Boiling tap water before use can remove at least 80 percent of the potentially harmful small plastic particles it contains.

Nanoplastics and microplastics (NMPs) are pieces of plastic such as polystyrene, polyethylene, and polypropylene that range in diameter from 0.001 to 5 millimeters. Although the health effects are still being studied, researchers suspect they may be harmful to humans.

Eddie Zen and colleagues from China's Jinan University took samples of tap water and measured levels of NMP and found that the average concentration was 1 milligram per liter. The samples were then boiled for 5 min and then cooled. NMP levels were then remeasured and found to have decreased by more than 80%.

“NMP intake from boiled water consumption was estimated to be two to five times lower than the daily intake from tap water,” Zeng said. “This simple but effective boiling water strategy can 'decontaminate' NMPs from household tap water and potentially harmlessly reduce human exposure to NMPs through water consumption.”

Zeng said NMP was removed by being incorporated into the crystalline structure of limescale, which is formed from calcium in the water. Hard water, which contains more calcium, removed more particles than soft water, which contains less calcium.

Bringing water to its boiling point was a major contributing factor to how efficiently these crystal structures were created. “Boiling water has several other benefits, including killing bacteria and parasites and removing traces of heavy metals,” he says.

“The way they demonstrated how things are deposited through the boiling process was amazing,” he says. caroline goshott lindsay At the University of Glasgow, UK. But the world should seek to solve the problem of microplastics in drinking water long before they reach homes, she added. “We should consider modifying drinking water treatment plants to remove microplastics,” she says.