Janitors are the first line of defense in public places to help control and limit the passing of a lot of viruses located in these place.  Janitors accept the responibility of insuring that these places are clean and disinfected. 

He/She will take the risk of becoming infected to help make sure that the general public risk is very low.  This is done throught a series of vital steps such as: disinfectanting, cleaning, mopping and replacing essentials in areas that are common places in public area.