Toxicity Thresholds Based on EDTA Extractable Nickel and Barley Root Elongation in Chinese Soils

摘要: The uncertainty in the risk assessment of trace metal elements soils when total contents are used can be decreased by assessing their availability and/or extractability have a high background value or different sources elements. In this study, added water-soluble nickel (Ni) toxicity to barley root elongation was studied 17 representative Chinese soil samples with and without artificial rainwater leaching. Ni estimated three sequential extractions ethylenediaminetetraacetic acid (EDTA). results showed that effective concentration EDTA extractable (EC50), which caused 50% inhibition elongation, ranged from 46 1019 mg/kg unleached 24 1563 leached soils. Regression models for against properties indicated significantly correlated pH most important control factor. thresholds based on citrate dithionate Fe more than predicting toxicity. These accurately assess contaminated values sources.