Greco Susan L, Wilson Andrew M, Hanna Steven R, Levy Jonathan I
Department of Environmental Health, Harvard School of Public Health, and Harvard Center for Risk Analysis, Boston, Massachusetts, USA.
Environ Sci Technol. 2007 Nov 15;41(22):7675-82. doi: 10.1021/es062213f.
Benefit-cost and regulatory impact analyses often use atmospheric dispersion models with coarse resolution to estimate the benefits of proposed mobile source emission control regulations. This approach may bias health estimates or miss important intra-urban variability for primary air pollutants. In this study, we estimate primary fine particulate matter (PM2.5) intake fractions (iF; the fraction of a pollutant emitted from a source that is inhaled by the population) for each of 23 398 road segments in the Boston Metro Core area to evaluate the potential for intra-urban variability in the emissions-to-exposure relationship. We estimate iFs using the CAL3QHCR line source model combined with residential populations within 5000 m of each road segment. The annual average values for the road segments range from 0.8 to 53 per million, with a mean of 12 per million. On average, 46% of the total exposure is realized within 200 m of the road segment, though this varies from 0 to 93% largely due to variable population patterns. Our findings indicate the likelihood of substantial intra-urban variability in mobile source primary PM2.5 iF that accounting for population movement with time, localized meteorological conditions, and street-canyon configurations would likely increase.
效益成本分析和监管影响分析通常使用低分辨率的大气扩散模型来估算拟议的移动源排放控制法规的效益。这种方法可能会使健康评估产生偏差，或者忽略主要空气污染物在城市内部的重要变异性。在本研究中，我们估算了波士顿地铁核心区域23398个路段中每一段的一次细颗粒物（PM2.5）吸入分数（iF；即源排放的污染物被人群吸入的比例），以评估排放与暴露关系在城市内部的变异性潜力。我们使用CAL3QHCR线源模型结合每个路段5000米范围内的常住人口来估算iF。各路段的年平均值范围为每百万分之0.8至53，平均为每百万分之12。平均而言，46%的总暴露发生在距路段200米范围内，不过这一比例在0%至93%之间变化，主要是由于人口模式不同。我们的研究结果表明，移动源一次PM2.5的iF在城市内部存在显著变异性，考虑到人口随时间的移动、局部气象条件和街道峡谷配置，这种变异性可能会增加。
