Dirtiest & Most Polluted Cities in the World: Who Tops the List?

What's the first country that came to your mind when you saw this?

If you've been up to date with current events, you'd probably think China's capital topped the list of the most polluted cities of the world. At least when it comes to air quality, that is.

But another country has shoved this hugely populous area off the top of the charts. As gasp-inducing that pronouncement may be, it doesn't mean that some other city just got more smoggy or polluted - part of the reason why Beijing is no longer in the top position is that the city has made "consistent and aggressive efforts" to improve air quality, CNN reported. Which means whichever came a very close second to Beijing as the most polluted city could now be the most polluted one.

That place is no other than New Delhi, India.

"At its worst, air pollution in New Delhi this winter was 60 times higher than the level considered safe, the research from India's Center for Science and Environment (CSE) reveals," the American news outlet said.

From November to January, New Delhi had an average of 575 micrograms per cubic meter of very harmful airborne pollutants, such as PM2.5. This is distinctly above Beijing's 400 micrograms, which also are recorded during the same duration in the said city. The normal standard is actually 12 micrograms per cubic meter, according to the U.S. Environmental Protection Agency (EPA).

The dirtiest city, based on online business publication Quartz's ranking as noted by Time magazine, is Iran's Ahwaz. This city is home to three million people and is the capital of Khuzestan Province, where most of Iran's oil is produced. It also has 372 micrograms per cubic meter of PM10 airborne pollutants. Sanandaj, Kermanshah, and Yasouj are three other areas in Iran that made it to the top 10 dirtiest cities in the world. Ulaanbaatar in Mongolia came in second, while Ludhiana and Kanpur in India also had a place in the top ten. The same is the case for Quetta and Peshawar in Pakistan.