State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China.
State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China.
Ecotoxicol Environ Saf. 2023 Mar 1;252:114622. doi: 10.1016/j.ecoenv.2023.114622. Epub 2023 Feb 8.
Combined pollution of cadmium (Cd) and lead (Pb) occurs frequently in agriculture lands, which has received increasing research attention. However, little is known about the interaction behaviors of Cd and Pb at various concentrations in the mixture. This study evaluated the single and combined effects of Cd and Pb on rice (Oryza sativa L.) root elongation through acute exposure test. The combined pollution was analyzed with the concentration addition (CA) model, independent action (IA) model and mathematical statistical methods. The dose-response results revealed that the interaction could weaken the toxicity of both Pb and Cd, and Cd had a more significant inhibitory effect on Pb toxicity. The predicted values of CA and IA models were consistently lower than the observed values in the relative root elongation range of 0-60%. Further, combining the CA or IA model with mathematical statistical methods, the interaction of Pb and Cd at similar concentrations showed a significant antagonistic effect on rice root elongation. At low Pb concentrations (Cd > 0.0195, Pb < 0.015 mg/L), there was a synergistic effect of the mixture on rice root; at high Pb concentrations (Cd < 0.225, Pb ≥ 1.25 mg/L), Pb dominated the toxicity on rice root. This is the first report of a systematic method for assessing heavy metal interaction at different concentration levels, which may facilitate the formulation of control standards of heavy metal combined pollution in agricultural land.
镉（Cd）和铅（Pb）的复合污染在农业用地中经常发生，已引起越来越多的研究关注。然而，对于混合物中不同浓度下 Cd 和 Pb 的相互作用行为知之甚少。本研究通过急性暴露试验评估了 Cd 和 Pb 单一和复合污染对水稻（Oryza sativa L.）根伸长的影响。采用浓度加和（CA）模型、独立作用（IA）模型和数学统计方法分析了复合污染。剂量-反应结果表明，相互作用可减弱 Pb 和 Cd 的毒性，Cd 对 Pb 毒性的抑制作用更为显著。在相对根伸长率为 0-60%的范围内，CA 和 IA 模型的预测值始终低于观察值。此外，将 CA 或 IA 模型与数学统计方法相结合，在相似浓度下，Pb 和 Cd 的相互作用对水稻根伸长表现出显著的拮抗作用。在低 Pb 浓度（Cd > 0.0195，Pb < 0.015 mg/L）下，混合物对水稻根具有协同作用；在高 Pb 浓度（Cd < 0.225，Pb ≥ 1.25 mg/L）下，Pb 主导了对水稻根的毒性。这是首次报道在不同浓度水平上评估重金属相互作用的系统方法，这可能有助于制定农业用地重金属复合污染的控制标准。
