Acute Toxicity of Nickel to Earthworm Eisenia fetida in Typical Chinese Soils
不同类型土壤中外源镍对赤子爱胜蚓的急性毒性

Acute toxicity of nickel to earthworm Eisenia fetida in 13 spiked soils was investigated using the methods of International Standardization Organization (ISO). The results show that nickel toxicity to E. fetida differs in different soils, and 50% lethal concentrations (14 LC50) varies from 243.8 to 1 970.6 mg kg-1. Nickel toxicity to E. fetida in a range of Chinese soils can be ranked as red soil (Hunan)>purple soil (Chongqing)>red earth (Jiangxi)>fluvo\|aquic soil (Henan)>black soil (Jilin)>paddy soil (Zhejiang)>grey desert soil (Xinjiang)>fluvo\|aquic soil (Beijing)>loessal soil (Shaanxi)>fluvo\|aquic soil (Shandong)>fluvo\|aquic soil (Hebei)>paddy soil (Jiangsu)>black soil (Heilongjiang). An eight\|fold difference of nickel LC50 exists between red soil (Hunan) and black soil (Heilongjiang). Stepwise multiple regressions are carried out to determine the relative contributions of some soil properties (pH, organic matter capacity, cation exchange content and clay content) to nickel LC50. Significant positive correlations were observed between soil pH, organic matter content and nickel LC50. Soil pH and organic matter content can account for 79.4% variance for nickel LC50. The ecotoxicity data generated in the current study may provide useful reference information for the development of ecological soil screening values in China.