National Research Centre, Cairo, Egypt.
Egyptian Meteorological Authority, Cairo, Egypt.
Environ Res. 2018 Jan;160:223-231. doi: 10.1016/j.envres.2017.09.028. Epub 2017 Oct 9.
The poor outdoor air quality in megacities of the developing world and its impact on health is a matter of concern for both the local populations and the decision-makers. The objective of this work is to quantify the mortality attributable to long-term exposure to PM2.5, NO, and O in Greater Cairo (Egypt).
We analyze the temporal and spatial variability of the three pollutants concentrations measured at 18 stations of the area. Then, we apply the method recommended by the WHO to estimate the excess mortality. In this assessment, three different shapes (log-linear, linear, and log-log) of the concentration-response functions (CRF) are used.
With PM2.5 concentrations varying from 50 to more than 100µg/m in the different sectors of the megacity, the spatial variability of this pollutant is found to be one important cause of uncertainty on the excess mortality associated with it. Also important is the choice of the CRF. With the average (75µg/m) PM2.5 concentration and the most favorable log-log shape of the CRF, 11% (CI, 9-14%) of the non-accidental mortality in the population older than 30 years can still be attributed to PM2.5, which corresponds to 12520 (CI, 10240-15930) yearly premature deaths. Should the Egyptian legal 70µg/m PM10 limit (corresponding to approximately 37.5µg/m for PM2.5) be met, this number would be reduced to 7970, meaning that 4550 premature deaths could be avoided each year. Except around some industrial or traffic hot spots, NO concentration is found to be below the 40µg/m air quality guideline of the WHO. However, the average concentration (34µg/m) of this gas exceeds the stricter 10µg/m recommendation of the HRAPIE project and it is thus estimated that from 7850 to 10470 yearly deaths can be attributed to NO. Finally, with the ozone concentration measured at one station only, it is found that, depending on the choice of the CRF, between 2.4% and 8.8% of the mortality due to respiratory diseases can be attributed to this gas.
In Greater Cairo, PM2.5 and NO constitute major health risks. The best estimate is that in the population older than 30 years, 11% and 8% of the non-accidental mortality can be attributed to these two pollutants, respectively.
发展中国家特大城市户外空气质量较差及其对健康的影响，不仅是当地居民关注的问题，也是决策者关注的问题。本研究旨在量化开罗大都市区（埃及）居民长期暴露于 PM2.5、NO 和 O 下的死亡率。
我们分析了该地区 18 个站点测量的三种污染物浓度的时空变化。然后，我们应用世界卫生组织推荐的方法来估计超额死亡率。在这项评估中，使用了三种不同的浓度-反应函数（CRF）形状（对数线性、线性和对数对数）。
由于大都市不同区域的 PM2.5 浓度从 50 微克/立方米到 100 微克/立方米以上不等，因此发现这种污染物的空间变异性是与它相关的超额死亡率不确定性的一个重要原因。选择 CRF 也很重要。以平均（75µg/m）PM2.5 浓度和最有利的 CRF 对数对数形状，30 岁以上人群中 11%（95%置信区间为 9-14%）的非意外死亡仍可归因于 PM2.5，这相当于每年 12520 人（95%置信区间为 10240-15930 人）过早死亡。如果达到埃及法定的 70µg/m PM10 限值（相当于 PM2.5 的约 37.5µg/m），这一数字将降至 7970，这意味着每年可避免 4550 人过早死亡。除了一些工业或交通热点地区外，NO 浓度被发现低于世界卫生组织的 40µg/m 空气质量指南。然而，这种气体的平均浓度（34µg/m）超过了 HRAPIE 项目更严格的 10µg/m 建议，因此估计每年有 7850 至 10470 人死亡可归因于 NO。最后，仅使用一个站点测量的臭氧浓度，发现根据 CRF 的选择，由于呼吸系统疾病导致的死亡率中，有 2.4%至 8.8%可归因于这种气体。
在开罗大都市区，PM2.5 和 NO 构成了主要的健康风险。最佳估计是，在 30 岁以上人群中，11%和 8%的非意外死亡率可归因于这两种污染物。
