Biological Responses On The Earthworm Eisenia Fetida Under Lead, Cadmium And Chromium In Soils Stress

In this paper,the research method of ecotoxicology is combined with field investigation and the artificial soil simulates the actual soils.The pollution of heavy metals in the soil samples from a battery plant were analyzed.The pollution of main heavy metals were Pb,Cd and Cr in lead acid battery that them were studied.Biological Responses on the Earthworm Eisenia fetida under Lead,Cadmium and Chromium in Soils stress was discussed.The results of sublethal effect and biomarker responses in Eisenia fetida under Pb,Cd and Cr exposure in soil.The primary resultsare as follows:1.Investigation of the pollution soils in a typical lead acid battery plant:the soil samples were all alkaline soil,the concentrations of heavy metals,especially Pb,decreased sharply with increase in distance,which may be due to the leaching and accumulation of Pb in soil during production processes.Lead is the main pollutant in lead acid battery plant and around farmland soils.Soil samples at 0,10,100,200,300 and 500m from a battery plant were collected and used to research the avoidance behavior and biochemical responses in Eisenia fetida.2.Acute test of Eisenia fetida?1?The acute toxicity test of Eisenia fetida,14 d LC₅₀ was 2526.048,362.827and 229.436 mg/kg on Eisenia fetida for lead,cadmium,chromium and according to concentration probit line for determination of LC₅₀.The toxicity is Cr>Cd>Pb.?2?The avoidance behavior test of Eisenia fetida,the total avoidance effect threshold was 2000.00,120.00,120.00 mg/kg respectively under exposures to lead,cadmium and chromium showde.The sensitivity is Cd?Cr>Pb.The avoidance rate of Eisenia fetida decreased gradually with the increase of soil samples distance in battery plant soils.The avoidance enddpoint was more sensitive than the mortality endpoint in assessing Pb,Cd and Cr contaminated soils.3.The accumulation of heavy metals in Eisenia fetida:the accumulation of heavy metals in Eisenia fetida decreased with the increasing soil samples distance.Eisenia fetida has a strong tolerance and accumulation capacity under lead,cadmium and chromium exposure in soil,the accumulation capacity of Eisenia fetida is Cd>Cr>Pb.4.The biomarker responses of Eisenia fetida under Pb,Cd and Cr exposure in soils.Laboratory acclimated Eisenia fetida were exposed to lead,cadmium and chromium in artificial soils for 1,3,7 and 14 days and its biomarker responses.The primary resultsare of Pearson analysis as follows:?1?Metallothionein?MT?and malonaldehyde?MDA?in Eisenia fetida were correlated to Pb,Cd and Cr contaminated soils for 1 day?p<0.05?;peroxidase?POD?,superoxide dismutase?SOD?and acetyl choliesterase?AChE?in Eisenia fetida were correlated to Pb and Cd contaminated soils for 1 day?p<0.05?.?2?MT and MDA in Eisenia fetida were correlated to Pb,Cd and Cr contaminated soilsfor 3 days?p<0.05?;SOD in Eisenia fetida were correlated to Cd and Cr contaminated soilsfor 3 days?p<0.05?;AChE in Eisenia fetida were correlated to Pb and Cd contaminated soils for 3 days?p<0.05?;gluathione-s-transferase?GST?in Eisenia fetida were correlated to Cd contaminated soils for 3 days?p<0.05?.?3?MT and MDA in Eisenia fetida were correlated to Pb,Cd and Cr contaminated soils for 7 days?p<0.05?;SOD in Eisenia fetida were correlated to Cd and Cr contaminated soilsfor 7 days?p<0.05?;AChE in Eisenia fetida were correlated to Pb and Cd contaminated soils for 7 days?p<0.05?.?4?MT,MDA,SOD and AChE in Eisenia fetida were correlated to Pb,Cd and Cr contaminated soils for 14 days?p<0.05?;GST in Eisenia fetida were correlated to Cd and Cr contaminated soils for 14 days?p<0.05?.5.The biomarker respoonses of Eisenia fetida in battery plant,the primary resultsare of Pearon analysis were as follows:MT,MDA,SOD,POD and AChE were correlated to sampling distance for 1 day?p<0.05?;MT,MDA,SOD and AChE were correlated to sampling distance for 3day3?p<0.05?;MT and SOD were correlated to sampling distance for 7 days?p<0.05?;The contents of MT,MDA,SOD and GST were correlated to sampling distance for 14 days?p<0.05?.Catalase?CAT?was no significant correlation with sampling distance?p<0.05?.The above research shows that the soils around the battery plant were polluted with metals giving rise to adverse biological effects.The soils around battery plant were polluted with metals that pose potential risks to the earthworms and environmental health.The avoidance behavior,the concentrations of MT and MDA in Eisenia fetida showed high sensitivity to heavy metal exposure indicating that may be regarded as the sensitive,simple,and general biomarker for monitoring and assessment application.It provides data support for ecotoxicity identification and rapid ecotoxicological diagnosis of heavy metals in soils of typical industrial sites in China.