Centre for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran; Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
International Laboratory for Air Quality and Health, Queensland University of Technology (QUT), Brisbane, Queensland, Australia.
Sci Total Environ. 2019 Dec 20;697:134123. doi: 10.1016/j.scitotenv.2019.134123. Epub 2019 Aug 26.
To investigate spatial inequality of ambient air pollutants and comparison of their heterogeneity and homogeneity across Tehran, the following quantitative indicators were utilized: coefficient of divergence (COD), the 90 percentile of the absolute differences between ambient air pollutant concentrations and coefficient of variation (CV). Real-time hourly concentrations of particulate matter (PM) and gaseous air pollutants (GAPs) of twenty-two air quality monitoring stations (AQMSs) were obtained from Tehran Air Quality Control Company (TAQCC) in 2017. Annual mean concentrations of PM, PM, and PM (PM) ranged from 21.7 to 40.5, 37.3 to 75.0 and 58.0 to 110.4 μg m, respectively. Annual mean PM and PM concentrations were higher than the World Health Organization air quality guideline (WHO AQG) and national standard levels. NO, O, SO and CO annual mean concentrations ranged from 27.0 to 76.8, 15.5 to 25.1, 4.6 to 12.2 ppb, and 1.9 to 3.8 ppm over AQMSs, respectively. Our generated spatial maps exhibited that ambient PM concentrations increased from the north into south and south-western areas as the hotspots of ambient PM in Tehran. O hotspots were observed in the north and south-west, while NO hotspots were in the west and south. COD values of PM demonstrated more results lower than the 0.2 cut off compared to GAPs; indicating high to moderate spatial homogeneity for PM and moderate to high spatial heterogeneity for GAPs. Regarding CV approach, the spatial variabilities of air pollutants followed in the order of O (87.3%) > SO (65.2%) > CO (61.8%) > PM (52.5%) > PM (48.9%) > NO (48.1%) > PM (42.9%), which were mainly in agreement with COD results, except for NO. COD values observed a statistically (P < 0.05) positive correlation with the values of the 90 percentile across AQMSs. Our study, for the first time, highlights spatial inequality of ambient PM and GAPs in Tehran in detail to better facilitate establishing new intra-urban control policies.
为了研究环境空气污染物的空间不平等性，并比较它们在德黑兰的异质性和同质性，我们利用了以下定量指标：离散系数 (COD) 和污染物浓度绝对差异的 90 百分位数与变异系数 (CV)。2017 年，从德黑兰空气质量控制公司 (TAQCC) 获取了 22 个空气质量监测站 (AQMS) 的实时逐时颗粒物 (PM) 和气态空气污染物 (GAP) 浓度。PM、PM 和 PM (PM) 的年平均浓度范围分别为 21.7 至 40.5、37.3 至 75.0 和 58.0 至 110.4 μg/m。PM 和 PM 的年平均浓度均高于世界卫生组织空气质量指南 (WHO AQG) 和国家标准水平。NO、O、SO 和 CO 的年平均浓度范围分别为 27.0 至 76.8、15.5 至 25.1、4.6 至 12.2 ppb 和 1.9 至 3.8 ppm。我们生成的空间图表明，环境 PM 浓度从北部到南部和西南部增加，成为德黑兰环境 PM 的热点。O 的热点在北部和西南部，而 NO 的热点在西部和南部。PM 的 COD 值比 GAPs 低的结果更多，表明 PM 的空间同质性较高，GAPs 的空间异质性中等至高。关于 CV 方法，空气污染物的空间变异性顺序为 O (87.3%) > SO (65.2%) > CO (61.8%) > PM (52.5%) > PM (48.9%) > NO (48.1%) > PM (42.9%)，这与 COD 结果基本一致，除了 NO。COD 值与 AQMS 之间的 90 百分位数值呈统计学上 (P < 0.05) 正相关。我们的研究首次详细强调了德黑兰环境 PM 和 GAPs 的空间不平等性，以便更好地促进制定新的城市内部控制政策。
