This Simple Solution Can Help Reduce Microplastics in Your Drinking Water

Nano- and microplastics (NMPs) have become so pervasive in air, water and soil that they have made their way into the bodies and blood of humans and animals.

While many methods have been attempted to remove the tiny plastic particles, a new study has found that a simple solution for reducing their presence in drinking water may be to boil it, as when you make a cup of coffee or tea.

In fact, filtering and boiling tap water containing calcium carbonate could help remove almost 90 percent of the plastics, a press release from the American Chemical Society (ACS) said.

“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. Drinking boiled water, an ancient tradition in some Asian countries, is supposedly beneficial for human health, as boiling can remove some chemicals and most biological substances,” the study said. “Boiling hard water… can remove at least 80% of polystyrene, polyethylene, and polypropylene NMPs size between 0.1 and 150 μm.”

The side effects of NMPs on humans are still being investigated, but recent studies indicate that their ingestion could impact the gut microbiome, the press release said. While some advanced water filtration systems are able to capture the plastic bits, less expensive strategies are necessary in order to help reduce their passive consumption on a larger scale.

In order to find out if boiling water could help effectively remove NMPs from soft and hard tap water, the research team collected hard water samples and “spiked them” with various amounts of NMPs. They boiled the water for five minutes, then allowed it to cool. When naturally mineral-rich hard water is boiled, it forms a chalky calcium carbonate substance known as limescale. The researchers then measured the remaining plastic content floating in the water. 

The results indicated that crystalline structures — or “incrustants” — formed as the temperature of the water increased and encapsulated the NMPs.

Eddy Zeng, one of the authors of the study, said the incrustants would build up over time as limescale usually does, and could then be scrubbed clean to remove the plastics. Zeng explained that any remaining incrustants could be removed by straining them through a coffee filter or other simple filter.

The experiments found that harder water produced a more pronounced encapsulation effect. For example, boiling a water sample with 300 milligrams of calcium carbonate in each liter removed as much as 90 percent of the free-floating NMPs. Roughly 25 percent were removed by boiling soft water containing less than 60 milligrams of calcium carbonate per liter.

The researchers said the results indicated that boiling water could be an easy and effective way of reducing NMP ingestion.

“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,” the authors wrote in the study.