Department of Physics, University of Ioannina, Ioannina, Greece.
Environ Int. 2010 Apr;36(3):281-9. doi: 10.1016/j.envint.2009.12.009. Epub 2010 Jan 25.
The exposure of citizens to elevated air pollution concentrations is one of the major factors leading to the deterioration of the quality of life and possibly to health problems in urban areas. The concentration of air pollutants depends largely on pollutant emission levels. If the statistical probability distribution function of the concentration of an air pollutant is known, it is possible to estimate how many times this concentration exceeds the air quality standards, or estimate changes in the emission levels in an area. It can be also used to estimate the long term exposure of population to certain pollutants. In this paper fifteen theoretical probability distribution functions, were used to fit the actual concentration frequency distributions of CO, NO(2), O(3,) SO(2), and Black Smoke (BS) in Athens, Greece for a 23-year period. The results showed that the theoretical distribution type best describing the distribution of the pollutants is Inverse Gaussian followed by the Extreme value distribution. The number of exceedances of air quality limits was used to validate the performance of the theoretical distributions that were best fitted to the observed ones. The temporal evolution of emission strength was estimated through the temporal evolution of the parameters of the probability distribution functions. Missing periods were accounted for by estimating the respective distribution functions through interpolation or extrapolation from the existing ones. The derived variation of emission levels consistently represents the emission reduction strategies enforced over the years, as well as the escalating growth of the passenger car fleet volume, and could be a useful tool for the design and assessment of emission control strategies.
公民暴露在高浓度的空气污染中是导致城市地区生活质量恶化和可能出现健康问题的主要因素之一。空气污染物的浓度在很大程度上取决于污染物的排放水平。如果已知空气污染物浓度的统计概率分布函数，则可以估计该浓度超过空气质量标准的次数，或估计某个区域的排放水平变化。它还可用于估计人口长期接触某些污染物的情况。在本文中，使用了十五种理论概率分布函数来拟合希腊雅典 23 年来 CO、NO₂、O₃、SO₂和黑烟（BS）的实际浓度频率分布。结果表明，描述污染物分布的最佳理论分布类型是逆高斯分布，其次是极值分布。超标空气质量限值的次数用于验证与观测值拟合最好的理论分布的性能。通过概率分布函数参数的时间演变来估计排放强度的时间演变。通过从现有数据进行内插或外推来估算缺失时段的分布函数。推导出的排放水平变化一致地反映了多年来实施的减排策略，以及乘用车数量的不断增长，并且可以成为设计和评估排放控制策略的有用工具。
