Over the years, bottled water has been hailed as squeaky clean and healthy. Still, new studies indicate that about a quarter of a million invisible plastics are inside one litre of bottled water, sparking fears that all is not that well there. This discussion reviews this study and looks at possible health hazards.
Researchers at Colombia and Rutgers Universities have done their maths and found that, on average, each litre of bottled water contains a quarter of a million nano plastic particles invisible to the eyesight but can be viewed through a microscope. These particles are less than a micron in size. There are 25,400 microns — also called micrometres because it is a millionth of a meter — in an inch. A human hair is about 83 microns wide.
Previous studies have looked at slightly bigger microplastics that range from the visible 5 millimetres, less than a quarter of an inch, to one micron. The study found about 10 to 100 times more nanoplastics than microplastics were discovered in bottled water.
What Do Scientists Say About Nanoplastics?
Much of the plastic seems to be coming from the bottle itself and the reverse osmosis membrane filter used to keep out other contaminants, said study lead author Naixin Qian, a Columbia physical chemist.
Researchers still can’t answer the big question: Are those nanoplastic pieces harmful to health?
The world “is drowning under the weight of plastic pollution, with more than 430 million tonnes of plastic produced annually” and microplastics found in the world’s oceans, food and drinking water, with some of them coming from clothing and cigarette filters, according to the United Nations Environment Programme. Efforts for a global plastics treaty continue after talks bogged down in November.
A new study found the average litre of bottled water has nearly a quarter million invisible pieces of nanoplastics, detected and categorized for the first time by a microscope.
All four co-authors interviewed said they were cutting back on their bottled water use after they conducted the study. The Columbia physical chemist Wei Min pioneered the dual laser microscope technology and said he has reduced his bottled water use by half. Stapleton said she now relies more on filtered water at home in New Jersey.
However, study co-author Beizhan Yan, a Columbia environmental chemist who increased his tap water usage, pointed out that filters themselves can be a problem by introducing plastics.
“There’s just no win,” Stapleton said.
Outside experts who praised the study agreed that there’s a general unease about the perils of fine plastic particles, but it’s too early to say for sure.
“The danger of the plastics themselves is still an unanswered question. For me, the additives are the most concerning,” said Duke University professor of medicine and comparative oncology group director Jason Somarelli, who wasn’t part of the research. “We and others have shown that these nanoplastics can be internalized into cells, and we know that nanoplastics carry all kinds of chemical additives that could cause cell stress and DNA damage and change metabolism or cell function.”
Somarelli said his work, which has not yet been published, has found more than 100 “known cancer-causing chemicals in these plastics.”
What’s disturbing, said University of Toronto evolutionary biologist Zoie Diana, is that “small particles can appear in different organs and may cross membranes that they aren’t meant to cross, such as the blood-brain barrier.”
Diana, who was not part of the study, said the new tool researchers used makes this an exciting development in studying plastics in the environment and body.
About 15 years ago, Min invented dual laser microscope technology that identifies specific compounds by their chemical properties and how they resonate when exposed to the lasers. Yan and Qian talked to him about using that technique to find and identify plastics that had been too small for researchers using established methods.
Kara Lavender Law, an oceanographer at the Sea Education Association, said, “The work can be an important advance in detecting nanoplastics.” Still, she said she’d like to see other analytical chemists replicate the technique and results.
Denise Hardesty, an Australian government oceanographer who studies plastic waste, said context is needed. The total weight of the nanoplastic found is “roughly equivalent to the weight of a single penny in the volume of two Olympic-sized swimming pools.”
Hardesty is less concerned than others about nanoplastics in bottled water, noting that “I’m privileged to live in a place where I have access to ‘clean’ tap water, and I don’t have to buy drinking water in single-use containers.”
Yan said he is studying other municipal water supplies in Boston, St. Louis, Los Angeles and elsewhere to see how much plastics are in their tap water. Previous studies looking for microplastics and some early tests indicate less nanoplastic in tap water than in bottled water.
