While cigarettes are the most commonly used tobacco product, leaves of the tobacco plant can be prepared and made into other products that are smoked, chewed, or inhaled.


Manufactured cigarettes consist of shredded tobacco, processed with hundreds of chemicals and different flavours such as menthol. Researches show that a lit cigarette releases over 7,000 chemical substances, of which 69 are carcinogens. The three main harmful chemicals found in smoked tobacco products are: tar, nicotine, and carbon monoxide.





  • A mixture of chemical compounds, many of which cause cancer

  • Inhibits or damages the cilia along the airways, so smokers become more susceptible to coughs and colds

  • Damages the bronchi and alveoli, leading to coughs, increased phlegm and difficulty in breathing

  • Long-term smoking may lead to emphysema or lung cancer





  • A stimulant drug found in tobacco products

  • Increases the heart rate, causes blood vessels to constrict, raising blood pressure, decreasing blood flow, and reducing oxygen in the blood

  • Is addictive



Carbon Monoxide


  • Colourless and odourless

  • It reduces the oxygen-carrying capacity of red blood cells, leading to less oxygen going to different parts of the body. This results in premature wrinkles and coronary heart disease.



Short-Term Health Effects


First-time smokers may experience dizziness and nausea. After one or two cigarettes, the blood pressure may rise, the heart may beat faster, the person may lose his/her appetite, and his/her skin temperature may drop. Other symptoms include:


  • Irritation to the eyes, causing them to water more, and the person may blink more frequently

  • Difficulty in breathing, especially during exercise

  • Athletic performance may decline

  • Poor circulation leading to cold hands and feet

  • Tremors

  • Less oxygen supply to the brain

  • Increase of stomach acid



Long-Term Health Effects


Addiction to nicotine develops quickly, as does the body’s tolerance to it. Over time, this means the body will need more nicotine, and need it more frequently to achieve the same effect. This may lead to long-term effects such as:


  • Chronic bronchitis and other diseases of the airways

  • Heart attacks and strokes caused by narrowing of the blood vessels that carry blood to the heart and brain

  • Emphysema, where alveoli loses elasticity and rupture, making breathing exhausting

  • Cancer of the lungs, oral cavity, throat, vocal cords, bronchi, stomach, bladder, kidneys, cervix, etc.

  • Gangrene (death of tissue in parts of the body, such as the toes) caused by poor blood circulation

  • Gastric ulcers

  • Osteoporosis (when bones become weak and brittle due to loss of tissue)

  • Decreased dexterity

  • Blindness


Cosmetic Effects


Studies have shown that young people are more concerned about the short-term effects of smoking, especially ones related to appearance and image. Some cosmetic effects include:


  • Body odour (from oral cavity, hair, clothes)

  • Stained teeth and fingers

  • Accelerates greying and thinning of hair

  • Wrinkles and premature ageing



Second-Hand Smoke


There are two types of second-hand smoke: mainstream smoke and sidestream smoke. Mainstream smoke refers to the exhaled smoke from a smoker’s lungs; it makes up roughly 15% of second-hand smoke. The remaining 85% is sidestream smoke which is released directly into the air from the burning end of a cigarette. Sidestream smoke burns at a lower temperature and is not filtered, therefore it is even more toxic than mainstream smoke.


The number of cigarettes lit, the distance a non-smoker is from a cigarette, the ventilation, and the size and kind of place where the second-hand smoke is inhaled, all contribute to the amount a person actually takes in. The more smoke a non-smoker inhales, the more his/her body is affected.


Whether the second-hand smoke is mainstream or sidestream, it contains over 7,000 chemical substances, of which many are known to cause cancer.


Effects of Second-Hand Smoke on Non-Smokers


Numerous studies have found that exposure to second-hand smoke can cause many of the same diseases as active smoking. It increases the risk of contracting lung cancer by 30% and coronary heart disease by 25%.


Summary of Effects of Second-Hand Smoke


  • Small but significant reduction in lung function, leading to a higher risk of lung cancer

  • Increased risk of lower respiratory tract infections, such as bronchitis and pneumonia

  • Increased chance of miscarriage or stillbirth in pregnant women

  • If pregnant women are exposed to second-hand smoke, babies are born smaller/lighter. There is also an increased risk of developmental problems in the baby at birth.

