The drastic measures enforced by China during the coronavirus outbreak have slashed deadly air pollution, potentially saving the lives of tens of thousands of people, a Stanford University researcher said.
In Italy, lockdown to fight the spread of COVID–19, which has killed thousands in the country, shows Venice empty of its usual boat traffic, photos on social media show clear waters and the return of wildlife.
An Italian official says the water isn't necessarily less polluted, but the air has cleared up.
What would a world without humans look like? As countries go under lockdown to prevent the spread of COVID–19, photos on social media suggest it might be a lot cleaner, for a start.
As one observer put it, “Nature just hit the reset button.”
Most nonessential travel to countries in the European Union is banned and Italy, the epicenter of the outbreak on the continent, has closed all nonessential businesses. In Venice, the canals normally teeming with tourists and boat traffic are nearly empty.
On social media, people are sharing photos and videos of clear water and wildlife rarely seen close to the city. For some, it was a small sign of hope as the country’s death toll rose above 2,500 on March 17. The Venice mayor's office told CNN that while the canals might look clearer than before the lockdown, the water quality hasn't necessarily improved."
The water now looks clearer because there is less traffic on the canals, allowing the sediment to stay at the bottom," "It's because there is less [of the] boat traffic that usually brings sediment to the top of the water's surface."
That’s not to say the lockdown hasn’t had any positive environmental effects for a city that months before was battling overtourism.
"The air, however, is less polluted since there are less vaporetti and boat traffic than usual because of the restricted movement of residents," the spokesman said, referring to the public waterbus, the Vaporetto.
Marshall Burke, an assistant professor at Stanford's Department of Earth System Science, said the better air quality could have saved between 50,000 and 75,000 people from dying prematurely.
"The reductions in air pollution in China caused by this economic disruption likely saved twenty times more lives in China than have currently been lost due to infection with the virus in that country," Burke wrote on G-Feed, a site run by a group of scientists researching the relationship between society and the environment.
The link between air pollution and premature deaths has been well established. A 30-year analysis of 652 cities in 24 countries and regions across six continents found that increases in air pollution were linked to increases in related deaths: The higher the levels of pollution, the faster people die.
Satellite images released by NASA and the European Space Agency also show a dramatic reduction in nitrogen dioxide emissions -- those released by vehicles, power plants and industrial facilities -- in major Chinese cities between January and February.
Burke focused on the impact of lower concentrations of PM2.5, the dangerous tiny particulate matter which can move deep into the lungs when inhaled and from there into the bloodstream.
Based on actual pollution data from four cities in China for 2016 to 2019, he calculated the reduction in pollution to be between 15 and 18 micrograms per cubic meter of air, or ug/m3.
NASA also observed a significant reduction in pollution levels.
Scientists analyzed the impact of these measures and found they dramatically reduced the number of premature deaths among children under five and adults over 70. The research suggested that monthly mortality of children under five increased 2.9% for every 1ug/m3 increase in PM2.5, and about 1.4% for people over 70 years old.
Based on those calculations, and considering a number of caveats, Burke calculated that the two months of cleaner air resulting from the coronavirus restrictions has saved the lives of between 1,400 and 4,000 children under 5, and 51,700 to 73,000 adults over 70 in China.
He said that while the cleaner air had likely saved lives, the broader disruption caused by Covid-19 could cause many additional deaths not directly attributable to being infected with the virus -- for example because of declines in economic well-being or the difficulty in accessing health services during the epidemic.
"Does this mean pandemics are good for health? No," he said. "Instead it means that the way our economies operate absent pandemics has massive hidden health costs, and it takes a pandemic to help see that."