In a world of combustion engines and smoke stacks, we are all sucking in poison with every breath. Invisible to the eye, each puff of air has innumerable particles that destroy our bodies from the inside. Some parts of the planet are worse than others; the following article outlines 10 cities where it’s most hazardous to breath.

Emissions fall into two categories – ozone pollution and particle pollution. Today, 1 in every 4 Americans are breathing air contaminated with one or the other (source: American Lung Association). The very air we breathe has become hazardous to our health.

Statistics from the U.S. EPA show that the average person breathes 3,400 gallons of air every day, with children breathing in more air than adults. This makes our air supply one of our most dangerous heath risks. “Addressing air pollution is the easiest way to be able to fix someone’s well being… there are all sorts of harmful particulates in the air – link ”

1. Milan

Pm10 – a particularly insidious particle – causes cancer and respiratory problems. Take a trip to Milan, Italy and you’ll get more than your fair share. Legambiente, an Italian environmental group, claims that Milan has more smog than any other European city. Cars are thought to be the primary culprit, but with a 26% drop in traffic since January (thanks to congestion pricing) the city‘s residents are hoping the smog clouds blow away.

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2. Norilsk, Russia

Blacksmith Institute, an environmental think tank, ranks the Russian city of Norilsk within the top 10 most polluted places in the world. The world’s largest smelting plant sits in Norilsk, coating the air with nickel and cobalt deposits. With adults dying 10 years younger than the average Russian plant worker and children developing serious respiratory diseases, the company has finally started taking curative steps. They’ve even pledged to move the plan outside of the city … eventually.

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3. Pittsburgh, Pennsylvania

Pittsburgh – the Steel City – has more soot, aerosols, heavy metals and exhaust in its air supply than Los Angeles. This, with a paltry population of about 335,000 residents (Interesting note: L.A. has over 10 times as many residents at about 3.8 million.) When figuring out the cause, researchers are pointing their finger west; they say dirty air is blowing over from Ohio factories and power plants.

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4. Mexico City, Mexico

3,000 buses. 8.84 million residents with the corresponding amount of cars, motorcycles and taxis. A deep valley, enclosing all of that in a 3 sided bowl of mountains and volcanoes… and you have Mexico City. Its natural tendency to limit airflow makes it one of the most polluted cities on the face of the planet. Being 7,400 feet above sea level accentuates the problem. And what has the government done to alleviate the problem? They’ve started a project to retrofit special filters on 25 diesel buses. Don’t ask about the other 2,975 buses, or the 4 million private cars.

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5. Linfen, China

Citizens of Linfen, China are strangled by clouds of coal dust as they walk the streets. The city’s drinking water is laced with arsenic, the same poison used in various chemical weapons. Linfen may be the world’s most polluted city. China’s lax environmental controls hold some of the blame. The fact that Linfen is the heart of China’s coal production operations doesn’t help.

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6. Ouagadougou, Burkina Faso

Benzene – a pollutant caused from burning motorbike petrol – and dust particles are 3 times the World Health Organization’s prescribed limits in Ouagandougou, Barkina Faso. As a result, cases of cancer and respiratory disease are up considerably.

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7. Bejing

The air in Beijing, China is literally gorged with nitrogen dioxide. This is the same pollutant that can fatally damage the human lung. Pollutants are just as prevalent in surrounding Chinese provinces; satellite data shows a 50% spike in breathable pollutants over the last 10 years.

Zhang Lijun, deputy director of the EPA, says the worse is yet to come. According to Lijun, pollution levels will quadruple over the next 15 years unless China gets a hold on its energy consumption methods.

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8. Tianying, China

An industrial city — though China doesn’t really have any other kind —in the country’s northeastern rust belt, Tianying accounts for over half of China’s lead production. Thanks to poor technology and worse regulation, much of that toxic metal ends up in Tianying’s soil and water, and then in the bloodstream of its children, where it can cause lowered IQ. Wheat has been found to contain lead levels up to 24 times Chinese standards, which are even more stringent that U.S. restrictions on lead. “China has a commitment to environmental protection, but it also has a commitment to industry,” says Richard Fuller of the Blacksmith Institute. “It’s a constant push that’s mostly won by industry.”

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9. Los Angeles County

Los Angeles metro has the United State’s highest levels of ozone pollution, according to the State of the Air report 2010 (publisher: American Lung Association). Dr. Norman H Edelman, a chief medical officer for the ALA, says breathing ozone is like “getting a sunburn on your airways.” Constant exposure increases chances of respiratory disease… not good news for those living in La La Land.

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10. Kolkatta

Calcutta, India has roughly18.4 cases of lung cancer per 100,000 residents yearly, eclipsing Delhi, India in the occurrence of the disease. (Delhi has13.34 cases per 100,000 residents per year.) This is despite having less than half the population count.

Apparently, the city’s high air pollution is the primary cause. 70% of the Calcutta’s respiratory diseases are said to be the direct result of air pollutants, according to a recent study by the Chittaranjan National Cancer Institute.

Suspended Particulate Matter (SMP), an air pollutant, should never have a count above 140 in a healthy environment. In Calcutta the average SPM count is 211. Likewise, Respiratory Particulate Matter (RPM) count should never pass 60. Calcutta almost doubles that figure with a RPM count of 105.

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BONUS 11. Rauðafell, Iceland (yes i know it’s not a city!)

Sometimes nature itself contaminates the air we breathe; it’s almost as if Mother Nature is protecting herself with proactive measures. This is especially apparent in the wake of the volcanic eruption in Iceland. Finnu Tryggvason, a farmer in Rauðafell, had to put down some of 4 of his horses in answer to the eruption. “I would have like to keep them a while longer,” he says, “but circumstances do not allow for that.”

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