International Report: Microplastics in Drinking Water (2026)

Last updated: May 25, 2026

What “the international report” actually refers to

There is no single “international report on microplastics in drinking water”, instead there is a body of work from major intergovernmental and academic institutions that together form the global evidence base. Most news coverage in 2024 and 2025 referenced one of four documents:

1. WHO, “Microplastics in drinking-water” (2019), the first comprehensive international assessment, updated technically through 2024.
2. Qian, Tao, et al., PNAS (January 2024), the Columbia/Rutgers team that used stimulated Raman scattering microscopy to detect nanoplastics in bottled water at scales 10–100× higher than older methods could measure.
3. UN Environment Programme “Plastic Pollution” report series, tracks plastic flows into freshwater systems globally.
4. European Food Safety Authority (EFSA) opinions, feeds into the EU's microplastics restriction that began taking effect in 2025.

Headline finding: 80%+ of drinking water samples worldwide contain microplastics

The 2018 Orb Media / SUNY Fredonia investigation tested 259 bottled-water samples from 11 brands across 9 countries and found microplastic contamination in 93% of them, with an average of 325 particles per liter. Independent tap-water sampling across 14 countries found microplastics in 83% of samples, averaging roughly 5.45 particles per liter. Subsequent peer-reviewed analyses through 2024 have replicated these ranges, meaning contamination is the rule, not the exception.

The 2024 PNAS study fundamentally shifted what we mean by “detected”: using stimulated Raman scattering microscopy, the Columbia/Rutgers team identified individual nanoplastic particles down to ~100 nanometres, most of which are invisible to the techniques used in earlier surveys. Their bottled-water samples averaged ~240,000 plastic particles per litre, approximately 90% of which were nanoplastics smaller than 1 µm.

Regions with the highest contamination levels

Contamination varies dramatically by country. The figures below combine peer-reviewed sampling studies, government monitoring data, and WHO regional reports. They reflect typical municipal tap water; bottled water in every region tested higher.

Ranges are typical reported values; individual studies use different size thresholds (often >10 µm), so direct comparisons should be treated as order-of-magnitude rather than precise. See our country-by-country deep-dive for full sourcing.

What the reports actually conclude about your health

The WHO's position (repeated in each technical update) is that current evidence does not indicate microplastics in drinking water pose a confirmed risk at typical concentrations. That conclusion sits alongside a clear acknowledgement of three gaps:

• Nanoplastics are essentially unmeasured in regulatory monitoring. The 2024 PNAS study suggests prior estimates undercounted by one to two orders of magnitude.
• Chronic, lifelong exposure has not been studied. All current risk statements are based on short-term toxicology.
• Vulnerable populations, pregnant women, infants, and people with chronic illness, are not separately characterised.

Several 2024–2025 peer-reviewed papers have begun filling these gaps. The New England Journal of Medicine 2024 study found microplastics in artery plaque correlated with a 4.53× increase in major cardiovascular events over a 34-month follow-up, the first prospective human evidence of harm. For our full coverage, see microplastics and cancer and microplastics health effects.

Bottled water versus tap water: what every report agrees on

Across every dataset published since 2018, bottled water has contained more microplastics than tap water from the same region, typically 2× to 22× more depending on the comparison and detection method. The dominant explanation is contact with PET, polypropylene caps, and processing equipment, accelerated by heat and UV during transport and storage.

For a full breakdown of why bottles leach, see microplastics in bottled water and microplastics in tap water.

What changed between 2024 and 2026

1. Nanoplastic detection went mainstream. SRS microscopy and Raman tweezers now allow routine quantification below 1 µm, exposing previously invisible exposure.
2. The EU microplastics restriction entered force (2023, in stages).Member states must phase out intentionally added microplastics in cosmetics, detergents, and other products through 2035. See our EU microplastics ban explainer.
3. California became the first US state to require microplastics monitoring in drinking water (SB 1422, four-year monitoring program beginning 2023, results being released 2025–2026).
4. WHO began updating its 2019 review with a planned second edition incorporating nanoplastic evidence; the draft entered consultation in late 2025.
5. The NEJM cardiovascular study (2024) shifted the conversation from “hypothetical risk” to “measurable association” in human patients.

What you can actually do today

While regulators continue to define risk, individual exposure can be meaningfully reduced with three changes the international literature consistently supports:

1. Use a reverse-osmosis or high-quality activated-carbon-block filter on your tap. RO removes 99%+ of microplastics including nanoplastics; carbon block removes most particles >2 µm.
2. Carry a glass or stainless-steel bottle. Eliminates the single largest exposure source identified across every report.
3. Avoid heating water or food in plastic. Thermal stress is the largest amplifier of leaching in every laboratory model.

For step-by-step practical changes, see how to avoid microplastics.