Does anyone have problems breathing the air around their computer?

I have a terrible time when I am at my computer.  It feels like the air is
thick with smoke ­ my sinuses plug up, nose and mouth dry out, throat gets
sore and a tickle starts in my lungs.  The effects stay with me long after
I¹ve left my computer and can last for days (although I¹m at my computer
every day) but sometimes I don¹t experience any problem with the air and
other times I do.  

Don¹t know what it is and no one else seems to notice any problem with the
air.  I have a Mac now but had the same problem with my PC.  Would sure like
to find out what it is.  I know it¹s not directly CS related but if I can
find out what the cause is, maybe I can apply CS in a way that will
intervene.