deltamethrin based on two biomarkers: deltamethrin in plasma and 3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane carboxylic acid (DBCA), a specific metabolite, in urine. BE values for deltamethrin in plasma were based on extrapolation from measured deltamethrin concentrations in plasma in rats under conditions consistent with the Point of Departure in the critical study underlying the USEPA RfD. BE values for DBCA in urine were derived based on pharmacokinetic data from a study in human volunteers on the urinary excretion of deltamethrin and metabolites. BE values for deltamethrin in plasma corresponding to the USEPA RfD for adults and children are 20 and 2μg/L, respectively. BE values for DBCA in urine corresponding to the adult and child-specific RfDs are 50 and 7μg/L, respectively. The urinary BE value corresponding to the ADI established by the European Commission and the Joint Meeting on Pesticide Residues is 60μg/L (as DBCA in urine). These values can be used to screen biomonitoring data in the context of current risk assessments for detlamethrin.
authors.affiliation: Summit Toxicology, LLP, Falls Church, VA 22044, USA. laylward@summittoxicology.com
authors.forename: Lesa L
authors.initials: LL
authors.lastname: Aylward
authors.forename: Kannan
authors.initials: K
authors.lastname: Krishnan
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Kirman
authors.forename: Andy
authors.initials: A
authors.lastname: Nong
authors.forename: Sean M
authors.initials: SM
authors.lastname: Hays
mesh_terms: D000328:Adult; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002648:Child; D004781:Environmental Exposure / Q000009:adverse effects*; D004784:Environmental Monitoring / Q000379:methods*; D017408:Guidelines as Topic; D006801:Humans; D007306:Insecticides / Q000493:pharmacokinetics*; D009570:Nitriles / Q000493:pharmacokinetics*; D011722:Pyrethrins / Q000493:pharmacokinetics*; D051381:Rats; D018570:Risk Assessment / Q000379:methods
chemical_list: D015415:Biomarkers; D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; C017180:decamethrin