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. 2021 Jun 30;222:112481. doi: 10.1016/j.ecoenv.2021.112481

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© 2021 The Authors

Since January 2020 Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID-19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre - including this research content - immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active.

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Fig. 2 — Daily air pollution concentrations from February 1 to March 31 in 2020 (red line represents predicted business-as-usual concentrations and blue line represents observed concentrations) and 2015–2019 (average value in green line). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)