Microplastics in Hungarian Tap Water: How Bad Is It?
So far in our series on micro- and nanoplastics we have looked at their effects on human health and at the ways they enter our bodies. This part examines how much micro- and nanoplastic Hungary's tap water contains, which drinking water sources are at risk, how serious those risks are and what can be done about them.
Hungary's drinking water supply is in a fortunate position: 94% of public supply comes from groundwater (deep wells, karst and riverbank filtration) and only 6% directly from surface water. That matters when we ask how much of the microplastic entering our bodies could come from the tap. It is worth saying at the outset that tap water is far from the main threat. Food packaging (PET bottles and the like) and plastic dust that we breathe in matter much more.
Plastic in tap water
As analytical tools grow more sensitive and smaller and smaller concentrations of pollutants, micro- and nanoplastics among them, can be detected in drinking water, the voices celebrating the excellent quality of Hungarian tap water have grown quieter. Drinking water sources differ considerably in this respect, and that is before counting the contamination water can pick up in the distribution network.
To get at the truth, we need to follow drinking water from the point of abstraction to the kitchen tap, because there is no such thing as drinking water in general. Looking at the sources, it is clear that rivers and other surface waters carry the most microplastics, followed by riverbank wells, while deep wells and karst water are practically above suspicion.
Measurements show that the Danube's Budapest stretch, the capital's main drinking water source, can carry as many as 100–147 particles per cubic metre, whereas Budapest tap water contains only 7–10 particles in 1,500 litres (Takács et al., 2020). The river figures depend on when the sample was taken, since concentrations differ between flood and low water. The tap water figure suggests that the gravel beds along the riverbank filter microplastics out of Danube water very effectively – and the plastic found in a cubic metre and a half of tap water may even have entered it in the network.
How do microplastics reach different water sources?
Hungary's drinking water supply rests on favourable foundations. 94% of the water supplied by utilities comes from groundwater (deep wells, karst and riverbank filtration wells), and only 6% directly from surface water (in Szolnok, for example, and seasonally in Siófok or Keszthely). That is a huge protection, because the soil layers act as a natural filter.
Surface waters – the Danube, the Tisza and Lake Balaton – are the most vulnerable. Researchers at the Budapest University of Technology and Economics (BME) measured an average concentration of 104–143 mg of microplastics per 1,000 m³ (about 0.10–0.14 mg/m³) in the Danube's Budapest stretch (Bányai-Stefanovits et al., 2024), mainly polystyrene (PS), polyethylene (PE), polypropylene (PP), PVC, PET and thermoplastic elastomers. Fibres, films and fragments dominate. They come from packaging waste, treatment plant discharges and urban stormwater. Joint sampling by Wessling Hungary and Greenpeace in 2020 found an even higher value of 147 particles/m³ in the Danube, probably because concentrations swing widely at flood or low water.
Riverbank filtration wells, which account for 36% of drinking water sources, are directly connected to the rivers, so some microplastic could in principle appear here too (Pittroff et al., 2025). In practice, however, the soil effectively filters out the larger particles (>30 μm), so at most nanoplastics could be present in the raw water – although confirming this needs further study. What we do know is that tap water samples from northern Buda and Csepel contained 7–10 microplastic particles in 1,500 litres – a fraction of the load in raw Danube water, and not necessarily even from the source rather than the network.
Karst water, with a 13% share, and deep wells, with around 45%, are the cleanest sources as far as microplastics are concerned. Thanks to deep soil layers and natural protection, they are practically free of contamination. International karst research (for example Panno et al., 2019) has shown some breakthrough, but in Hungary the MicroDrink Interreg project (2024–2026, with Eurofins Hungary as a partner) focuses on exactly these sources and has reached reassuring results. It uses harmonised methods to test water from karst, intergranular and riverbank filtration wells across the Danube region, and preliminary results show negligible concentrations in the deeper, protected sources (Danube Water Quality Platform, 2024).
Put simply: the deeper and better protected the source, the less microplastic it contains. Surface water is the main point of entry, but thanks to Hungary's geology it affects only a small share of supply – though even that small share is not negligible.
Does water pick up microplastics in the network?
Even if the water fed into the network is free of plastics – or other pollutants – that does not guarantee it stays clean on the way. As PE and PVC pipes, seals and fittings wear, tiny plastic fragments break off, especially on old or high-pressure sections.
According to Hungarian measurements from 2020, some of the particles found in Budapest tap water may indeed come from the network.
International studies (such as Zhang et al., 2024) confirm that long pipelines make a contribution to micro- and nanoplastic contamination that cannot be ignored. Nanoplastics (<1 μm) pass easily through any mechanical filter, because they neither settle nor readily stick to surfaces.
The good news is that in Hungary, continuous monitoring by the water utilities and a network in good condition keep this secondary contamination to a minimum. According to the review by Izsák and Vargha (2020), there is no evidence that the pipe network significantly degrades water quality – but a reassuring answer will take more research.
