Further Readings

Harms of Tobacco Smoking

• Tobacco smoke contains at least 69 recognised carcinogens, toxic substances such as tar and carbon monoxide, and the highly addictive stimulant nicotine, which can inflict damages on nearly every organ system, increase the risk of cardiovascular diseases and cancers, particularly lung cancer.^{6, 7} Smoking during preconception period and pregnancy is associated with increased risks of infertility, ectopic pregnancy, miscarriage, preterm birth, and low birth weight (S Table 1.).^{8, 9}
• E-cigarette vaporizes e-liquid that contains nicotine, flavorings and solvents, and can generate harmful substances (e.g. carcinogenic aldehydes and chromium) when heated. The amount of nicotine inhaled may exceed that of traditional cigarettes, and some marketed as nicotine-free have been found to actually contain nicotine.¹⁰ Vaping can also result in specific complications such as lipoid pneumonia, subacute bronchiolitis, acute eosinophilic pneumonia, multiple reactive pulmonary nodules, hypersensitivity pneumonia, diffuse alveolar haemorrhage, and organising pneumonia.¹¹
• Waterpipe tobacco (also known as shisha, goza, narghile, ghalyoon, or hookah) involves heating a tobacco product (with or without flavorings) by hot charcoal to emit smoke that the user inhales by puffing on a hose connected to a water container. During a typical 1-hour long waterpipe smoking session, large volume of smoke is produced, which contains high level of toxins, including nearly nine times the carbon monoxide and 1.7 times the nicotine found in a single cigarette, and poses serious health risks comparable to traditional cigarette smoking.^12-15
• The inhalation of environmental tobacco smoke, refers as secondhand smoke, raises the likelihood of developing lung cancer, heart disease and respiratory symptoms among non-smokers.⁷
• Nicotine and other chemicals from cigarette and e-cigarette use can linger on the skin, clothing, and surfaces, exposing children and family members of smokers to the harmful effects of these substances, even when the person is not actively smoking or vaping in their presence.⁷
• Prolonged exposure to nicotine leads to dependence, marked by withdrawal symptoms such as irritability, anxiety, increased appetite, and cravings when not smoking.¹⁶

Interventions for Smoking Cessation

• Quitting smoking is beneficial at any age, yielding immediate and progressive health improvements. Substantial health improvements and reduced disease risk were observed among those who stop, regardless of when they quit.¹⁷ Within 20 minutes, blood pressure and heart rate return to normal. After 10 years, the risk of dying from lung cancer is about half that of smokers, and by 15 years, the risk of coronary heart disease matches that of a non-smoker.¹⁸
• Structural interventions such as brief intervention and motivational interviewing provided by healthcare professionals have been shown to be effective in helping smokers to quit smoking.¹⁹
• A meta-analysis in 2022 concluded that varenicline alone was more effective for smoking cessation compared to placebo (OR 2.88, 95% CI 2.10-3.96) and counselling (OR 3.27, 95% CI 1.48-7.21).²⁰
• A Cochrane review of 65 trials demonstrated that enhancing behavioural support for individuals already using smoking cessation medication could further improve their likelihood of quitting. Approximately 17% of participants with minimal or no support managed to quit, while around 20% in the groups that received additional support succeeded. Moreover, providing support through personal interactions, whether in person or via phone, proved beneficial.²¹