Department of Earth Science, 6105 Sherman Fairchild Hall, Dartmouth College, Hanover, NH, 03755, USA.
Department of Epidemiology, Geisel School of Medicine, 1 Medical Center Drive 7927 Rubin Building, Lebanon, NH, 03756, USA.
Sci Rep. 2017 Jun 20;7(1):3920. doi: 10.1038/s41598-017-03883-7.
Seaweeds contain arsenic primarily in the form of arsenosugars, which can be metabolized to a wide range of arsenic compounds. To characterize human exposure to arsenic from seaweed consumption, we determined concentrations of arsenic species in locally available seaweeds, and assessed urinary arsenic compounds in an experimental feeding study. A total of 11 volunteers consumed 10 g per day of three types of seaweeds (nori, kombu, and wakame) for three days each, while abstaining from rice and seafood following a three-day washout period. Urinary arsenosugars and their metabolites (including dimethyl arsenate (DMA), thio-dimethylarsinoylethanol (thio-DMAE), thio-dimethylarsinoylacetate (thio-DMAA), and thio-DMA) were measured in spot urine samples prior to seaweed consumption, and in 24-hour urine samples while consuming seaweed. Commercial products made from whole seaweed had substantial concentrations of arsenic (12-84 µg/g), dominated by arsenosugars. Intact arsenosugars along with DMA, thio-DMAA, thio-DMAE all increased in urine after ingesting each type of seaweed, and varied between seaweed types and between individuals. Only trace levels of the known toxic metabolite, thio-DMA, were observed, across individuals. Thio-DMAE and thio-DMAA are unique products of arsenosugar breakdown, thus assessment of these compounds may help to identify dietary intake of arsenic from seaweed from other exposure pathways.
海藻中的砷主要以砷糖的形式存在，这些砷糖可被代谢为多种砷化合物。为了确定从食用海藻中摄入砷的人体暴露情况，我们测定了当地可获得的海藻中砷的形态浓度，并在一项实验性喂养研究中评估了尿液中的砷化合物。共有 11 名志愿者连续三天每天食用 10 克三种海藻（紫菜、昆布和裙带菜），在三天的洗脱期后，停止食用大米和海鲜。在食用海藻前和食用海藻期间，采集 24 小时尿液样本，测定尿中砷糖及其代谢物（包括二甲基砷酸（DMA）、二甲基砷酸硫代乙氧基乙醇（thio-DMAE）、二甲基砷酸硫代乙酸酯（thio-DMAA）和二甲基砷酸硫代甲醚（thio-DMA））的浓度。由全海藻制成的商业产品含有大量的砷（12-84μg/g），主要是砷糖。摄入每种海藻后，尿液中的完整砷糖以及 DMA、thio-DMAA、thio-DMAE 均增加，且在不同海藻类型和个体之间存在差异。仅在个体中观察到痕量已知的有毒代谢物 thio-DMA。thio-DMAE 和 thio-DMAA 是砷糖分解的独特产物，因此评估这些化合物可能有助于确定通过食用海藻从其他暴露途径摄入的砷。
