Smog in central London in 2011. Photograph: Leon Neal/AFP/Getty Images

The World Health Organisation has issued a stark new warning about deadly levels of pollution in many of the world’s biggest cities, claiming poor air quality is killing millions and threatening to overwhelm health services across the globe.

Before the release next month of figures that will show air pollution has worsened since 2014 in hundreds of already blighted urban areas, the WHO says there is now a global “public health emergency” that will have untold financial implications for governments.

The latest data, taken from 2,000 cities, will show further deterioration in many places as populations have grown, leaving large areas under clouds of smog created by a mix of transport fumes, construction dust, toxic gases from power generation and wood burning in homes.

“We have a public health emergency in many countries from pollution. It’s dramatic, one of the biggest problems we are facing globally, with horrible future costs to society,” said Maria Neira, head of public health at the WHO, which is a specialist agency of the United Nations. “Air pollution leads to chronic diseases which require hospital space. Before, we knew that pollution was responsible for diseases like pneumonia and asthma. Now we know that it leads to bloodstream, heart and cardiovascular diseases, too – even dementia. We are storing up problems. These are chronic diseases that require hospital beds. The cost will be enormous,” said Neira.

The latest scientific research, published in the journal Nature, suggests that air pollution now kills more people a year than malaria and HIV combined, and in many countries accounts for roughly 10 times more deaths than road accidents.

According to the WHO, air quality is deteriorating around the world to the point where only one in eight people live in cities that meet recommended air pollution levels.

Courtesy of Guardian News & Media Ltd