Innovative Benefit–Risk-Value Assessment for Cadmium and Selenium Coexposure in Black Shale Regions

The coexistence of cadmium (Cd) and selenium (Se) in black shale regions poses challenges for assessing health risks in local populations. Traditional risk assessments focus exclusively on single Cd contamination and total dietary intake, neglecting the interactions between them and the digestion and adsorption processes in the human body. This study established a novel benefit–risk-value (BRV) criterion to assess coexposure effects. Besides, we compared existing single-element risk assessment criteria and evaluated changes in risk before and after the incorporation of bioaccessibility using in vitro simulation. Rice constituted the major exposure source for Cd, whereas Se intake primarily relied on meat and rice. Integrating bioaccessibility with traditional risk assessment criteria significantly reduced the health risks associated with Cd exposure, while revealing notable Se deficiency in adults and seniors. Different from traditional models, BRV analysis indicated that children were safe from Cd and Se exposure, whereas adults and the seniors suffered from Se deficiency. As a biomarker, hair further validated the feasibility of the new standard. Correlation analysis demonstrates an age-dependent decline in the molar ratio of Se to Cd in hair samples. This study reveals that the mitigation of Se on Cd toxicity may contribute to Se deficiency.

黑色页岩区域中镉（Cd）与硒（Se）的共存，给当地人群的健康风险评估带来了挑战。传统风险评估仅聚焦于单一镉污染与膳食总摄入量，忽略了二者间的相互作用以及人体的消化与吸附过程。本研究建立了一种新型获益风险值（benefit–risk-value, BRV）评估标准，用于评估联合暴露效应。此外，本研究对比了现有单一元素风险评估标准，并借助体外模拟实验，评估了纳入生物可及性前后的风险变化。稻米是镉的主要暴露来源，而硒的摄入主要依赖肉类与稻米。将生物可及性与传统风险评估标准相结合，可显著降低镉暴露相关的健康风险，同时揭示出成人与老年人存在显著的硒缺乏问题。与传统模型不同，获益风险值分析结果显示，儿童的镉与硒暴露处于安全状态，而成人与老年人则面临硒缺乏问题。作为生物标志物的毛发样本，进一步验证了新标准的可行性。相关性分析结果表明，毛发样本中硒与镉的摩尔比随年龄增长呈下降趋势。本研究揭示，硒对镉毒性的缓解作用可能会加剧硒缺乏问题。