Scientists have shown that people swallow hundreds of thousands of microscopic pieces of plastic every time they drink a liter of bottled water, a discovery that could have profound implications for human health.
Scientists have discovered between 100 and 1,000 times the amount of plastic in bottled water
by aparodyoflife ·
For the past several years, scientists have been searching for “microplastics,” or pieces of plastic ranging from one micrometer to half a centimeter in length, and they have found them almost everywhere. Tiny plastic fragments have been detected in the deepest depths of the ocean, in the frozen hollows of Antarctic sea ice and in human placentas. They leak from laundry machines and hide in soil and wildlife. Microplastics are also found in the food we eat and the water we drink: in 2018, scientists discovered that one bottle of water contained, on average, 325 microplastics.
But researchers at Columbia University have now been able to quantify the impact of nanoplastics as well pose a threat.
“Whatever microplastics do to human health, I would say nanoplastics will be more dangerous,” said Wei Min, a professor of chemistry at Columbia University and one of the authors of the new paper.
Scientists have also found microplastic particles in tap water, but in smaller quantities.
Plastics are a bit like skin, shedding pieces into water, food or whatever substance they touch, says Sherri Mason, a professor and director of sustainability at Penn State Behrend in Erie, Pennsylvania.
“We know at this point that our skin is constantly shedding,” she said. “And that’s what these plastic items do, they keep falling off.”
Typical methods for finding microplastics cannot be easily applied to find smaller molecules, but Min has co-invented a method that involves pointing two lasers at a sample and observing the resonance of different molecules. Using machine learning, the group was able to identify seven Types of plastic particles in a sample of three types of bottled water.
“There are some other techniques that have identified nanoplastics before,” said Naixin Qian, a doctoral student in chemistry at Columbia University and first author of the new paper. “But before our study, people didn’t have a set number for their number.”
“It’s really groundbreaking,” said Mason, who is not yet involved in the research. He was one of the first researchers to discover plastics in bottled water. She says the new study demonstrates the prevalence of nanoplastics and provides a starting point for evaluating their health effects.
“Ordinary humans look at a sample of water, if there is visible plastic in it, they will be turned off,” she said. “But they don’t realize that invisible plastics are actually the biggest concern.”
The new study found pieces of PET (polyethylene terephthalate), the material most plastic water bottles are made of, and polyamide, a type of plastic found in water filters. The researchers assumed this meant that plastic was entering the water from the bottle and from the filtration process.
Researchers do not yet know how dangerous microplastics are to human health. In a large review published in 2019, the World Health Organization said there was not enough strong evidence linking microplastics in water to human health, but described an urgent need for more research.
In theory, nanoplastics are small enough to reach a person’s blood, liver and brain. Nanoplastics are likely to occur in much larger quantities than microplastics. In the new research, 90% of the plastic particles in the sample were nanoplastics, and only 10% were larger microplastics.
Finding a connection between microplastics and health problems in humans is complex, as there are thousands of types of plastics, and more than 10,000 chemicals used to manufacture them. But at some point, Mason said, policymakers and the public need to prepare for the possibility that microplastics in the air we breathe, the water we drink, and the clothes we wear will have serious and serious impacts.
“There are still a lot of people, because of marketing, who are convinced that bottled water is better,” Mason said. “But that’s what you drink in addition to that water.”