How can microplastics be detected and removed?
Detecting plastic particles is not simple, because they range in size from 1 μm to 5 mm, and nanoplastics are close to invisible. The international standard is large-volume sampling (500–1,000 litres) through a mesh of 500 μm or finer, followed by density separation (NaCl or ZnCl₂), hydrogen peroxide digestion to remove organic matter and, finally, FTIR or Raman spectroscopy or Py-GC/MS mass spectrometry to identify the polymer type. In Hungary, the laboratories of Wessling and BME use this method.
Removal at the waterworks: conventional treatment (coagulation, sand filtration and activated carbon) already removes 70–97.5% of particles >20 μm (Balkenbusch et al., 2025, based on data from 10 US water utilities). Ultrafiltration and membrane technologies do even better, exceeding 99%. Nanoplastics are harder to remove, with typical removal rates of around 80–90% (Xu et al., 2024; Romphophak et al., 2024).
Household solutions: reverse osmosis (RO), ultrafiltration, and GAC and membrane filters achieve 71–100% removal for particles >10 μm. An interesting new finding: in hard water, boiling, cooling and then filtering can remove as much as 90%, as the calcium carbonate that precipitates traps the plastics. Biological methods using bacteria, and ferrofluids, are also being tested.
What are Hungary's prospects for filtering microplastics out of drinking water?
The starting point is good: with 94% of supply drawn from groundwater, contamination levels are low to begin with. Existing coagulation and filtration at the waterworks are effective, and the MicroDrink project, with a Hungarian partner (Eurofins), is now developing a common monitoring and risk assessment method for the Danube region. That means more precise data on karst, riverbank filtration and deep-well sources will soon be available, and treatment methods can be improved where they are needed.
The outlook does not call for drastic investment everywhere. Where surface water or riverbank filtration is the source (parts of Budapest, Szolnok), adding membrane filtration or a more advanced activated carbon stage is already realistic. Against secondary contamination in the network, pipe replacement and pressure optimisation are the key.
Overall, according to the WHO and Hungarian experts (Izsák and Vargha), the health risk from microplastics in drinking water is low – especially compared with the far larger amounts that enter the body from food and air (Koelmans et al., 2019). Tap water remains a safe and recommended choice. But awareness and ongoing research (MicroDrink, the BME measurements) mean Hungary can stay ahead of the problem rather than merely react to it.
Microplastics will not disappear on their own. But thanks to the structure of its water sources and the expertise of its utilities, Hungary is already among the least affected countries in Europe – and it can stay that way, if it keeps paying attention.
To be continued
This was the third part of our four-part series. As it showed, surface waters are the drinking water sources most exposed to microplastic pollution, as measurements have confirmed. One significant source of river pollution can be the treated wastewater discharged into them, since treatment plants, whatever their technology, are far from able to remove every pollutant from wastewater. In the next part we ask whether different kinds of wastewater can be freed of microplastics before they are released into the environment.
Hungary is in a favourable position when it comes to microplastics in drinking water. 94% of public supply comes from groundwater – deep wells, karst water and riverbank filtration – where natural soil layers act as an effective filter. Only 6% is drawn directly from surface water. The most exposed sources are rivers, above all the Danube and the Tisza. Yet Budapest tap water contains only 7–10 microplastic particles per 1,500 litres, a fraction of what is found in the river. Wear on plastic pipes in the distribution network is a secondary source of contamination, but a small one. Conventional water treatment removes 70–97.5% of particles larger than 20 μm, and membrane filtration does even better. According to the WHO and Hungarian experts, the health risk is low: tap water remains a safe choice.
By European standards, the microplastic load in Hungary's drinking water is low, mainly because groundwater dominates the supply. 94% of public drinking water comes from deep wells, karst water or riverbank filtration, where soil layers act as a natural filter that holds back contaminant particles. Direct use of surface water, just 6% of supply, carries a much higher exposure.
Among surface waters, the Danube carries the heaviest load. Measurements by the Budapest University of Technology and Economics (BME) found 104–143 mg of microplastics per 1,000 m³ in the river's Budapest stretch, mostly from packaging waste, treatment plant discharges and urban stormwater. At riverbank filtration wells the gravel bed holds back the larger particles, so Budapest tap water contains only 7–10 particles per 1,500 litres. In deep wells and karst water, microplastic contamination is negligible.
Wear on PE and PVC pipes in the network is a secondary source, particularly on old or high-pressure sections, but continuous monitoring and good maintenance keep it to a minimum. In treatment, a combination of coagulation, sand filtration and activated carbon removes 70–97.5% of particles above 20 μm; ultrafiltration and membrane filtration do even better, exceeding 99%. Nanoplastics are harder to remove.
Research under the MicroDrink Interreg project will provide more precise data on drinking water sources across the Danube region, allowing targeted improvements. According to the WHO and Hungarian experts, the health risk is low, and tap water remains a safe and recommended choice.
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