Pneumonitis occurs when the tissue in your lungs become inflamed. Pneumonitis differs from pneumonia because of the different causes between the two illnesses. Pneumonitis can be caused by occupational exposure to airborne particles (asbestos or slilica), drugs, such as chemotherapy drugs, radiation therapy to the chest, exposure to poultry, and many types of molds. You can find more
. information here: http://www.mayoclinic.com/health/pneumonitis/DS00962
