In 2019 a study came out suggesting that humans consume up to 5 grams of microplastics every week. This result has been frequently cited by numerous high profile and credible sources since, including Stanford Medical News Centre, in the form of "humans are consuming up to a credit card of plastic per week". This became a powerful statistic in environmental advocacy and was the basis for numerous campaigns/advertisements. The outcome of this is positive; microplastics are known to be bad for us and incredibly abundant, this is indisputable. But the "credit card per week" stat has largely been discredited. In fact it is likely an overestimation by around a factor of 1 million. So how much does it matter that the statistic is wrong, if the outcome is still positive? A lot, I think. For statistics to have impact when they matter, we need to have faith that they are true. Otherwise, people will have a reason to discredit those that are accurate when it is convenient for them. So, even if the gist of the argument remains the same, rectifying miscalculations is crucial to maintain its integrity.