As COVID-19 spreads globally, health authorities worldwide emphasize basic hygiene practices: washing hands frequently (at least hourly), using hand sanitizer, coughing or sneezing into your elbow, and using disposable tissues. To highlight this, we're sharing a compelling 2017 classroom experiment by Donna Gill Allen, an experienced teacher in North Carolina, USA.
Donna conducted a straightforward yet eye-opening demonstration during a lesson on germs. To show her students the risks of touching food with dirty hands, she prepared four slices of bread, handling each differently before sealing them in individual transparent bags for one month.
One slice was touched with soap-washed hands; another with hands cleaned using hand sanitizer; a third was rubbed on a computer keyboard; and the fourth was handled by multiple unwashed students. The unwashed slice quickly developed heavy mold, turning greenish, while the others stayed relatively fresh. This stark visual proof motivated her students to prioritize handwashing before meals.
Donna's post went viral, shared nearly 73,000 times on Facebook, inspiring countless teachers and parents to replicate the experiment, as noted in enthusiastic comments. A smart, science-backed teaching win!
Control slice (untouched).
Slice handled by soap-washed hands.
Slice handled by hand sanitizer-cleaned hands.
Slice rubbed on computer keyboard.
Slice handled by unwashed hands.
There you have it...
