A thick layer of toxic foam has once again covered parts of a holy river near New Delhi as the Indian capital struggles with a layer of acrid, noxious smog that has spread across the city.
The white foam, a mixture of sewage and industrial waste, has formed on sections of the Yamuna River, a tributary of the sacred Ganges River, which flows some 855 miles (1,376 kilometers) south from the Himalayas through several states.
The shocking foam contains high levels of ammonia and phosphates, which experts say can cause respiratory and skin problems. This coincides with dangerous levels of pollution that have sickened many of New Delhi’s more than 20 million residents and forced the closure of primary schools and some offices.
A similar-looking mixture appeared in a canal in the southern Indian state of Tamil Nadu, according to Press Trust of India. Video released by the news agency on Thursday shows strong gusts of wind blowing the foam onto roads and into the paths of cars and motorcycles.
For decades, parts of the Yamuna have been affected by the dumping of toxic chemicals and raw sewage. In several sections, the river appears dark and muddy as plastic waste accumulates on its banks.
The river is more polluted in the areas surrounding Delhi due to the dense population in the area and high levels of waste. Only 2% of the river’s length flows through the capital, but Delhi contributes about 76% of the river’s total pollution, according to a government monitoring committee.
Mixing is commonplace in the Yamuna and, despite its toxicity, many villagers downstream continue to use the water for bathing and even drinking, experts say. Photographs in September also showed toxic foam forming in the Yamuna.
Devoted people are often seen performing rituals in the river, surrounded by the dense foam. Every year, many people gather on the banks of the Yamuna to celebrate Chhath Puja, a festival dedicated to the sun god Lord Surya, and some walk through the foam to bathe and pray.
This week, the toxic foam in New Delhi was joined by a blanket of smog that prompted many terrified residents to buy air purifiers and wear face masks to minimize exposure to the fumes.
New Delhi has ranked as the world’s most polluted city for several consecutive days this week, according to Swiss air quality company IQAir. On Thursday, the city had an air quality index (AQI) of 517, a level considered hazardous, according to the company.
By comparison, the world’s least polluted city, Oslo, has an AQI of just three. China’s capital, Beijing, which used to be frequently on the list of the world’s most polluted, has in recent years taken great measures to clean up its air and has a current AQI of 25, a figure considered “good.”
Two other Indian cities – Kolkata and Mumbai – are on IQAir’s list of the world’s 20 most polluted cities, with AQI numbers of 205 and 102, both considered unhealthy.