广州市区交通路口氮氧化物的组成分析

目的:为项目《机动车尾气污染健康效应评价技术的研究》选择高暴露人群及环境监测方法,内容包括通过对城市交通路口氮氧化物(NOx)浓度的监测,评估市区汽车尾气污染的水平和高暴露人群的NOx暴露特征;NOx浓度的监测采用盐酸萘乙二胺比色法,并用电子仪器监测结果加以对照,比较两种监测方法的监测结果的差异。方法:对NOx进行比色法与仪器法的现场监测,并进行统计分析。结果:交通路口NOx污染指标浓度均比对照点高(交通路口的NOx、NO2、NO浓度,NO/NO2比值的中位数分别为0.61、0.26、0.29、1.71,对照点为0.14、0.10、0.03、0.38),P<0.05,交通路口的NOx暴露以NO暴露为主,对照点以NO2为主;两种检测方法的结果有一定相关性(Spearmen秩相关分析P<0.05)。结论:交通路口NOx污染较重,污染物以NO为主;清洁对照点污染物以NO2为主;在反映NOx浓度变化趋势上,仪器法有参考价值。

Analysis of nitrogen oxides characteristics of Canton urban traffic junctions

Objective:To choose exposed group and method of environmental monitoring for the program "Study on the assessment technology of health effect of vehicle emission pollution",including the monitoring of nitrogen oxides in urban traffic junction,to describe the characteristics of automobile pollution in the city and the NOx exposure characteristics of high-risk people.Methods: NOx concentration was monitored by colorimetry of Naphthylethylenediamine dihydrochloride and the result was compared with that obtained by instrument method.Then the differences between the two methods were compared and analyzed by statistics.Results: On-site monitoring of NOx and statistical analysis showed that NOx pollutant concentration was higher at the traffic junction than control point(NOx,NO2,NO concentration and the median ratio of NO/NO2 were 0.61,0.26,0.29,1.71 at the traffic junction,while 0.14,0.10,0.03,0.38 at the control point);the results of the two detection methods had a certain correlation(Spearmen rank correlation P<0.05).Conclusion: At traffic junctions,NOx exceeds limits and it is NO-based;at control points,NOx basically reaches the standards and it is NO2-based.On observing the trend of the NOx concentration changes,instrument method has reference value.