Biomarker of pyrethrum exposure

Pyrethrum as well as synthetic pyrethroids like allethrin, resmethrin, phenothrin, tetramethrin, cyfluthrin, cypermethrin, deltamethrin or permethrin are among the insecticides most often used worldwide. With a sensitive and valid gas-chromatographic–high resolution mass spectrometric method, it is possible to detect all pyrethrum and pyrethroid metabolites in one analytical run. Thus, for the first time a background level of trans-chrysanthemumdicarboxylic acid (CDCA) in urine (95th percentile: 0.15 μg/l) as a characteristic, e.g. for a pyrethrum exposure was found. Following a pyrethrum exposure lasting 1 day, CDCA was found in 27 out of 30 subjects with concentrations going up to 54 μg/l urine (mean: 1.1 ± 4.4 μg/l). To obtain information about the elimination kinetics of pyrethrum in humans, urinary excretion of CDCA was investigated in three volunteers after oral intake of 0.3 mg pyrethrin I. CDCA was detected during the first 36 h after intake with elimination being most rapid during the first 4 h (mean elimination half-life: 4.2 h).