Quarantines and restrictions reduce pollution in Italy, China and NY

Quarantined for twelve days, residents of Venice saw for the first time in many years the waters of the city's canals become clear - and even dolphins, swans and schools of fish were caught swimming around. With factories stopped and traffic almost non-existent, Italy has seen considerable improvement in air quality. But the nation was not the only one in which nature benefited from the coronavirus pandemic :  scientists have already reported reduced pollution in China and the United States.

Studies have shown a 21.5% improvement in air quality in China , where residents of the capital, Beijing, often wear masks to protect themselves from pollution. A researcher at Stanford University estimates that, despite the many lives taken by Covid-19, the shutdown of factories and traffic in the country may have saved between 50,000 and 75,000 people who could die prematurely from pollution. The researcher, Marshall Burke, however, warned that it would be "incorrect and imprudent" to conclude that "pandemics are good for health" because of this.

The coronavirus outbreak began in late December in Wuhan, China. With a rapid spread to neighboring cities and regions, the disease led to the total isolation of sixteen cities. At least 60 million people were confined throughout Hubei province, of which Wuhan is the capital.

With the restrictions, industrial operations across the region were suspended. The ban on Chinese traveling between and within provincial cities has also slowed the flow of cars, buses, trains and planes across the country.

According to the Energy and Air Cleanliness Research Center, whose headquarters are located in Finland, all the changes observed in China led to a 25% reduction in carbon dioxide emissions over four weeks between the end of January and mid-February. , when compared to the same period last year.

The organization also points out that industrial operations have been reduced from 15% to 40% in some regions of the country. In some sectors, consumption of coal fell 36%. The country is the current world champion of these emissions.

Pollution monitoring satellites operated by NASA and the European Space Agency (ESA) also saw dramatic reductions in air pollution over China for two weeks in February, when quarantine was in effect in several provinces. The satellites measured the concentrations of nitrogen dioxide, which is released by cars, plants and industrial facilities, from January 1st to 20th and again from February 10th to 25th. The difference between the two periods is notable.NASA scientists said similar emission reductions were seen in other countries during the economic crisis, but that the fall in air pollution in China during the quarantine period was especially rapid. "It is the first time that I have seen such a dramatic drop in such a wide area for a specific event," said Fei Liu, an air quality researcher at the American agency, in a statement. 

China has so far had nearly 81,000 cases of Covid-19 and 3,248 deaths. The country registered on Sunday the first case of local transmission in three days - a consequence of more than forty cases imported from abroad.