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Pack-years
A pack-year is a clinical quantification of cigarette smoking used to measure a person's exposure to tobacco. This is used to assess their risk of developing lung cancer or other pathologies related to tobacco use. However, it is difficult to rely on the assessment based on the pack-year due to the different nature of the packaging by different companies. Definition The pack-year is a unit for measuring the amount a person has smoked over a long period of time. It is calculated by multiplying the number of packs of cigarettes smoked per day by the number of years the person has smoked. For example, 1 pack-year is equal to smoking 20 cigarettes (1 pack) per day for 1 year, or 40 cigarettes per day for half a year, and so on.http://www.cancer.gov/dictionary?CdrID=306510 National Cancer Institute definition of pack year One pack-year is the equivalent of 365 packs of cigarettes or 7,300 cigarettes, in a year as smoker. Calculation Number of pack-years = (packs smoked per day) × ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantification (science)
In mathematics and empirical science, quantification (or quantitation) is the act of counting and measuring that maps human sense observations and experiences into quantity, quantities. Quantification in this sense is fundamental to the scientific method. Natural science Some measure of the undisputed general importance of quantification in the natural sciences can be gleaned from the following comments: * "these are mere facts, but they are quantitative facts and the basis of science." * It seems to be held as universally true that "the foundation of quantification is measurement." * There is little doubt that "quantification provided a basis for the objectivity of science." * In ancient times, "musicians and artists ... rejected quantification, but merchants, by definition, quantified their affairs, in order to survive, made them visible on parchment and paper." * Any reasonable "comparison between Aristotle and Galileo shows clearly that there can be no unique lawfulness discov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cigarette Smoking
Tobacco smoking is the practice of burning tobacco and ingesting the resulting smoke. The smoke may be inhaled, as is done with cigarettes, or 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 onward but embedded itself in certain strata of several societies before becoming widespread upon the introduction of automated cigarette-rolling apparatus. Smoking is the most common method of consuming tobacco, and tobacco is the most common substance smoked. The agricultural product is often mixed with additives and then combusted. The resulting smoke, which contains various active substances, the most significant of which is the addictive psychostimulant drug nicotine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tobacco Products
Tobacco is the agricultural product of the leaves of plants in the genus ''Nicotiana'', commonly termed ''tobacco plants''. All species of ''Nicotiana'' contain the addictive drug nicotine—a psychostimulant alkaloid found in all parts of the plants except the seeds, and most heavily-concentrated in the leaves—which occurs in varying amounts depending on the species of ''Nicotiana'' grown; the breed, type, or variety of tobacco cultivated and produced; and the method used to cure and process tobacco leaves once they have been harvested. This article provides a list of tobacco preparations and products. This list includes both tobacco products meant for consumption and those intended for other uses. Under the heading of consumable tobacco products, several categories of tobacco product are described in this list. Of these four basic categories, the first two include what are most often traditional types of tobacco products and preparations, relegated to the broad sub-cate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lung Cancer
Lung cancer, also known as lung carcinoma, is a malignant tumor that begins in the lung. Lung cancer is caused by genetic damage to the DNA of cells in the airways, often caused by cigarette smoking or inhaling damaging chemicals. Damaged airway cells gain the ability to multiply unchecked, causing the growth of a tumor. Without treatment, tumors spread throughout the lung, damaging lung function. Eventually lung tumors metastasize, spreading to other parts of the body. Early lung cancer often has no symptoms and can only be detected by medical imaging. As the cancer progresses, most people experience nonspecific respiratory problems: coughing, shortness of breath, or chest pain. Other symptoms depend on the location and size of the tumor. Those suspected of having lung cancer typically undergo a series of imaging tests to determine the location and extent of any tumors. Definitive diagnosis of lung cancer requires a biopsy of the suspected tumor be examined by a patholo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cigarette
A cigarette is a narrow cylinder containing a combustible material, typically tobacco, that is rolled into Rolling paper, 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 joint (cannabis), cannabis cigarette or a herbal cigarette. A cigarette is distinguished from a cigar by its usually smaller size, use of processed leaf, different smoking method, and paper wrapping, which is typically white. There are significant negative health effects from smoking cigarettes such as cancer, chronic obstructive pulmonary disease (COPD), cardiovascular disease, heart disease, birth defects, and other Health effects of tobacco, health problems relating to nearly every organ of the body. Most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tobacco
Tobacco is the common name of several plants in the genus '' Nicotiana'' of the family Solanaceae, and the general term for any product prepared from the cured leaves of these plants. More than 70 species of tobacco are known, but the chief commercial crop is ''N. tabacum''. The more potent variant ''N. rustica'' is also used in some countries. Dried tobacco leaves are mainly used for smoking in cigarettes and cigars, as well as pipes and shishas. They can also be consumed as snuff, chewing tobacco, dipping tobacco, and snus. Tobacco contains the highly addictive stimulant alkaloid nicotine as well as harmala alkaloids. Tobacco use is a cause or risk factor for many deadly diseases, especially those affecting the heart, liver, and lungs, as well as many cancers. In 2008, the World Health Organization named tobacco use as the world's single greatest preventable cause of death. Etymology The English word 'tobacco' originates from the Spanish word ''taba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smoking
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. Smoking is primarily practised as a route of administration for psychoactive chemicals because the active substances within the burnt dried plant leaves vaporize and can be airborne-delivered into the respiratory tract, where they are rapidly absorbed into the bloodstream of the lungs and then reach the central nervous system. In the case of tobacco smoking, these active substances are a mixture of aerosol particles that includes the pharmacologically active alkaloid nicotine, which stimulates the nicotinic acetylcholine receptors in the brain. Other notable active ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
