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In chemistry, brown carbon (C brown /BrC) is brown smoke released by the combustion of organic matter. It coexists with black carbon when released in the atmosphere. [1] Black carbon is primarily released by high-temperature combustion and brown carbon is emitted mainly by biomass combustion. These two are the two most important light absorbing ...
A 2013 study by the Massachusetts Institute of Technology (MIT) indicates that 53,000 early deaths occur per year in the United States alone because of vehicle emissions. [41] According to another study from the same university, traffic fumes alone cause the death of 5,000 people every year just in the United Kingdom. [42]
Smoke emissions may contain characteristic trace elements. Vanadium is present in emissions from oil fired power plants and refineries; oil plants also emit some nickel. Coal combustion produces emissions containing aluminium, arsenic, chromium, cobalt, copper, iron, mercury, selenium, and uranium.
Photochemical 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. These pollutants react in the atmosphere with sunlight to form secondary pollutants that also combine with the primary emissions to form photochemical smog.
Many gases have toxic properties, which are often assessed using the LC 50 (median lethal concentration) measure. In the United States, many of these gases have been assigned an NFPA 704 health rating of 4 (may be fatal) or 3 (may cause serious or permanent injury), and/or exposure limits (TLV, TWA/PEL, STEL, or REL) determined by the ACGIH professional association.
Today, the majority of black carbon emissions are from developing countries [37] and this trend is expected to increase. [38] The largest sources of black carbon are Asia, Latin America, and Africa. [39] China and India together account for 25–35% of global black carbon emissions. [5] Black carbon emissions from China doubled from 2000 to ...
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Lignite (derived from Latin lignum meaning 'wood'), often referred to as brown coal, [1] is a soft, brown, combustible sedimentary rock formed from naturally compressed peat. It has a carbon content around 25–35% [ 1 ] [ 2 ] and is considered the lowest rank of coal due to its relatively low heat content .