城市道路交叉口颗粒物浓度及行人暴露研究

Particle Concentration and Pedestrian Exposure Assessment at Urban Road Intersections

为研究城市道路交叉口内部颗粒物浓度的分布规律以及评估行人暴露水平,探究了6种粒径颗粒物(0.3~0.49、0.5~0.99、1~1.99、2~4.99、5~9.99、>10μm)在交叉口的分布规律,分析研究气象要素(温度、相对湿度、风速和气压)对颗粒物浓度变化的影响,并基于交叉口微环境内的颗粒物浓度对不同人群的颗粒物暴露水平进行了评估。实验结果表明:粒径>5μm的颗粒物冬季高于夏季,<5μm的颗粒物夏季高于冬季,6种颗粒物数量浓度早高峰均高于晚高峰以及工作日均高于非工作日;相邻粒径范围颗粒物间显示出强相关,同时温度和气压对粒径在0.5~0.99μm间的颗粒物影响较大,相对湿度对粒径>5μm的颗粒物影响较大;PM1、PM2和PM10这3种颗粒物均在老年人的体内沉积率最高,这表明环境颗粒物对老年弱势群体的危害更大;夏季PM1、PM2和PM10的沉积率分别比冬季高出116%、112%和20%,因此相较于粗颗粒物,细颗粒物对人体健康危害更为严重。

In order to study the distribution of particulate matter concentration in urban road intersections and the assessment of pedestrian exposure level,the distribution of six kinds of particles(0.3~0.49μm,0.5~0.99μm,1~1.99μm,2~4.99μm,5~9.99μm,>10μm)at the intersection and the impact of meteorological factors(temperature,relative humidity,wind speed and pressure)were analyzed.Based on the particulate matter concentration in microenvironment of intersection,the exposure levels in different populations was assessed.The experimental results show that the particle concentration,with size is larger than 5μm,is higher in winter than in summer,and less than 5μm are opposite.For all the particulate matter,the concentration is higher in the morning peak than in the evening peak,and higher in the weekday than in the weekend.There was a strong correlation between particles in the adjacent range.For the particle size ranging from 0.5 to 0.99μm,temperature and pressure have great impact on particulate matter.And for the size with larger than 5μm,relative humidity is the great impact factor.In contrast,RDD of PM1,PM2 and PM10 in the aged was the highest,which shows the impact of particulate matter is more harmful to the elderly vulnerable groups.RDD of PM1,PM2 and PM10 in summer were 116%,112%and 20%higher than those in winter,respectively.In consequence compared with coarse particulate matter,fine particulate matter is more harmful to human health.