Related Research Articles
A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive substances are considered carcinogens, but their carcinogenic activity is attributed to the radiation, for example gamma rays and alpha particles, which they emit. Common examples of non-radioactive carcinogens are inhaled asbestos, certain dioxins, and tobacco smoke. Although the public generally associates carcinogenicity with synthetic chemicals, it is equally likely to arise from both natural and synthetic substances. Carcinogens are not necessarily immediately toxic; thus, their effect can be insidious.
A cigarette is a narrow cylinder containing a combustible material, typically tobacco, that is rolled into thin paper for smoking. The cigarette is ignited at one end, causing it to smolder; the resulting smoke is orally inhaled via the opposite end. Cigarette smoking is the most common method of tobacco consumption. The term cigarette, as commonly used, refers to a tobacco cigarette, but the word is sometimes used to refer to other substances, such as a cannabis cigarette or an herbal cigarette. A cigarette is distinguished from a cigar by its usually smaller size, use of processed leaf, and paper wrapping, which is typically white. Most modern cigarettes are filtered, although this does not make the smoke inhaled from them contain fewer carcinogens and harmful chemicals.
Tobacco smoke is a sooty aerosol produced by the incomplete combustion of tobacco during the smoking of cigarettes and other tobacco products. Temperatures in burning cigarettes range from about 400 °C between puffs to about 900 °C during a puff. During the burning of the cigarette tobacco, thousands of chemical substances are generated by combustion, distillation, pyrolysis and pyrosynthesis. Tobacco smoke is used as a fumigant and inhalant.
Tobacco smoking is the practice of burning tobacco and ingesting the resulting smoke. The smoke may be inhaled, as is done with cigarettes, or simply released from the mouth, as is generally done with pipes and cigars. The practice is believed to have begun as early as 5000–3000 BC in Mesoamerica and South America. Tobacco was introduced to Eurasia in the late 17th century by European colonists, where it followed common trade routes. The practice encountered criticism from its first import into the Western world onwards but embedded itself in certain strata of a number of societies before becoming widespread upon the introduction of automated cigarette-rolling apparatus.Out of 8 million annual deaths, second hand smoke due to smoking is responsible for 1.3 million deaths worldwide as per WHO report.
Passive smoking is the inhalation of tobacco smoke, called passive smoke, secondhand smoke (SHS) or environmental tobacco smoke (ETS), by individuals other than the active smoker. It occurs when tobacco smoke diffuses into the surrounding atmosphere as an aerosol pollutant, which leads to its inhalation by nearby bystanders within the same environment. Exposure to secondhand tobacco smoke causes many of the same diseases caused by active smoking, although to a lower prevalence due to the reduced concentration of smoke that enters the airway.
Tobacco products, especially when smoked or used orally, have negative effects on human health. Researchers have addressed concerns about these effects for a long time. They have focused primarily on cigarette smoking.
Cannabis smoking is the inhalation of smoke or vapor released by heating the flowers, leaves, or extracts of cannabis and releasing the main psychoactive chemical, Δ9-tetrahydrocannabinol (THC), which is absorbed into the bloodstream via the lungs. Archaeological evidence indicates cannabis with high levels of THC was being smoked at least 2,500 years ago. As of 2021, cannabis is the most commonly consumed federally illegal drug in the United States, with 36.4 million people consuming it monthly.
A cigarette filter, also known as a filter tip, is a component of a cigarette, along with cigarette paper, capsules and adhesives. Filters were introduced in the early 1950s.
Herbal cigarettes are cigarettes that usually do not contain any tobacco or nicotine, instead being composed of a mixture of various herbs and/or other plant material. However, Chinese herbal cigarettes contain tobacco and nicotine with herbs added, unlike European and North American herbal cigarettes which have tobacco and nicotine omitted. Like herbal smokeless tobacco, they are often used as a substitute for standard tobacco products. Herbal cigarettes are often advertised as a smoking cessation aid. They are also used in acting scenes by performers who are non-smokers, or where anti-smoking legislation prohibits the use of tobacco in public spaces. Herbal cigarettes can carry carcinogens.
Sidestream smoke is smoke which goes into the air directly from a burning cigarette, cigar, or smoking pipe. Sidestream smoke is the main component of second-hand smoke (SHS), also known as Environmental Tobacco Smoke (ETS) or passive smoking. The relative quantity of chemical constituents of sidestream smoke are different from those of directly inhaled ("mainstream") smoke, although their chemical composition is similar. Sidestream smoke has been classified as a Class A carcinogen by the U.S. Environmental Protection Agency.
Tobacco harm reduction (THR) is a public health strategy to lower the health risks to individuals and wider society associated with using tobacco products. It is an example of the concept of harm reduction, a strategy for dealing with the use of drugs. Tobacco smoking is widely acknowledged as a leading cause of illness and death, and reducing smoking is vital to public health.
Third-hand smoke is contamination by tobacco smoke that lingers following the extinguishing of a cigarette, cigar, or other combustible tobacco product. First-hand smoke refers to what is inhaled into the smoker's own lungs, while second-hand smoke is a mixture of exhaled smoke and other substances leaving the smoldering end of the cigarette that enters the atmosphere and can be inhaled by others. Third-hand smoke or "THS" is a neologism coined by a research team from the Dana–Farber/Harvard Cancer Center, where "third-hand" is a reference to the smoking residue on surfaces after "second-hand smoke" has cleared out.
