Distribution and Depletion of Radioactivity in Hens Treated Dermally with 14C-Labeled Permethrin

Abstract

The 25/75 cis-trans mixture of permethrin (BW21Z), one of the new broad-spectrum pyrethroid insecticides, was labeled with 14C in the alcohol methylene carbon moiety and mist sprayed at two rates (3.77 or 11.94 mg/hen) on 28 hens. Peak permethrin equivalents in both treatment groups were found in the skins, .414 and l.69 ppm, respectively. Total permethrin equivalents peaked 3 days after treatment, but permethrin equivalents in eggs peaked 5 days after treatment.

Comparative Toxicology of the Pyrethroid Insecticides

“…Results with the ovaries were highly variable and may have been related to egg production. Pyrethroid kinetics in egg fractions were consistent with previous studies (Gaughan et al 1978b;Hunt et al 1979;Staiger et al 1982;Huston and Stoyden 1987). Fat and skin, less readily perfused tissues, exhibited peak concentrations at d 5 (fat, 0.1 to 0.15Itg/g; skin, 0.1 to 0.2 ltg/g).…”

“…About 0.1 (trans-permethrin) to 0.5% (cis-permethrin) of the administered dose was eliminated in the eggs, with the radiocarbon largely associated with the yolk. Peak yolk concentrations occurred 5 d postdose, which is consistent with the findings of Hunt et al (1979) after dermal application to chickens. At 9 d postdose most body compartments contained less than 0.01 % of the total administered radiocarbon.…”

“…Radiocarbon eliminated via the eggs amounted to approximately 0.5% of the dose. Yolk concentrations peaked between 4 and 6 d postdose, which is consistent with permethrin (Gaughan et al 1978b;Hunt et al 1979) and cypermethrin (Hutson and Steydin 1987). Peak fluvalinate equivalents in the yolk ranged from approximately 0.005 to 4.0 J,tg/g, as the administered dose increased from 0.1 to 100 mg/kg.…”

Percutaneous absorption ofcis‐andtrans‐permethrin in rhesus monkeys and rats: Anatomic site and interspecies variation

“…Although dermal exposure of spray personnel to pesticides is well documented, estimation of the potential health risk is usually derived from animal oral dose studies (Franklin et al, 1986). Previous reports have described permethrin metabolism in mammals following oral ingestion (Miyamoto, 1976;Elliott et al, 1976;Gaughan et al, 1977;Ivie and Hunt, 1980) and skin absorption in hens after spray applications (Hunt et al, 1979); however, there are no studies showing the comparative dermal absorption of permethrin at different anatomic sites in primates and rats. Primates are generally considered to be more predictive of percutaneous absorption in humans than in nonprimate species Maibach, 1976, 1985); however, there is no animal skin that alone provides a completely adequate experimental model (Montagna, 1971).…”

Pharmacokinetics of veterinary drugs in laying hens and residues in eggs: a review of the literature

“…Pyrethroids are most often administered to poultry topically, as a spray or dust (Bishop, 2001). When topically applied, pyrethroids are absorbed and widely distributed to tissues, but concentrate particularly in fat and skin (Hunt et al. , 1979; Braun et al.…”