Air pollution is a major global problem that impacts the health and welfare of millions.

The World Health Organization reports that virtually the entire world’s population, about 99%, breathes air that surpasses their air quality standards.

The WHO measures air quality using PM2.5 concentration, referring to fine particles that are 2.5 micrometres or less. These particles can enter the lungs and bloodstream, threatening major organs.

Here are the world’s air pollution hot spots.

Pollutant levels in these cities, including Lahore, Pakistan (the worst offender), pose a dangerous threat due to excess emissions from vehicles and industry, brick kiln and crop residue smoke, waste and construction site dust.

Air pollution levels can also be influenced by practices like large-scale tree removal for infrastructure development, such as building new roads and buildings.

This highlights the urgent need for effective measures to address air pollution and protect public health.