Evil orbs

ANTHONY RICCIARDI, a scientist at McGill University, was looking for evidence that an invasive Asian clam had colonised a warm spot in the St Lawrence river when a member of his team made a more headline-worthy discovery. Peering through a microscope at sand scooped up from the riverbed, the student saw hundreds of tiny plastic spheres that stood out for their perfect roundness and unnatural colours.

“Ugelstad spheres”, named for the Norwegian scientist who invented them in 1976, are used in cancer research, HIV treatments and the manufacture of flat-panel televisions. Only in the past decade has the cosmetics industry discovered how useful they are for scrubbing teeth and faces. New Yorkers now rinse 19 tonnes of microbeads down drains each year. Too tiny to be caught by municipal water filters, they easily flow into the world’s oceans, lakes and rivers. In water they can break down, releasing toxins, or become coated with other poisons, such as PCBs.