People stand under a bridge next to the polluted water of the river Yamuna ahead of World Water Day, in New Delhi, India, March 21, 2018.

A boy stands as foam is seen covering the polluted water of the river Yamuna ahead of World Water Day, in New Delhi, India, March 21, 2018.

A boat is seen parked in the polluted water of the river Yamuna ahead of World Water Day, in New Delhi, India, March 21, 2018.

A man swims as he collects recyclable items in the polluted water of the river Yamuna ahead of World Water Day, in New Delhi, India, March 21, 2018. REUTERS/Adnan Abidi

A man swims as he collects recyclable items in the polluted water of the river Yamuna ahead of World Water Day, in New Delhi, India, March 21, 2018.