Kwaliteit van bewijs 4.88/5
Beoordelingsscore op acht dimensies volgens de kwaliteitsrubriek . Elke dimensie krijgt een score van 1 tot 5.
- D1 Verankering in bronnen
- 4/5
- D2 Autoriteit van bronnen
- 5/5
- D3 Rekenkunde
- 5/5
- D4 Onzekerheid
- 5/5
- D5 Bereik
- 5/5
- D6 Proza
- 5/5
- D7 Eerlijkheid over perceptie
- 5/5
- D8 Volledigheid van voorbehouden
- 5/5
Hoe het risico varieert
Het hoofdcijfer is een gemiddelde over zeer verschillende situaties. Zo varieert de waarschijnlijkheid per scenario of context:
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No epidemiological study has measured attributable disease from dietary or airborne microplastic exposure in the general US population. Exposure is real; harm is unquantified.
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Workers in synthetic textile and plastics manufacturing have higher inhalation exposure. Some occupational studies report elevated respiratory symptoms (flock worker's lung), but these involve specific fiber types at industrial concentrations, not general microplastic exposure. Signal is weak and confounded by co-exposures.
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Shellfish and small pelagic fish bioaccumulate microplastics. Consumers of large quantities of mussels, oysters, and sardines have higher ingestion estimates, but no cohort study has linked this dietary pattern to measurable health outcomes in humans.
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Bottled water contains roughly 10-100x more microplastic particles per liter than tap water in most studies, likely from packaging. WHO's 2019 review found no health risk from either source at observed levels.
De lengte en tint van de balk rangschikken deze scenario's ten opzichte van elkaar, niet ten opzichte van andere risico's. De exacte kansen staan naast elk scenario.
De kloof tussen angst en bewijs over microplastics is groot, maar loopt in een ongebruikelijke richting: de angst is niet dat de wetenschap zegt dat microplastics veilig zijn — het is dat de wetenschap nog niet veel bruikbaars zegt. De WHO’s review uit 2019 van microplastics in drinkwater vond “geen betrouwbaar bewijs” voor gezondheidsrisico’s bij de huidige blootstellingsniveaus. EFSA heeft, na het beoordelen van meer dan 100 studies, geen gekwantificeerd risicocijfer uitgegeven en verwacht haar formele standpunt pas eind 2027 af te ronden. Geen enkele epidemiologische cohort heeft toerekenbare menselijke ziekten gemeten als gevolg van blootstelling aan microplastics via voeding of lucht op algemene bevolkingsniveaus. De vermelding draagt no_reliable_estimate niet omdat het risico bekend is als nul, maar omdat niemand het goed genoeg heeft gemeten om er een getal aan te koppelen.
Wat de angst aanwakkert, is een detectie-gelijk-gevaar-heuristiek. Leslie et al. (2022) vonden microplasticdeeltjes in 77% van de menselijke bloedmonsters — een oprechte en opvallende bevinding die systemische blootstelling bewijst. Ragusa et al. vonden ze in placenta’s. Marfella et al. (2024), gepubliceerd in de NEJM, rapporteerden dat patiënten met detecteerbare micro- en nanoplastics in halsslagaderplaque een 4,5 keer hoger percentage cardiovasculaire gebeurtenissen hadden dan degenen zonder. Maar de cohort van Marfella was vooraf geselecteerd (allen hadden asymptomatische halsslagaderziekte die chirurgie vereiste), de studie miste anticontaminatiecontroles in de operatieomgeving, en associatie in een zieke populatie is geen causaliteit bij het grote publiek. Ondertussen is aangetoond dat de bewering over blootstelling van een “creditcard per week” die de publieke perceptie verankerde, de werkelijke inname met één tot twee ordes van grootte overschat — realistische schattingen liggen rond 0,01-0,1 gram per week, niet 5 gram.
Het getal bestaat nog niet, en dat is belangrijker dan welke placeholder dan ook. Beroepsmatige blootstelling (textiel- en plasticarbeiders die synthetische vezels inademen in industriële concentraties) heeft een dunne maar reële bewijsbasis voor respiratoire effecten, hoewel verward door co-blootstellingen. Zware zeevruchtenconsumenten nemen meer deeltjes op via bioaccumulatie in schelpdieren. Flessenwater levert ruwweg 10-100x meer deeltjes per liter dan kraanwater. Geen van deze blootstellingsgradiënten is gekoppeld aan meetbare gezondheidsresultaten bij mensen. Het vakgebied is pre-epidemiologisch: we weten dat blootstelling universeel is, we vermoeden biologische plausibiliteit uit dier- en in-vitro modellen, en we hebben één provocatieve maar methodologisch betwiste associatiestudie. Dat is niet niets, maar het is ook geen waarschijnlijkheid.
Gerelateerde weetjes
Microplastics duiken op in menselijk bloed, longen en placenta's, en een meerderheid van de volwassenen rekent ze tot de grootste zorgen over voedselveiligheid. Maar de WHO vond geen betrouwbaar bewijs dat microplastics bij de huidige blootstellingsniveaus de gezondheid schaden. Detectie is niet hetzelfde als een gemeten risico.
