Dr. Michael G. Stewart of Weill Cornell Medical College in New York said health complications from smoking affect the entire body. In addition to cancers of the lungs, smoking contributes to chronic obstructive pulmonary disease and cardiovascular disease.

Stewart said smoking can cause slow less noticeable damage to many other organs and body systems such as:

-- Exposure to secondhand smoke can cause damage to a child's developing organs, like the lungs and brain.

-- Active smoking produces a negative effect on middle-ear function by chronically irritating the Eustachian tube and the lining of the middle ear.

-- Smoking aggravates conditions like allergies and sinusitis.

"We know that quitting is no easy task, but the overall health benefits are immeasurable," Stewart said in a statement. "Doctors and other medical professionals are here to help you. You don't have to go it alone."