The Citarum (Indonesia) has been called the world's most polluted river. Around 5 million people live in the river's basin, and most of them rely on its flow for their water supply.

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.

Countries with the worst air pollution ranked by World Health Organisation

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.

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.

Vehicular emissions adding to the cancerous toxins in Delhi

Rondônia is a state in northwest Brazil which, along with the states of Mato Grosso and Pará, is one of the most deforested regions of the Amazon rain forest. Thousands of acres of forest have been slashed and burned here, mostly to make room for cattle ranching.

The Yamuna is the largest tributary of the Ganges River. Where it flows through Delhi, it's estimated that 58 percent of the city's waste gets dumped straight into the river. Millions of Indians still rely on these murky, sewage-filled waters for washing, waste disposal and drinking water.

Scientists warn of pollution in Malta’s seas

According to a report by the Worldwatch Institute on nuclear waste, Karachay is the most polluted spot on Earth. It was used by the Soviet Union as a nuclear dumping site, and now the radiation level here is so high that it's sufficient to give a lethal dose after just an hour of exposure.