Chung Stephen W C
Department of Food Science and Nutrition, Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2025 Mar;42(3):342-358. doi: 10.1080/19440049.2025.2449663. Epub 2025 Jan 8.
Arsenic (As) occurs naturally in different forms and oxidation states. Amongst them, inorganic arsenic (iAs) is classified as both genotoxic and carcinogenic whilst other organic arsenic species are considered less toxic. As in rice is mainly present in the form of iAs which therefore poses a health risk to populations that consume rice as a staple food. In 2011, the Joint Food and Agriculture Organisation/World Health Organisation Expert Committee on Food Additives determined the iAs benchmark dose lower confidence limit for a 0.5% increased incidence of lung cancer in humans (BMDL) which computed to be 3.0 μg/kg body weight (bw)/day. However, the European Food Safety Authority (EFSA) has recently lowered the BMDL of iAs to 0.06 μg iAs/kg bw per day based on a low risk of bias case-control/cohort study on skin cancer as a Reference Point (RP). Subsequently, EFSA established a BMDL of 18.2 mg monomethylarsenic (V) (MMA(V))/kg bw/day and 1.1 mg dimethylarsenic (V) (DMA(V))/kg bw/day as RPs with reference to studies on skin cancer and urinary bladder tumours in rats respectively. Therefore, As speciation is essential when conducting dietary exposure assessment. Recent studies showed thiolated counterparts of MMA and DMA were found in certain foodstuffs, especially grain. However, these thiolated As species were not recognised in acidic, basic or peroxide systems as they transformed to MMA and DMA in these extractants. Therefore, one of the objectives of this review was to assess whether published analytical methods are fit for As speciation analysis, especially for iAs, MMA and DMA, in foodstuffs. Besides, discussion was conducted on whether limits of detection are sufficiently low for dietary exposure assessment with respect to recently established RPs of iAs, MMA and DMA when an upper bound approach is applied. Moreover, possible future research gaps are identified based on current knowledge and existing literature.
砷（As）以不同的形式和氧化态天然存在。其中，无机砷（iAs）被归类为具有基因毒性和致癌性，而其他有机砷物种的毒性则被认为较低。大米中的砷主要以iAs的形式存在，因此对以大米为主食的人群构成健康风险。2011年，联合国粮食及农业组织/世界卫生组织食品添加剂联合专家委员会确定了人类肺癌发病率增加0.5%时的iAs基准剂量下限（BMDL），经计算为3.0微克/千克体重（bw）/天。然而，欧洲食品安全局（EFSA）最近根据一项关于皮肤癌的低偏倚风险病例对照/队列研究，将iAs的BMDL降低至0.06微克iAs/千克bw/天作为参考点（RP）。随后，EFSA分别根据大鼠皮肤癌和膀胱肿瘤的研究，确定了18.2毫克一甲基砷（V）（MMA（V））/千克bw/天和1.1毫克二甲基砷（V）（DMA（V））/千克bw/天的BMDL作为RP。因此，在进行膳食暴露评估时，砷的形态分析至关重要。最近的研究表明，在某些食品，尤其是谷物中发现了MMA和DMA的硫醇化对应物。然而，这些硫醇化砷物种在酸性、碱性或过氧化物体系中未被识别，因为它们在这些萃取剂中转化为MMA和DMA。因此，本综述的目标之一是评估已发表的分析方法是否适用于食品中砷的形态分析，特别是iAs、MMA和DMA。此外，还讨论了在应用上限法时，相对于最近确定的iAs、MMA和DMA的RP，检测限是否足够低以进行膳食暴露评估。此外，根据当前知识和现有文献确定了未来可能的研究空白。
