World's 10 Most Polluted Cities

2. Ulaanbaatar, Mongolia:

The second most polluted city is Ulaan Baatar in Mongolia. The city records for 279 micrograms of polluting particles per cubic meter. Ulaan Baatar is not only the capital of Mongolia but it also serves as the country's transport and industrial center. It manufactures nearly everything, from textiles to processed foods to cement and just around the corner are the coal mines powering these industries.

1. Ahvaz, Iran:

Ahvaz in Iran is the most polluted city in the world. It records for 372 micrograms of polluting particles per cubic meter. The Iranian capital of Ahvaz is found to have the highest annual average for outdoor air pollutants. It is an oil center, transportation hub, and industrial city. The city is known for producing sugar and silk, and for linking roads, rails, and pipelines to ports in the Persian Gulf.