The 10 cities with the most polluted air in the world

Alarming data from the World Health Organization (WHO) indicate that 80% of cities have a level of air pollution above what is healthy for humans. For cities with more than 100, 000 inhabitants, this rate rises to alarmingly 98%! In other words, practically all of them look unfit for people.

The most harmful pollutant is called particulate matter 2.5 (PM 2.5), which is less than 2.5 microns in diameter and is found in soot, dust and smoke. This material is lodged in the lungs and causes major long-term health problems such as asthma or chronic disease.

Levels above 35.5 micrograms (µg) of PM 2.5 per cubic meter (m³) of air are considered to be hazardous to human health. Through this scale, WHO has developed a ranking of the worst cities to breathe on the planet. Check out the Top 10:

9th place (tie): Baoding - China

Pollution level: 128 µg / m³ PM 2.5

Baoding's main pollution comes from factories using coal-fired machines

9th place (tie): Xingtai - China

Pollution level: 128 µg / m³ PM 2.5

The cause of Xingtai pollution is also the burning of coal in factories.

8th place: Bamenda - Cameroon

Pollution level: 132 µg / m³ PM 2.5

The rapid urbanization of the city has led to a large amount of soil erosion, increasing pollution

7th place: Raipur - India

Pollution level: 144 µg / m³ PM 2.5

Coal, aluminum and steel plants are the great air villains in Raipur

6th place: Patna - India

Pollution level: 149 µg / m³ PM 2.5

Transportation, power plants and other industries contribute to Patna's polluted air

5th place: Al Jubail - Saudi Arabia

Pollution level: 152 µg / m³ PM 2.5

The rapid industrialization of the city in the 1970s still has effects on air quality.

4th place: Riyadh - Saudi Arabia

Pollution level: 156 µg / m³ PM 2.5

Saudi Arabia's capital and largest city also has the most polluted air: Riyadh retains this status because of its strong industrialization.

3rd place: Allahabad - India

Pollution level: 170 µg / m³ PM 2.5

Droughts on the Ganga River raise dust levels, making Allahabad the third worst in air quality

2nd place: Gwalior - India

Pollution level: 176 µg / m³ PM 2.5

Traffic, coal-fired power plants and misuse of buildings contribute to the historic city of Gwalior having India's worst air

1st place: Zabol - Iran

Pollution level: 217 µg / m³ of PM 2.5

Zabol's air pollution level, which is heavily dusted by severe droughts affecting the region, is 20 times higher than acceptable to WHO

* Posted on 6/14/2016