Although it was the year of lockdowns almost everywhere on the planet, 2020 will not be remembered for an effective improvement in air quality. Nell studio conducted by the Swiss research company IQ Air we are not talking about CO2 emissions (those are climate-altering factors) but about air pollution, i.e. the presence of fine particles (Pm 2,5, the most harmful to health) in cities all over the world. The verdict is disarming: in 84% of countries there was indeed a decrease in particle values detected during the year, but overall in more than three quarters of the world's countries they remained well above the alarm threshold established by the World Health Organization.
Especially in large cities (New Delhi, the worst, but also Beijing, Chicago, Seoul, London) and above all in the United States, where the concentration of Pm 2,5 has even increased, by 6,7%, due to the large fires that broke out above all in California. This meant that 38% of American cities have not complied with the limits set by WHO in 2020, against 21% in 2019. At the end of the accounts, out of the total of 106 countries examined, only 24, despite the lockdown and the slowdown of activities and urban traffic, were found to be in order. Italy is not among these, while in Europe the worst performances are recorded by Bosnia, Macedonia and Bulgaria.
Globally, as usual, Asian cities stand out in the negative: according to IQ Air New Delhi is confirmed as the capital with the worst air quality, followed by Dhaka, Ulan Bator, Kabul and Doha. Beijing is fifteenth, but above all it is impressive that 42 of the 50 most polluted cities in the world are concentrated in three countries: India, Bangladesh and Pakistan. Considering also China, there is almost en plein: 49 out of 50. The capitals with the cleanest air are Stockholm, Helsinki and the capital of New Zealand Wellington.
However, the study notes that the drop in fine particles in some large cities (for example Beijing -11%, London -16%) has helped save thousands of human lives because it must be remembered that air pollution causes about 7 million premature deaths every year according to WHO (but other studies estimate 9-10 million deaths), e reduces the average life expectancy in the world by 3 years. In European countries this figure is lower, but those who live in China have an average survival expectation of 4,1 years lower, which becomes 6 years in the province of Hebei and even 8,5 years in Uttar Prasdesh, a state in the North India.
