title: Individual and joint toxicity effects of Cu, Cr(III), and Cr(VI) on pakchoi: a comparison between solution and soil cultures.
abstract: The single and joint toxicity effects of Cu, Cr(III), and Cr(VI) on the root elongation of pakchoi in solution and soil were investigated. The median effective concentration (EC(50)) was determined to examine the toxic thresholds of the test elements. The results showed that individual contamination by Cu, Cr(III), or Cr(VI) can inhibit the root elongation of pakchoi. The EC(50) values of the test elements were 2.02 mg/L and 195.8 mg/kg, 62.2 mg/L and 1,773 mg/kg, and 6.88 mg/L and 8.08 mg/kg in solution and soil, respectively. Toxic unit (TU) was introduced to determine the outcome in combined tests, and different behaviors were observed in both solution and soil. The coexistence of Cu and Cr(III) in solution exhibited an antagonistic effect (EC(50mix) = 1.76 TU(mix)), whereas a synergistic effect was observed in soil (EC(50mix) = 0.76 TU(mix)). In contrast, combined Cu-Cr(VI) showed a less than additive toxicity both in solution and soil, with EC(50mix) values of 3.31 and 1.24 TU(mix). In conclusion, the coexistence of toxicity in Cu-Cr(III) and Cu-Cr(VI) differs from the toxicity exhibited individually by Cu, Cr(III), and Cr(VI). Heavy metal interaction also changes depending on the medium.
authors.affiliation: College of Resources and Environment, Northwest A & F University, Yangling, Shaanxi, 712100, China. shandandan807@163.com
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.forename: Dongli
authors.initials: D
authors.lastname: Liang
authors.forename: Songshan
authors.initials: S
authors.lastname: Wang
authors.forename: Bin
authors.initials: B
authors.lastname: Hu
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
mesh_terms: D001937:Brassica / Q000187:drug effects* / Q000254:growth & development; D002857:Chromium / Q000633:toxicity*; D003300:Copper / Q000633:toxicity*; D019216:Metals, Heavy / Q000633:toxicity*; D012989:Soil Pollutants / Q000633:toxicity*
chemical_list: D019216:Metals, Heavy; D012989:Soil Pollutants; D002857:Chromium; D003300:Copper