If the relative humidity is more than 50 percent, mold spores will grow. To prevent spore growth, keep air ducts clean, use ventilating fans in kitchen and bathroom areas, vent clothes dryers outside or install a dehumidifier. Mold may also collect in ducts after summer and becomes airborne once the heating system starts working. When the heating system starts working it is common for people to get cold-like symptoms from the mold. Asbestos - This mineral fiber has been used as a fire retardant or to wrap water pipes.
Asbestos is associated with lung cancer and asbestosis, a disease which scars the lungs.
If you suspect the presence of asbestos in your home, leave it alone and contact the Department of Health on how to test for asbestos and methods used to seal or remove asbestos.