Percutaneous absorption of diazinon in humans

• Published in: Food and chemical toxicology Vol. 31; no. 8; pp. 569 - 572
• Main Authors: Wester, R.C., Sedik, L., Melendres, J., Logan, F., Maibach, H.I., Russell, I.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.08.1993; New York, NY Elsevier Science
• Subjects: Administration, Cutaneous; Adult; Aged; Animals; Biological and medical sciences; Diazinon - pharmacokinetics; Diazinon - urine; Female; Humans; Injections, Intravenous; Macaca mulatta; Male; Medical sciences; Middle Aged; Pesticides, fertilizers and other agrochemicals toxicology; Skin Absorption; Toxicology; Human; In vivo; Insecticide; Penetration; Volunteer; Pesticides; Organophosphorus compounds; Skin; In vitro; Topical administration; Percutaneous route
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/0278-6915(93)90206-E

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 μg/cm 2) to the forearm or abdomen, or in lanolin wool grease (1.47 μg/cm 2) 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 μCi[ 14C]diazinon, 31.8 μg) 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 μg/cm 2 (acetone vehicle). The calculated mass absorbed was the same (0.035 μg/cm 2) for both in vitro and in vivo absorption through human skin.