Inside The World's Most Polluted City: Ahvaz, Iran [VIDEO]

Several Chinese cities have been consistently ranked among the world’s most polluted destinations. This is no surprise considering how much publicity the toxic air quality and bodies of water teeming with trash in China have been getting internationally.

And as terrible as the statistics are in China, their air pollution problem does not come close to the worst in the world. According to the World Health Organization, lesser-known cities in Iran have enormously more toxic air than Beijing.

Ahvaz, Iran, for example, is ranked by the WHO as the city with the world’s highest levels of air pollution. China’s air is ranked on an index that measures the amount of PM2.5 particles in the air, and has been known to reach levels that are literally off the index. PM2.5 refers to the diameter of the air particulates, smaller than 2.5 micrometers, which is considered “fine” particles. In Iran, air is measured according to a PM10 scale. PM10, are larger, coarser dust particles. Pollutants between the two sizes are considered dangerous because their small size allows them to penetrate deep parts of the lungs.

The average level of particulate pollution globally is just 71 on the scale, which is considered “moderate” according to the Air Quality Index. In Ahvaz, the average level of PM10 is estimated at a “hazardous” 372.

Here’s a look at some videos of what hazardous air in Ahvaz looks like:

A lot of the pollution is attributed to the factories pumping out toxic air in the 1.2 million-people city, which is in Iran's oil-rich southwest. The factory emissions, combined with massive regional sandstorms, are both contributing factors to the high particulate levels. In particular, the area's steel and iron industries have been the cause of polluting emissions.

“Unusual development and growth of the city, undesired placement of heavy industries, such as iron and steel plants, airport, and exploration of oil wells in a nearby city, in addition to heavy traffic … have made the city like an island of heat and pollution,” said a report by S.A. Tabatabaie of the Chamran University in Ahvaz, published in 2002.

The report cites two black carbon factories, and a pipe factory of the Iranian national oil company, which are located inside the city, as the core of the problem.