A recent study published in the journal Proceedings of the National Academy of Sciences has revealed startling findings about the presence of nanoplastics in bottled water. The study is the first to evaluate bottled water for "nanoplastics" - plastic particles smaller than 1 micrometer. These are significantly smaller than microplastics, which range between 1 and 5,000 micrometers.

Researchers found an average of 240,000 plastic fragments in a one-liter bottle of water, a quantity up to 100 times more than previous estimates which only considered microplastics. This higher count is due to the inclusion of nanoplastics, which are small enough to penetrate human cells and potentially affect organs, even reaching unborn babies through the placenta.

To detect these tiny particles, researchers developed a new microscopy technique and programmed a data-driven algorithm. They analyzed about 25 liters of bottled water from three popular US brands, discovering 110,000 to 370,000 plastic particles per liter, with 90% being nanoplastics. The study focused on seven common plastic types, including polyethylene terephthalate (PET) and polyamide.

The presence of unidentified nanoparticles in the water suggests the actual number of nanoplastics could be even higher. The International Bottled Water Association has called for a full review of the study's methodology by the scientific community and noted the lack of consensus on the health impacts of nano- and microplastic particles.

This research comes amidst growing concerns about plastic pollution, as over 450 million tons of plastic are produced annually worldwide. The study's authors plan to extend their research to tap water and snow samples from western Antarctica, emphasizing the urgency to understand the pervasive nature of nanoplastics in our environment.