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Top 10 Smoggiest Countries in the World

Top 10 Smoggiest Countries in the World
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The word “smog” has existed since one Dr. H.A. des Voeux, treasurer of the Coal Smoke Abatement Society, coined it in reference to London by combining “smoke” and “fog” to describe the “black fog” that was “not unknown in other large cities.”

More than a century later, “smog” is a commonplace word and phenomenon. Air pollution has become a major threat to public health around the globe, with urban outdoor air pollution estimated to cause 1.3 million deaths worldwide per year according to the World Health Organization (WHO). The air that residents of cities around the world breathe is full of particulate matter (which contains sulfate, nitrates, ammonia, sodium chloride, carbon and mineral dust) and ozone (which is created when sunlight reacts with pollutants from vehicle and industrial emissions). These substances can cause respiratory problems, trigger asthma, irritate eyes and much more.

Drawing in part on WHO data, here are ten of the smoggiest countries on earth based on measures including the number of parts per million of particles smaller than 10 micrometers (PM10) floating around in the air. Notably, many are in the Middle East and Asia.

1. Iran

Fire altar (modern version)

(Photo of Ahvaz via dynamosquito/Flickr)

Four cities in Iran are among the ten smoggiest in the world according to the WHO. One of the country’s largest, Ahvaz, is listed as the most smoggy, period. Located in southwestern Iran, Ahvaz is the capital of Khuzestan province, a region that traces its history all the way back to one of the oldest cities ever, Susa, one of the capitals of the ancient Achaemenid Persian Empire.

Modern-day Ahvaz has an average PM10 of 372 as a result of untrammeled development in the form of heavy industries including iron and steel plants and oil drilling. In the summer, temperatures can average 50-55 degrees Celsius.

2. Mongolia


(Photo of Ulaanbaatar via AaverageJoe/Flickr)

Located at an elevation of about 4,300 feet, Ulaanbaatar is the capital of Mongolia and a place where the old (a Buddhist monastic center was founded there  in 1639) meets the modern (the city is connected by rail to both the Trans-Siberian Railway in Russia and the Chinese railway system). The WHO ranks Ulaanbaatar as the world’s second most polluted city, with a PM10 of 279 that stems from both coal-fueled power plants and stoves used for heating and cooking in the city’s yurt quarters.

With a burgeoning economy — due in part to copper and coal mines —  a huge new coal fire power plant that uses “newer, cleaner” technology is under construction. But government officials have also shown interest in wind energy and wind turbines have been erected outside Ulaanbaatar.

3. India

View of West of Delhi

(Photo of Delhi via jepoirrier/Flickr)

India’s capital city of Delhi has more than four million registered vehicles — many powered by diesel fuel — and that is one reason it is ranked as the twelfth most polluted in the world with a PM10 of 198. The city’s poor air quality is also due to industry (including power plants) and road dust.

Air pollution is a huge problem for all of India. Other Indian cities noted by the WHO as being especially polluted are Lucknow with a PM10 of 186, Kolkata with a PM10 of 148 and Mumbai with a PM10 of 132. The burning of wood, agricultural waste and other materials has resulted in a near-perpetual haze hanging over urban and rural areas of India (and neighboring Bangladesh) that is visible in satellite photos.


4. Pakistan


(Photo of Peshawar via Omer Wazir/Flickr)

The Pakistani city of Quetta is (along with the Indian city of Ludhiana) ranked by the WHO as the fourth-most polluted in the world. Peshawar, an ancient city situated at one end of the legendary Khyber Pass, on the border of Pakistan and Afghanistan — that is, at the very crossroads of Central Asia and South Asia — is ranked seventh worse; a number of other cities (Lahore, Karachi and Islamabad) are ranked by the WHO as among the 15 most polluted.

Peshawar’s PM10 of 219 is  the result of a rapid increase in vehicular traffic as well as the uses of hundreds of coal-burning brick kilns. As a whole, “highly inefficient energy use” is noted as a reason for the air pollution throughout Pakistan as well as an increase in industrial activity (including marble and steel factories) without regulation and the burning of materials including plastic.

5. Botswana

Gaborone, Botswana

(Photo of Gaborone via pmecologic/Flickr)

Botswana’s capital, Gaborone, is listed as the eighth most polluted city in the world by the WHO with a PM10 of 216. A steep rise in the use of vehicles is one reason; another is the use of fire wood, paraffin and animal dung to start fires for cooking and other purposes. Nor is Botswana the only country in Africa with serious pollution: Dakar, the capital of Senegal, is 28th with a PM10 of 156 and Lagos, Nigeria’s capital, has a PM10 of 122 and is ranked 46th worst.

Currently, Botswana is a “lightly industrialized country with a relatively sparse population” and, outside Gaborone, “air pollution is not perceived to be a major problem at present.” The government’s national development strategy seeks to expand light industry: can Botswana learn from what has happened in Iran, India and Pakistan?

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3:23PM PST on Jan 29, 2014

Thanks for the article....and pictures!

9:56AM PST on Jan 29, 2014

As a Canadian, I'm glad we didn't make the list!

5:58AM PST on Jan 29, 2014


1:33AM PDT on Sep 19, 2013

Cairo used to have the highest incidence of lung cancer in the world, don't know if that's still true. The pollution is bad and every person smokes, so what do they expect?

10:56AM PDT on Jul 9, 2013


8:10AM PDT on Jun 27, 2013

thanks for sharing :)

12:03PM PDT on Jun 6, 2013

just reading it is making me cough

7:01PM PDT on May 28, 2013

Pollution of the air such a unhealthy environment to live in. So glad I have no experience of it, feel sad for the people that have chest problems.

7:33PM PDT on May 27, 2013

I would have thought China would be # 1

5:31PM PDT on May 27, 2013

Good thing the U.S. has laws to reduce smog.

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