(环境管理)演讲材料维基百科空气污染

空气污染（或大气污染）指一些危害人体健康及周边环境的物质对大气层所造成的污染。

这些物质可能是气体、固体或液体悬浮物等。

我们日常呼吸的空气，是由多种化学物质
所组成，最普遍的元素是氮，其次是氧。

每种气体的成份并不是固定的，会有轻微的转变。

如果空气中的污染物数量少的话，对人体和环境的影响会比较轻微，但当这些污染物增加至危险的水平，我们就要想办法把他们从空气里消除。

空气污染主要可以分为化学污染和生物污染两部份。

也有人把噪音、热量、辐射和光的污染归入空气污染的类别里。

主要成因[编辑]
一般的空气污染成因可以大致分为自然和人为两种原因：•天然的空气污染：
•火山活动
•来自沙漠区或缺乏植被地区所刮起的风沙
•来自动物排出的有毒气体，如牛只在消化完植物后所排放的甲烷。

•山火所释出的烟
•人为的空气污染通常由于燃烧燃料引致，而这可能由下列各种活动引起：
•很多资源被消耗
•过度畜牧时所引起的沙尘或在耕种时所产生的化学残余物
•燃烧稻草,不断砍伐树林
•一般工业活动
•使用内燃机的车辆及飞机
•燃烧化石燃料引起的污染
•油漆或其他挥发性溶剂
•气溶胶
•二手烟
•烧金纸
空气污染不限于室外，室内的空气也会受污染，但污染的机制有所不同，例如吸烟造成的整体空气污染很低、但是最常见伤害性最大的室内空气污染来源。

详见室内空气污染。

污染物[编辑]
空气的污染物可分为污染气体和悬浮物。

常见的污染气体包括：
•可以和水混合而成酸雨的酸性气体，如二氧化硫(SO2）、氮氧化物(NO x)；
•氯氟烃(英语：Chlorofluorocarbons，簡稱:CFC(s))，会破坏臭氧层，现已被禁用。

•对人体有毒气体，如一氧化碳(CO)、碳氢化合物等。

•对流层臭氧。

（注：在对流层以上的臭氧，如果在平流层的话，不会扩散；在电离层的话，可以阻挡紫外光及其他来自太阳的强烈辐射，反而对环境有好处。

）
•光化学烟雾。

大气中的氮氧化物与碳氢化合物经过紫外线照射发生反应就形成了有害的光化学烟雾。

•可构成悬浮微粒的化学物质，例如钡、铜、铍、汞、铬、砷和氟化物皆为可构成悬浮微粒的化学物质。

悬浮物通常以颗粒的大小来区分，而当中的可吸入悬浮粒子则可影响人体健康。

悬浮的颗粒物，在环境科学中，特指悬浮在空气中的固体颗粒或液滴，是空气污染的主要来源之一。

其中，空气动力学直径（以
下简称直径）小于或等于10微米的颗粒物称为可吸入颗粒物（PM10）；直径小于或等于2.5微米的颗粒物称为细颗粒物（PM2.5）。

颗粒物能够在大气中停留很长时间，并可随呼吸进入体内，积聚在气管或肺中，影响身体健康。

这些可吸入悬浮颗粒还可以再细分为PM10和PM2.5两类：•PM10（即直径小于10微米）的颗粒，这种颗粒不能被身体的防御机制阻挡，可以直达肺部，所以十分危险；
•PM2.5的颗粒比PM10的更危险，因为它的颗粒小于2.5微米，可以穿透肺泡到达血液。

直径约为0.1mm的粉尘颗粒有超过50%会沉积在肺部，含硅的粉尘更会对人体造成永久伤害，例如引致矽肺病。

香烟尘是常见的悬浮颗粒，因粒径小（在0.001至0.1mm之间）、扩散力强，在静止空气中几乎可以不沉落，不仅即时可见污染恶果，长期吸入更可以导致肺癌。

其他常见的悬浮颗粒：
•硅(Silicon)、铝(Aluminum)、钙(calcium)、锰(manganese)、铁(iron)（来源：泥土、地壳和建筑活动）
•钒(Vanadium)、镍(Nickel) （来源：以油作为燃料的燃烧工序）•镉(Cadmium) 、碳氢化合物(Hydrocarbons) （来源：焚化）
•碳、铅(Lead)、溴(Bromine)、碳氢化合物（来源：汽车废气）•钠(Sodium)、氯(Chloride)、镁、钾(Potassium)（来源：海洋）•硝酸盐(Nitrate)、硫酸盐(Sulphate)、铵(Ammonium) （来源：次
生污染形成物）
影响[编辑]
空气污染可严重影响人体健康、生态系统和社会。

