Is it true that we consume up to a credit card’s worth of plastic every week?
This claim is certainly false. It misrepresents the state of scientific research. It is true that plastics have been found in the human body. Microplastics can be ingested or inhaled. However, the average quantity of plastic which enters the human body is unclear. Scientific estimates still differ strongly, however there is no doubt that ‘one credit card per week’ is a gross overestimate. Other studies estimate that humans eat less than the equivalent of a grain of salt per week, and that it would take 4700 years to consume the weight of a plastic bank card.
Detailed information
In 2019, the results of a study commissioned by the environmental organization WWF were published. One of the study’s main assumptions, regarding the mean mass of microplastics eaten and inhaled by people, was badly flawed. This resulted in mass estimates which were greater than any realistic value by several orders of magnitude.
The problem was exacerbated by the WWF highlighting only the highest estimate from the study. This resulted in the ‘plastic credit-card’ comparison spreading swiftly on media outlets and social media. For example, news agency Reuters turned this claim into an infographic story titled “A plateful of plastic: Visualising the amount of microplastic we eat” using shredded plastics and kitchen utensils to illustrate the quantity of 5 grams per week over time.
Another study estimates that people might consume several hundreds of tiny particles of plastics a day. However at most the mass will be a few milligrams. The impact of ingesting microplastics on human health is still uncertain.
Expert check
Thanks toBart Koelmans of Wageningen University andPeter Ryan of the University of Cape Town for scientific fact-checking.
Updated on: October 13, 2023