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. 2021 Jul 14;74:103170. doi: 10.1016/j.scs.2021.103170

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Fig 2 — a: Processing algorithm for comparing air quality data collected during the pandemic (2020) with baseline conditions based on 2-year averaged data (2018–2019). The proposed algorithm has three main operational steps and considers parameters such as PM2.5, NO2, and AQI. b: Flowchart of research work activities indicating the actual processing steps followed in this study.

Fig 2 — a: Processing algorithm for comparing air quality data collected during the pandemic (2020) with baseline conditions based on 2-year averaged data (2018–2019). The proposed algorithm has three main operational steps and considers parameters such as PM2.5, NO2, and AQI. b: Flowchart of research work activities indicating the actual processing steps followed in this study.