Bioconcentration factors of some carbamates BPMC, carbaryl and carbofuran were determined. The tested fishes were zebrafish (Brachydanio rerio) and red sword tail (Xiphophorus hellieri). The fishes were exposed to 0.05 ppm, 0.01 ppm, 0.50 ppm, one- hundredth concentration of 96-hrs LC_(50) and one-thousandth concentration of 96-hrs LC_(50) and test periods were 3, 5 and 8 days. Obtained results are summerized as follows: In the case of BPMC and carbaryl, BPMC and carbaryl concentration in zebrafish extract and BCFs of BPMC, carbaryl were lower than those of red sword tail, and increased as increasing test concentration. In the case of same experimental concentrations, BPMC concentration in zebrafish extract and BCFs of BPMC were decreased as prolonging test periods. In the case of same experimental periods, carbaryl concentration in zebrafish extract and BCFs of carbaryl were decreased as increasing test concentration, especially dropped at 0.50 ppm. Carbofuran did not bioaccumulate in zebrafish for test periods, in the case of red sword tail, it was impossible to calculate on BCFs data because test concentration of one-hundredth and one-thousandth of 96hrs LC_(50) was under the detecting limit on GC. Test concentration of 0.05 and 0.10 ppm were the same tendency with BPMC and carbaryl. Determined depuration rate conatant were highest on carbofuran, and followed by carbaryl, and BPMC. It is suggested that low BCF of carbofuran is due to its relatively high water solubility and depuration rate, compared to BPMC and carbaryl. Therefore, carbofuran had no little bioconcentration effect on the aquatic ecosystem.

We investigated the toxic effects of carbaryl on early embryo development in the African clawed frog, Xenopus laevis. To test the toxic effects, frog embryo teratogenesis assays using Xenopus were performed. Embryos were exposed to various concentrations of carbaryl (5∼320 μM). LC100 for carbaryl was 320 μM, and the LC50 determined by probit analysis was the concentration of 235.68 μM. Exposure to 160 μM of carbaryl resulted in 10 different types of severe external malformations. Histological examination revealed dysplasia of the eyes, heart, guts, somatic muscle, dorsal, liver, blood vessel and swelling of the pronephric ducts. Malformation of neural tissue and brain was not severe even in the high dose of carbaryl. Benzidine blood stain showed distinct inhibition of inducing erythrocytes in embryos and animal cap explants. Electron micrographs of embryo revealed retinal detachment, loose photoreceptor lamella and the degeneration of sarcomeres in the carbaryl-treated group. The mitochondrial degeneration was also observed in the test group.