This archive report was first published on 2 December 2019.
Marina Beach, a centrepiece of Chennai life for over a century, has been plagued by a toxic foam that has formed every monsoon season, but has been particularly severe this year.
Despite warnings from doctors that the foam can cause skin problems, hundreds of families continue to throng the beach, letting their children play and take selfies in the clouds of white suds.
"It is definitely not good for people to go into the foam but they just do not understand the risks," said Pravakar Mishra, a scientist at the National Centre for Coastal Research in Chennai.
Authorities are also on alert for a repeat of a 2017 incident when thousands of fish were killed by pollution that hit beaches around the same time.
Experts blame heavy rain in recent days that has carried untreated sewage and phosphate down to the sea, mixing with washing detergent residue to create the toxic foam.
Only 40 percent of sewage in Chennai and other big cities gets proper treatment, according to Mishra, who is setting up a buoy to monitor pollution levels in the sea.
"Pollution is now a bigger threat to India's beaches than the rising seas," said Mishra, highlighting the sewage, micro plastic that is killing fish and the bags and cups that cover the sand.
