Abstract
Most pesticides are poorly soluble in water and must be dissolved in a solvent carrier before being added to the test medium on aquatic toxicity test. The concentration of solvent is critical to the success of a test. This study were conducted to recommend possible organic solvents which have good solubility for pesticides and low toxicity to Korean native water flea to establish new standard toxicity test methods using Korean native water flea for ecological risk assessment of pesticide. Four Korean freshwater cladocerans, Daphnia obtusa, Daphnia sp., Moina macrocopa and Simocephalus vetulus were exposed to 10 different organic solvents during 48 hours to evaluate their toxic response to solvents. Ethyl acetate was the most toxic to cladocerans tested. Although ethyl ether was the least toxic to cladocerans tested, it may not adequate as possible solvent in aquatic toxicity test due to high volatility and low water solubility. In conclusion, acetone, methanol, ethanol and acetonitrile which has low toxicity as well as good water solubility are recommended as optimal organic solvent to use in aquatic toxicity tests with Korean native cladocerans tested.
국내서식 물벼룩종을 이용한 표준생태독성시험법 개발을 위한 기초연구로서 4종의 한국산 물벼룩 Daphnia sp., Daphnia obtusa, Moina macrocopa, Simocephalus vetulus과 국제표준종 Daphnia magna대한 10종 유기용매에 대한 급성독성을 조사하여 독성이 낮으면서도 농약의 용해도가 좋은 유기용매를 시험에 사용하도록 제안하고자 하였다. 한국산 물벼룩에 대해 급성독성이 가장 강한 유기용매는 ethyl acetate로 조사되었으며 DMF, dioxane, isopropanol 3종은 무영향 농도가 EPA에서 급성독성시험에 추천하는 최고 사용농도인 0.5 ml/L 이하로 조사되어 다른 유기용매에 비해 독성이 강하였다. 따라서 독성이 낮으면서 수용해도가 높고 농약원제의 용해성이 좋은 acetone, methanol, ethanol, acetonitrile을 권장 시험용매로 제안한다.
