轮作模式下多种农作物8种重金属的富集特征与膳食风险评估

Enrichment characteristics and dietary risk assessment of 8 kinds of heavy metals in multiple crops under rotation planting systems

中文关键词:  重金属  富集特征  膳食暴露风险评估  目标危害商数  致癌风险  农产品安全

英文关键词:heavy metals  enrichment characteristics  dietary risk assessment  target hazard quotient  total carcinogenic risk  agricultural product safety

中文摘要:

      目的 研究同一地块中轮作种植下不同农作物对Pb、As、Cd、Cr、Ni、Sn、Sb、Tl等8种重金属的富集特征及膳食健康风险。方法 2023–2025年间系统采集该地块38种轮作种植的农作物样品, 测定其重金属含量, 系统解析其富集特征与差异, 依据GB 2762—2022《食品安全国家标准 食品中污染物限量》规定的限值进行安全评价, 并运用每日摄入量(estimated daily intake, EDI)、目标危害商数(target hazard quotient, THQ)和总致癌风险(total carcinogenic risk, TCR)模型评估成人与学龄前儿童的暴露风险。结果 农作物中重金属富集能力呈现明显类别与元素特异性。Pb、Cd在叶菜类(如生菜、油麦菜等)中富集较强; Ni在豆类(如蚕豆、豌豆)中相对易富集; Sn相对高富集于叶菜类(黄芽菜、油冬菜等)与部分芸薹类; As、Cr在叶菜类中也具有一定富集能力, 但总体污染水平较低; Sb与Tl未出现明显积累。风险评估显示, 多种作物(如生菜、菠菜、茄子、油麦菜、芹菜)对Cd存在潜在致癌风险(TCR>10–4), 生菜中的Pb、Cd对儿童构成潜在非致癌风险(THQ>1), 豆类对Ni的暴露风险相对较其他农作物突出, 特别是蚕豆对儿童与成人均构成潜在非致癌风险等。结论 本研究表明, 在同地块轮作种植中, 不同农作物对重金属的富集特征与健康风险存在明显差异。为保障农产品安全与健康膳食, 建议在农田源头推行基于作物的分级管控策略, 规避、限制重金属高富集品种, 推广种植重金属低积累品种, 并通过膳食指南引导公众(尤其是儿童)合理消费, 构建从种植到食用的全链条安全健康防护体系。

英文摘要:

      Objective To investigate the enrichment characteristics and dietary health risks of 8 kinds of heavy metals (Pb, As, Cd, Cr, Ni, Sn, Sb, Tl) in various crops under rotational planting in the same field. Methods From 2023 to 2025, a total of 38 kinds of rotationally planted crop samples were systematically collected from the field. The heavy metal content was measured, and their enrichment characteristics and differences were analyzed. The monitoring results were evaluated based on the limits specified in the GB 2762—2022 National food safety standards-Limits of contaminants in food and the exposure risks for adults and preschool children were assessed using the estimated daily intake (EDI), target hazard quotient (THQ) and total carcinogenic risk (TCR) models. Results The enrichment capacity of heavy metals in crops exhibited significant category- and element-specific characteristics. Pb and Cd showed stronger enrichment in leafy vegetables (e.g., lettuce, youmai cabbage, etc); Ni was relatively highly enriched in legumes (e.g., broad beans, peas); Sn was relatively highly enriched in leafy vegetables (e.g., yellow sprout cabbage, youdong cabbage) and some brassica vegetables; As and Cr also demonstrated certain enrichment capabilities in leafy vegetables, though overall pollution levels were low; no significant accumulation of Sb or Tl was observed. Risk assessment indicated that multiple crops (e.g., lettuce, spinach, eggplant, youmai cabbage, celery) showed potential carcinogenic risks for Cd (TCR>10–4). Pb and Cd in lettuce pose potential non carcinogenic risks to children (THQ>1). The exposure risk of Ni from legumes was relatively higher than that from other crops. In particular, broad beans posed a potential non-carcinogenic risk to both children and adults. Conclusion This study indicates that there are significant differences in the enrichment characteristics and health risks of heavy metals among different crops in crop rotation on the same plot. To ensure the safety of agricultural products and a healthy diet, it is recommended to implement a crop based graded control strategy at the source of farmland avoid and restrict high accumulation varieties of heavy metals, and promote the cultivation of low-accumulation crop varieties; and guide public consumption, especially for children, through dietary guidelines. This approach will help establish a full-chain health protection system from planting to consumption.