  • Children who live with smokers have an increased chance of developing fluid in the middle ear, a sign of chronic middle ear disease; catching upper respiratory tract infections (common colds and flu); and an increased frequency and severity of asthmatic episodes. They will also be more likely to smoke due to parental behaviour towards smoking.


Third-Hand Smoke


Third-hand smoke refers to the chemical residue of tobacco smoke left behind on clothing, walls, furniture, carpets, hair, skin and other materials after the cigarette is extinguished.


As well as nicotine, toxic substances in third-hand smoke include the following:

  • Carbon monoxide

  • Hydrocyanic acid (used in chemical weapons)

  • Butane (used in lighter fluid)

  • Toluene (found in paint thinners)

  • Arsenic

  • Lead

  • Polonium-210 (which is a highly radioactive carcinogen)


Even if smokers smoke outside, a residue of nicotine will permeate into their skin and clothing. Tobacco toxins can persist on the surface of objects for weeks and even months after nicotine vapour has been absorbed. Even opening the windows will not remove the third-hand smoke straight away.



Effects of Third-Hand Smoke on Non-Smokers


Many studies have shown that infants and children are at a higher risk than adults. As they crawl around and play, they tend to touch and sometimes swallow dangerous particles from tobacco residue, allowing harmful chemicals to enter their bodies.


Some of the effects of third-hand smoke are as follows:

  • Leads to respiratory problems and increased risk of asthma

  • Increased risk of middle ear infection

  • Cognitive deficits in children, e.g. the higher the exposure to tobacco smoke, the higher the risk of reading deficit



For detailed information, please refer to the following websites:


Hong Kong


Tobacco and Alcohol Control Office


Hong Kong Council on Smoking and Health


Department of Health


Hospital Authority





Chinese Association on Tobacco Control





John Tung Foundation





World Health Organization


The Tobacco Atlas



Societal and Global Effects of Smoking


Environmental Harm


Tobacco plants are monocrops that are vulnerable to different pests and diseases, prompting farmers to use large amounts of chemical fertilizers, growth regulators and insecticides, which deplete the soil of nutrients, resulting in a polluted environment.


With polluted soil and decreasing areas of good land, many low and middle-income countries look for new places for tobacco farming and the wood needed for curing tobacco leaves, leading to large-scale deforestation. This contributes to climate change by removing trees that eliminate carbon dioxide from the atmosphere.



Tobacco Farmers


Tobacco farmers work without protective gear, resulting in the daily absorption of about 54 mg of nicotine through the skin, equivalent to smoking 50 cigarettes. According to the World Health Organization, people who have long-term direct contact with nicotine-containing plants will experience dizziness, nausea and vomiting. In severe cases, it may lead to anaemia or nicotine poisoning. In addition, many tobacco farmers take their children with them to work, believing their health will not be endangered if they do not smoke. However, contact with these plants can be harmful to children, causing headaches, abdominal pain, muscle weakness, difficulty in breathing and other symptoms. In severe cases, exposure leads to problems with the nervous system.



Financial Burden


Tobacco use is the most common preventable cause of death. Studies have shown that for every two long-term smokers, one will die prematurely, with an average loss of 10 years of life. The World Health Organization estimates that more than 5.7 million people around the world die each year from tobacco use, and the death toll will increase to more than 8 million deaths by 2030. In Hong Kong, the number of deaths due to smoking and second-hand smoke is about 7,000 each year. Smoking-related diseases such as cancer, heart and vascular diseases, and chronic lung diseases also incur considerable medical expenses and loss of productivity in Hong Kong, leading to the loss of more than HK$5 billion every year.



Smoking Statistics in Hong Kong


Hong Kong's daily smoking prevalence is recorded in the following surveys:


  1. Thematic Household Survey Report

  2. Survey of Drug Use among Students



Thematic Household Survey Report


The survey is an independent, territory-wide survey conducted by the Census and Statistics Department. The sample of households is drawn up scientifically to collect statistics on various social issues, including smoking in Hong Kong.


According to the 2019 survey, the daily cigarette smoking prevalence of the Hong Kong population (aged 15 or above) was 10.2%. In the 15-19 age group, the daily cigarette smoking prevalence has been decreasing in the past 10 years. The report has also revealed that the percentage of daily electronic cigarettes smokers aged 15 and above has increased 26.3% in 2019, compared to the 2017 survey. Therefore, we must educate young people on the effects of tobacco use at an early stage, helping them to break the myths of different tobacco products and lead them to live a healthy and drug free lifestyle.



