COVID-19 and air pollution: the worst is yet to come.

To the Editor:

We read with interest the article by Wang et al. highlighting the burden of transport industry to carbon emissions in China (Wang et al. 2020). The authors described a massive increase of carbon emissions from fossil fuel in China, with an average annual growth rate of 9.72%. Interestingly, Northeastern China (epicenter of the beginning of COVID-19 pandemic) is particularly affected by this massive increase of carbon emissions related to transportation, with a northeast-southwest pattern. However, satellite images showed a massive decrease in nitrogen dioxide (NO2), carbon dioxide (CO2), and ozone (O3), which was related to the reduction of human activities during the SARS-CoV-2 outbreak, i.e., traffic road, industrial productions, and individual traffic commuting (Dutheil et al. 2020). In the dramatical context of the SARS-CoV-2 pandemic, this global reduction in air pollution was a great sign for the preservation of our environment and some of the related cardiovascular and respiratory tract diseases (Guan et al. 2016; Cramer et al. 2020). More than half of humanity stayed at home for several months to avoid SARS-CoV-2 spreading. The isolation period has been referred to as a global economic crisis similar to the peak unemployment problems of the Great Depression (Arengo and Fuller 2020). However, to reduce the extent of the financial market collapse, some countries promptly reviewed the strict social distancing policy to boost industrial production and economic recovery (McCaffrey 2020). Some countries have already publicly stated that they will not meet the Paris agreement on climate change initiatives in order to boost their economic growth. China seems to increase the carbon-intensive development path, in accordance with the USA that wants to rescue struggling fossil fuel production firms (Harrabin 2020). Moreover, most of the worldwide trade routes were disrupted to fight against the COVID-19 pandemic, limiting economic exchanges and access to energy resources. This critical situation increases the exploitation of pollutant fossil fuels, particularly the redevelopment of previously closed carbon mines (Lelieveld et al. 2019). In addition to the probable increase in air pollution to fight against the 2-month lockdown in relation to the economy, individual behavior will also increase air pollution. Fearing the contagion in mass transit, people are more frequently using their individual cars for commuting (Smargiassi et al. 2020)—taking into account that traffic involves around 70% of air pollutants in urban areas (Ramacher and Karl 2020). There is also a noticeable upsurge in the use of disposable plastic, in line with mass media disseminating the survival of SARS-Cov-2 on inert surfaces (Otter et al. 2016). Considering the millions of tons of plastic waste entering the ocean each year, the global burden of plastic pollution will probably characterize the Anthropocene era as geological marker in the history of humanity (Jambeck et al. 2015). Thus, even if people fear a second wave of COVID-19, there may also be a tsunami of global pollution. Countries that are most affected by the SARS-CoV-2 pandemic may also be those with the highest economic consequences of the lockdown, and these countries may also have the highest increases in air pollution. Even if the global lockdown period benefitted air quality, we fear that countries worldwide will choose to protect the economy rather than the environment. This strategy might paradoxically cost more money than the massive containment due to SARS-CoV-2 restrictions—not meeting the Paris agreement may cost more than 600 trillion USD over the twenty-first century (Wei et al. 2020). The SARS-CoV-2 outbreak seems likely to be a brief respite in the fate of the world’s increased air pollution.