Calling Bullshit: The Art of Skepticism in a Data-Driven World

by Carl T. Bergstrom

BEWARE OF UNFAIR COMPARISONS “Airport Security Trays Carry More Germs Than Toilets!” Media outlets around the world ran some version of this headline after a research study was published in September 2018, confirming the fears of every germophobe who has ever suffered through the airport security screening process. But the claim is somewhat disingenuous. The scientists who did this study looked only at respiratory viruses, the kind transmitted through the air or through droplets on people’s hands when they cough or sneeze. It isn’t surprising that security trays have more respiratory viruses than toilet seats. People don’t usually cough or sneeze onto toilet seats, nor do they tend to touch them extensively with their hands. Toilet seats have plenty of germs, just not of the kinds that the researchers were tallying.