我需要一篇关于空气环保的英文

我需要一篇关于空气环保的英文
我需要一篇关于空气环保的英文

我需要一篇关于空气环保的英文
Air pollution is the human introduction into the atmosphere of chemicals,particulate matter,or biological materials that cause harm or discomfort to humans or other living organisms,or damages the environment.Air pollution causes deaths and respiratory disease Air pollution is often identified with major stationary sources,but the greatest source of emissions is mobile sources,mainly automobiles.Gases such as carbon dioxide,which contribute to global warming,have recently gained recognition as pollutants by climate scientists,while they also recognize that carbon dioxide is essential for plant life through photosynthesis.
The atmosphere is a complex,dynamic natural gaseous system that is essential to support life on planet Earth.Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the Earth's ecosystems.
An air pollutant is known as a substance in the air that can cause harm to humans and the environment.Pollutants can be in the form of solid particles,liquid droplets,or gases.In addition,they may be natural or man-made.
Pollutants can be classified as either primary or secondary.Usually,primary pollutants are substances directly emitted from a process,such as ash from a volcanic eruption,the carbon monoxide gas from a motor vehicle exhaust or sulfur dioxide released from factories.
Secondary pollutants are not emitted directly.Rather,they form in the air when primary pollutants react or interact.An important example of a secondary pollutant is ground level ozone - one of the many secondary pollutants that make up photochemical smog.
Note that some pollutants may be both primary and secondary:that is,they are both emitted directly and formed from other primary pollutants.
Major primary pollutants produced by human activity include:
Sulfur oxides (SOx) especially sulfur dioxide are emitted from burning of coal and oil.
Nitrogen oxides (NOx) especially nitrogen dioxide are emitted from high temperature combustion.Can be seen as the brown haze dome above or plume downwind of cities.
Carbon monoxide is colourless,odourless,non-irritating but very poisonous gas.It is a product by incomplete combustion of fuel such as natural gas,coal or wood.Vehicular exhaust is a major source of carbon monoxide.
Carbon dioxide (CO2),a greenhouse gas emitted from combustion.
Volatile organic compounds (VOC),such as hydrocarbon fuel vapors and solvents.
Particulate matter (PM),measured as smoke and dust.PM10 is the fraction of suspended particles 10 micrometers in diameter and smaller that will enter the nasal cavity.PM2.5 has a maximum particle size of 2.5 µm and will enter the bronchies and lungs.
Toxic metals,such as lead,cadmium and copper.
Chlorofluorocarbons (CFCs),harmful to the ozone layer emitted from products currently banned from use.
Ammonia (NH3) emitted from agricultural processes.
Odors,such as from garbage,sewage,and industrial processes
Radioactive pollutants produced by nuclear explosions,war explosives,and natural processes such as the radioactive decay of radon.
Secondary pollutants include:
Particulate matter formed from gaseous primary pollutants and compounds in photochemical smog,such as nitrogen dioxide.
Ground level ozone (O3) formed from NOx and VOCs.
Peroxyacetyl nitrate (PAN) similarly formed from NOx and VOCs.
Minor air pollutants include:
A large number of minor hazardous air pollutants.Some of these are regulated in USA under the Clean Air Act and in Europe under the Air Framework Directive.
A variety of persistent organic pollutants,which can attach to particulate matter.
The World Health Organization states that 2.4 million people die each year from causes directly attributable to air pollution,with 1.5 million of these deaths attributable to indoor air pollution.
"Epidemiological studies suggest that more than 500,000 Americans die each year from cardiopulmonary disease linked to breathing fine particle air pollution..." A study by the University of Birmingham has shown a strong correlation between pneumonia related deaths and air pollution from motor vehicles.Worldwide more deaths per year are linked to air pollution than to automobile accidents.Published in 2005 suggests that 310,000 Europeans die from air pollution annually.Direct causes of air pollution related deaths include aggravated asthma,bronchitis,emphysema,lung and heart diseases,and respiratory allergies.The US EPA estimates that a proposed set of changes in diesel engine technology (Tier 2) could result in 12,000 fewer premature mortalities,15,000 fewer heart attacks,6,000 fewer emergency room visits by children with asthma,and 8,900 fewer respiratory-related hospital admissions each year in the United States.
The worst short term civilian pollution crisis in India was the 1984 Bhopal Disaster.Leaked industrial vapors from the Union Carbide factory,belonging to Union Carbide,Inc.,U.S.A.,killed more than 2,000 people outright and injured anywhere from 150,000 to 600,000 others,some 6,000 of whom would later die from their injuries.
The United Kingdom suffered its worst air pollution event when the December 4 Great Smog of 1952 formed over London.In six days more than 4,000 died,and 8,000 more died within the following months.An accidental leak of anthrax spores from a biological warfare laboratory in the former USSR in 1979 near Sverdlovsk is believed to have been the cause of hundreds of civilian deaths.The worst single incident of air pollution to occur in the United States of America occurred in Donora,Pennsylvania in late October,1948,when 20 people died and over 7,000 were injured.
The health effects caused by air pollutants may range from subtle biochemical and physiological changes to difficulty in breathing,wheezing,coughing and aggravation of existing respiratory and cardiac conditions.These effects can result in increased medication use,increased doctor or emergency room visits,more hospital admissions and premature death.The human health effects of poor air quality are far reaching,but principally affect the body's respiratory system and the cardiovascular system.Individual reactions to air pollutants depend on the type of pollutant a person is exposed to,the degree of exposure,the individual's health status and genetics.

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