Bronnenverantwoording
Elk getal hieronder is wat elke bron rapporteerde, met het letterlijke citaat waarop we ons baseerden en hoe we tot ons cijfer kwamen. Klik op een link om rechtstreeks te verifiëren.
1/7 bronnen onafhankelijk woordelijk geverifieerd tegenover de geciteerde bron
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[1] World Health Organization — Microplastics in Drinking-Water
Microplastics in Drinking-WaterSee all 3 Likelier entries citing this source →
- Statistiek
No reliable evidence that microplastics in drinking water at current exposure levels pose a risk to human health- Fragment
“"Based on the limited information we have, microplastics in drinking water don't appear to pose a health risk at current levels. But we need to find out more." ”
- Brongegevens van
- 2019-08-22
- Geraadpleegd
- 2026-04-18 · gearchiveerde kopie
- Berekening
- WHO reviewed all available evidence on microplastic occurrence in drinking water (tap and bottled) and assessed potential health impacts from ingestion. The report concluded that particles larger than 150 micrometres are unlikely to be absorbed, uptake of smaller particles is expected to be limited, and no epidemiological data link drinking-water microplastic exposure to adverse health outcomes. WHO called for more research but did not identify a quantifiable risk, supporting the no_reliable_estimate classification.
- Onafhankelijkheid
- WHO review synthesised global evidence independently of the Marfella, Leslie, and EFSA analyses cited below.
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[2] New England Journal of Medicine / Marfella et al. — Microplastics and Nanoplastics in Atheromas and Cardiovascular Events Geverifieerd
Microplastics and Nanoplastics in Atheromas and Cardiovascular Events- Statistiek
Patients with detectable MNPs in carotid plaque had HR 4.53 (95% CI 2.00-10.27) for composite cardiovascular endpoint vs those without- Fragment
“"Patients in whom microplastics and nanoplastics were detected within the atheroma had a higher risk of a composite of myocardial infarction, stroke, or death from any cause than those in whom microplastics and nanoplastics were not detected." ”
- Brongegevens van
- 2024-03-07
- Geraadpleegd
- 2026-04-18 · gearchiveerde kopie
- Verificatie
- Fragment onafhankelijk opnieuw opgehaald en woord voor woord bevestigd tegenover de geciteerde bron tijdens onze onderbouwingsaudit.
- Berekening
- Marfella et al. prospectively followed 257 patients who underwent carotid endarterectomy and analyzed excised plaque for MNPs via pyrolysis-GC/MS. Polyethylene was detected in 58.4% of plaques (150 of 257); PVC in 12.1% (31 patients). After 34 months, the MNP-positive group had significantly higher cardiovascular events. However, this is an observational study in a high-risk surgical cohort (all had asymptomatic carotid disease), and critics note no pre-analytical anticontamination procedures were used — the surgical environment itself contains PE and PVC. The study demonstrates association in a diseased population, not causation in the general public, and cannot be converted to a population-level attributable risk.
- Onafhankelijkheid
- Prospective clinical cohort study by Italian researchers using pyrolysis-GC/MS on excised plaque tissue; independent of WHO review and Leslie blood-detection study.
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[3] Environment International / Leslie et al. — Discovery and quantification of plastic particle pollution in human blood
Discovery and quantification of plastic particle pollution in human blood- Statistiek
Microplastics detected in 17 of 22 (77%) healthy adult blood samples at mean concentration of 1.6 µg/mL- Fragment
“"This is the first study to report quantitative data on plastic particle pollution in human blood, showing that plastic particles are bioavailable for uptake into the human bloodstream." ”
- Brongegevens van
- 2022-03-24
- Geraadpleegd
- 2026-04-18 · gearchiveerde kopie
- Berekening
- Leslie et al. analyzed blood from 22 healthy Dutch volunteers using pyrolysis-GC/MS for five high-production polymers. PET was the most prevalent (50% of samples), followed by polystyrene (36%) and PE (23%). The study proves systemic exposure (detection) but does not measure health outcomes. No dose-response relationship, no disease endpoint, no follow-up. Detection of a substance in blood is a necessary but not sufficient condition for harm — the dose, persistence, and biological activity all remain unquantified for general-population microplastic exposure. This study is included because it is the most-cited driver of public fear, illustrating the detection-equals-danger heuristic.
- Onafhankelijkheid
- Dutch laboratory study using independent pyrolysis-GC/MS methodology on volunteer blood samples; no overlap with the Marfella clinical cohort or WHO/EFSA reviews.
