The health implications of nanoplastics are still uncertain, but researchers assert that these minute particles harbor over 100 carcinogenic chemicals. Participants in the study report a reduction in their consumption of bottled water following alarming revelations from standard 1-liter samples. Although scientists had long presumed the presence of minuscule plastic fragments in bottled water, the quantity and type remained unknown. In a groundbreaking effort, researchers from Columbia and Rutgers universities in the US utilized a dual-laser microscope to identify and categorize these particles for the first time. Examining five samples from three common bottled water brands, the scientists determined particle levels ranging from 110,000 to 400,000 per liter, averaging around 240,000. The study, published in Proceedings of the National Academy of Sciences, focused on particles smaller than a micron, with 10 to 100 times more nanoplastics than previously studied microplastics. The source of much of the plastic appears to be the bottle itself and the reverse osmosis membrane filter employed to exclude other contaminants, according to Naixin Qian, the lead author and a Columbia physical chemist. The study's co-author, toxicologist Phoebe Stapleton from Rutgers, emphasized that the extent of health risks associated with nanoplastic consumption is currently under review. Despite the study's findings, the International Bottled Water Association emphasized the lack of standardized measuring methods and the absence of a scientific consensus on the potential health impacts of nano and microplastic particles. The American Chemistry Council, representing plastics manufacturers, chose not to comment. The global issue of plastic pollution, generating over 430 million tonnes annually, extends to microplastics infiltrating oceans, food, and drinking water, as highlighted by the United Nations Environment Programme. Ongoing efforts for a global plastics treaty persist, following stalled talks in November.