Q. Do many germs escape into the air when a toilet is flushed, and do they affect our health?

A. The jury is still out on this age-old question, a new review of the scientific literature suggests.

The possible peril of a toilet plume became famous through a 1975 study by Charles P. Gerba in the journal Applied Microbiology. Dr. Gerba seeded household toilets with disease germs and then tested to see if they survived after flushing. He concluded that “there is a possibility that a person may acquire an infection from an aerosol produced by a toilet.”