不同浓度饮水型砷暴露人群尿砷代谢产物的研究

Research on Urinary Arsenic Metabolites of Population Exposed to Different Concentrations of Arsenic by Drinking Water

目的结合WHO推荐的饮水砷卫生标准(0.01mg/L)和我国农村分散式供水采用的饮水砷卫生标准(0.05mg/L),初步探讨不同浓度饮水砷暴露人群的砷代谢状况和甲基化水平。方法于2008年10月选择山西高砷地区不同饮水砷浓度暴露的部分成年人为研究对象,高暴露组124人,饮水砷浓度≥0.05mg/L;低暴露组154人,0.01mg/L≤饮水砷浓度<0.05mg/L;对照组70人,饮水砷浓度<0.01mg/L。采用氢化物发生原子吸收分光光度法检测其尿中不同形态的砷代谢产物。结果随着饮水砷暴露浓度的升高,尿中各种形态砷代谢产物以及总砷含量也逐渐增高(P<0.05)。在同一水砷浓度暴露水平下,高暴露组中女性DMA,TAs含量以及SMR水平显著高于男性(P<0.05);低暴露组和对照组iAs、MMA、DMA、TAs含量、FMR和SMR水平在不同性别间差异均无统计学意义(P>0.05)。高暴露组中60岁～人群FMR水平显著高于18～39岁人群和40～49岁人群(P<0.05)。而低暴露组与对照组内不同年龄段人群FMR和SMR水平均无显著差异(P>0.05)。结论成人在较高饮水砷暴露水平下,女性二甲基化能力高于男性,高年龄组显示甲基化能力增强。在低饮水砷暴露条件下,性别、年龄对机体甲基化能力未见明显影响。

Objective Based on the health standards for arsenic in drinking water recommended by WHO （0.01 mg/L） and adopted by decentralized rural water supply in China （0.05 mg/L）, to explore the conditions of arsenic metabolism and levels of methylation in population consuming drinking water with different concentrations of arsenic. Methods Three hundred and forty- eight adults in Shanxi exposed to different concentrations of arsenie（≥0.05 mg/L, ≥0.01-〈0.05 mg/L, 〈0.01 mg/L） in drinking water were chosen as the objects for study in Oct.2008, which were divided into higher （n=124,≥ 0.05 mg/L ） ,lower （n=154, ≥0.01-〈0.05 mg/L） exposure group, control group（n=70, 〈0.01 mg/L） ,and the arsenic species and TAs in the urine samples were detected with hydride generation atomic absorption spectroscopy. Results With the concentrations of arsenic in drinking water increasing, the concentrations of arsenic species and TAs in the urine increased （P〈0.05）. DMA, TAs and secondary methylation ratio （SMR） of female were significantly higher than those of male （P〈0.05） in higher exposure group, while no gender differences were found （P〉0.05） in arsenic species, TAs, first methylation ratio （FMR） and SMR in lower exposure group and the control group. In higher exposure group, the FMR of adults aged over 60 years was significantly higher than that in groups of 18- 39 years old and 40-49 years old （P〈0.05）, while no differences of the FMR and SMR were found among each age group in lower exposure group and control group （P〉0.05）. Conclusion In higher exposure group, the 2nd reaction of the metabolic pathway is more active in female than that in male, and arsenic methylation capacity of the higher age group arise. No significant effects of gender and age on arsenic methylation capacity is found among population exposed to drinking water with lower level of arsenic.