Khomsi K, Najmi H, Amghar H, Chelhaoui Y, Souhaili Z
General Directorate of Meteorology, Face Préfecture Hay Hassani, B.P. 8106 Casa- Oasis, Casablanca, Morocco.
Laboratory of Drugs Science, Biomedical and Biotechnological Research, Faculty of Medicine and Pharmacy, Hassan II University, Casablanca, Morocco.
One Health. 2021 Jun;11:100200. doi: 10.1016/j.onehlt.2020.100200. Epub 2020 Nov 25.
On April 20th, 2020, 2,403,410 cases of corona Virus were confirmed globally. This date matches the end of the first strict lockdown in Morocco.. The number of Morocco confirmed cases attended 2990 and 143 deaths were recorded. Due to the pandemic, all avoidable activities in the country were prohibited since the kingdom announced the general lockdown on March 20th, 2020. This study aims at comparing the air quality status, before the pandemic and during the confinement. It was performed in Casablanca and Marrakech from Morocco. The main objective is to show whether COVID-19 compelled lockdown may have saved lives by restraining air pollution than by preventing infection. We used the difference-in-difference and the Theil and Sen non-parametric approaches for univariate time series. We defined the before quarantine period as between February 16th and March 19th and the during quarantine as between the March 20th and April 20th. We assessed changes in air quality during vs. before the quarantine period in 2020 and compared these with corresponding changes in the same lunar calendar periods in 2016-2019. Then we calculated the avoided cause-specific mortality attributable to the decreases in NO and PM based on the concentration-response functions from previous studies. We found that NO dropped by -12 μg/m in Casablanca and - 7 μg/m in Marrakech. PM dropped by -18 μg/m in Casablanca and - 14 μg/m in Marrakech. CO dropped by -0.04 mg/m in Casablanca and - 0.12 mg/m in Marrakech. This air pollution reduction had created human health benefits. It reduced mortality, and saved lives mainly from cardiovascular diseases. Further investigation may be undertaken to explore the reduction in the concentrations of industry-related pollutants.
2020年4月20日，全球确诊2403410例冠状病毒病例。这一日期与摩洛哥首次严格封锁结束的时间相符。摩洛哥的确诊病例数为2990例，记录的死亡病例为143例。由于这场大流行病，自该国于2020年3月20日宣布全面封锁以来，国内所有可避免的活动都被禁止。本研究旨在比较大流行之前和封锁期间的空气质量状况。研究在摩洛哥的卡萨布兰卡和马拉喀什进行。主要目的是表明，因新冠疫情实施的封锁通过抑制空气污染而非预防感染是否可能挽救了生命。我们对单变量时间序列采用了双重差分法以及泰尔和森非参数方法。我们将检疫前时期定义为2月16日至3月19日，将检疫期间定义为3月20日至4月20日。我们评估了2020年检疫期间与检疫前空气质量的变化，并将这些变化与2016 - 2019年相同农历时期的相应变化进行比较。然后，我们根据以往研究的浓度 - 反应函数，计算了因一氧化氮（NO）和颗粒物（PM）浓度下降而避免的特定病因死亡率。我们发现，卡萨布兰卡的NO下降了 - 12μg/m，马拉喀什下降了 - 7μg/m。卡萨布兰卡的PM下降了 - 18μg/m，马拉喀什下降了 - 14μg/m。一氧化碳（CO）在卡萨布兰卡下降了 - 0.04mg/m，在马拉喀什下降了 - 0.12mg/m。这种空气污染的减少带来了人类健康益处。它降低了死亡率，主要挽救了心血管疾病患者的生命。可能需要进一步调查，以探索与工业相关污染物浓度的降低情况。
