It seems anywhere scientists look for plastic, they find it: from the ice in Antarctica, to the first bowel movement produced by newborn babies.

Now, researchers are finding that the amount of microscopic plastics floating in bottled drinking water is far greater than initially believed.

Using sophisticated imaging technology, scientists at Columbia University’s Lamont-Doherty laboratory examined water samples from three popular brands (they won’t say which ones) and found hundreds of thousands of bits of plastic per liter of water.

Ninety percent of those plastics were small enough to qualify as nanoplastics: microscopic flecks so small that they can be absorbed into human cells and tissue, as well as cross the blood-brain barrier.

The research, which was published Monday in the journal Proceedings of the National Academy of Sciences, raises new concerns about the potentially harmful health effects — and prevalence — of nanoplastics. The researchers found that the quantity of such particles was 10 to 100 times greater than previously estimated.