Boiling water found effective in removing microplastics
Plastic particles are seeping into our bodies in disturbing amounts, mainly through food and drink. Researchers from Chinese universities have discovered a straightforward and effective method to remove them from water.
Tiny plastic fragments enter our bodies primarily through eating and drinking. In 2024, scientists discovered a straightforward and effective way to remove them from water. A team from Guangzhou Medical University and Jinan University in China conducted tests on both soft and hard water. The research was published in the scientific journal "Environmental Science & Technology Letters".
The effectiveness of boiling and filtering
“Tap water nano/microplastics (NMPs) escaping from centralized water treatment systems are of increasing global concern, because they pose potential health risk to humans via water consumption,” the researchers write in their article. They added nanoplastics and microplastics to the water, then boiled it and filtered out the sediments. In some cases, up to 90% of particles were removed thanks to the boiling and filtering process, although the effectiveness varied depending on the type of water.
The biggest advantage of this method is that most people can implement it using what they already have in their kitchens. “This simple boiling-water strategy can 'decontaminate' NMPs from household tap water and has the potential for harmlessly alleviating human intake of NMPs through water consumption,” believes Zimin Yu, the lead author of the study and a biomedical engineer at Guangzhou Medical University, along with his collaborators.
The impact of water hardness
A higher concentration of NMP was removed from samples of hard tap water that naturally form limescale deposits (calcium carbonate) when heated. “Our results showed that nanoplastic precipitation efficiency increased with increasing water hardness upon boiling,” the team writes. For example, from 34% at 80 milligrams per litre to 84% and 90% at 180 and 300 milligrams per litre of calcium carbonate.
Even in soft water, where less calcium carbonate is dissolved, about a quarter of the NMP was removed. The plastic fragments covered with lime deposits can then be removed using a simple filter, like a stainless steel mesh used for brewing tea.
Long-term benefits
Previous studies have shown the presence of polystyrene, polyethylene, polypropylene, and polyethylene terephthalate fragments in the drinking water we consume daily in varying amounts. To test the strategy, researchers added even more nanoplastic particles, which were effectively reduced in number.
“Drinking boiled water apparently is a viable long-term strategy for reducing global exposure to NMPs,” the researchers write, adding that “drinking boiled water, however, is often regarded as a local tradition and prevails only in a few regions.” The research team hopes that drinking boiled water will become a more widespread practice as plastic continues to grow in importance worldwide.
Although it is not yet certain how harmful this plastic is to our bodies, it is known that it is not the healthiest to ingest. Plastic has already been linked to changes in the gut microbiome and the body's resistance to antibiotics. The team behind this latest study wants to see more research into how boiled water can protect our bodies from artificial materials and counteract the concerning effects of microplastics.
“Our results have ratified a highly feasible strategy to reduce human NMP exposure and established the foundation for further investigations with a much larger number of samples,” write the authors of the study published in "Environmental Science & Technology Letters.”
