The Indirect Benefit on Respiratory Health From the World's Effort to Reduce Transmission of SARS-CoV-2.

Air pollution is recognized as a global public health issue. Exposure to environmental air pollutants amplifies respiratory illness.1, 2, 3, 4 The World Health Organization estimates that ambient air pollution causes 25% of COPD cases (ie, 65 million cases) and 26% of respiratory infection deaths (ie, 600,000 preventable deaths per year). Air pollution, particularly fine particulate matter and nitrogen dioxide, is also associated with asthma and pneumonia prevalence among children.

In December 2019, pneumonia cases of unknown origin appeared in Wuhan, Hubei province, China. Analysis showed that symptoms were caused by a novel coronavirus labeled severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The movement of people, through worldwide tourism and business travel, led to rapid increases in the numbers of cases and countries affected. On March 1, 2020, a total of 87,137 cases were confirmed with 2,977 deaths according to the World Health Organization.

To fight the increase in cases, local authorities of affected areas established quarantine periods that resulted in a decrease in industry activities, mass transit, and individual car circulation. All of these elements contribute to air pollution. , Pollution-monitoring satellites of NASA and the European Space Agency have detected significant decreases in nitrogen dioxide across China from January 1 to 20, 2020 (before the quarantine), to February 10 to 25, 2020 (during the quarantine). Nitrogen dioxide pollution was drastically reduced first near Wuhan, and eventually reduced across China and around the world (Fig 1 ). A decrease of 6% in global pollution was measured following the decrease of global activities due to the coronavirus pandemic. The public health benefit of the world’s efforts to reduce transmission of SARS-CoV-2 may have indirect health benefits by lowering the impact of air pollution.

Figure 1

Effect of quarantine due to severe acute respiratory syndrome coronavirus 2 on air pollution.