Gupta Ashok Kumar, Verma Girraj Prasad, Jain Khyali Lal
College of Fisheries, Maharana Pratap University ofAgriculture and Technology, Udaipur 313 001, India.
J Environ Biol. 2008 Nov;29(6):837-9.
Toxicity of organophosphate insecticide, i.e. dichlorvos has been investigated in relation to selected water hardness for the freshwater zooplankters such as Moina, Daphnia, cyclops and nauplii. Results revealed that dichlorvos was highly toxic to the tested zooplankters, as the LC50 values are noticed in ppb. Trend of sensitivity for different zooplankters to dichlorvos was recorded as Moina < Daphnia < nauplii < cyclops. The LC50 were found to change significantly with the change in water hardness. The zooplankters were more susceptible to dichlorvos at water hardness of 275 mgl(-1) as compared to water hardness of 540 mgl(-1) as revealed from low LC50 values. The range of safe dischargeable concentrations (1.063-1.137ppb) were too low as compared to harmless or safe concentrations (43.895-89.194 ppb) for the zooplankters at both the hardness.
已针对淡水浮游动物（如裸腹溞、水蚤、剑水蚤和无节幼体），研究了有机磷杀虫剂敌敌畏在特定水硬度条件下的毒性。结果显示，敌敌畏对受试浮游动物具有高毒性，因为半数致死浓度（LC50）值以十亿分比（ppb）计。不同浮游动物对敌敌畏的敏感趋势记录为：裸腹溞＜水蚤＜无节幼体＜剑水蚤。发现LC50会随着水硬度的变化而显著改变。从较低的LC50值可知，与水硬度为540毫克/升相比，浮游动物在水硬度为275毫克/升时对敌敌畏更敏感。与两种硬度条件下浮游动物的无害或安全浓度（43.895 - 89.194 ppb）相比，安全排放浓度范围（1.063 - 1.137 ppb）过低。
