Guobing Lin, Chao Zhang, Zhongfang Yang, Yong Li, Chenjing Liu, Lena Q. Ma
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引用次数: 0
Abstract
High geological background concentrations of toxic metal(loid)s arsenic (As) and cadmium (Cd) from natural enrichment in soils of karst regions have attracted much attention. In this study, paired soil-rice samples were collected from karst and non-karst regions in Guangxi, China to assess the potential risks of metal(loid) transfer from soil to rice grains, and rice grains to humans. Our results indicate that the karstic soils had greater As (25.7 vs. 12.4 mg·kg-1) and Cd (2.12 vs. 1.04 mg·kg-1) contents than those in non-karstic soils. However, metal(loid) transfer from soil to rice grains (ratio of rice grains to soil content) of As and Cd was 40 and 49% lower in karst regions, which may relate to their 42 and 61% lower HNO3-extractable As and CaCl2-extractable Cd, resulting in similar As/Cd contents in karstic and non-karstic rice grains. In vitro assay using a modified physiologically-based extraction test showed that karstic rice grains had a lower As/Cd bioaccessibility than non-karstic grains, which can be attributed to their ~50% greater P content, which negatively correlated with As/Cd bioaccessibility. Additionally, karstic rice grains had 39% greater phytate and exhibited 45% and 9.4% lower As and Cd bioaccessibility in the gastric phase with phytate supplement at 0.6%. Our work indicates that despite the greater As/Cd contents in karstic soils, the risks of As/Cd transfer from soil to rice grains as well as their exposure risks to humans via rice consumption may not be greater than non-karst regions.
期刊介绍:
The Journal of Hazardous Materials serves as a global platform for promoting cutting-edge research in the field of Environmental Science and Engineering. Our publication features a wide range of articles, including full-length research papers, review articles, and perspectives, with the aim of enhancing our understanding of the dangers and risks associated with various materials concerning public health and the environment. It is important to note that the term "environmental contaminants" refers specifically to substances that pose hazardous effects through contamination, while excluding those that do not have such impacts on the environment or human health. Moreover, we emphasize the distinction between wastes and hazardous materials in order to provide further clarity on the scope of the journal. We have a keen interest in exploring specific compounds and microbial agents that have adverse effects on the environment.