From MNN.com

As the world’s population balloons to almost 7 billion, it’s become more and more difficult to find anywhere on Earth unaffected by man-made pollution and development, and far too often it takes things going really wrong before people
take action to keep our planet clean. So here’s a list that might help to
motivate: The 15 most polluted places in the world.

Citarum River, Indonesia

The Citarum has been called the world’s most polluted river. Around five million people live in the river’s basin, and most of them rely on its flow for their water supply.

Chernobyl, Ukraine

Chernobyl is the town in northern Ukraine home to the Chernobyl disaster of 1986, the worst nuclear power plant accident in history. Once home to more than 14,000 residents, the town remains mostly uninhabited and unsafe
today due to extensive radioactive contamination.

CREDIT: Stuck in Customs/Flickr

Linfen, China

Linfen has more air pollution than any other city in the world. Sitting at the heart of China’s coal belt, smog and soot from industrial pollutants and automobiles blacken the air at all
hours. It is said that if you hang your laundry here, it will turn
black before it dries.

CREDIT: sheilaz413/Flickr

The North Pacific Gyre

An island of trash twice the size of Texas floats in the middle of the Pacific Ocean, circulated by the currents of the North Pacific Gyre. The trash, which is mostly made up of plastic debris, floats as deep as 30 feet below the surface.

CREDIT: Cesarharada.com/Flickr

La Oroya, Peru

La Oroya is a soot-covered mining town in the Peruvian Andes. Ninety-nine percent of the children who live here have blood levels that exceed acceptable limits for lead poisoning, which
can be directly attributed to an American-owned smelter that has been
polluting the city since 1922.

CREDIT: Lakerae/Flickr

Dzerzhinsk, Russia

The Guinness Book of World Records has named Dzerzhinsk the most chemically polluted city on Earth, and in 2003 its death rate exceeded its birth rate by 260 percent. More than 300,000
tons of chemical waste were improperly dumped here between 1930 and
1998.

CREDIT: Spendruleziya/Flickr

Riachuelo Basin, Argentina

The Riachuelo Basin is a waterway whose name is synonymous with pollution. More than 3,500 factories operate along the banks of the river, a landscape that also includes 13 slums, numerous
illegal sewage pipes running directly into the river, and 42 open
garbage dumps.

CREDIT: FJTU/Flickr

To see pictures of eight more toxic places in the world, visit the original article found on MNN.com.