Study on the biological effects of the environmental arsenic expo-sure

砷存在于鱼类、贝类和海藻等海产品中，也存在于温泉水中。为了评估这些环境砷暴露的生物效应，我们建议检测3组人群的尿砷浓度，a)日本普通健康人，b)吃大量海产品的人，c)日常使用温泉的人。对健康人群尿液中无机砷(IAS)、单甲基砷(MA)、二甲基砷(DMA)和三甲基砷(TMA)进行了检测，其中二甲基砷(DMA)和三甲基砷(TMA)的含量高达70%以上。以IAS及其代谢产物(MA和DMA)之和表示的IMD水平是无机砷中毒的有用标志物。由于在许多没有接触过砷的健康人中检测到了更高水平的尿IMD，我们不得不考虑它在未来的意义。食用大量海产品的人群尿砷水平显著高于健康人，尤其是DMA和TMA。有人认为，这一结果反映了海产品的大量摄入量。为评价氧化应激在环境砷中的作用，建立砷的生物监测方法，测定了3组人群的尿8-羟基脱氧鸟苷(8-0HdG)水平。健康人尿8-0HdG水平无性别和年龄差异。食用大量海产品者和日常饮用温泉水者的8-0HdG水平均显著高于健康人。而尿砷浓度与8-0HdG水平无明显相关性，提示两组人群中8-0HdG水平偏高与环境砷暴露有关。

Arsenic occurs in marine products, such as fish, shellfish and seaweed and also occurs in hot spring water. To evaluate the biological effects of these environmental arsenic exposures, we proposed to examine the urinary concentrations of arsenic species in 3 groups, a)Japanese ordinary healthy people, b)peosons who eat much marine products, c)persons who daily use the hot spring water. Inorganic arsenic(iAs), monomethyl arsenic(MA), dimethyl arsenic(DMA) and trimethyl arsenic(TMA) were detected in urine of healthy people and it was composed 70% more by TMA. IMD level that indicated as the sum of iAs and its metabolites (MA and DMA) was a useful marker of inorganic arsenic poisoning. Because higher levels of urinary IMD were detected in many healthy people who were not suffered from arsenic exposure, we have to consider its meaning in the future. Urinary arsenic levels of all species, especially DMA and TMA were significantly higher in the persons who eat much marine products than healthy people. It was suggested that much intake of marine products reflected on this result. To evaluate the role of oxidative stress in environmental arsenic and to establish the biological monitoring for arsenic, urinary 8-hydroxydeoxyguanosine(8-0HdG) levels of all persons in 3 groups were measured. Neither sex nor age differences were found in urinary 8-0HdG levels of healthy people. 8-0HdG levels in both persons who eat much marine products and who daily use the hot spring water were significantly higher than healthy people. However no significant correlation was shown between the urinary concentrations of arsenic species and 8-0HdG levels, such high level of 8-0HdG in 2 groups was suggested due to the environmental arsenic exposure.