Hi Anny! 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. TAKE CARE!