Particular forms of tobacco use - Smoking

Chewing tobacco

Chewing tobacco has been known to cause cancer, particularly of the mouth and throat. According to the International Agency for Research on Cancer, "Some health scientists have suggested that smokeless tobacco should be used in smoking cessation programmes and have made implicit or explicit claims that its use would partly reduce the exposure of smokers to carcinogens and the risk for cancer. These claims, however, are not supported by the available evidence. "Oral and spit tobacco increase the risk for leukoplakia a precursor to oral cancer.

Cigars

Like other forms of tobacco use, cigar smoking poses a significant health risk depending on dosage: risks are greater for those who inhale more when they smoke, smoke more cigars, or smoke them longer. The risk of dying from any cause is significantly greater for cigar smokers, with the risk particularly higher for smokers less than 65 years old, and with risk for moderate and deep inhalers reaching levels similar to cigarette smokers. Little cigars are commonly inhaled and likely pose the same health risks as cigarettes. The increased risk for those smoking 1–2 cigars per day is too small to be statistically significant, and the health risks of the 3/4 of cigar smokers who smoke less than daily are not known and are hard to measure; although it has been claimed that people who smoke few cigars have no increased risk, a more accurate statement is that their risks are proportionate to their exposure. Health risks are similar to cigarette smoking in nicotine addiction, periodontal health, tooth loss, and many types of cancer, including cancers of the mouth, throat, and esophagus. Cigar smoking also can cause cancers of the lung and larynx, where the increased risk is less than that of cigarettes. Many of these cancers have extremely low cure rates. Cigar smoking also increases the risk of lung and heart diseases such as chronic obstructive pulmonary disease.

Hookahs

A common belief among users is that the smoke is significantly less dangerous than that from cigarettes. The water moisture induced by the hookah makes the smoke less irritating and may give a false sense of security and reduce concerns about true health effects.[190] Doctors at institutions including the Mayo Clinic have stated that use of hookah can be as detrimental to a person's health as smoking cigarettes, and a study by the World Health Organization also confirmed these findings.

Each hookah session typically lasts more than 40 minutes, and consists of 50 to 200 inhalations that each range from 0.15 to 0.50 liters of smoke. In an hour-long smoking session of hookah, users consume about 100 to 200 times the smoke of a single cigarette; in a 45-minute smoking session a typical smoker would inhale 1.7 times the nicotine of a single cigarette. A study in the Journal of Periodontology found that water pipes smokers were five times more likely than non-smokers to show signs of gum disease. People who smoked water pipes had five times the risk of lung cancer of non-smokers.

A study on hookah smoking and cancer in Pakistan was published in 2008. Its objective was "to find serum CEA levels in ever/exclusive hookah smokers, i.e. those who smoked only hookah (no cigarettes, bidis, etc.), prepared between 1 and 4 times a day with a quantity of up to 120 g of a tobacco-molasses mixture each (i.e. the tobacco weight equivalent of up to 60 cigarettes of 1 g each) and consumed in 1 to 8 sessions". Carcinoembryonic antigen (CEA) is a marker found in several forms of cancer. Levels in exclusive hookah smokers were lower compared to cigarette smokers although the difference was not statistically significant between a hookah smoker and a non-smoker. Also the study concluded that heavy hookah smoking (2–4 daily preparations; 3–8 sessions a day ; >2 hrs to ≤ 6 hours) substantially raises CEA levels. A recent study published in the Asia Pacific Journal of Cancer Prevention (Koul PA et al. Hookah Smoking and Lung Cancer in the Kashmir Valley of the Indian SubcontinentAsian Pacific J Cancer Prev, 12, 519-524; doi.) documented that hookah smokers were nearly 6-times at risk for development of lung cancer as compared to healthy non-smokers in Kashmir (India). Hookah in Kashmir has some peculiar features in having a direct contact of the live embers with the burning tobbaco thus resulting in high temperatures that augments the production of carcinogenic products from tobacco burning. Additionally water in the hookah base is not changed after every session that renders the water contaminated to a greater degree and thus a possible source of dissolved carcinogens.

Snuff

Users of snuff are believed to face less cancer risk than smokers, but are still at greater risk than people who do not use any tobacco products. They also have an equal risk of other health problems directly linked to nicotine such as increased rate of atherosclerosis.