The present study was performed to investigate biodegradation rate of BPMC(2-sec-butylphenyl methyl carbamate) and chlorothalonil. In the biodegradation test of two pesticides by the modified river die-away method from June 17 to August 22, 1998, the biodegradation rate constants and half-life were determined in Nakdong(A) and Kumho River(B). Bio- degradation rate of BPMC was 27% in A sampling point, 40% in B sampling point after 7 days. Biodegradation rate constants and half-life of BPMC were 0.0460 and 15.1 days in A sampling point, 0.0749 and 9.3 days in B sampling point, respectively. Biodegradation rate of chlorothalonil was 100% in A and B sampling points after 7 days. Biodegradation rate constants and half-life of chlorothalonil were 0.1416 and 4.9 hours in A sampling point, 0.1803 and 3.8 hours in B sampling point, respectively. Biodegradation rate of chlorothalonil was faster than that of BPMC. Correlation analysis between biodegradation rate constants of pesticides and water quality(DO, BOD, SS, ABS, NH₃-N and NO₃-N) showed significant correlation with BOD, SS and NH,-N. Furthermore, regression analysis with BOD, SS and NH₃-N as independent variable and biodegradation rate constant as independent variable showed a significant linear equation. These results suggested that BPMC and chlorothalonil were mainly degraded by biodegradation, and the difference in biodegradation of two pesticides was due to difference of water quality.

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.

Tetranactin과 BPMC 혼합유제의 사과 재배 중 살포횟수 및 처리시기에 따른 잔류정도와 토양에 처리한 후의 분해정도를 조사한 결과는 다음과 같다. Tetranactin과 BPMC의 잔류분석시의 회수율은 사과에서 0.5ppm과 1.0ppm의 농도 수준에서 tetranactin은 74.0-77.5% 이었으며 BPMC는 83.6-87.1% 이었다. 토양에서의 회수율은 tetranactin 82.3-84.4%, BPMC 83.6-87.1% 이었다. Tetranactin 및 BPMC의 잔류분석시의 검출한계는 두 약제 모두 사과의 과육 부분에서는 0.01ppm, 사과의 과피 및 토양에서는 0.3ppm 이었다. 사과의 과육 및 과피부분에서 tetranactin 및 BPMC의 잔류량은 수확 3일전 5회 처리에서 잔류량의 96% 정도가 사과의 과피 부분에 잔류되는 것으로 나타났다. 사과에 대한 tetranactin 및 BPMC의 잔류량은 수확 3일전 5회 처리에서 tetranactin은 0.39ppm, BPMC는 0.75ppm이 잔류되어 tetranactin 및 BPMC의 사과에 대한 안전사용기준은 수확 30일전, 2회 이내의 사용으로 추천할 수 있다. Tetranactin 및 BPMC의 토양 중 분해 반감기는 포장시험 조건에서 각각 6.9일과 6.3일 이었으며 실내시험 조건에서는 각각 24.4 및 23.2일로 나타났다.