近日，华中农业大学资源与环境学院国家环境保护土壤健康诊断与绿色修复重点实验室土壤化学与环境团队在稻米重金属污染特征分析及健康风险评价方面取得重要进展，相关研究成果以“Heavy metal concentrations in rice that meet safety standards can still pose a risk to human health”发表在Communications Earth & Environment。
食品安全关乎人类健康和社会福祉。稻米是世界上一半以上人口的主食，极易受重金属污染。为了最大限度降低健康风险，国际组织和各国政府制定了稻米重金属的最大可接受浓度（MAC）。然而，食用人群的个体差异也会对人体健康风险产生重要影响，致使长期暴露于低于MAC浓度的稻米仍可能对部分人群存在健康风险。
针对受体和区域饮食习惯差异对健康风险的影响尚不清晰这一问题，土壤化学与环境课题组联合概率和模糊方法，精准识别了全国32个省份的关键受体，并测算了相应健康风险的超标概率，评估了不同省份5种重金属(镉、砷、汞、铅、铬)对健康风险的贡献率。研究结果表明，长期食用符合食品安全国家标准的稻米仍会可能造成不可忽视的健康风险，而长期暴露的儿童和幼儿最为严重。这种健康风险主要来自砷与镉。由于贸易发生空间转移等因素的影响，土壤重金属污染区与健康高风险区空间分布并不完全吻合。本研究近一步提高了重金属污染人体健康风险评估的精准性，为食品安全标准优化与农业污染治理规划提供理论支撑。
我校资源与环境学院硕士研究生魏仁皓为论文第一作者，陈畅副教授为通讯作者。资源与环境学院谭文峰教授、王真教授、刘朝阳副教授、湖北省生态环境科学研究院蔡俊雄教授等参与了研究工作。该研究得到了国家自然科学基金、湖北省自然科学基金和湖北省创新研究岗位项目的资助。
【英文摘要】
Long-term consumption of rice containing heavy metal(loid)s poses significant risks to public health, which can be scientifically evaluated through food safety assessment. However, spatial variability and uncertainty in exposure parameters are generally neglected in existing food safety assessment standards. This study focused on rice consumption in 32 provinces of China, and extracted 3,376 data points of five heavy metal(loid)s (cadmium, arsenic, mercury, lead, and chromium) and two nutrient elements (copper and zinc) from 408 articles. Probability and fuzzy methods were integrated to cope with the spatial variability or uncertainty and more accurately evaluate the risk. The results demonstrated that long-term consumption of rice that meets the national food safety standards still can cause non-negligible health risks, particularly for children and toddlers with chronical exposure. Arsenic and Cd were found to be the most critical elements, which contribute to 64.57% and 22.38% of the overall human health risk, respectively. Fuzzy assessment indicated that the score in northern China is approximately eight folds of that in southern China, indicating that northern rice has lower risks and better nutrition. Our results demonstrate that the food safety standards need to be tailored according to local conditions with more specific receptor parameters and risk acceptance.
论文链接：https://www.nature.com/articles/s43247-023-00723-7
