Public Health

You can see the affiliations of the authors in the original study, they are only associated with their universities and medical facilities. They also tested a handful of dryers before and after being fitted with HEPA filters.

Therefore, we compared bacterial recovery from five hand dryers before and after retrofitting the dryers with HEPA filters. While bacterial recoveries prior to HEPA filter retrofit were comparable to those seen in previous experiments, bacterial counts at 9 days after HEPA filter retrofitting were reduced ∼4-fold, and this difference was significant (P < 0.001) (Table 2; note that for the hand dryer data in Table 1, air exposure was 30 s whereas it was 1 min for the data in Table 2). Thus, the HEPA filter retrofit reduced, but did not eliminate, microbe deposition by hand dryers.

Ultimately this is an important pilot study, but more studies are needed. This information is particularly important for immunocompromised people who may not know the best way to avoid illnesses when in public bathrooms. Also, many places do not have the HEPA filtered dryers and may not upgrade to HEPA filters for a long time.

Prove it