NIEHS Asthma Prevention: Cigarette Smoke - People with allergies may be more sensitive to cigarette smoke than others and research indicates that smoking aggravates allergies. - http://www.niehs.nih.gov/airborne/prevent/smoke.html
Smoking and Respiratory Disease - ASH-UK Factsheet on smoking and lung cancer, COPD, pneumonia. - http://www.ash.org.uk/html/factsheets/html/fact05.html
Specimen 156.9: Lung: Emphysema - From a library of medical images, a lung with emphysema ("smoker's lung"). - http://www.med.unsw.edu.au/pathology/Pathmus/F0839044.htm