O n the beach in Pamunugama, on Sri Lanka’s west coast, women in uniform work under the scorching sun. They sift through rubbish washed ashore, searching among the usual litter for something much smaller: tiny plastic pellets.

Five years ago, in May 2021, this same beach was swamped with pellets as smoke rose over the Indian Ocean.

In May 2021, after the MV X-Press Pearl caught fire 10 miles off this stretch of coast. The Singapore-flagged container ship was carrying 1,486 containers, including tonnes of hazardous materials such as nitric acid. As the blaze intensified, containers fell overboard and billions of pellets known as nurdles , which are used to make most plastic items, spilled into the sea before the vessel sank .

Workers in protective clothing remove plastic pellets from the X-Press Pearl washed up on a beach at Pamunugama in May 2021.…