The role of smoking

Smoking, particularly of cigarettes, is by far the main contributor to lung cancer, which at least in theory makes it one of the easiest diseases to prevent. In the United States, smoking is estimated to account for 87% of lung cancer cases (90% in men and 79% in women), and in the UK for 90%. Cigarette smoke contains 19 known carcinogens[2] including radioisotopes from the radon decay sequence, nitrosamine, and benzopyrene. Additionally, nicotine appears to depress the immune response to malignant growths in exposed tissue. The length of time a person continues to smoke as well as the amount smoked increases the person's chances of contracting lung cancer. If a person stops smoking, these chances steadily decrease as damage to the lungs is repaired and contaminant particles are gradually vacated. More recent work has shown that, across the developed world, almost 90% of lung cancer deaths are caused by smoking[3].

Passive smoking—the inhalation of smoke from another's smoking— is claimed to be a cause of lung cancer in non-smokers. Studies from the USA (1986[4], [5], 1992[6], 1997[7], 2001[8], 2003 [9]), Europe (1998[10]), the UK (1998[11], [12]), and Australia (1997[13]) have consistently shown a significant increase in relative risk among those exposed to passive smoke.

The (EPA) in 1993 claimed that about 3,000 lung cancer-related deaths a year were caused by passive smoking. However, since this report was based on a study that was alleged to be heavily biased and was ruled by a federal judge to be "unscientific", the EPA report was declared null and void by a federal judge in 1998([14],[15]).

Smoking, particularly of cigarettes, is by far the main contributor to lung cancer, which at least in theory makes it one of the easiest diseases to prevent. In the United States, smoking is estimated to account for 87% of lung cancer cases (90% in men and 79% in women), and in the UK for 90%. Cigarette smoke contains 19 known carcinogens[2] including radioisotopes from the radon decay sequence, nitrosamine, and benzopyrene. Additionally, nicotine appears to depress the immune response to malignant growths in exposed tissue. The length of time a person continues to smoke as well as the amount smoked increases the person's chances of contracting lung cancer. If a person stops smoking, these chances steadily decrease as damage to the lungs is repaired and contaminant particles are gradually vacated. More recent work has shown that, across the developed world, almost 90% of lung cancer deaths are caused by smoking[3].

Passive smoking—the inhalation of smoke from another's smoking— is claimed to be a cause of lung cancer in non-smokers. Studies from the USA (1986[4], [5], 1992[6], 1997[7], 2001[8], 2003 [9]), Europe (1998[10]), the UK (1998[11], [12]), and Australia (1997[13]) have consistently shown a significant increase in relative risk among those exposed to passive smoke.

The (EPA) in 1993 claimed that about 3,000 lung cancer-related deaths a year were caused by passive smoking. However, since this report was based on a study that was alleged to be heavily biased and was ruled by a federal judge to be "unscientific", the EPA report was declared null and void by a federal judge in 1998([14],[15]).