Acute and chronic toxic effects of ammoniato Chironomus riparius

摘要

The toxicity of ammonia to Chironomus riparius (Diptera) was first evaluatedin static 48-h test based on OECD 235. The 24- and 48-h LC50 values ofammonia to C. riparius are 347.19 and 246.74 mg/L, respectively. Ammonia wassubsequently used in 21-day chronic test which was carried out based on OECDGuideline 219 using a spiked water-sediment system. Test species were exposedto concentrations ranging from 25 to 800 mg/L. The results show that theemergence ratio is the most sensitive indicator with a significant adverse effect(P < 0.05) compared to the solvent control at 50 mg/L. The EC50 value ofemergence ratio is 121.94 mg/L. Significant adverse effect (P < 0.05) was alsoobserved compared to the solvent control for developmental ratio at 200 mg/L.The toxicity test provides additional information, which might develop toxicitydatabase and be useful in the risk assessment of ammonia.