A great deal has been written and said about the relationship between the new coronavirus and air pollution and air quality. This in-depth piece seeks to clarify the facts, setting opinions aside.
Ascolta "07. Coronavirus, quando una pandemia apre il decennio più importante per il clima" su Spreaker.
Satellite images leave no room for doubt. The lockdown — the (near-)total halt, the isolation imposed in the wake of the new coronavirus pandemic, first in China and then in Italy — has, perhaps, had just one welcome effect: a reduction in smog. In particular, the standstill of human activity in the Po Valley, one of the most polluted areas in Europe, is making the decrease in certain pollutants visible to the naked eye, among them the dreaded nitrogen dioxide (NO2), which alone causes the premature death of 14,600 people in Italy every year out of a total of 76,200 from pollution and fine particles, according to estimates by the European Environment Agency.
As anticipated by Nasa and Esa, the space agencies of the United States and Europe, and subsequently confirmed by the atmosphere monitoring service of Copernicus, the European Union's Earth observation programme, the Covid-19 effect on air quality in Lombardy has caused a reduction in NO2 concentration levels of 10 per cent per week over the past month. In Milan, experts explain, "average nitrogen dioxide concentrations were around 65 μg per cubic metre in January, 50 micrograms (μg) per cubic metre in February, and below 40 μg per cubic metre in the first half of March."
Similar trends are found in other cities in northern Italy, such as Turin or Bergamo. In Bologna, concentrations averaged around 30 μg per cubic metre in January. "Nitrogen dioxide is a short-lived pollutant. Once emitted, it typically remains in the atmosphere for less than a day before being deposited or reacting with other gases in the atmosphere," Copernicus experts reiterate.
https://youtu.be/ARpxtAKsORw
The data, European and Italian experts emphasise from various quarters, must be interpreted carefully and over time, not immediately, "as they are variable and also determined by winds and weather patterns — variations that make it difficult to detect and characterise trends over the short term." Nor can they be assessed hastily, the environmental technicians at Arpa Lombardia also stress: "One cannot simply compare the situation of these three weeks with that of the previous year or the previous three weeks."
Indeed, Copernicus points out that "as a paradox, until a complete lockdown is decided upon, emissions from certain sectors, such as those from heating or industry, could increase." It therefore underlines that a definitive assessment will only be possible at a later stage, once final statistics on traffic, industry and energy demand become available.
Climate change expert Stefano Caserini, an environmental engineer, has developed a series of reflections on the effect of coronavirus in the fight against smog and global warming, and shares the same view: "After China, for which a reduction of 200 million tonnes of CO2 is estimated, due to the reduction in the use of coal in industry, a reduction in pollutant and CO2 emissions is also expected for Italy, linked to lower traffic in many cities and reduced travel. As well as to the scaled-back operation of productive activities in many areas."
Caserini's advice is not to rush to conclusions. "Air pollution does not depend solely on emissions, but also, and above all, on meteorology, which in some areas such as the Po Valley plays a key role. The climatologist reiterates: "The reductions in PM10 and NO2 concentrations recorded in Lombardy on 26 and 27 February were due to a significant foehn wind episode, for example. That counted for far more in clearing the air than the reduction in traffic caused by the coronavirus emergency."
Time is needed to carry out comprehensive assessments of both environmental policy and public health, based on data processed by experts. This is all the more true of epidemiological data relating to the coronavirus epidemic. There are no reliable estimates of how many people have tested positive for the epidemic, only projections, as Fabrizio Bianchi, epidemiologist and head of the Institute of Clinical Physiology (Ifc) of the Cnr in Pisa, reiterates. Consequently, it is not currently possible to produce reliable estimates of the virus's lethality. Despite every statistic, we will have to wait.
What is certain, unfortunately, is that people do fall ill and die from coronavirus, just as they do from air pollution. And the inhabitants of the Po Valley and of Lombardy are paying an extremely high price in human lives on both fronts, as Anna Gerometta, president of Cittadini per l'aria, an association that has long campaigned for serious air quality improvement policies, has pointed out. Are the two phenomena related? "From the beginning of December to the first week of February 2020, particulate matter concentrations — PM10 and PM2.5 — and NO2 in Lombardy were well above the legal limits," Anna Gerometta reminds us. By mid-February, the annual 35 days permitted by European regulations for PM10 to exceed the limit of 50 micrograms (µg) per cubic metre had already been "used up". "All of this led to an increase in emergency room admissions of children and adults due to a rise in respiratory conditions, already in the months before," she reiterates. "We hope that the health situation, so dramatic in the way it has been unleashed by coronavirus, will also change regional environmental policies."
"In Italy, and especially in the north, acute and chronic diseases of the respiratory system are increasingly on the rise and are in a proven relationship with the quantity of fine particles inhaled," pulmonologist Roberto Dal Negro had explained to us in recent months. Both the World Health Organization (WHO) and the international scientific literature have long been reiterating the tragedy caused by air pollution. At least 7 million deaths a year, of which 500,000 in Europe and more than 76,000 in Italy. A planetary public health problem that the coronavirus emergency is partly overshadowing.
But there are those, even in medical and scientific circles, who are beginning to correlate the two factors. According to estimates by Marshall Burke, scientist and researcher at Stanford University, two months of reduced pollution in China "have probably saved the lives of around four thousand children under 5 and 73,000 adults over 70". The researcher explains, therefore, that "the drop in pollutants due to the coronavirus shutdown in both China and Europe could save more lives than will be directly lost to Covid-19". Although, he stresses, "at present it is only possible to produce a projection of mortality impacts, not a proper measurement. Here too, time will be needed." He concludes that "this study is not yet possible, as the epidemic is still ongoing and complete all-cause mortality data are not yet available."
