The Importance of Critical Thinking

This post is not about COVID-19 or masks. Instead, it’s about simple, back-of-the-envelope fact-checking and, more importantly, about critical thinking and why it’s so important as a way of helping to prevent the spread of misinformation.

An article in the Daily Mail from March 12, 2021 reports that “Face masks are a ‘ticking plastic bomb’: Three MILLION coverings are thrown out every minute and serve as carriers for other toxicants in the environment, experts warn“. The article is based on an analysis from researchers at the University of Southern Denmark and Princeton University.

Three million per minute? Let’s see if that’s possible:

  • There are 1,440 minutes per day (60 minutes per hour x 24 hours per day)
  • Three million masks tossed per minute equals 4.32 billion masks tossed per day (1,440 x 3 million)
  • That equates to 131.4 billion masks per month (to be fair, the researchers estimated the total at 129 billion per month, so we will use that figure)
  • That means that 1.548 trillion masks are disposed of each year (129 billion x 12)

If 1.548 trillion masks are disposed of each year, we can safely assume that about that many are produced each year, since existing stockpiles of masks could not have supplied this many. Could that production figure be accurate? Not really.

If we assume a retail price of just US$0.10 per mask (substantially less than the price of many masks on or in the United States), that means that the worldwide retail value of mask production is US$154.8 billion annually. While estimates of the total annual market value of face mask production differ, one source has the market at US$15.83 billion for 2020, while another source pegs it at US$7.24 billion. If we assume that the annual production volume of 1.548 trillion masks is accurate, that would put the production value per mask at between roughly US$0.005 and US$0.01 each. Production costs that low, even in very large volumes and for the least expensive paper masks, are not realistic.

Another way to determine that the 1.548 trillion annual mask production figure is unlikely to be accurate is to check mask production estimates. For example, China’s total production of face masks in 2020 was estimated to be 10.1 billion units, or about 0.65% of 1.548 trillion. Could it be true that China is producing less than one percent of the world’s total production of face masks each year? Not really, since prior to the pandemic China was producing about one-half of the world’s face masks and ramped up production 12 times once it had started.

I have no doubt that the researchers who concluded that we dispose of 129 billion face masks each month did their research with the best of intentions. But even a cursory analysis like the one discussed above reveals that their estimate is highly suspect. At a minimum, the researchers should have been queried about their research methodology and independent sources consulted to determine if similar findings were available. A failure to do so enables either the spread of misinformation, assuming the researchers are wrong; or it results in information that is difficult to believe for those who do the math, assuming they were right.