I just moved to an older apartment 2 months ago. Since I have been here I have noticed thick mucous in my throat and coughing and itchy throat that only seems to get worse over time. My nose is not any more stopped up than usual. There is not a place for a return air filter here. The vent where return air flows is very long and odd shaped. The dust in behind there is thick in places approximately 5 to 6 inches deep. My step-dad and I are going to try to clean that out and come up with a home-made air filter for it. In the meantime, is there anything I can do to help clear my symptoms or at least ease them up until that can be gotten under control. The constant coughing and itching throat is beginning the get the best of me.