Dichotomous analysis of gaseous emissions as influenced by the impacts of COVID-19 in Brazil: São Paulo and Legal Amazon.

Atmospheric contaminants severely impact air quality in large global urban centers. The emergence of COVID-19 in China in December 2019 and its expansion around the world reduced human activities on account of the implementation of a social isolation policy. In Brazil, COVID-19 arrived in February 2020, and a policy of social isolation was adopted in March by state governments; this work aimed to evaluate pollutant gas emissions in Brazil in the face of the pandemic. In the city of São Paulo, the concentrations of nitrogen dioxide (NO) and carbon monoxide (CO) were analyzed at three automatic monitoring stations of the Environmental Company of the State of São Paulo (CETESB). In this way, reductions in concentrations of these gases were observed after the decree of social isolation on March 24, due to a noticeable drop in vehicle traffic in the city. A reduction in concentrations of NO, between 53.6 and 73%, and a decrease in concentrations of CO, from 50 to 66.7%, were obtained at the monitoring stations. Another impact caused by COVID-19 was the increase in deforestation and fires was identified in the Brazilian Legal Amazon after social isolation, due to the decrease in the inspection of environmental agencies. The fires produce thermal degradation of the biomass, generating polluting gases and material particulate. These atmospheric contaminants are extremely harmful to the health of Amazonian populations. Summed to the expansion of COVID-19 in this region, all these factors combined cause the public health system to collapse. CO emissions increase estimates, according to the Greenhouse Gas Emissions Estimation System technical report, ranged from 10 to 20% in 2020, compared to those from 2018. If Brazil maintains deforestation at this pace, it will be difficult to meet the emission reduction targets agreed at COP21.