Using the nematode Caenorhabditis elegans to predict mammalian acute lethality to metallic salts

The acute lethality of the salts of eight metals--HgCl2, BeSO4.4H2O, Al(NO3)3.9H2O, CuCl2.2H2O, ZnCl2, Pb(NO3)2, CdCl2, and Sr(NO3)2--was determined using a type of free-living nematode, Caenorhabditis elegans. The LC50 values were compared to the published mammalian oral LD50 values for salts of the same metals. Within this set of chemicals, C. elegans was found to be a predictor of mammalian acute lethality, generating LC50 values parallel to the rat and mouse LD50 values. The total expenses for this testing are about 10% of the cost for mammalian acute lethality testing. The method is considered to have great promise, but further study is needed.