Up to 11. 5 million plastic particles can show up in a single liter of bottled water, at least in a small slice of samples tested by a team working near Lake Erie.

Researchers tested spring, groundwater, and purified bottled waters against local tap to see how treatment shapes the byproducts that emerge — and the differences were striking.

For years, bottled water has been marketed as the cleaner, safer alternative to whatever comes out of the kitchen faucet. Now the scientist behind one of the most detailed tests of plastic ...