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[4] Nature Medicine / Nihart et al. — Bioaccumulation of microplastics in decedent human brains
Bioaccumulation of microplastics in decedent human brains- Statistiek
MNP concentration 7-30x higher in brain (median ~4900 µg/g) than liver/kidney; rose ~50% from 2016 to 2024; up to 10x higher in brains with documented dementia- Fragment
“"Concentrations in decedent brain samples were 7 to 30 times higher than in the liver or kidney... brain tissue from people who had been diagnosed with dementia had up to 10 times as much plastic in their brains as everyone else... the study design cannot show whether higher levels of plastic in the brain caused the dementia symptoms — they may simply accumulate more due to the disease process itself." ”
- Brongegevens van
- 2025-02-03
- Geraadpleegd
- 2026-06-14 · gearchiveerde kopie
- Berekening
- Nihart et al. applied pyrolysis-GC/MS (corroborated by FTIR and electron microscopy) to >50 autopsy samples from the Albuquerque medical examiner, from decedents in 2016 and 2024. Brain MNP load (predominantly polyethylene, largely nanoscale shard-like fragments) far exceeded liver and kidney, and rose ~50% across the eight-year window. Brains with a documented dementia diagnosis showed up to 10x more plastic, concentrated in cerebrovascular walls and immune cells. This is a cross-sectional autopsy series: the dementia association is explicitly correlation, not causation, and the authors flag reverse causation (impaired clearance / blood-brain-barrier breakdown in dementia could increase deposition). It quantifies tissue burden and its temporal rise, not attributable disease risk, so it does not change the no_reliable_estimate classification.
- Onafhankelijkheid
- US autopsy-tissue study using pyrolysis-GC/MS plus FTIR and electron microscopy; methodologically independent of the WHO review, the Marfella plaque cohort, the Leslie blood study, and the EFSA assessment.
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[5] European Food Safety Authority — Microplastics and nanoplastics in food
Microplastics and nanoplastics in food- Statistiek
EFSA risk assessment on microplastics in food scheduled for completion by end of 2027; no quantified health risk established as of 2025- Fragment
“"The European Parliament has requested EFSA to deliver a scientific opinion on the potential health risks posed by microplastics in food, water and air." ”
- Brongegevens van
- 2025-10-28
- Geraadpleegd
- 2026-04-18 · gearchiveerde kopie
- Berekening
- EFSA's 2025 literature review of micro- and nanoplastic release from food contact materials analyzed over 100 studies (2015-2025) and concluded that while microplastic release from FCMs is real, current studies likely overestimate quantities, and nanoplastic data remain insufficient for reliable exposure estimates. EFSA has not issued a quantified risk figure. Their formal scientific opinion is not expected until end of 2027. The absence of an EFSA opinion after years of review is itself evidence of the epistemic gap — not of safety, but of insufficient data to quantify risk in either direction.
- Onafhankelijkheid
- EFSA risk assessment is an independent EU regulatory review, methodologically separate from the WHO 2019 review and from individual primary studies.
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[6] Journal of Hazardous Materials Letters / Pletz (2022) — Ingested Microplastics: Do Humans Eat One Credit Card per Week?
Ingested Microplastics: Do Humans Eat One Credit Card per Week?- Statistiek
The widely cited 5g/week estimate overestimates ingestion by several orders of magnitude; realistic estimates are 0.01-0.1g/week- Fragment
“"Our analysis suggests that the widely reported figure of 5 g per week overestimates microplastic ingestion by several orders of magnitude." ”
- Brongegevens van
- 2022-12-01
- Geraadpleegd
- 2026-04-18 · gearchiveerde kopie
- Berekening
- Pletz (2022) critically reviewed the Senathirajah et al. (2021) analysis that generated the "credit card per week" claim. The 5g figure was the extreme upper bound of a 0.1-5g range, and the underlying methodology conflated particle counts with mass in ways that inflate estimates. More careful analyses suggest typical adult ingestion is roughly 0.01-0.1g per week — still nonzero, but 50-500x lower than the headline figure. This matters because the perceived threat level is anchored to an exposure estimate that is almost certainly wrong by orders of magnitude.
- Onafhankelijkheid
- Critical reanalysis of the WWF/Newcastle exposure estimate by independent food-science researchers; not affiliated with WHO, EFSA, or the original 2019 study authors.
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[7] Environment International / Ragusa et al. — Plasticenta: First evidence of microplastics in human placenta
Plasticenta: First evidence of microplastics in human placenta- Statistiek
12 microplastic fragments (5-10 micrometers) detected via Raman microspectroscopy in 4 of 6 human placentas from uneventful pregnancies- Fragment
“"In total, 12 microplastic fragments (ranging from 5 to 10 [micrometers] in size)...were found in 4 placentas." ”
- Brongegevens van
- 2021-01-01
- Geraadpleegd
- 2026-07-03 · gearchiveerde kopie
- Berekening
- Substantiates the body prose's "Ragusa et al. found them in placentas" claim. First reported detection of microplastics in human placental tissue (fetal side, maternal side, and chorioamniotic membranes) in a small sample of six placentas from uneventful pregnancies. Like the Leslie blood study, this proves detection/bioavailability, not attributable health harm -- no outcome data, no dose-response, no disease endpoint measured. Does not change the no_reliable_estimate classification.
- Onafhankelijkheid
- Italian clinical/laboratory study using Raman microspectroscopy on placental tissue; methodologically independent of the WHO review, the Marfella plaque cohort, the Leslie blood study, the Nihart brain study, and the EFSA assessment.