中国砷中毒病区腐植酸样品致突变性研究

目的探讨砷中毒地区的腐植酸样品有无致突变性。方法用Ａｍｅｓ试验检测了从中国贵州省高砷煤、台湾乌脚病病区井水和内蒙古砷中毒病区井水中提取的天然腐植酸样品。结果贵州高砷煤中腐植酸在不加大鼠肝匀浆（＋Ｓ９）时回复突变系数为１．０２～０．８２ｒｅｖ／μｇ，在加入大鼠肝匀浆（＋Ｓ９）时回复突变数为１．５３～１．１２ｒｅｖ／μｇ。并有明显的剂量反应关系存在。结论贵州高砷煤中腐植酸对ＴＡ９８（移码突变型）菌株有较强的直接致突变性，台湾乌脚病病区井水中腐植酸对ＴＡ９８（－Ｓ９）有较弱的致突变作用，而内蒙腐植酸没有致突变作用。同时还研究了商品腐植酸、砷和铁的致突变性，发现单纯的砷、铁和商品腐植酸均无致突变作用，但是砷与腐植酸共同作用，在某一浓度时，不论有没有铁存在，对ＴＡ９８（－Ｓ９）都有微弱的致突变作用。以上各种样品对ＴＡ１００（±Ｓ９）（碱基取代型）菌株均不表现出致突变作用。

Studies on Mutagenicity of Humic Acid Samples Collected from Arsenosis affected Areas in China

OBJECTIVE: To explore whether there is mutagenicity of humic acid samples collected from arsenosis affected areas in China. METHODS: Ames' test was used for natural humic acid samples extracted from the coal containing high arsenic in Guizhou Province, and the well water in the areas with blackfoot disease in Taiwan and with arsenosis in Inner Mongolia of China. RESULTS: Coefficients of revertant mutation were 1.02-0.82 net revertant per microgram (rev/microgram) of humic acid extracted from the coal containing high arsenic in Guizhou without rat liver homogenate (-S9), and 1.53-1.12 rev/microgram of that with rat liver homogenate (+S9), with an obvious dose-response relationship. CONCLUSION: Humic acid extracted from the coal containing high arsenic produced in Guizhou could cause stronger direct mutation in Salmonella typhimurium TA98 (frameshift mutation) and that extracted from the well water in the areas with blackfoot disease in Taiwan could cause weaker direct mutation in Salmonella typhimurium (-S9), but that extracted from the well water with arsenosis in Inner Mongolia could not cause mutation. Mutagenicity of commercial humic acid, purchased from Aldrich Co. in the United States, arsenic and iron was also studied, and no mutagenicity was found for them independently, but arsenic combined with humic acid, at certain concentrations, could cause weak mutation in TA98 (-S9), with or without iron. No mutagenicity in TA100 (+/- S9, base pair substitution mutation) was found in all the samples mentioned above.