Volume 8, Issue 6 (November 1980)
Development of a Chronic Toxicity Test Using Chironomus riparius and the Sublethal Effects of Trisodium Carboxymethyloxysuccinate
The preliminary development of a 24- to 34-day life-cycle test using the freshwater midge Chironomus riparius is described. The method allows the determination of the sublethal effects of a toxicant on the survival of each life stage, overall growth of the larval stages, egg production, and hatchability of the F1 generation eggs. Trisodium carboxymethyloxysuccinate (Na3CMOS), a potential partial replacement for phosphates in fabric washing powders, is used to demonstrate the method.
There was no effect on survival from stage to stage or overall survival from the egg to the fourth larval instar at up to 92 mg/L Na3CMOS. There were no effects on growth or egg production at ≤92 mg/L Na3CMOS or on hatchability of the F1 eggs at ≤42 mg/L Na3CMOS. None of the F1 generation eggs hatched in 92 mg/L Na3CMOS. The number of adults produced clearly decreased with increasing concentration >12 mg/L Na3CMOS but, in this preliminary work the data did not permit statistical verification of the threshold of effect.
This method has been shown to be sensitive enough to identify sublethal effects of toxicants and shows considerable promise as a method for hazard evaluation. Limited evidence suggests that the test species C. riparius has a sensitivity to toxicants of a similar order to other commonly used test organisms.