Smog_and_Smoke

✒ *Smog*

Smog is a type of air pollutant . The word "smog" was coined in the early 20th century as a portmanteau of the words smoke and fog to refer to smoky fog, its opacity, and odour. The word was then intended to refer to what was sometimes known as pea soup fog , a familiar and serious problem in London from the 19th century to the mid-20th century. This kind of visible air pollution is composed of nitrogen oxides, sulphur oxides, ozone, smoke or dirt particles and also less visible particles such as CFC's.
Human-made smog is derived from coal
emissions, vehicular emissions, industrial emissions, forest and agricultural fires and photochemical reactions of these emissions.
Modern smog, as found for example in Los Angeles, is a type of air pollution derived from vehicular emission from internal combustion engines and industrial fumes that react in the atmosphere with sunlight to form secondary pollutants that also combine with the primary emissions to form photochemical smog . In certain other cities, such as Delhi, smog severity is often aggravated by stubble burning in neighboring agricultural areas. The atmospheric pollution levels of Los Angeles, Beijing, Delhi, Lahore, Mexico City, Tehran and other cities are increased by inversion that. traps pollution close to the ground. It isusually very highly toxic to humans and cancause severe sickness, shortened life or death.

✒ *Smoke*

Smoke is a collection of airborne solid and liquid particulates and gases emitted when a material undergoes combustion or pyrolysis , together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-product of fires (including stoves , candles , oil lamps , and fireplaces), but may also be used for pest control (fumigation ), communication ( smoke signals), defensive and offensive capabilities in the military ( smoke screen ), cooking , or smoking ( tobacco, cannabis , etc.). Smoke is used in rituals where incense, sage, or resin is burned to produce a smell for spiritual purposes. Smoke is sometimes used as a flavoring agent, and preservative for various foodstuffs. Smoke is also a component of internal combustion engine exhaust gas , particularly diesel exhaust. Smoke inhalation is the primary cause of death in victims of indoor fires . The smoke kills by a combination of thermal damage,poisoning and pulmonary irritation caused by carbon monoxide , hydrogen cyanide and other combustion products.
Smoke is an aerosol (or mist) of solid
particles and liquid droplets that are close to the ideal range of sizes for Mie scattering of visible light. This effect has been likened to three-dimensional textured privacy glass [ citation needed ] — a smoke cloud does not obstruct an image, but thoroughly scrambles it.