•人体健康：
•二氧化硫、二氧化氮等气体和悬浮粒子可刺激呼吸系统、眼睛，造成不适；高浓度时可引发心脏病及呼吸系统疾病。

•一氧化碳与身体血红蛋白结合，形成不易分解的碳氧血红蛋白，影响血液运送氧气的能力。

•铅影响人的神经系统，令儿童智力发展迟缓。

•二氧化氮在阳光下与空气中的碳氢化合生化学作用，形成对流层臭氧和硝酸过氧化乙醘（光化学烟雾的主要成份）。

•碳氢化合物，尤其是多环性芳香化合物可致癌。

•氟氯碳化物会破坏臭氧层，导致更多紫外线抵达地面，增加患癌的机会。

•空气中的烟尘使气喘患者发作的频率升高。

•使腹中胎儿出生后畸型的机率上升。

•可能影响生殖系统，从而导致人类生育能力下降[1]。

•世界卫生组织估计，每年空气污染造成大约200万人早死，其中一多半早死的人在发展中国家[2]。

•容易致癌。

•生态系统：
•烟尘等粒子覆盖植物的叶片，阻碍植物吸收阳光，因此降
低光合作用的效率。

•二氧化硫、二氧化氮溶于空气中的水份，形成酸雨、酸雾、酸雪，或直接溶于水体（湖泊、溪涧），降低水土酸碱度，
使植物和水中生物死亡。

•二氧化硫能直接杀死地衣。

•全球增温
•臭氧耗损
•破坏生态系统
•社会：
•酸雨侵蚀金属及大理石建筑、雕像，毁坏户外文物、艺术品。

•酸雨降低土壤酸碱度，降低农产品收成。

•光化学烟雾降低能见度，影响旅游业及对空中交通造成危险。

•因空气污染而致病的人口造成医疗负担。

•令能见度下降，游客减少，经济倒退.
污染物的测量[编辑]
一般用μg/m3（微克／每立方米）作为单位；也有用PPM（parts per million，百万分率）作为单位。

测量的标地为一般常见单一污染物，例如可吸入悬浮粒子、一氧化碳或二氧化碳。

在不同天气、风向、风速、气温、相对湿度下测量得的各项数值有差异。

在周末／工作天、繁忙／非繁忙时段、空气污染高峰时间／平时，
所测量得的数值皆有差异。

空气污染指数（API，Air Pollution Index）是一个表达空气污染程度的数值，而每个国家的标准不同。

其优点是简单易记；但缺点则是含糊抽象、太笼统。

香港的空气污染指数20年来都没有检讨过，远远落后世界卫生组织的安全标准。

故此，绿色和平制订了空气污染真相指数，如实反映香港空气污染的情况，保障市民的健康。

中国大陆政府正逐步开始发布空气污染指数。

[3]美国驻中国大使馆和领事馆使用美国联邦参考监测(FRM2.5)仪器对北京和广州的空气质量(PM2.5和臭氧含量)进行24小时监测并每小时在twitter发布空气污染指数.
如何减低空气污染[编辑]
•拒绝购买较高污染的车辆，如没有催化转化器（catalytic converter）的汽车（转化器可以把一氧化碳、碳氢化合物及二氧化氮转化为水、二氧化碳和氮气）、柴油车要有微粒过滤器等最新型环保设计才能购买、二冲程引擎机车需要采取缸内直喷污染才会低。

•使用无铅汽油和超低含硫量柴油，避免铅化合物和二氧化硫的产生；所有标示使用含铅汽油的旧型车辆，都可以使用无铅汽油，其中也只有少数车辆需要偶尔添加代铅剂或偶尔使用含铅汽油。

