Ecotoxicological responses of the earthworm Eisenia fetida to EDTA addition under turfgrass growing conditions.

As a commonly used chelator, ethylenediaminetetraacetic acid (EDTA) enters soil environment inevitably and has the potential to cause negative effects on soil organisms. The objective of the current study was to investigate the effects of EDTA on earthworm growth, survival and activities of antioxidant enzymes. The assessment for EDTA toxicity toward earthworms (Eisenia fetida) was conducted on day 14 and 35 after exposure to four concentrations (0, 5, 10, 15 mmol kg-1) of EDTA under turfgrass growing conditions. Exposure to EDTA resulted in a significant decrease of earthworm growth and survival. The toxicity of EDTA increased with the increase in concentration and exposure duration. The activities of antioxidant enzymes increased at low concentration and decreased at high concentration, which indicates that oxidative stress was induced by EDTA addition. These results suggest EDTA is highly toxic and ecologically dangerous to earthworms.