How Much Plastic Do We Eat Per Week? The Credit-Card Stat Explained
Quick Answer
Key Takeaways
- The “credit-card per week” figure is real-but-contested: WWF's 2019 report cited Cox et al. 2019 in Environmental Science & Technology.
- Bottled-water drinkers can ingest 22× more microplastic than tap-water drinkers, making bottled water the single biggest exposure variable.
- Updated 2021–2024 reviews estimate weekly ingestion of 0.1 to 5 grams, with most defensible mid-range estimates around 0.4–4 grams.
- Annual exposure adds up: even at 0.4 g/week, that's about 21 grams per year, or roughly the weight of a plastic hanger.
- Cutting bottled water alone can drop your weekly intake by 60–80% in most diets.
Where the credit-card figure came from
In June 2019, WWF commissioned a literature review from the University of Newcastle (Australia) titled No Plastic in Nature: Assessing Plastic Ingestion from Nature to People. The review estimated that an average person ingests roughly 2,000 microplastic particles per week— about 5 grams — equivalent in mass to a single credit card.
The figure went viral because it was concrete, visual, and shareable. It was also based on extrapolation, not direct measurement of individuals.
How the figure was calculated
The Cox et al. 2019 paper that underpinned WWF's claim estimated ingestion across major dietary sources:
| Source | Particles per year | Particles per week |
|---|---|---|
| Water (bottled) | ~90,000 | ~1,730 |
| Water (tap only) | ~4,000 | ~75 |
| Air (inhalation) | ~38,000–90,000 | ~730–1,730 |
| Salt | ~11,000 | ~210 |
| Shellfish | ~11,000 | ~210 |
| Sugar | ~3,000 | ~58 |
| Total (typical Western diet, bottled water) | ~158,000 | ~3,000 |
Converting particles to mass requires assumptions about average particle size and density. The 5-gram credit-card mass came from applying typical PET density to these particle counts — a step several researchers have since challenged as overestimating average particle size.
The 2021 and 2024 reanalyses
A 2021 review by Senathirajah et al. in Journal of Hazardous Materialsapplied stricter weighting and concluded the typical human ingests approximately 0.1–5 grams of microplastics per week, with 0.7 g/week being a defensible mid-point. They also pointed out that the bottled-water signal dominated the original WWF figure.
A 2024 review by Mohamed Nor et al. in Environmental Science & Technology— which incorporated the 2024 PNAS nanoplastic data — argued that the credit-card figure understates if you count nanoplastics by particle but overstates if you count by mass, because nanoplastics weigh essentially nothing individually.
What the figure means depending on your habits
| Lifestyle profile | Estimated weekly mass | Visual equivalent |
|---|---|---|
| Bottled water + microwave-plastic + takeout heavy | ~4–5 g/week | About 1 credit card |
| Average Western diet, mixed habits | ~0.5–2 g/week | About 1 grain of rice |
| Filtered water, glass storage, low-takeout | ~0.1–0.5 g/week | About 1 pencil shaving |
| Same as above + HEPA air + chicle gum + no plastic-heated food | ~0.05–0.2 g/week | Trace |
Does eating 0.5 to 5 grams of plastic per week actually harm you?
That question isn't yet answered with certainty, but the trend is moving toward “yes”. Animal studies consistently show inflammation, oxidative stress, and gut microbiome disruption at exposures comparable to human dietary intake. The first human prospective study (NEJM 2024) found a 4.53× higher cardiovascular-event risk in patients with microplastics in their arterial plaque. See our arterial plaque study explainer for details.
The five highest-impact reductions
- Switch from bottled water to filtered tap (removes the single biggest source)
- Stop heating food in plastic (removes the biggest amplifier per gram)
- Replace plastic food storage with glass
- HEPA-filter indoor air, especially bedrooms
- Reduce takeout and canned foods (epoxy can liners + plastic-lined paper)
See how to avoid microplastics for the full 50-item checklist.
What the MicroPlastics app checks
- Product packaging — PET, HDPE, PP, PS, PVC, multi-layer, glass, aluminum.
- Container condition from photo — scratches, dents, fade.
- Brand and product category — flags for known PFAS / BPA / fragranced lines.
- Use-context flags — heat exposure, microwave, reuse cycles.
- Cited research — every score links the specific studies behind it.
Use the App
Translate the research into 5-second shelf decisions
Reading the studies is step one. Acting on them at the grocery store is step two. The MicroPlastics app scores each product 0–100 using research like this.
Get the MicroPlastics appFrequently Asked Questions
Do we really eat a credit card of plastic per week?
How much microplastic is in the average person per year?
What is the single biggest source of microplastics in our diet?
How can I measure how much plastic I eat?
Sources
- Cox KD, Covernton GA, Davies HL, et al. (2019). Human consumption of microplastics. Environmental Science & Technology.
- Senathirajah K, Attwood S, Bhagwat G, et al. (2021). Estimation of the mass of microplastics ingested - A pivotal first step towards human health risk assessment. Journal of Hazardous Materials.
- Mohamed Nor NH, Kooi M, Diepens NJ, Koelmans AA (2021). Lifetime accumulation of microplastic in children and adults. Environmental Science & Technology.
- Qian N, Gao X, Lang X, et al. (2024). Rapid single-particle chemical imaging of nanoplastics by SRS microscopy. PNAS.
- WWF International (2019). No Plastic in Nature: Assessing Plastic Ingestion from Nature to People. WWF.
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