Second-hand smoke, also called passive smoke and environmental tobacco smoke (ETS), is smoke that comes from a lit cigarette, cigar or pipe (called sidestream smoke), or is exhaled by a smoker (called mainstream smoke).
Constituents of second-hand smoke
Second-hand smoke contains about 7,000 different chemicals, called smoke constituents. Approximately 70 of these have been identified to cause cancer, emphysema, and heart disease while at least 200 are considered toxic.
- Tar is the solid residue that results from tobacco combustion. It is not a smoke constituent in itself but is made up of several smoke constituents. Since it is solid, tar adheres to surfaces, such as the teeth (creating black stains) and the mucous membrane of the respiratory tract (creating a coat over the ciliae, rendering them ineffective in filtering air).
- Nicotine, named after Jean Nicot who first used tobacco for its medicinal properties in 1560, is a chemical found in some plants, with exceptionally higher concentration in tobacco. The addictive characteristic of tobacco products is attributed to nicotine. Air nicotine is usually measured to determine the amount of second-hand smoke in the environment.
- Carbon monoxide is a tasteless, odorless toxic gas that is given off during the combustion of tobacco and fuel. It has been identified as the leading cause of among smokers. Symptoms of carbon monoxide poisoning include headache, dizziness, nausea, vomiting, chest pain, depression, fainting, and seizure.
- Benzene is a colorless, sweet-smelling volatile liquid compound that is widely used as a solvent. Benzene is a known human carcinogen, and long-term exposure can result to anemia (specifically, aplastic anemia) and leukemia. Benzene poisoning may cause dizziness, tachycardia (rapid heartbeat), headache, tremors, confusion, coma, and death.
- Formaldehyde is a pungent-smelling industrial chemical used as a preservative (as in human embalming), antiseptic (as in vaccines), and as an adhesive in plastic and wood resins among many other uses. It is one of the identified cancer-causing smoke constituents, proven to cause lung cancer and leukemia. Exposure to formaldehyde causes eye and throat irritation, headache, dizziness, dyspnea (difficulty in breathing), and may trigger an asthma attack.
- Toluene is a sweet-smelling volatile chemical that is widely used as a solvent and found in paints, paint thinners, lacquers, nail polish, glues (locally known in the Philippines as “rugby”), and second-hand smoke. Exposure, usually through inhalation, may lead to dizziness, headache, nausea, loss of appetite, tiredness, confusion, weakness, memory loss, hearing and color vision loss, coma, kidney damage, and death.
- Arsenic is a toxic heavy metal that is known to be carcinogenic to humans. It is commonly used as an ingredient in weed killers and pesticides. Exposure to arsenic may manifest with vomiting, diarrhea, decreased levels of red blood cells and white blood cells, arrhythmia, and the tingling sensation on the hands and feet.
- Other toxic metals found in second-hand smoke are cadmium, chromium, beryllium, nickel, lead, and polonium. The latter two are also radioactive elements.
- Tobacco-specific nitrosamines (TSNAs) are said to be the most potent smoke constituents, being highly carcinogenic. Dried and cured tobacco leaves have higher levels of TSNAs than green tobacco leaves. TSNAs have been linked to lung cancer, oral cancer, and esophageal cancer.
Health impact of second-hand smoke
In 1981, Takeshi Hirayama published the first conclusive study that linked second-hand smoke to lung cancer among non-smoking women who were married to smokers. Since then, numerous different studies that support his conclusion have been published.
In 1986, the International Agency for Research on Cancer (IARC) published a study on tobacco smoking with the following conclusions:
- There is sufficient evidence that inhalation of tobacco smoke as well as topical application of tobacco smoke condensate cause cancer in experimental animals.
- There is sufficient evidence that tobacco smoke is carcinogenic to humans.
- The occurrence of malignant tumours of the respiratory tract and of the upper digestive tract is causally related to the smoking of different forms of tobacco (cigarettes, cigars, pipes, bidis). The occurrence of malignant tumours of the bladder, renal pelvis and pancreas is causally related to the smoking of cigarettes.
Second-hand smoke kills about 600,000 people worldwide every year, according to a global assessment released in November 2010 on the medical journal The Lancet. One-third of those deaths are among children, and half are females. Sixty percent were caused by cardiovascular diseases, thirty percent by lower respiratory infections, and the remaining ten percent by asthma and lung cancer.
According to the World Health Organization (WHO), the risk for lung cancer of a non-smoker exposed to passive smoke is increased by about 20 to 30 percent, while the risk for heart disease by 23%.
In the Philippines, 55% of children ages 13 to15 are exposed to second-hand smoke at home while 65% are exposed in public places.
Children are most vulnerable to the ill health effects of second-hand smoke. Second-hand smoke exposure among children causes respiratory illnesses such as pneumonia, bronchitis and asthma, middle ear infection, possible brain damage, developmental disorders, and cardiovascular disease during adulthood.
Pregnant women who are second-hand smokers are also exposing their fetus to its health hazards. There is also no safe level of exposure to second-hand smoke. Studies have shown that even small amounts of second-hand smoke or brief exposures can have harmful effects on the non-smoker's health.
Reducing second-hand smoke exposure
Because second-hand smoke impinges on the right of the non-smoker to breathe healthy air, the government must protect this right. According to a survey of Filipinos on smoking conducted by the Social Weather Station in 2009, 74% of Filipinos recognize the health benefit from laws enforcing smoke-free areas. Ninety-three percent (93%) were opposed to second-hand smoke. The survey was commissioned by the Department of Health under the helm of former Health Secretary Esperanza Cabral.
Section 24 under Article 5 of the Philippine Clean Air Act states that “smoking inside a public building or an enclosed public place including public vehicles and other means of transport or in any enclosed area outside of one’s private residence, private place of work or any duly designated smoking area is hereby prohibited under this Act. This provision shall be implemented by the LGUs.”
Sections 5 and 6 of Republic Act No. 9211 (known as the Tobacco Regulation act of 2003) stipulates a smoking ban in all public places and the designation of smoking and non-smoking areas.
Under the Civil Service Commission’s Memorandum Circular No. 17, series of 2009, smoking in government buildings, offices, premises and grounds is prohibited. The rule covers government employees and anyone transacting within the premises of government offices.
Local government units such as Makati City and Davao City have anti-smoking campaigns that are strictly implemented and, consequently, very successful.
In 2009, the World Lung Foundation (WLF) and the Center for Health Development-Metro Manila (CHD-MM) of the DOH launched a campaign called “Say No to Second-hand Smoking” through a video that depicted the ill effects of passive smoke on non-smokers, especially women and children, who are the most vulnerable segments of society.
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