Outdoor air pollution has increased by 8% worldwide in the past five years, with billions of people worldwide exposed to dangerous air, according to new data from more than 3,000 cities compiled by the United States. World Health Organization. (WHO)
Although all regions are affected, fast-growing cities in the Middle East, Southeast Asia, and the Western Pacific are the most affected, with many levels of pollution five to ten times higher than the levels recommended by WHO.
According to the new WHO database, ultrafine particle concentrations of less than 2.5 microns (PM2.5) are the highest in India, accounting for 16 of the 30 most polluted cities in the world.
China, affected by air pollution, has improved air quality since 2011 and now has only five cities in the top 30. Nine other countries, including Pakistan and Iran, have one of the worst cities out of 30.
Among the largest but slightly less dangerous PM10 particles, India has eight cities among the 30 best in the world. Nigeria, Saudi Arabia, and Pakistan have two of the top 10 cities. The actual growth rate of air pollution is likely to be worse because only a few African cities are monitoring their levels.
According to WHO data, the world's most polluted city is Onitsha, a port and transit city in southeastern Nigeria, with levels of nearly 600 micrograms per cubic meter of PM10. approximately 30 times the WHO recommended the level of 20 micrograms per cubic meter.
Air pollution levels in general were much lower in the cities of the developed countries, Sydney, New York, and London registering respectively 17, 16 and 22 micrograms per cubic meter for PM10. However, the data includes only particle measurements and does not include forms of air pollution such as NO2 and ozone.
"We have a public health emergency in many countries, urban air pollution continues to grow at an alarming rate, wreaking havoc on human health, this is dramatic, one of the biggest problems we face worldwide, with huge costs for the society in the future, "said Dr. Maria Neira, Director of Public Health at the World Health Center. WHO in Geneva.
"The cost to the countries is enormous: air pollution affects the economies and quality of life of people, which leads to serious chronic diseases and the death of many people," he said.
New data from academic records and cities show a rapid deterioration in air quality as low-income cities become uncontrollable and people can not escape the smog and soot clouds of transportation. industry, construction sites, agriculture, and wood burning. the houses
Outdoor air pollution causes more than 3 million deaths a year, more than malaria and HIV / AIDS, and is now the deadliest in the world. The balance sheet is expected to double with the increase in the urban population and the number of cars approaching 2 billion by 2050.
Air pollutants, such as sulphates, nitrates, and black carbon, penetrate deeply into the lungs and the cardiovascular system, posing the greatest risk to human health, the UN said.
"As urban air quality declines, the risk of stroke, heart disease, lung cancer, and chronic and acute respiratory diseases, including asthma, increases for people As polluted air covers our cities, the most vulnerable urban populations, the youngest, the oldest and the poorest, are the most affected, "said Flavia Bustreo, Deputy Director-General of WHO. .
Encouragingly, WHO data shows that many cities are tackling air pollution. More than half of the cities surveyed in high-income countries and more than one-third of cities in low- and middle-income countries have reduced their level of air pollution by more than 5% in five years. Delhi, one of the most polluted cities in the world, has banned big diesel cars from entering the city center. Among the measures taken by the cities are the reduction of chimney emissions, the increase in the use of renewable energy sources, such as solar and wind energy, and the priority given to rapid transit, pedestrian networks. And cyclists in cities. Many cities are also committed to reducing car traffic and diesel vehicles in particular.
The third United Nations database on outdoor air pollution suggests that the cleanest cities in the world are generally small, rich and located far from industrial centers. In Finland, a city located on the Arctic Circle, Muonio has the purest urban air in the world, registering only 2 micrograms per cubic meter of contamination and 2.5 micrograms per cubic meter of PM10. He is followed closely by Norman Wells in Canada, Campisbalos in Spain and Converse County, Wyoming in the United States.
More than 80 percent of urban dwellers monitoring air pollution are exposed to levels of air quality that exceed the limits set by the World Health Organization. While all regions of the world are affected, the populations of low-income cities are the most affected. 98% of cities in low- and middle-income countries with more than 100,000 inhabitants do not meet WHO's air quality standards. However, in high-income countries this percentage drops to 56%, "said WHO.
"It is essential that municipal and national governments make urban air quality a priority for health and development," said Dr. Carlos Dora, coordinator of WHO's Healthy Environments Program. "When air quality improves, the health costs of air pollution-related illnesses decrease, the productivity of workers increases and life expectancy increases." The reduction of air pollution also brings additional climate benefit, which can become an integral part of the commitments of the countries signatory to the climate treaty. "