Toxic foam covers one of India's most sacred rivers putting millions of Hindus at risk

One of India’s most sacred rivers, the Yamuna in New Delhi, is covered in white toxic foam.

The pollution puts millions of residents at risk as the river provides more than half of the Indian capital's water and Hindu devotees bathe in it, believing the body of water to be sacred.

The foam has formed from pollutants dumped by industries around the city.

Jasraj, a 70-year-old retired government clerk, said he has been visiting the river for a bathing ritual since 1980.

"I worship the river as a mother, and there is no question of its being clean or dirty. It's dirty on the surface but clean below the top," he said.

The 1,376-kilometer Yamuna is one of the holiest rivers for Hindus. It is also among the most polluted in the world. Dangerously unhealthy waterways are a concern for many, especially with pollution expected to worsen during the upcoming Chhath Puja, a Hindu festival.

During the festival, thousands of Hindus are expected to stand knee-deep in the Yamuna's frothy, toxic waters, sometimes even immersing themselves in a holy dip to mark Chhath Puja.

The river has become dirtier over the years as sewage, farm pesticides and industrial effluents flow into the waterway despite laws against polluting and authorities setting up dozens of sewage treatment plants.

The New Delhi government said officials were using defoamers to tackle the problem. Authorities have deployed dozens of motorboats to disperse the foam and erected bamboo barricades to keep people away from the river banks.

New Delhi also has some of the world’s most polluted air every year, and the current festival season is exacerbating the situation.

On Tuesday, the air-quality index deteriorated to a 'very poor' reading of 273, 18 times higher than the World Health