Do filters remove microplastics?

Do Filters Remove Microplastics?

⚕️ MEDICAL DISCLAIMER: This article is for informational and educational purposes only and is not intended as medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider before making any changes to your health regimen, diet, or supplement use, especially if you have existing medical conditions or take medications. The information presented here should not be used to diagnose, treat, cure, or prevent any disease.

Water is the most consistent pathway for daily microplastic exposure. Studies have shown that microplastics are in tap water, plastic and glass bottled water, and even filtered water. Each time we consume water, microplastics enter the body. Although water filters do reduce microplastic exposure, there are factors that influence the ability and extent of that filtration.

Water Treatment Plants Filter Microplastics First

Large-scale drinking water treatment plants use sand and activated carbon filtration to remove most microplastics from municipal supplies. Studies report that 70% of particles larger than ~60 µm, roughly the diameter of a thin human hair, are retained during sand filtration, while total removal rises to 98% after activated carbon [4], which binds to microplastics.

Unfortunately, anyone who spends time reviewing these scientific studies will find that scientific reports vary widely by the detection and measurement methods used. Detection methods yield inconsistent numbers. For example, a Danish waterworks measured 78% removal using μFTIR but only 43% when analyzed with μRaman [3]. Even at scale, complete removal remains elusive and, currently, it’s nearly impossible to put a definitive number of the reduction in microplastics in water from large-scale treatment plants. This problem is exacerbated when we consider nanoplastics. 

On the other hand, another process, coagulation, an engineered process where particulates are induced to clump, pushes microplastic filtration efficiency even higher. Coagulation can often reduce 95% off microplastic like polyethylene and PVC. Irregularly shaped fragments are particularly susceptible to coagulation, making them easier to capture in treatment systems [2]. Biofiltration, which relies on microbial activity, has also shown 79–89% removal rates, though performance drops sharply for particles under 100 µm [6], which is roughly the diameter of thicker human hair. 

How Filters Remove Microplastics From Water

Microplastics are intercepted through adsorption, size exclusion, and physical entrapment across filter media. Activated carbon granules provide high-surface-area adsorption sites, explaining their ability to eliminate up to 97% of particles greater than ~60 µm [4]. Sand filters remove microplastics consistently, with efficiencies reported at 99% in some stages [13]. These traditional processes demonstrate how physical and chemical interactions converge to trap plastics before they reach the tap.

Paradoxically, some water filters themselves become a liability. Reports suggest that consumer-grade “water purifiers” can leach plastic particles into drinking water [4,15]. As filter membranes are frequently polymer-based, their degradation or shedding adds uncertainty to claims of purity. Capture without contribution remains the true test of filter effectiveness. It does no good if your water filter is adding microplastics to the filtered water.

Reverse Osmosis: High Efficiency, High Energy

Reverse osmosis (RO) has emerged as the most consistent technology for removing microplastics. Laboratory studies show that RO membranes block polyethylene, polystyrene, PET, and polypropylene particles with 90% efficiency in the 100–190 µm range, or roughly 1-2 thick human hairs [11]. When assessing water filtration methods, RO is more energy intensive and often more expensive than traditional consumer water filters [11,12].

Commercial RO membranes are typically made from cellulose acetate or polyamide, offering high selectivity for particle rejection [11]. The caveat is that while these membranes excel at exclusion, they cannot capture the vast numbers of nanoplastics below detection thresholds. These particles, invisible to μFTIR and Raman systems, as they’re usually the size of viruses, represent the hidden frontier of microplastic exposure [3,10].

Home Filters, Boiling, and Bottled Water

Simple practices provide partial relief. One study found that boiling water can eliminate up to 90% of microplastic load [7], while home filtration systems reduce exposure compared to bottled water, but do not eliminate it completely [7]. Plastic contamination is consistently higher in bottled beverages, both glass and plastic, where packaging and capping introduce massive additional loads. Global estimates suggest that drinking bottled water may yield 20 times more microplastic ingestion compared to tap water [4,5,9]. As stated earlier, research is still emerging and yielding inconsistent results on how effectively different filters remove microplastics. 

While tap water might have less microplastics and nanoplastics than bottled water, surveys show 81% of global water supplies carry microplastic fragments, contributing hundreds of particles to daily intake [4,6]. Even distribution pipes, sometimes made of plastics themselves, can act as secondary sources, releasing fragments as water flows through aging plastic infrastructure [5]. Filtration may reduce burden, but it cannot fully sever the link between polymer production and human hydration. 

Why It Matters That Our Water Has Microplastics

We rely on water, which makes microplastic contamination uniquely consequential. Filters remove microplastics to a degree, but limitations in detection, the persistence of nanoplastics, and the shedding of filter materials themselves mean no system offers absolute protection. For individuals seeking to minimize exposure, filtration is best viewed as reduction rather than elimination. At this time, it appears nearly impossible to completely eliminate microplastics from our water.

Take Control Against Microplastic Exposure

Filters remove microplastics to some extent but, currently, no system or process can remove them entirely. Sand, carbon, and reverse osmosis each intercept fragments, yet nanoplastics slip through undetected, and filter media may even add to the problem. Based on scientific findings, bottled water magnifies exposure even further, making tap water, paired with effective filtration, the best option available. 

While it’s seemingly impossible to remove all microplastics from our water, there are many small, simple actions that you can take each day to lower the amount of microplastics you consume. This is why we developed the Deplasto platform. 

Our platform, consisting of a science-backed supplement, a microplastic intake app, and lifestyle recommendations is intended to help you avoid microplastics. Our all-natural supplement is formulated to support your body’s natural detoxification defenses, including oxidative stress management, cellular repair, and antioxidant support. Our microplastic intake calculator is designed to show you an estimate of your daily exposure, with every datapoint backed by scientific studies, to help you understand how you can best avoid microplastics. Lastly, given that it’s nearly impossible to completely avoid microplastic exposure, we have a plethora of lifestyle recommendations designed to help you make small changes for big impacts. 

Overall, we believe that the best way to eliminate microplastics begins with you and the changes you make to your daily life. Over time, collectively, we can make a significant difference. 

Sources

1. A review of methods for mitigating microplastic contamination in biosolids from wastewater treatment plants before agricultural soil application
2. Elimination of a Mixture of Microplastics Using Conventional and Detergent-Assisted Coagulation
3. It matters how we measure – Quantification of microplastics in drinking water by μFTIR and μRaman
4. Contamination and removal efficiency of microplastics and synthetic fibres in a conventional drinking water treatment plant in Geneva, Switzerland
5. Are Microplastics a Macro Issue_ A Review on the Sources of Contamination, Analytical Challenges and Impact on Human Health of Microplastics in Food
6. A review of methods for mitigating microplastic contamination in biosolids from wastewater treatment plants before agricultural soil application
7. Internal and external microplastic exposure in young adults- A pilot study involving 26 college students in Changsha, China
8. A systematic review and quality assessment of estimated daily intake of microplastics through food
9. Identification of Poly(ethylene terephthalate) Nanoplastics in Commercially Bottled Drinking Water Using Surface-Enhanced Raman Spectroscopy
10. Exposure of U.S. adults to microplastics from commonly-consumed proteins
11. Harnessing Magnetic Nanoparticles for the Effective Removal of Micro- and Nanoplastics- A Critical Review
12. Hydrophobins from Aspergillus mediate fungal interactions with microplastics
13. High removal of PS and PET microplastics from tap water by using Fe2O3 porous microparticles and photothermal irradiation with NIR light
14. Elimination of a Mixture of Microplastics Using Conventional and Detergent-Assisted Coagulation
15. Impact of Microplastics and Nanoplastics on Human Health