Membrane units removed most test particles. Some carbon or ion-exchange units released more particles than went in. The WHO (2019, 2022) finds little evidence of harm to humans at the levels found. Most health evidence is from animals and is not tied to drinking water.
| Source | What it found (quoted) and its limits | Evidence |
|---|---|---|
| WHO. Dietary and inhalation exposure to nano- and microplastic particles and potential implications for human health. ISBN 978-92-4-005460-8. (2022) · new Agency review · International (WHO) · n = n/a |
'the available data are of only very limited use for assessing the risk of MNP to humans'; 'the limited data provide little evidence that MNPs have adverse effects in humans'; 'measures should be taken to mitigate exposure' (quotes via Food Packaging Forum) Limits: Full PDF not retrieved; quotes secondary |
Evidence: strong Free to read · source · added 2026-10-30 |
| WHO. Microplastics in drinking-water. ISBN 978-92-4-151619-8. (2019) · new Agency review · International (WHO) · n = n/a |
Particles >150 um 'are not likely to be absorbed in the human body'; 'the uptake of smaller particles is likely to be limited'; 'Wastewater treatment can remove over 90 percent of microplastics'; 'further research is necessary' (quotes via IISD summary 22 Aug 2019) Limits: Full report not fetched; numbers from secondary summary |
Evidence: strong Free to read · source · added 2026-10-30 |
| Marfella R, et al. Microplastics and nanoplastics in atheromas and cardiovascular events. N Engl J Med. (2024) · new Prospective observational cohort · Patients undergoing carotid endarterectomy (country not retrieved) · n = 304 enrolled; 257 followed |
Polyethylene detected in 150 patients (58.4%); HR 4.53 for MI, stroke or death (MNP present vs absent); mean follow-up 33.7 +/- 6.9 months (via HealthDay summary; 95% CI not retrieved) Limits: Association only; exposure source unknown (not linked to drinking water); confounding; contamination concerns; numbers secondary |
Evidence: moderate Paywalled · source · added 2026-10-30 |
| Chartres N, Cooper C, Bland G, Pelch K, Gandhi S, BakenRa A, Woodruff TJ, et al. Effects of microplastic exposure on human digestive, reproductive, and respiratory health: a rapid systematic review. Environ Sci Technol. (2024) · new Rapid systematic review (human + animal) · International · n = 31 studies (3 human; 28 animal) |
'We concluded that microplastics are suspected to harm human reproductive, digestive, and respiratory health' 'with a suggested link to colon and lung cancer'; birth outcomes 'unclassifiable' Limits: Mostly animal evidence at high doses; exposure route not drinking water specific |
Evidence: moderate Free to read · source · added 2026-10-30 |
| Cherian AG, Liu Z, McKie MJ, Almuhtaram H, Andrews RC. Microplastic removal from drinking water using point-of-use devices. Polymers 15(6):1331. (2023) · new Lab challenge test of NSF 42/53-certified pour-through POU devices · Lab; spiked PVC, PET, nylon · n = 3 device types x 2 units |
'Two POU devices that incorporate MF technologies exhibited 78-86% and 94-100% removal values for PVC and PET fragments'; GAC+IX device 'resulted in a greater number of particles in its effluent when compared to the influent' (PET at 75%, PVC at 50-125% of rated capacity); system blanks 0-3 MPs Limits: Only 2 units per device; spiked large particles (~28-1862 um); abstract/results/conclusions inconsistent |
Evidence: moderate Free to read · source · added 2026-10-30 |
| Pivokonsky M, Cermakova L, Novotna K, Peer P, Cajthaml T, Janda V. Occurrence of microplastics in raw and treated drinking water. Sci Total Environ 643:1644-1651. (2018) · new Field study of drinking-water treatment plants · Czech Republic; treatment plants (number not on summary page) · n = not retrieved |
Raw water ~1,500-3,600 particles/L; treated ~340-630 particles/L; decrease of roughly 70-83% Limits: Data via institute summary page; plant treatment, not POU; method includes small particles >=1 um |
Evidence: moderate Paywalled · source · added 2026-10-30 |
| Wang Z, Wu Z, Janssen SE, Harrington GW, Wei H, Qin M. Microplastics undergo fragmentation during pressurized membrane filtration. Environ Sci Technol Lett. (2026) · new Lab membrane filtration experiment · lab · n = not stated |
'After operating for 3 h at 20 bar, 67.9 +/- 8.0% of the PS spheres in the concentrate' were transformed into fractured particles; fragments detected down to 1 um Limits: Abstract only; 20 bar lab conditions with PS spheres, not a household RO unit |
Evidence: weak Access unknown · source · added 2026-10-30 |
| Maliwan T, ... Hu J (5 authors; NUS/Chulalongkorn). Revisiting microplastic removal and release by point-of-use ultrafiltration membranes: 1-year monitoring and interpretable machine learning. Water Research. (2025) · new Long-term monitoring of POU UF membranes · Singapore · n = not retrieved |
Numbers not retrieved (abstract inaccessible). Author presentation (NUS, Sept 2025): membranes trap MPs, 'can also release plastic fragments of their own'; 'fouling ... can actually help capture microplastics more effectively' Limits: Abstract not read; qualitative only; first author inferred from NUS news page |
Evidence: weak Paywalled · source · added 2026-10-30 |
| da Costa ID, Nunes NNdS, Costa LL, Zalmon IR. Are water filters effective against microplastics? Water 16(22):3189. (2024) · new Field sampling of household/institutional filters · Lower Paraiba do Sul basin, Brazil; 9 sites · n = 54 samples (18 per treatment; 170 L each) |
Ceramic candle 0.49 +/- 0.07 MPs/L; tap (carbon) filters 1.41 +/- 0.20 MPs/L; unfiltered tap 1.13 +/- 0.35 MPs/L (ANOVA F = 68.16; p < 0.01) Limits: No paired influent-effluent; tap filter vs tap not significantly different; only ~16% FTIR-confirmed |
Evidence: weak Free to read · source · added 2026-10-30 |
| Altaee RN, Al-Ahmady K, Mhemid RKS. Study the effectiveness of household water filtration systems in eliminating plastic particles in Mosul City, Iraq. J Ecol Eng 25(9):24-33. (2024) · new Field survey of household filtration systems · Mosul, Iraq; 12 areas · n = not stated |
'the efficiency of HWFS ranged from 93% to 30%'; efficiency varied with filter age and number of stages Limits: Abstract only; filter types unspecified; non-US source water |
Evidence: weak Free to read · source · added 2026-10-30 |
| Kosuth M, Mason SA, Wattenberg EV. Anthropogenic contamination of tap water, beer, and sea salt. PLoS ONE 13(4):e0194970. (2018) · new Cross-sectional occurrence survey · 14 countries incl. USA · n = 159 tap samples (33 US) |
'Anthropogenic debris was found in 81% of the 159 samples tested'; mean 5.45 particles/L (range 0-61); US mean 9.24 particles/L (SD 11.8) Limits: Visual identification, limited polymer confirmation; size limit excludes small particles |
Evidence: weak Free to read · source · added 2026-10-30 |
Evidence grade: strong = trials, large field studies or official datasets; moderate = smaller or lab studies with real water; weak = single small studies, makers' specs or secondary reports. "Free to read" means the source itself is free to read online.