Microplastics in the Rehbach
16. June 2025
Plastification of our body during our lifetime
24. June 2025
The credit card lie: why microplastic marketing uses false figures
"We eat a credit card a week!" - You come across this headline everywhere when it comes to microplastics. From environmental organizations to filter manufacturers, toothbrushes, and even water bottle advertising...: the supposedly shocking figure of 5 grams of microplastics per week is repeated like a mantra. However, this catchy claim is not only scientifically questionable but is also systematically misused by marketing to sell products and collect donations.
The birth of a marketing legend
The famous "credit card study" dates back to 2019 and was commissioned by the WWF. The University of Newcastle in Australia carried out a meta-analysis of various studies and came to the conclusion that, on a global average, people could consume around 5 grams of microplastics per week - roughly equivalent to the weight of a credit card.
The problem starts with the methodology: the study was not based on direct measurements, but on a summary of various smaller studies with different measurement methods, different definitions of microplastics and often tiny sample sizes; for example: Microplastics Everywhere, Landmark study links microplastics to serious health problems, or Microplastics are invading our bodies. How severe is the damage?
Many of the studies included only examined specific foods or certain regions - deriving a global statement from this is scientifically highly problematic
Why the 5-gram figure is misleading
Scientists criticize the WWF study for several reasons:
- Methodological weaknesses: The original studies used different analysis techniques, different size definitions for microplastics and often inadequate control groups. Many measurements could have been falsified by contamination during sampling.
- Lack of validation: The 5-gram figure has never been confirmed by independent, large-scale studies. Newer, methodologically cleaner studies often arrive at significantly lower values.
- Regional differences: The alleged "global average" ignores massive regional differences in microplastic pollution. What is measured in a heavily polluted coastal area cannot be transferred to rural areas with clean drinking water.
- Definition of microplastics: The studies use different size ranges for microplastic particles. Some only count particles as small as 0.1 millimetres, others as small as 0.001 millimetres - this makes a huge difference to the total quantity.
The marketing abuse of the wrong numbers
The catchy credit card metaphor has quickly become a favorite tool of various interest groups:
Environmental organizations use the shocking number to generate attention and collect donations. The more dramatic the message, the greater the response - and the greater the willingness to donate.
Water filter manufacturers advertise aggressively with the claim that their products protect against weekly "credit card consumption". However, most household filters do not effectively filter out microplastics.
Paradoxically, the packaging industry uses the figures both to justify itself ("everyone else is to blame too") and to promote supposedly "microplastic-free" alternatives.
The media likes to use a catchy headline without questioning the scientific basis. A complex environmental problem is reduced to a simple, viral soundbite.
The reality is more complex - and more important
The real problem with the credit card story is not just that it is scientifically unsound. It also distracts from the really important issues:
Instead of discussing questionable levels of consumption, we should focus on where microplastics actually come from and how we can reduce the sources. The main culprits are not mysterious particles in our food, but the abrasion of car tires, synthetic textiles in the washing machine, and the improper disposal of plastic waste.
In addition, the health risks of microplastics have not yet been conclusively researched. While marketing messages are stirring up panic, scientists are working to find out which particle sizes, quantities and types could be problematic.
What can consumers do?
Instead of falling for expensive filter systems or "microplastic-free" miracle products, consumers can take simple steps to reduce their microplastic footprint:
- Use less plastic packaging
- Use the right washing parameters when washing synthetic clothing
- Avoid cosmetics with microplastics and soluble / liquid polymers
- Buy locally and unpackaged when, and where possible.
Conclusion: Microplastics needs more science, less marketing
The story of "We Consume a Credit Card a Week" is a good example of how scientific uncertainty is exploited by marketing interests. A questionable figure is stylized into a supposed certainty and then exploited commercially.
Genuine environmental policy needs solid data, not catchy phrases. Instead of relying on shock figures, we should focus on proven sources of microplastics and start to act where real improvements are possible. This is the only way to move from marketing panic to meaningful solutions for a real environmental problem. The truth about microplastics is more complicated than ingesting a credit card a week - but it is also more important than marketing would have us believe.
