Plastic is everywhere, from the Arctic ice to vital organs in the human body. In fact, previous estimates suggest that the average person swallows a credit card-worth of microscopic plastic particles（颗粒） every week. But new research shows that this could actually be an understatement.
Microplastics are plastics smaller than 5 millimeters, found in industrial waste, beauty products, and formed during the degradation of larger plastic pieces. Over time, they break down into even smaller nanoplastics. These tiny particles can pass through our intestines and lungs into our bloodstreams, reaching vital organs like the heart and brain.
While the idea of eating plastic is unsettling in itself, the major concern here is that these plastic particles contain chemicals that can interrupt our body' s natural release of hormones, potentially increasing our risk of reproductive disorders and certain cancers. They can also carry toxins（毒素） on their surface like heavy metals.
In the past, researchers have shown bottled water can contain tens of thousands of identifiable plastic fragments in a single container. However, until recently, only the larger microplastics were detectable with available measuring tools, leaving the area of nanoplastics largely a mystery.
Using Raman microscopy （显微镜学）， capable of detecting particles down to the size of a flu virus, the team measured an average of 240, 000 particles of plastic per liter of bottled water, 90 percent of which were nanoplastics, a revelation 10 to 100 times larger than previous estimates.
These plastics likely originate from the bottle material, filters used to " purify" the water, and the source water itself. " It is not totally unexpected to find so much of this stuff, " the study' s lead author, Columbia graduate student Naixin Qian, said in a statement. His team hopes to expand their research into tap water and other water sources to better inform our exposure to these potentially dangerous particles. " The idea is that the smaller things get, the more of them I reveal, " he added.