Even with unknowns about human health, Yan said he does have one recommendation for worried people: Use reusable bottles instead of single-use plastics.
READ RELATED: Turning Plastic Waste into Green Jobs: A Path to Prosperity and Sustainability.
Are Nanoplastic Harmful?
A litre of bottled water contains nearly a quarter of a million pieces of nanoplastic on average, according to new research published this week in the Proceedings of the National Academy of Sciences.
Measuring less than a micron, these nanoplastics are often a tiny fraction of the size of a speck of household dust. In the new study, scientists developed a novel imaging technique which showed that the number of nanoplastic particles in bottled water was 10 and 100 times higher than previously estimated, said Wei Min, a biophysicist at Columbia University and a co-author of the study.
“Millions of tons of plastic are produced worldwide each year,” said Douglas Walker, an analytical chemist at Emory University who was not involved in the new research. Microscopic particles from those plastics can end up in food and beverages in the manufacturing process — they might be introduced through plastic tubing used in machinery, for example — or leach in from packaging such as plastic bottles.
“If you think about the potential for their presence as environmental contaminants, it’s huge,” he said.
But while nanoplastics and slightly larger particles, known as microplastics, are increasingly being found in our food, drinks and even our bodies, their effects on our health are still unclear.
Here’s what we know and what you can do to reduce your exposure.
Researchers don’t have strong evidence yet for how these particles affect our health. A handful of small studies have found that they can cross the blood-brain barrier, enter the placenta and show up in our urine.
“But if a particular microplastic or neoplastic is present in a tissue, that doesn’t necessarily mean that it causes damage,” said Dr Konstantinos Lazaridis, a gastroenterologist who studies the role of environmental factors in liver disease at Mayo Clinic.
Dr. Lazaridis said that tiny plastic pieces may pass through most people’s bodies without causing much harm. Or it might be that these environmental particles only impact people with genetic predispositions to disease, he said.
Some researchers have theorized that microplastics may be behind disease patterns that haven’t yet been explained by other causes, such as the increase in colorectal cancers among young people or the uptick in Crohn’s disease and ulcerative colitis. However, studies are far from conclusive.
Scientists who study microplastics and nanoplastics believe that “the smaller the particle size, the more dangerous it may be,” Dr. Min said. In other words, nanoplastics may have a more significant impact on health than microplastics because there are more of them and because they may be able to enter cells more efficiently.
A growing body of literature suggests that at least some additives and chemicals found in and alongside plastics can harm our health, Dr Walker said. This includes chemicals like bisphenol A, or BPA, linked to increased blood pressure and type 2 diabetes; per- and poly-fluoroalkyl substances, or PFAS, which may affect fertility; and phthalates, which may interfere with hormones.
However, many other chemicals used in plastic manufacturing haven’t been studied for toxicity in humans. Dr. Walker said one study identified more than 10,000 unique compounds used in plastic manufacturing and found that only a tiny fraction had been evaluated for their potential health effects.
Experts also need to understand how quickly various plastic particles and additives get into our systems, how much may need to accumulate to cause an effect and how long they linger.
How Can You Minimize Your Exposure?
You may not be able to avoid nanoplastics or microplastics entirely, but Dr. Walker said you can reduce your exposure if you want to err on caution.
Drink filtered tap water whenever possible. A filter with a 1-micron or less pore size can help reduce microplastics in your water; smaller micron pores will better filter out smaller particles. But you should ensure your filter is not made out of plastic itself, Dr. Walker said. Instead, use ceramic or carbon filters certified by NSF International or the Water Quality Association.
Consider your glass or stainless steel bottle when you’re on your own. But if you need to hydrate and all you can access is a plastic water bottle, that’s okay; Walker said that can minimize plastic degradation by protecting your bottle from sunlight and heat.
If you want to reduce your exposure further, Dr Walker said, try limiting your use of other plastic products, such as food containers and single-use grocery bags.
