90% of the world’s population breathes polluted air

A Nigerian student stands in the middle of a dusty road.

The World Health Organization (WHO) collected air data from more than 4,300 cities and 108 countries between 2008 and 2015. In a report published on May 1, each year the world has 7 million people.

`I fear the real tragedy is that air pollution levels remain at dangerous levels in many areas of the world,` said Dr. Maria Neira, director of the Public Health, Environment and Impact Committee.

`Air pollution today is not only the biggest environmental health risk, but also a huge public health challenge and one of the biggest challenges we predict.`

According to the WHO Air Quality Guidelines, the average limit for routine monitoring of particulate matter with a diameter of less than 2.5 micrometers (PM2.5) is 10 μg/m3, in this form or less, the

Particulate matter in the air includes substances such as sulfates, nitrates and black carbon, created mainly by cars and trucks on the road, industrial plants, power plants and agriculture.

`Many megacities in the world have PM2.5 concentrations that exceed WHO standards by up to 5 times, meaning that people here are exposed to huge health risks,` Ms. Neira said.

People in Asia and Africa are most affected.

Black dust covered the roof of this Nigerian’s car.

Another source of air pollution, a problem mainly in developing areas, is indoor pollution.

According to Ms. Neira, a positive sign is that many cities are paying attention and monitoring air quality.

Experts suggest many ways to reduce air pollution locally, such as walking, cycling or using public transport, instead of driving.