Welcome to HCM!
Since your work place has dark/black molds you are continually breathing in mold spores from the air. These spores trigger allergic reactions like sneezing
and a runny nose. The spores can also irritate throat and nose.a sore throat
can be caused by the mold spores irritating mucus membranes in the throat.
The immune system might create a build up of mucus in the throat because of mold. This allergic reaction helps trap mold spores in the mucus before the spores can get into a person's lungs.
since other people are also falling sick so the best thing to do is get rid of the mold that's causing them.
You must get blood test
done for moulds and take antiallergents under guidance of your doctor.