Researchers from Guangzhou Medical University and Jinan University in China have uncovered a simple yet effective way to reduce microplastics in drinking water by using boiling. Their findings, published in Environmental Science and Technology Letters, show that boiling water can cause microplastic particles to bind with minerals present in the water and form residues that settle out, making removal easier than before.
In the experiments, scientists examined tap water with varying hardness, which means different levels of dissolved calcium and magnesium salts. They added three common plastic types to the water: polystyrene, polyethylene, and polypropylene, with particle sizes ranging from 0.1 to 150 micrometers. These tiny particles are collectively known as microplastics and originate from a range of everyday sources such as cosmetics, textiles, and industrial processes. They can also result from the fragmentation of larger plastic items. Numerous studies have linked microplastics to potential health concerns, including the possibility of harming organs and releasing harmful chemicals when ingested.
The researchers boiled water samples containing microplastics, allowed the water to cool, and then measured the remaining concentration of particles. The results indicate that boiling can remove up to 90 percent of microplastics in hard water and up to 25 percent in soft water. The key appears to be the chemistry of hard water. During boiling, insoluble calcium carbonate forms in hard water and plays a crucial role by attaching to microplastic particles. This binding promotes the settling of microplastics to the bottom of the container as sediment, where they can be filtered out more easily. This simple physical process can thus reduce the microplastic burden without the need for sophisticated equipment.
The team notes that the presence of calcium carbonate acts like a natural catcher for microplastics, pulling them out of suspension as the water boils and cools. By removing the sediment through standard filtration after boiling, a significant portion of microplastics can be eliminated from the water supply accessible in homes and smaller facilities. This approach provides an accessible option for households looking to reduce microplastic contamination using readily available methods and demonstrates how existing water chemistry can be leveraged to improve water quality.
These findings also highlight a broader implication for water treatment strategies. By understanding the interactions between minerals in water and microplastic particles, communities can explore low-cost adjustments that enhance filtration efficiency. The study underscores that microplastics are not just a concern in rivers and oceans; they can be present in tap water as well, and innovative, practical steps may help limit exposure at the point of use. As researchers continue to explore the behavior of microplastics under different conditions, simple processes like boiling in conjunction with natural mineral interactions could contribute to safer drinking water for people across different regions.
Beyond the immediate implications for home use, the research adds to the growing body of knowledge about how microplastics move through water systems and how they can be removed with conventional treatment steps. While boiling is not a complete solution to microplastic pollution, it represents a meaningful, approachable improvement in reducing personal exposure and demonstrates the value of paying attention to water chemistry when designing low-cost mitigation strategies.
Overall, the study offers a practical reminder that sometimes straightforward changes in everyday habits, guided by scientific insight, can yield tangible benefits for health and safety. As science continues to explore the many facets of microplastic pollution, the potential for simple, accessible remedies remains an encouraging area of investigation for households and communities alike.