Microplastics, tiny plastic particles less than 5 millimeters in size, have become a global concern as they infiltrate our environment and our bodies. Found in everything from the oceans to the air, these particles are now a major contaminant in our drinking water. The implications for human health are significant, but a new study offers a surprisingly simple solution: boiling and filtering tap water can dramatically reduce the amount of microplastics we consume.
What Are Microplastics?
Microplastics are a byproduct of our reliance on plastic. They originate from the breakdown of larger plastic items, synthetic clothing fibers, industrial processes, and even everyday products like cosmetics. These tiny fragments are often so small they are invisible to the naked eye, but their size allows them to travel through the air, water, and soil, eventually finding their way into our food and drink.
A particularly concerning subset of microplastics is nanoplastics, which are so tiny they are measured in micrometers or nanometers—much smaller than the width of a human hair. Due to their small size, nanoplastics can penetrate biological barriers and accumulate in human tissues, making them especially dangerous.
How Do Microplastics Enter Drinking Water?
Drinking water, both tap and bottled, is contaminated with microplastics. These particles enter water systems through surface runoff after rain, untreated wastewater, degraded plastic waste, and even atmospheric deposition. According to the World Health Organization (WHO), common plastic types such as polyethylene (used in plastic bags) and polypropylene (used in bottle caps) have been identified in drinking water. Alarmingly, studies have shown that bottled water often contains significantly more microplastics than tap water, with one study estimating that a liter of bottled water can contain as many as 240,000 tiny plastic fragments.
Why Are Microplastics Dangerous?
The health risks posed by microplastics stem from three primary sources: the particles themselves, the chemicals they carry, and the biofilms of bacteria they may host.
- Physical Hazards: Microplastics can physically irritate tissues, particularly when they are small enough to enter cells. Research suggests that nanoplastics may accumulate in vital organs, including the brain, potentially leading to inflammation and other adverse effects.
- Chemical Contamination: Plastics often contain additives like BPA and phthalates, known to disrupt hormones. Additionally, microplastics can absorb environmental toxins such as pesticides and heavy metals, effectively turning them into carriers for harmful substances.
- Microbial Risks: Microplastics can serve as a platform for bacterial growth. Pathogens such as Legionella and Pseudomonas aeruginosa can adhere to these particles, increasing the potential for waterborne illnesses.
“Although there is insufficient information to draw firm conclusions on the toxicity of plastic particles, particularly the nano-sized particles, no reliable information suggests it is a concern,” notes a WHO report. However, scientists agree that the potential risks cannot be ignored, especially given the growing evidence of plastics’ impact on human health.
Microplastics are everywhere. A study highlighted in the journal Environmental Science & Technology Letters reports that people in the U.S. alone may ingest thousands of microplastic particles each year through tap water. The problem is even more severe with bottled water, which can increase exposure to microplastics by up to six times.
Globally, microplastics are detected in freshwater sources, wastewater, and treated drinking water. A review of 50 studies revealed that microplastic levels in freshwater and drinking water vary widely, with concentrations ranging from 1 particle per liter to over 10,000 particles per liter. Despite these alarming figures, monitoring and regulation of microplastics in drinking water are still in their infancy.
A Simple and Effective Solution
In response to this growing crisis, a team of researchers from Guangzhou Medical University and Jinan University in China has discovered an effective method for reducing microplastics in drinking water. Their study, published in Environmental Science & Technology Letters, reveals that boiling water and filtering it can remove up to 90% of nanoplastics and microplastics (NMPs) from household tap water.
“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,” explains biomedical engineer Zimin Yu, one of the study’s authors.
The process works particularly well with hard water, which contains minerals like calcium carbonate. As the water boils, calcium carbonate precipitates out, forming a limescale crust that traps microplastic particles. These lime-encrusted particles can then be removed using a basic filter, such as a tea strainer or a stainless-steel mesh. In experiments, the researchers found that microplastic removal rates increased as the hardness of the water rose. For instance, water with high calcium carbonate levels achieved removal rates of up to 90%.
Even with soft water, which contains fewer minerals, boiling and filtering captured roughly 25% of microplastic particles. This method is accessible to most households and requires no special equipment, making it a practical solution for millions of people.
Can we reduce this in the environment?
While boiling and filtering water is a significant step toward reducing microplastic exposure, it is not a complete solution. Policymakers, researchers, and industries must address the root causes of plastic pollution. Reducing single-use plastics, improving waste management, and investing in advanced water treatment technologies are all critical actions.
Additionally, the scientific community must prioritize research on the health impacts of microplastics. The WHO and other organizations recommend targeted studies to understand how these particles affect the human body over time. “To better assess the human health risks and inform management actions, researchers should undertake targeted, well-designed and quality-controlled investigative studies,” advises the WHO.
Public education also plays a vital role. The researchers from Guangzhou hope their findings will encourage more widespread adoption of boiling and filtering practices, particularly in regions where untreated water poses a dual threat of microplastics and microbial pathogens.
Microplastics in drinking water represent a growing public health challenge, but solutions are within reach. By boiling and filtering tap water, individuals can significantly reduce their exposure to these contaminants. However, addressing the broader issue of plastic pollution requires systemic change at all levels, from local communities to global industries. As plastic continues to pervade our environment, taking proactive steps now will help protect both human health and the planet for future generations.