Survey of Drug Use among Students


The Narcotics Division of the Security Bureau commissions an investigatory body every four years to conduct a large-scale survey on drug use, including smoking, among students in Hong Kong. In the last survey, the students were from local schools (Primary 4 to Secondary 6), International schools (Year 5 to 13) and tertiary programmes (including public-funded and self-financing degree programmes and sub-degree programmes). The proportion of students who had smoked increased from 7% in 2017/18 to 7.4% in 2020/21.


Note: Data above are updated regularly.


For detailed information, please refer to the following websites:


Census and Statistics Department: Thematic Household Survey Report No. 75



Narcotics Division, Security Bureau: 2020/21 Survey of Drug Use among Students



Marketing Strategies of Tobacco Companies


A number of different tobacco control laws have been enacted around the world, including those restricting tobacco advertising. In Hong Kong, under Part IV of the Smoking (Public Health) Ordinance (Cap 31), no person shall display or cause to be displayed, or publish or distribute any form of tobacco advertisement for display purposes. The display of tobacco advertisements in printed publications, public places, films and the Internet is also prohibited. However, this leads to tobacco companies using grey areas of legislation to promote tobacco products.


Brand Extension


Brand extension is extending the original brand name into other new product items; an indirect way of advertising tobacco products. This not only increases the sales of new and old products, but also brings publicity to the tobacco brand.


In Hong Kong, the tobacco industry benefits from grey areas in the existing legislation since it does not regulate any advertising of non-tobacco products that are an extension from cigarette brands. As long as these advertisements do not show any cigarette products, they can promote any products with lifestyle messages that may resonate with young adults and at the same time make associations with the tobacco brand. As a result, brand extension will continue to attract people to start smoking.


Youth Smoking Prevention (YSP) Programmes


Tobacco companies around the world have provided financial sponsorship, professional advice and support to relevant government and civil society organizations to help them organise programmes to prevent young people from smoking. Their ultimate goal is actually not to prevent young people from smoking, but rather to build a responsible corporate citizen image for themselves, tricking young people into smoking with their publicity.


In summary, YSP programmes sponsored by tobacco companies have the following problems:

  • They portray smoking as an adult choice which leads students to thinking that smoking is related to freedom and maturity, and may stir a rebellious attitude in some young people to try smoking

  • They fail to discuss how tobacco advertising promotes smoking or the health risks of smoking

  • There is no evidence that these programmes decrease smoking among young people



New Products: Electronic Cigarettes


Electronic cigarettes, known as e-cigarettes or electronic nicotine delivery systems, are battery-powered devices designed to look and feel like traditional cigarettes. They use cartridges filled with a liquid that contains nicotine. A heating device in the e-cigarette converts the liquid into a vapour that is inhaled into the lungs.


Chemical substances in electronic cigarettes may include:

  • nicotine

  • propylene glycol

  • formaldehyde

  • acetaldehyde

  • glycerol

  • additives



Effects of Electronic Cigarettes


Studies have pointed out that the electronic cigarettes contain many toxic substances, including propylene glycol which irritates the eyes and respiratory tract, increasing the risk of respiratory problems; and formaldehyde which is a known carcinogen.



Legislation on Electronic Cigarettes


Under the Pharmacy and Poisons Ordinance (Cap. 138), electronic cigarettes containing nicotine are classified as pharmaceutical products and must be registered with the Pharmacy and Poisons Board of Hong Kong before they can be sold or distributed locally. Under the Smoking (Public Health) Ordinance (Cap. 371), it is an offence to use e-cigarettes in a no-smoking area. The offender is liable to a fixed penalty of HK$ 1,500. From April 30, 2022, no person may import, promote, manufacture, sell, or possess for commercial purposes alternative smoking products, including electronic smoking products, heated tobacco products and herbal cigarettes. 



Grey Areas of Electronic Cigarettes


Electronic cigarettes vary in taste, shape and packaging. Most do not list their ingredients, and some packaging even has misleading phrases such as "not addictive" or "help quit smoking". According to a report by the World Health Organization, there is still only limited evidence to show that electronic cigarettes can help people quit smoking. It is therefore important to remind students not to try electronic cigarettes.



For detailed information, please refer to the following websites:


Tobacco and Alchohol Control Office



Hong Kong Council on Smoking and Health (COSH)