| Fine particulate pollution in cities mainly comes from vehicle emissions. Traffic-related particulate matter pollution not only contains many harmful substances, but also concentrated discharges during the crowd commuting time. The height of emissions is so close to the breath height that it has a great impact on hunman health.This study used APEX model to evaluate the hunman exposure characteristics to road traffic air pollution in Shanghai, adopting the activities sample and micro-environmental parameters, which can reflect the local commuting characters. The simulation results showed that the spatial distribution of exposure levels presented a decreasing trend from the central city to the suburbs, urban average exposure concentration was in the range of 30.5～63.3μg/mJ, rural average exposure concentration was in the range of 16.4～27.2μg/mJ. The overall exposure levels of three groups can be ranked as:the elderly>adults>minors; In various micro-environments, the exposure concentration can be ranked as following:outdoor> transit>residence>office>school. The commuting exposure peak was obvious during the rush hours, the exposure peak of non-commuting also showed a relatively high value caused by the high traffic emissions to some extent. Traffic pollution has an important impact on commuting and outdoor activities and the commuting course is a key link in the study of human exposure.This research further developed on exposure study of road traffic-related particulate matter pollution during commuting course, in order to provide experimental basis support for the follow-up exposure evaluation methods which based on commuting dynamic simulation.The regular monitoring showed that the main road concentration of PM10 in rush hours was 2.08～5.45 times over the city's daily average level, also the level in branch road was 1.58～4.98 times as high as the city's daily average degree. At the same time, the level of fine particulate matter was very high. In rush hour, the concentration of PM10 in main road and branch road reached 0.053 mg/m3 and 0.037 mg/m3 respectively in clean day, and they changed between 0.115～0.393 mg/m3 and 0.094～0.372 mg/m3 in well condition day, while they even reached 1.263 mg/m3 and 0.941 mg/m3 in polluted day. In addition, the urban traffic fine particulate pollution was serious. The ratio of p(PM1) to p(PM2.5) reached 88%, and the ratio of p(PM2.5) to p(PM10) reached 91%. The exposure characteristics study by using different commuting ways found that the exposure levels in typical micro-environments can be ranked as:on the bus> at the bus station>on foot>by bicycle>in the subway. The exposure levels reached 0.255mg/m3 in the bus during the rush hours,and the concentration at the bus station which reached 0.246mg/m3 was the second, follwed by walking (0.241 mg/m3,by bicycle (0.236 mg/m3), the lowest level was in the subway (0.118 mg/m3). The exposure dose by different ways ranked as:on foot>by bicycle>by bus>take subway>take taxi, the exposure of walking reached 389.4mg·s/m3 during the rush hours, followed by the by bus way(288.4 mg·s/m3),commuting by subway got the lowest exposure, just 122.2 mg·s /m3. The potential dose ranked as:by bicycle>on foot>take subway>by bus>take taxi. The average potential dose of commting by bicycle was the highest which reached 95.9μg during the rush hours, followed by walking (77.9μg), commuting by take taxi got the lowest potential dose, just 17.5μg. |
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