Pollution in Delhi: Toxic foam on India's Yamuna River

It looks as if the two men are navigating their boat through icy waters — but it is actually a layer of toxic foam that partially covers the Yamuna River in India's capital, Delhi. The cause of the foam is the Yamuna River's high phosphate content. The tributary is one of the most polluted rivers in the world.

Just as the four-day Hindu festival of Chhath Puja was about to begin on Saturday, toxic foam began to appear on the Yamuna River. But believers were not deterred and celebrated the ancient religious festival worshipping the sun god not only on the river bank, but also in it.

With offerings and incense sticks, people wade waist-deep into the river and pray towards the setting sun. Many Chhath Puja worshippers are women who pray for good luck for their husbands and families. After worshipping the sun god, Chhath songs are sung into the night. Day three of the festival ends with the welcoming of the sunrise.

The foam that piles up on the bank comes from deposited sludge and waste, environmental engineer Ankit Srivastava, a former advisor to the Delhi government, told the Reuters news agency. "The foam is not lethal by nature," Srivastava said. "You will not die [from] consuming it, but you would fall ill."

The toxic foam can cause skin and respiratory problems. Delhi's ruling Aam Aadmi Party (AAP) has been promising to clean the sacred, but dirty, river for some time now. However, the situation remains unchanged. In an immediate response to the situation, the city's water authority sprayed food-grade chemicals and enzymes on Monday in a bid to dissolve the foam.

Not fog, but smog, envelops four worshippers making offerings to the sun god. The air in India's capital is also toxic — a thick, yellow-grey cloud hangs over New Delhi, one of the most polluted cities in the world. The air pollution caused by exhaust fumes from factories and traffic is exacerbated by seasonal agricultural fires.

This passer-by is barely recognizable amongst the thick haze. Around 32 million people in the world's second-largest city suffer from particle pollution which far exceeds the World Health Organization's limit value. Many people complain of breathing difficulties, coughs and headaches, especially in fall and winter, when the smog hangs particularly thick over Delhi.

At the beginning of November, emergency measures were ordered to counteract air pollution and protect the population. In addition to school closures, a temporary halt to construction work that causes dust was also enforced. Schools only reopened recently, but the air quality index is still in the dangerous range.