Particularly if you recall how SARS was spread through the type of plumbing common in HK residential blocks. Fill all the gas traps with water by flushing those floor drains you never use.
Very good advice.
It is the water in the sewer gas traps that keeps the dangerous gas in the sewer pipes. This issue in HK is the heat evaporating the water in these not normally used traps.
Hopefully, many of the population has learned from 2003 about the importance of cleanliness and good personal hygiene as well as prevention of transmission of diseases.
Are they going to modify the facemask ordinance soon?
BTW
Stay away from protesters who got trapped at Poly U and tried escaping through the sewers. It only works in the movie.