Biological monitoring for exposure to deltamethrin: A human oral dosing study and background levels in the UK general population

An oral dose of the pyrethroid insecticide deltamethrin was administered to five volunteers at the acceptable daily intake (ADI, 0.01 mg/kg).Total urine was collected from the volunteers at timed intervals for 60 h post-exposure. The metabolites 3-(2,2-dibromovinyl)-2,2-dimethyl-(1-cyclopropane)carboxylic acid (DBVA) and 3-phenoxybenzoic acid (3-PBA) were quantified in hydrolysed urine using GC-MS analysis.Both metabolites exhibited rapid elimination half-lives of 3.6 and 7.1 h, respectively. Levels of DBVA quantified in urine were approximately 5 times greater than 3-PBA. Mean metabolite levels found in 24 h total urine collections, normalised for a 70 kg individual, were 42.8 μmol DBVA/mol creatinine (range 34.6–63.2; CV = 28%) and 8.7 μmol 3-PBA/mol creatinine (range 6.6–12.7; CV = 31%).We calculate that a 70 kg person receiving a dose of deltamethrin at the ADI would be expected to have a 24-h total urine collection level of 32–53 μmol DBVA/mol creatinine (95% confidence interval). Analysis of 336 samples from adult UK residents with no known exposure to deltamethrin derives an upper reference value (95th percentile) of 0.5 μmol DBVA/mol creatinine (maximum 4.2 μmol DBVA/mol creatinine), demonstrating that general population exposure to deltamethrin in the UK is very low and well within levels expected at the ADI.

► We describe the urinary excretion of deltamethrin metabolites.
► Five volunteers were given an oral dose at the acceptable daily intake (ADI).
► Metabolites exhibited rapid half-lives.
► 336 spot urine samples from non-exposed adults were also analysed.
► Exposure to deltamethrin in the UK is well within levels expected at the ADI.