The drainpipe under the sink should have a "U" shaped bend called a P-trap. Its purpose is to always hold a small amount of water in it which will block sewer gases from coming up through the sink and into the living space.
The problem could be:
No P-trap at all, which is unlikely.
P-trap water has evaporated from prolonged lack of use, unlikely in most homes.
The P-trap leaks, which may permit sewer gas escape.
The P-trap is dirty and needs to be removed and cleaned.
P-traps are not maintainence free. It would be a good idea to remove and clean them after years of use, and you don't need a plumber to do this if you are reasonably handy. And in the meantime, occasionally pour a little bleach in your sinks before you go to bed.
ANS 2 - Remove the P trap and clean it and the pipe above it thoroughly. If necessary fit a new P trap.
Sewage is the dirty water which is poured down sewers from drains and lavatories.
Discharge and grey water from drains.
Sewage is the waste matter carried off by sewer drains and pipes. Sewerage refers to the physical facilities (e.g., pipes, lift stations, and treatment and disposal facilities) through which sewage flows.
Sewage Treatment Plant
so where exactly doe the sewage go? To the rivers and oceans?
Cancer for one
Uh, sewage?
A large underground pipe that carries away sewage from drains and water from road surfaces. Sewers can also be aboveground ditches, which are called "open sewers" if they carry sewage.
dirty, no sewage drains, no clean water, very little clothing and proper living possibilities.
Close the affected area and clean it.
Excreta = any form of waste matter expelled from the body e.g. sweat, urine and feces. In cellular level it can be a chemical byproduct. In insects they are called 'fecula' and for bats and sea birds 'guano'. Sewage = It's related to the word 'sewer'. Sewage is all waste carried by drains and sewers (hence its name). The source for sewage can be either industrial or domestic.
If you think you smell sewer gas in your bathroom, it could be that a sewage blockage is in your pipes, causing the sewage to back up in the lines.