Water bottles are a major source of nanoplastics: Montreal researcher

Bottled water consumers swallow 90,000 more microplastic particles each year than people who drink tap water, warns a new analysis by a Montreal researcher.

Sarah Sajedi calculated, by combing through more than 140 scientific articles on the subject, that the average population swallows between 39,000 and 52,000 microplastic particles per year.

But those who choose to drink bottled water—presumably because they believe it’s better for their health—probably don’t realize that they’re actually increasing their exposure to particles whose potential health impacts are as worrying as they are poorly understood, she said.

“People know that drinking plenty of water is good for their health, and they associate that with drinking cleaner water,” explained Sajedi, who was sufficiently concerned about the plastic waste problem that she returned to school after a hiatus of more than 30 years to complete a doctorate on the subject at Concordia University.

“They think water bottles are cleaner and safer, but that’s really not the case.”

Bottled water alone can account for an annual exposure to microplastic particles equivalent to that generated by all other sources combined, according to some studies.

These bottles are often made of very poor-quality plastic. Microplastic or even nanoplastic particles are released during their manufacturing, handling, storage, and transport, or when they decompose throughout their life cycle, for example, through exposure to sunlight or temperature fluctuations.

Moreover, unlike other types of plastic particles that pass through the food chain before entering the human body, these are ingested directly at the source.

“Ten years ago, we didn’t have the technology to study nanoplastics, so we focused on microplastics,” said Sajedi, who, before returning to school at an age when others are considering retirement, co-founded ERA Environmental Management Solutions, a leading provider of software specializing in health, safety, and environmental issues.

“We’re talking about chronic exposure. We’re not saying you’re going to die if you drink a bottle of water. But if you drink it for ten or twenty years… there’s going to be an accumulation.”

The situation is particularly worrying for young people (even though they are well-educated) who are among the main consumers of this type of product, added Sajedi. Not only do they begin their exposure very early in life, but it also occurs at a time when they are still growing.

In recent years, we have observed an explosion in the younger population of cases of certain diseases—from colorectal cancer to neurodegenerative disorders—that were previously found, especially in older people.

The phenomenon remains unexplained for the moment, and no study has yet established a causal link between this upsurge and exposure to micro- or nanoplastics. But until the enigma is solved, this hypothesis is worth another, the researcher believes.

“When I was younger, there were refreshment stands everywhere; you didn’t see people carrying water bottles with them everywhere. Water was essential and always available,” said Sajedi, who will soon publish two other studies on the subject. “If the government intervenes and brings back refreshment stands, it will be less fashionable to carry your water bottle.”

Health Impacts

Micro- and nanoplastic particles originate from the degradation of larger plastic items. Microplastics range in size from one micrometer (one millionth of a meter) to about five millimeters. Nanoplastics are measured in billionths of a meter. For comparison, the circumference of a human hair is about 70 micrometers.

Nanoplastic particles are so tiny that they can enter the bloodstream (for example, by crossing the intestinal barrier) and travel directly to organs.

The impact of these particles on human health is still poorly understood, but they have been found in all parts of the human body, from the brain to the testicles, including the lungs, heart, liver, and placenta. They may interfere with the function of these organs. They may also have carcinogenic properties, be a source of oxidative stress, and mimic the action of certain hormones (known as endocrine disruptors).

We also know that microplastics can cause inflammation, which will have the effect of “opening” cellular barriers that would otherwise remain closed—barriers like the blood-brain barrier, which is supposed to protect the brain from unwanted elements.

A US study published earlier this year warned that the human brain contains, on average, a spoonful of microplastics and nanoplastics, and that this could be linked to the explosion in dementia cases.

This amount, the US researchers added, is three to five times higher in individuals diagnosed with dementia. Worse still, there are seven to thirty times more microplastics and nanoplastics in the brain than in any other organ.

An alarming 50 per cent increase in brain concentrations of microplastics and nanoplastics was observed between 2016 and 2024, which corresponds to the exponential explosion in the quantity of plastic particles in the environment.

Micro- and nanoplastic particles are ubiquitous and no one is immune to them, warned Sajedi, who emphasized the importance of public education.

“We must avoid talking about everything at once, otherwise people stop listening and tell us that we have to die from something,” she said. “If I try to fight everything, I’ll lose, so I focus on plastic bottles, which are a huge source (of microplastics and nanoplastics).”

And once people get the message about bottles, hopefully they’ll start extrapolating to other products, added Sajedi, citing as an example her decision to only buy jam in glass jars.

In addition to leaving plastic water bottles on retail shelves, it’s recommended, for example, to switch from plastic containers to steel or glass containers for storing and/or heating food.

Some plastic containers can release up to 4.22 million microplastic particles and 2.11 billion plastic nanoparticles from a single square centimeter of plastic surface within three minutes of microwave heating, according to a report published in the journal Brain Medicine.

The findings of the new study were published in the Journal of Hazardous Materials.

–This report by La Presse Canadienne was translated by CityNews