西安市大气悬浮颗粒提取物致突变性及其金属元素含量的研究

背景提高西安市大气质量,掌握和评价西安市大气质量状况及大气悬浮颗粒物的致癌危险性,能为采取有效措施防治大气悬浮颗粒提取物致实变性疾病的发生提供依据.目的了解西安市采暖期和非采暖期的大气总悬浮颗粒物(totalsuspended particulates,TSP)质量浓度、有机提取物的致突变性及无机提取物中铅、锰、镉、镍、铬等金属元素特征.设计随机抽样调查.地点、材料和方法西安市开关厂(工业区)、纺织城(混合区)、市环境监测站(交通繁忙区)、草滩(对照区)4个具有代表性的采样点.各采样点分别于1998年6,7,8,12月和1999年1,2月根据西安市城市功能分区,用网格式布点法随机选择了4个大气质量监测点,于采暖期和非采暖期共采集大气悬浮颗粒物样品96份,分别采用增重法、Ames试验-平板掺入法和火焰原子吸收法,对样品中大气TSP质量浓度、有机提取物的致突变性及无机提取物中铅、锰、镉、镍、铬等金属元素含量进行测定.主要观察指标样品中大气TSP质量浓度、有机提取物的致突变性及无机提取物中铅、锰、镉、镍、铬等金属元素含量.结果西安市采暖期大气TSP质量浓度为0.5865 mg/m3,非采暖期为0.353 5 mg/m3,差异有显著性意义(P＜0.05),且两期TSP质量浓度均显著高于其各自对照区(F=1.659,P＜0.05).各采样点TSP的有机提取物致突变性检测结果显示各功能区均可检出致突变阳性样品,同一季节各监测点致突变阳性检出率无显著性差异(P＞0.05),但采暖期致突变阳性检出率显著高于非采暖期(x2=4.20,P＜0.05).各采样点TSP无机提取物中5种金属元素质量浓度由高到低依次为铅、锰、镉、镍、铬.采暖期各金属质量浓度显著高于非采暖期(t=3.644,P＜0.05).结论西安市大气TSP水平与采暖燃煤关系密切;燃煤可能是造成西安市大气TSP致突变性增强及各种金属质量浓度升高的主要原因之一.

Study on the mutagenicity of organic extracts and metal features of total suspended particulates in Xi''''an city

AIM: To study the concentration, mutagenicity of organic extracts and metal element(Pb, Mn, Cr, Ni, Cd) features of the total suspended particulates (TSP) in heating and non-heating seasons in Xi' an city.METHODS: There are four representational surveillance spots in Xi'an. These are switch plate factory of Xi' an(industry zone), spinning milldistrict ( mixed zone ), the station of environmental surveillance (heavy traffic)and Cao tan district(control zone) . According to the distribution of the city functional district, four surveillance spot were chosen by the method of grid on June, July, August and December in 1998 and January, February in 1999. The concentration, mutagenicity of organic extracts and the Pb, Mn,Cr, Cd metal element features were investigated in 96 TSP samples obtained from two seasons by means of increasing weight, Ames test-planer penetration and atomic absorption by spectrophotometry, respectively. The concentration,mutagenicity of organic extracts and the Pb, Mn, Cr, Cd metal element features were investigated.RESULTS: In the heating and non-heating seasons, the TSP concentration were 0.586 5 mg/m3 and 0.353 5 mg/m3 respectively, the former was higher significantly ( P ＜ 0.05 ), and the TPS concentration in two seasons was also higher than the control group of themselves( P ＜ 0.05 ) . The positive mutagenicity of organic extracts were tested in all functional sampling spot, and the positive rate in heating period was higher than non-heating season significantly (P ＜ 0.05 ), but there was no difference among the same season samples ( P ＞ 0.05 ) . The concentration level sequence of five metal elements were Pb, Mn, Cr, Ni, Cd from high to low,and the individual concentration in heating season was higher than non-heating period ( P ＜ 0.05 ).CONCLUSION: There is a close relationship between the TSP concentration and the coal consumption, and the coal consumption is probably a main reason in enhancing the mutagenicity of TSP in Xi' an city.