中国科学院地球化学研究所刘意章团队研究了受高地球化学背景和手工锌冶炼活动影响的土壤中镉的来源和环境风险。相关论文于2025年4月9日发表在《地球化学学报》杂志上。

土壤镉污染是一个备受关注的全球性环境问题。在中国西南部，土壤镉含量受到高地球化学背景和采矿/冶炼活动的显著影响。然而，这些镉源对土壤中镉富集和环境风险的具体贡献仍然知之甚少。因此，研究组调查了黔西北草海周边表层土和底土中的总镉和生物可利用镉等金属。

该研究旨在识别镉源，评估污染特征，并评估潜在的环境风险。结果表明，碳酸盐岩基岩的平均Cd含量为0.66mg/kg，证实了研究区Cd的天然高地球化学背景。土壤镉含量范围为0.14至6.69mg/kg，表层土壤的平均镉含量（2.29mg/kg）高于底土（0.71mg/kg）。统计分析表明，底土中的镉主要来源于地质。相比之下，表层土壤中约87%的镉来自与历史手工锌冶炼活动相关的大气沉积。

研究发现，表层土壤中的镉达到中等污染水平，具有很高的潜在生态风险。此外，表层土壤中生物可利用镉（DTPA可提取）的比例（26%）明显高于底土（13%）。表层土壤中镉生物可利用性的提高归因于大气中镉的沉积、较低的土壤pH值和较高的有机质含量。这些发现为管理高地球化学背景和冶炼活动地区土壤中的镉风险提供了关键见解。

附：英文原文

Title: Sources and environmental risks of cadmium in soils affected by high geochemical background and artisanal zinc smelting activities

Author: Luo, Chao, Zhou, Wangwang, Liu, Yizhang, Long, Jian, Ning, Zengping, Liu, Chengshuai

Issue&Volume: 2025-04-09

Abstract: Soil cadmium (Cd) pollution is a global environmental issue of significant concern. In southwestern China, soil Cd content is notably influenced by high geochemical background and mining/smelting activities. However, the specific contributions of these Cd sources to Cd enrichment and environmental risks in soils remain poorly understood. Therefore, this study investigated the total and bioavailable Cd and other metals in the topsoil and subsoils surrounding Caohai Lake in northwestern Guizhou Province. This research aimed to identify Cd sources, assess pollution characteristics, and evaluate the potential environmental risks. The results revealed that the carbonate bedrock has average Cd content of 0.66 mg/kg, confirming a naturally high geochemical background of Cd in the study area. Soil Cd content ranged from 0.14 to 6.69 mg/kg, with topsoil exhibiting higher average Cd content (2.29 mg/kg) than subsoil (0.71 mg/kg). Statistical analyses indicated that Cd in subsoil is primarily of geogenic origin. In contrast, approximately 87% of the total Cd in topsoil originates from atmospheric deposition linked to historical artisanal zinc smelting activities. The study found that Cd in topsoil reaches a moderate pollution level and poses a high potential ecological risk. Furthermore, the proportion of bioavailable Cd (DTPA-extractable) was significantly higher in topsoil (26%) than in subsoil (13%). This elevated Cd bioavailability in topsoil is attributed to atmospheric Cd deposition, lower soil pH, and higher organic matter content. These findings provide critical insights for managing Cd risks in soils from regions with high geochemical backgrounds and smelting activities.

DOI: 10.1007/s11631-025-00775-w

Source: https://link.springer.com/article/10.1007/s11631-025-00775-w