A new study conducted by researchers at Columbia University has found that a litre of bottled water could contain about 2.4 lakh (240,000) plastic pieces on average. This number is about 10 to 100 times greater than previous estimates that mainly focused on larger-sized plastics. The study analyzed three popular brands of bottled water sold in the US and detected approximately 1.1-3.7 lakh (110,000-370,000) plastic fragments in each litre, with 90% of them being nanoplastics and the rest microplastics .
The researchers used a technique called stimulated Raman scattering microscopy to measure plastic particles as small as 100 nanometres in size. They targeted seven common types of plastics and found that polyethylene terephthalate (PET), which is the material used to make water bottles, was the most common plastic present. They also found polyamide, a type of nylon, in greater quantity than PET. Other common plastics detected included polystyrene, polyvinyl chloride, and polymethyl methacrylate .
It is worth noting that the seven plastic types the researchers searched for accounted for only about 10% of all the nanoparticles found in the bottled water samples. The composition of the remaining particles remains unknown, highlighting the complexity of the particle composition in seemingly simple water samples .
The study’s findings shed light on the presence of nanoplastics in bottled water, a category that previous studies were unable to account for. Nanoplastics are smaller than a micrometre and are measured in billionths of a metre. While nanoplastics have less mass than microplastics, their smaller size makes them more easily able to enter the human body .
The implications of consuming plastic-contaminated water on human health and the environment are still being studied. However, the presence of microplastics and nanoplastics in various ecosystems, including soil, drinking water, food, and even polar ice, raises concerns about their potential effects on both human health and the ecosystem.
The researchers believe that their study opens a window into a previously uncharted world and emphasizes the need for further research on nanoplastics. They are now expanding their research beyond bottled water to explore the vast realm of nanoplastics .