Boiling tap water can significantly reduce microplastic particles, with studies showing a reduction of up to 90 percent. The evidence comes from research published in Environmental Science and Technology Letters, which details how heating water exposes these tiny plastics to conditions that cause them to settle out or become trapped before cooling.
Microplastics are plastic fragments smaller than 5 millimeters. They originate from the breakdown of larger plastic items, industrial processes, and consumer products. These tiny particles have been found across environments—from the world’s oceans and air to bottled water and even inside the human body—raising concerns about exposure and potential health effects.
In the experimental setup, researchers recreated typical tap water by adding minerals commonly present in it. They also introduced a variety of microplastic types, including polystyrene, polyethylene, and polypropylene, to mirror real-world contamination. The goal was to observe how a simple heating step would influence microplastic concentrations in a controlled but realistic water sample.
The water samples were brought to a boil for five minutes and then allowed to cool under standard conditions. After cooling, measurements showed a pronounced drop in microplastic levels. The effect was more pronounced in harder water, which contains higher amounts of calcium carbonate. In these harder samples, the microplastic content declined by nearly 90 percent. The proposed mechanism involves high temperatures promoting interactions between plastic particles and mineral components, leading to entrapment within mineral lattices. After this phase, the mixture was filtered to separate remaining solids using a simple coffee filter, illustrating a practical approach for sample clarification.
On the health front, the World Health Organization notes that current evidence on microplastics and health effects is still limited, calling for more research. What is known from laboratory studies indicates that micropolystyrene can affect human cells in vitro and may be linked to intestinal inflammation and reduced fertility in animal models. These findings underscore the need for cautious interpretation and continued investigation into how microplastics may interact with human biology over long-term exposures.
Earlier discussions in the scientific community have highlighted dramatic environmental dynamics connected to plastic pollution patterns, including rapid sedimentation and distribution trends that influence where microplastics accumulate. These observations contribute to a broader understanding of the pathways by which microplastics move through ecosystems and eventually reach water supplies used by households.