School of the Environment, Henan University of Technology, Zhengzhou, Henan 450001, China; International Joint Laboratory of Environmental Pollution, Remediation and Grain Quality Safety of Henan Province, Zhengzhou, Henan 450001, China.
School of Environment and Natural Resources, Ohio State University, Columbus, OH 43210, USA; International Joint Laboratory of Environmental Pollution, Remediation and Grain Quality Safety of Henan Province, Zhengzhou, Henan 450001, China.
Sci Total Environ. 2023 Nov 20;900:166370. doi: 10.1016/j.scitotenv.2023.166370. Epub 2023 Aug 19.
Effect of commonly used heavy metal immobilizing agents on risks of soil heavy metals has not been well investigated. In this work, a contaminated acidic soil (total Cd = 8.05, total Pb = 261 mg kg) was amended with soluble phosphate (P: 160 mg kg) and bentonite (3 g kg) and incubated for 360 d. The soil was then added to mouse feed at 1:9 soil: feed ratio (weight) and fed to mouse for 10 days, after which the liver, kidney and bone Pb and Cd concentrations were measured. The amended soils were extracted with SBRC and PBET to assay bioaccessibility, and extracted with DTPA to assess the environmental availability. The amendments did not affect the DTPA-Pb/Cd significantly (p > 0.05), while the Cd bioaccessibility in the gastric phase of the SBRC assay was reduced from 90.0 to 20.4 % for the bentonite amended treatment (p < 0.05). Kidney Pb and Cd concentrations of the mice fed with feed containing phosphate spiked soil was 80.2 and 66.0 % lower than the control mice fed with unamended soil (CK), respectively. Significant linear correlations were found between DTPA-extractable concentration and kidney concentrations for Pb/Cd. The effect of amendment on Pb/Cd bioavailability differed between the results calculated with different endpoints. The phosphate amendment resulted in 82.7 and 34.3 % lower Pb RBA compared with the unamended soil calculated with kidney and kidney+liver+bone Pb concentrations, respectively, and 68.8 and 49.7 % lower Cd RBA than the control with kidney and kidney+liver concentrations, respectively. However, no significant effect was observed with both amendments when the RBA was calculated with liver or bone Pb/Cd concentrations, or on Pb RBA with kidney, liver or bone metal concentrations. Results indicate the complex effect of amendments on organ, tissue and overall health risk of soil Pb/Cd to animal/human.
常用重金属固定剂对土壤重金属风险的影响尚未得到充分研究。在这项工作中，用可溶磷酸盐（P：160mgkg）和膨润土（3gkg）处理受污染的酸性土壤（总 Cd=8.05，总 Pb=261mgkg），并在 360 天内进行孵育。然后将土壤以 1:9 的土壤：饲料比例（重量）添加到老鼠饲料中，并喂食老鼠 10 天，之后测量肝脏、肾脏和骨骼中的 Pb 和 Cd 浓度。用 SBRC 和 PBET 提取改性土壤以测定生物可利用性，并用水提取 DTPA 以评估环境可用性。改良剂对 DTPA-Pb/Cd 没有显著影响（p>0.05），而 SBRC 试验胃相中膨润土处理的 Cd 生物可利用性从 90.0%降低至 20.4%（p<0.05）。与喂食未改良土壤（CK）的对照小鼠相比，喂食含磷酸盐污染土壤的饲料的小鼠肾脏中的 Pb 和 Cd 浓度分别降低了 80.2%和 66.0%。发现 DTPA 可提取浓度与肾脏中 Pb/Cd 浓度之间存在显著的线性相关性。改良剂对 Pb/Cd 生物有效性的影响因不同终点计算的结果而异。与未改良土壤相比，磷酸盐改良剂导致计算肾 Pb 和肾+肝+骨 Pb 浓度时的 Pb RBA 分别降低了 82.7%和 34.3%，而计算肾和肾+肝浓度时的 Cd RBA 分别降低了 68.8%和 49.7%与对照相比，而用肝或骨 Pb/Cd 浓度计算 RBA 时，或用肾、肝或骨金属浓度计算 Pb RBA 时，两种改良剂均未观察到显著影响。结果表明，改良剂对动物/人类土壤 Pb/Cd 对器官、组织和整体健康风险的影响复杂。
