Small fragments of plastic make their way deep into our bodies in alarming amounts, especially through our food and drink.
In 2024, Chinese scientists have found a simple and effective way to remove them from water. The team conducted tests on both soft and hard tap water (which is richer in minerals).
They added nanoplastics and microplastics before boiling the liquid and then filtering out any precipitates.
Related: Your food packaging is dumping microplastics into every meal, study finds
“Tap water nano/microplastics (NMPs) escaping from centralized water treatment systems are a growing concern worldwide as they pose potential risks to human health through water consumption,” the researchers write in their published paper.
Watch the video below for a summary of the findings:
In some cases, up to 90% of NMPs were removed by the boiling and filtering process, although the effectiveness varied by water type.
Of course, the big benefit is that most people can do it with what they already have in their kitchen.
“This simple boiling water strategy can ‘decontaminate’ NMPs in household tap water and has the potential to harmlessly reduce human intake of NMPs through drinking water,” write biomedical engineer Zimin Yu of Guangzhou Medical University and colleagues.
A higher concentration of NMP was removed from samples of hard tap water, which naturally forms a scale (or calcium carbonate) build-up as it is heated.
Commonly seen inside kitchen kettles, the chalky substance forms on the surface of the plastic as temperature changes force the calcium carbonate out of solution, effectively trapping the plastic fragments in a crust.
Subscribe to the free ScienceAlert newsletter verified
“Our results showed that the efficiency of nanoplastic precipitation increased with increasing boiling water hardness,” the team writes.
“For example, from 34% to 80 mg L-1 to 84% and 90% at 180 and 300 mg L-1 of calcium carbonate, respectively.”
Even in soft water, where less calcium carbonate is dissolved, about a quarter of the NMPs were collected from the water.
Any bits of plastic encrusted with lime could then be removed through a simple filter, such as the stainless steel mesh used to strain tea, the researchers say.
Previous studies have measured fragments of polystyrene, polyethylene, polypropylene and polyethylene terephthalate in tap water, which we consume in varying amounts every day.
This simple water boiling strategy can “decontaminate” NMPs in household tap water. (Yu et al., The environment. Sci. Tech. Lett., 2024)
To put the strategy to the ultimate test, the researchers added even more nanoplastic particles, which were effectively reduced in number.
“Apparently, drinking boiled water is a viable long-term strategy for reducing global NMP exposure,” Yu and team write.
“However, the consumption of boiled water is often regarded as a local tradition and only prevails in a few regions.”
Scientists hope it could become a more widespread practice as plastic continues to take over the world.
Related: Microplastics seem to be in every kind of animal…Except one
Small pieces of plastic are a growing problem. Microplastics come from clothing, kitchen utensils, personal care products and countless other everyday items.
Their durability makes them persistent in the environment, including in human bodies.
Human exposure to NMP through consumption of drinking water. (a) World map of drinking water hardness. (b) Daily consumption of NMP through boiled and tap water in 67 regions. (Yu et al., The environment. Sci. Tech. Lett.2024)
Not only are many people on Earth already contaminated with microplastics, but we are still exposed every day because there is minimal regulation of these insidious stains.
According to a 2025 literature review from the University of Texas at Arlington, a significant portion of our exposure to microplastics may come from drinking water because wastewater treatment plants still do not effectively remove microplastics.
About 9 billion metric tons of plastic have been produced globally since plastic production began, much of which has progressively degraded into smaller and smaller fragments without actually decomposing, forming a fine plastic dust that now permeates the planet.
Wastewater treatment plants actually remove many of these small particles, the new review shows, but not enough.
Related: Glass bottles actually contain more microplastics, scientists have found
While it’s still uncertain how harmful this plastic is to our bodies, it’s clearly not the healthiest of snacks.
Plastics have already been linked to changes in the gut microbiome and the body’s resistance to antibiotics.
The team behind this study want to see more research into how boiling water could keep man-made materials out of our bodies – and counteract some of the alarming effects of emerging microplastics.
“Our results have ratified a highly feasible strategy to reduce human exposure to NMP and set the stage for further investigations with much larger numbers of samples,” Yu and colleagues conclude.
The research was published in Environmental Science and Technology Letters.
An earlier version of this article was published in March 2024.