Smoking is a practice in which a substance is combusted and the resulting smoke is typically inhaled to be tasted and absorbed into the bloodstream of a person. Most commonly, the substance used is the dried leaves of the tobacco plant, which have been rolled with a small rectangle of paper into an elongated cylinder called a cigarette. Other forms of smoking include the use of a smoking pipe or a bong.
Smoker's melanosis is seen with the naked eye as a brown to black pigmentation of the oral tissue i.e. the gums, cheeks or palate as well as in larynx. It is most often seen in the lower labial gingiva of tobacco users. Most easily it is found in Caucasians, due to their lack of a genetically caused melanin pigmentation.
Ventilated cigarettes are considered to have a milder flavor than regular cigarettes. These cigarette brands may be listed as having lower levels of tar ("low-tar"), nicotine, or other chemicals as "inhaled" by a "smoking machine". However, the scientific evidence is that switching from regular to light or low-tar cigarettes does not reduce the health risks of smoking or lower the smoker's exposure to the nicotine, tar, and carcinogens present in cigarette smoke.
Animals are exposed to tobacco smoke and other cigarette by-products through their use as experimental subjects and through contact with smokers, as in the case of pets in houses where smoking takes place.
The use of electronic cigarettes (vaping) carries health risks. The risk depends on the fluid and varies according to design and user behavior. In the United Kingdom, vaping is considered by some to be around 95% less harmful than tobacco after a controversial landmark review by Public Health England.
The scientific community in the United States and Europe are primarily concerned with the possible effect of electronic cigarette use on public health. There is concern among public health experts that e-cigarettes could renormalize smoking, weaken measures to control tobacco, and serve as a gateway for smoking among youth. The public health community is divided over whether to support e-cigarettes, because their safety and efficacy for quitting smoking is unclear. Many in the public health community acknowledge the potential for their quitting smoking and decreasing harm benefits, but there remains a concern over their long-term safety and potential for a new era of users to get addicted to nicotine and then tobacco. There is concern among tobacco control academics and advocates that prevalent universal vaping "will bring its own distinct but as yet unknown health risks in the same way tobacco smoking did, as a result of chronic exposure", among other things.
The chemical composition of the electronic cigarette aerosol varies across and within manufacturers. Limited data exists regarding their chemistry. However, researchers at Johns Hopkins University analyzed the vape clouds of popular brands such as Juul and Vuse, and found "nearly 2,000 chemicals, the vast majority of which are unidentified."
Smoker’s macrophages are alveolar macrophages whose characteristics, including appearance, cellularity, phenotypes, immune response, and other functions, have been affected upon the exposure to cigarettes. These altered immune cells are derived from several signaling pathways and are able to induce numerous respiratory diseases. They are involved in asthma, chronic obstructive pulmonary diseases (COPD), pulmonary fibrosis, and lung cancer. Smoker’s macrophages are observed in both firsthand and secondhand smokers, so anyone exposed to cigarette contents, or cigarette smoke extract (CSE), would be susceptible to these macrophages, thus in turns leading to future complications.
References
- ↑ Nicole Wolverton (Sep 2, 2010), Effects of Tar in Cigarette Smoke, Livestrong, retrieved Jan 16, 2013
- ↑ Luch, A. (2005), The Carcinogenic Effects of Polycyclic Aromatic Hydrocarbons, Imperial College Press, ISBN 978-1-86094-417-8
- ↑ "Cigarette Manufacturer and Production - British American Tobacco Malaysia - Tar and Nicotine". Archived from the original on 2007-12-23.
- ↑ British American tobacco (21 September 1966). "Minutes of the 32nd Meeting of the Chemistry Study Group".
- ↑ Tomar, Rajpal C.; Beaumont and Hsieh (August 2009). "Evidence on the carcinogenicity of marijuana smoke" (PDF). Reproductive and Cancer Hazard Assessment Branch Office of Environmental Health Hazard Assessment, California Environmental Protection Agency. Retrieved 23 June 2012.
- ↑ Hornby, Sydney. "The Effects of Tar in Smoking".
- ↑ "Thirdhand smoke: What are the dangers to nonsmokers? - Mayo Clinic". www.mayoclinic.org. Retrieved 2015-04-17.
- ↑ Sleiman, Mohamad; Logue, Jennifer M.; Luo, Wentai; Pankow, James F.; Gundel, Lara A.; Destaillats, Hugo (November 18, 2014). "Inhalable Constituents of Thirdhand Tobacco Smoke: Chemical Characterization and Health Impact Considerations" (PDF). Environmental Science & Technology. 48 (22): 13093–13101. doi:10.1021/es5036333. ISSN 0013-936X. PMID 25317906. S2CID 31844788.
- ↑ Matt, Georg E.; Quintana, Penelope J. E.; Destaillats, Hugo; Gundel, Lara A.; Sleiman, Mohamad; Singer, Brett C.; Jacob, Peyton; Benowitz, Neal; Winickoff, Jonathan P.; Rehan, Virender; Talbot, Prue; Schick, Suzaynn; Samet, Jonathan; Wang, Yinsheng; Hang, Bo; Martins-Green, Manuela; Pankow, James F.; Hovell, Melbourne F. (2011). "EHP – Thirdhand Tobacco Smoke: Emerging Evidence and Arguments for a Multidisciplinary Research Agenda". Environmental Health Perspectives. 119 (9): 1218–1226. doi:10.1289/ehp.1103500. PMC 3230406 . PMID 21628107 . Retrieved 2015-04-17.