title: Percutaneous absorption of diazinon in humans.
abstract: Diazinon is an organophosphorus insecticide which, through general use, comes into contact with human skin. To investigate its percutaneous absorption, human volunteers were exposed for 24 hr to 14C-labelled diazinon applied in acetone solution (2 micrograms/cm2) to the forearm or abdomen, or in lanolin wool grease (1.47 micrograms/cm2) to the abdomen. Complete void urine samples were collected daily for 7 days. Percutaneous absorption ranged from 2.87 +/- 1.16% (mean +/- SD, n = 6) to 3.85 +/- 2.16% of the applied dose, and there were no statistically significant differences with regard to site or vehicle of application. In rhesus monkeys, over the 7 days after iv dosing (2.1 microCi [14C]diazinon, 31.8 micrograms) a total of 55.8 +/- 6.8% (n = 4) of the dose was excreted in the urine, and 22.6 +/- 5.2% was eliminated in the faeces (78.4% total accountability). In in vitro percutaneous absorption studies with human abdominal skin, 14.1 +/- 9.2% of the applied dose accumulated in the receptor fluid over 24 hr of exposure to 0.25 microgram/cm2 (acetone vehicle). The calculated mass absorbed was the same (0.035 microgram/cm2) for both in vitro and in vivo absorption through human skin.
authors.affiliation: Department of Dermatology, University of California, San Francisco 94143.
authors.forename: R C
authors.initials: RC
authors.lastname: Wester
authors.forename: L
authors.initials: L
authors.lastname: Sedik
authors.forename: J
authors.initials: J
authors.lastname: Melendres
authors.forename: F
authors.initials: F
authors.lastname: Logan
authors.forename: H I
authors.initials: HI
authors.lastname: Maibach
authors.forename: I
authors.initials: I
authors.lastname: Russell
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D000368:Aged; D000818:Animals; D003976:Diazinon / Q000493:pharmacokinetics* / Q000652:urine; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008253:Macaca mulatta; D008297:Male; D008875:Middle Aged; D012869:Skin Absorption
chemical_list: D003976:Diazinon