The public is increasingly conscious of the teeny-tiny particles called microplastics that are turning up everywhere from snow-capped mountains to the ocean. They’re even getting into our food and drinking water.

Now Columbia University scientists have figured out how to measure microplastic’s tinier cousin — nanoplastics. Their findings are unsettling.

Nanoplastics are so small they can pass through intestines and lungs and go directly into the bloodstream, and then into our organs.

The research team, using a new microscopic technique, found that a one-liter plastic bottle of water contains an average 240,000 fragments of plastic small enough to breach our bodies.

Nanoplastics are particles less than 1 micrometer long. Microplastics range from less than a quarter-inch to 1 micrometer. By comparison, a human hair is about 70 micrometers wide.

With the new technique, researchers probe samples with two lasers tuned to make specific molecules resonate.

Testing three popular bottled-water brands, they found 110,000 to 370,000 particles in each liter. Ninety percent were nanoplastics; the rest were microplastics.

A common find was polyethylene terephthalate [pol-ee-eth-uh-lean terr-eff-thuh-late], or PET [P-E-T]. Many plastic water bottles are made of it. So are bottles for soda, sports drinks and ketchup. Even more prevalent was polyamide [poly-ah-myde], a nylon used in plastic filters purported to purify water before it’s bottled.

Some researchers note that these invaders can be toxic to humans.

Another plot twist: The seven types of known plastics the researchers looked for accounted for only about 10% of the nanoparticles they spotted. The other 90%, the researchers said, could be almost anything.