1996년과 1997년에 남조류가 발생한 여러 호수에서 microcystin-RR, microcystin-LR, microcystin-YR의 함량을 정량하였고, 쥐를 이용하여 독성 검사를 실시하였다. 소양호를 제외한 모든 호수에서 Microcystis속의 종 들이 우점하였으며 전체 남조류 발생 호수의 시료에 대한 독소 검출의 빈도는 85%이였다. 조류세포내 총 microcystin의 함량은 0.29~2.61 mg/g이었으며 수중의 농도로 환산하면 0.4~21.6 μg/l이였다. 독소 함량은 1996년 보다 1997년에 높았고, 세 종류의 microcystin중 microcystin-RR이 가장 많이 검출되었다. 각 시료의 쥐에 대한 LD50은 총 microcystin함량과 LD50의 상관관계식에 의해 계산되었다. 화학분석에 의해 microcystin이 검출된 시료의 추출물이 주입되었을 때 쥐의 치사효과가 나타난 것으로 보아 microcystin 함량의 화학분석결 과와 bioassay 결과는 잘 일치하는 것으로 보이며, 영랑호 시료를 대상으로 실측한 LD50은 경험식으로 계산된 LD50과 일치하였다. 대상호수의 LD50은 27~338 mg/kg 의 범위로서 국내외에서 보고된 것에 비하여 높은 독성을 나타냈다.

Algal cells samples were collected and microcystin contents were determined in warm seasons of 1996~1997 in ten large reservoirs which are used for drinking water supply in Korea. High density of Microcystis was observed in all lakes except Lake Soyang where Anabaena dominated. The content of three microcystin variants (microcystin-RR, -YR, -LR) in algal cells was analysed with HPLC and acute toxicity was tested by mouse bioassay. Microcystin-RR was the main component of microcystins variants. The total content of microcystins ranged from 288 to 2612 μg/g which corresponds to the concentration per water volume of 0.4 to 21.6 μg/L. Most samples collected in 1997 showed higher toxin contents than those of 1996. In mouse bioassay, lethal effect was observed in Lake Andong (1996), L. Hapchon (1997), L. Okjong (1997) and Kyounganchon (1996). The livers of mice which died after injection of algal extract were bigger than those of healthy mice, which indicated the presence of hepatotoxin. The frequency of toxic bloom was 85% of total samples. The LD50 to mouse were estimated from the empirical relationship between LD50 and total microcystin content. The LD50 measured with mouse bioassay for one of the samples well coincided with the estimated LD50. Estimated LD50 of samples ranged from 27 to 338 mg/kg, which shows similar toxicity with reports from other countries.

• 김범철(강원대학교 자연과학대학 환경과학과) | Kim Bomchul (Department of Environmental science, Kangwon National University) Corresponding author
• 김호섭(강원대학교 자연과학대학 환경과학과) | Ho- Sub Kim (Department of Environmental science, Kangwon National University)
• 박호동(日本信州大學理學部物質循環學科) | Ho- Dong Park (Department of Environmental science, Shinshu University)
• 최광순(강원대학교 자연과학대학 환경과학과) | Kwangsoon Choi (Department of Environmental science, Kangwon National University)
• 박종근(한국수자원공사 수자원연구소) | Jong- Geun Park (Water resources research institute, KOWACO)