“There is so much plastic in the bottled water we drink?”
An American academic study found that bottled water commonly consumed on the market contains approximately 240,000 invisible nanoplastics per liter. In particular, he warned that nanoplastics are already introduced into bottled water before manufacturers bottle it, and that it is difficult to completely eliminate it even if you drink tap water or purified water. The problem of nanoplastics in bottled water has been pointed out in previous studies, but this is the first time that it has been revealed that the amount of plastics harmful to health is much higher than expected.
In a paper published in the Proceedings of the National Academy of Sciences (PNAS) on the 8th (local time), researchers at Columbia University disclosed the results of analyzing the amount and composition of nanoplastics in bottled water. Specific numbers were found using advanced laser microscope technology and special algorithms, which are much more advanced than before.
The researchers selected three brands of bottled water sold at Walmart and examined five samples of each. As a result, an average of about 240,000 particles were found per liter. Depending on the brand, there were cases where there were anywhere from 110,000 to as many as 400,000 pieces. More than 90% of the particles were identified as nanoplastics.
The size of nanoplastics is usually less than 1 μm (1 micrometer, 1 millionth of a meter). It is much smaller than the commonly called ‘microplastics (less than 5mm)’. It is less than 1/100th the thickness of a human hair and can penetrate through blood vessels into cells, brain, and placenta. Professor Wei Min, a co-researcher, explained, “What is important in the plastic issue is not the mass but the size,” adding, “This is because the smaller the particle, the more easily it can enter the human body.”
It should also be noted that among the nanoplastics whose composition was revealed in this study, polyamide (PA), known as a material for the synthetic fiber nylon, was the most common. For the two bottled water brands that were the subject of the survey, the proportion of PA reached 63% and 49%, respectively. The remaining brand accounted for 19%.
In general, bottled water is purified using the ‘reverse osmosis’ method using concentration differences between solutions. In this process, highly durable PA is used as a filter material to filter water. In other words, this means that many of the nanoplastics in the water may not have fallen off from water bottles or caps, but may have been introduced during the production process.
Columbia University researchers told the Associated Press, “As a result of this study, study participants drank less bottled water in plastic bottles.” Researcher Bayzan Yan said, “Until now, nanoplastics have been an unknown area, and toxicity research has remained at the level of speculation,” adding, “With this research, we have opened a window to a new world that has not been seen in the past.”
There is also a counterargument that there is no need to overreact as related research has only just gotten off the ground. The International Bottled Water Association protested in a statement immediately after the paper was published, saying, “The effects of nanoplastics on the human body have not yet been scientifically proven,” and “there is much content that unnecessarily scares consumers.”
Sherry Mason, a professor at Pennsylvania State University’s Behrand College who first raised the issue of bottled water plastic in 2018, advised on CNN, “To reduce exposure to nanoplastics, it is best to put all food, not just tap water, in glass or stainless steel containers.”
Source: Donga
Mark Jones is a world traveler and journalist for News Rebeat. With a curious mind and a love of adventure, Mark brings a unique perspective to the latest global events and provides in-depth and thought-provoking coverage of the world at large.