Dermal absorption and distribution of (14)C carbaryl in Wistar rats

The level of (14)C carbaryl was determined in blood (leukocytes, erythrocytes, all blood cells, plasma) and organs (brain, heart, lungs, liver, spleen, skin at the site of exposure) of male Wistar rats after dermal administration. The application liquid was (14)C carbaryl solution in 96% ethyl alcohol. This preparation, possessing an activity of 670 kBq/ml, containing 1.67 mg of carbaryl, was applied to the skin of the tail according to Massmann's method in own modification. The amount of the preparation per 1 cm(2) of the tail skin was 0.19 mg of carbaryl (74.4 kBq). The tails of experimental rats were exposed to (14)C carbaryl by soaking for 4 h daily: once, twice or three times. Beta radiation from (14)C was measured in homogenized organs (brain, heart, lungs, liver, skin) and in blood by computer controlled Wallac scintillation counter Model 1409, using Multi Calc software. The dermal absorption of carbaryl at the site of exposure and in the surrounding area of about 2 cm was observed already during 4 hour exposure. Carbaryl reached plasma within 4 h of a single dermal exposure and penetrated into leukocytes, erythrocytes, heart, liver, lung, kidney and brain. The largest amount of (14)C carbaryl, about 2% of absorbed dose, was detected in liver