Ecotoxicological Effects of combined Pollution between Cadmium and Prometryn on Earthworms

In order to investigate the biochemical toxicity and cytotoxicity of the heavy metal cadmium and the pesticide prometryn, single and combined effects on soil animals, the effects of single and combined exposure to cadmium and prometryn on the levels of acetylcholinesterase(AchE), superoxide dismutase(SOD) activity, malondialdehyde(MDA), and the growth of the earthworms were studied with the ruddy love winsome earthworm, Eisenia fetida, as the test organism, reproduction, avoidance behavior and DNA damage in coelomocyte.The results showed that: The LC50 of prometryn for earthworms at 24 and 48 h were 66.72 mg/kg and 29.41 mg/kg, respectively, which were 11.03 and 12.67 times higher than those of cadmium, obtained by the filter paper method; AchE and SOD activities in earthworms were significantly inhibited(p < 0.05) with the extension of the dyeing time under the combined exposure of cadmium and prometryn; Compound pollution resulted in enhanced oxidative damage in earthworms, with all MDA levels higher than those in the single treatment group; earthworm body weight was not significantly suppressed(p > 0.05) within 21 d of combined exposure, but reproduction was significantly reduced(p < 0.05), and avoidance responses were more significant(p < 0.05);Combined exposure to cadmium and prometryn induced DNA damage in the coelomocyte of earthworms, and there was a dose-effect relationship with the concentration of the two composite pollutants.The combined exposure of cadmium-prometryn resulted in more severe toxicity to earthworms, aggravated the oxidative stress effect of the organism, and enhanced the environmental stress.