•加速淘汰高污染车辆。

•选购低排气污染的车辆，例如混合动力车、电动机车。

•长时间等候时关掉引擎，减少汽车废气。

•少开车、尽量使用公共交通工具、步行或自行车。

•减少乘搭飞机。

•使用环保电池。

•烧金纸时使用环保金纸与环保金炉，在都会区最好是集中在焚化炉燃烧。

•不使用线香、旧型蚊香，因为不完全燃烧的线香绝对会造成严重的空气污染；线香可以用隔水加热高品质精油取代（劣质精油仍会造成伤害），蚊香可以采用电蚊香取代。

•避免使用含氟氯碳化物（CFCs）的产品如冷冻剂和气溶胶的喷雾剂、喷发剂等。

•避免在日间天气较热的时段加油，以减少汽油在油缸受热而泄出的汽油汽体。

•戒烟，如无法戒烟则改用无烟烟品（没有二手烟害的烟品），如无烟烟品无法满足则慎选抽烟地点（一定要在室外空旷且没有禁烟之处），避免二手烟害影响别人。

•购买少包装的产品，因印刷包装物料时，会释出挥发性有机化合物。

"Bad air quality" redirects here. For the obsolete medical theory, see Bad
air.
"Air quality" redirects here. For the measure of how polluted the air is, see Air quality index.
Not to be confused with Qualities of air.
Air pollution from a World War II wartime production plant
Air pollution is the introduction into the atmosphere of chemicals, particulates, or biological materials that cause discomfort, disease, or death to humans, damage other living organisms such as food crops, or damage the natural environment or built environment.
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.
Indoor air pollution (see Airlog) and urban air quality are listed as two of the World’s Worst Toxic Pollution Problems in the 2008 Blacksmith Institute World's Worst Polluted Places report.[1]
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Contents [hide]
1 Pollutants
1.1 Sources
1.2 Emission factors
2 Indoor air quality (IAQ)
3 Health effects
3.1 Effects on cardiovascular health
3.2 Effects on cystic fibrosis
3.3 Effects on COPD and asthma
3.4 Links to cancer
3.5 Effects on children
3.6 Health effects in relatively "clean" areas
4 Reduction efforts
4.1 Control devices
5 Legal regulations
5.1 Canada
5.2 Germany
6 Cities
7 NATA
8 Governing urban air pollution – a regional example (London)
9 Atmospheric dispersion
10 See also
11 References
12 External links
Pollutants[edit]
Main articles: Pollutant and Greenhouse gas
Before flue-gas desulfurization was installed, the emissions from this
power plant in New Mexico contained excessive amounts of sulfur dioxide.
Schematic drawing, causes and effects of air pollution: (1) greenhouse effect, (2) particulate contamination, (3) increased UV radiation, (4) acid rain, (5) increased ground level ozone concentration, (6) increased levels of nitrogen oxides.
A substance in the air that can be adverse to humans and the environment is known as an air pollutant. 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 primary or secondary. Usually, primary pollutants are directly produced from a process, such as ash from a volcanic eruption, the carbon monoxide gas from a motor vehicle exhaust or sulphur 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. 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:
Sulphur oxides (SOx) - especially sulphur dioxide, a chemical compound
with the formula SO2. SO2 is produced by volcanoes and in various industrial processes. Since coal and petroleum often contain sulphur compounds, their combustion generates sulfur dioxide. Further oxidation of SO2, usually in the presence of a catalyst such as NO2, forms H2SO4, and thus acid rain.[2] This is one of the causes for concern over the environmental impact of the use of these fuels as power sources. Nitrogen oxides (NOx) - especially nitrogen dioxide are expelled from high temperature combustion, and are also produced naturally during thunderstorms by electric discharge. Can be seen as the brown haze dome above or plume downwind of cities. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of the several nitrogen oxides. This reddish-brown toxic gas has a characteristic sharp, biting odor. NO2 is one of the most prominent air pollutants.
Carbon monoxide (CO)- is a colourless, odorless, 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.
Volatile organic compounds - VOCs are an important outdoor air pollutant. In this field they are often divided into the separate categories of methane (CH4) and non-methane (NMVOCs). Methane is an extremely efficient greenhouse gas which contributes to enhanced global warming. Other hydrocarbon VOCs are also significant greenhouse gases via their role in
creating ozone and in prolonging the life of methane in the atmosphere, although the effect varies depending on local air quality. Within the NMVOCs, the aromatic compounds benzene, toluene and xylene are suspected carcinogens and may lead to leukemia through prolonged exposure. 1,3-butadiene is another dangerous compound which is often associated with industrial uses.
Particulates, alternatively referred to as particulate matter (PM), atmospheric particulate matter, or fine particles, are tiny particles of solid or liquid suspended in a gas. In contrast, aerosol refers to particles and the gas together. Sources of particulates can be man made or natural. Some particulates occur naturally, originating from volcanoes, dust storms, forest and grassland fires, living vegetation, and sea spray. Human activities, such as the burning of fossil fuels in vehicles, power plants and various industrial processes also generate significant amounts of aerosols. Averaged over the globe, anthropogenic aerosols—those made by human activities—currently account for about 10 percent of the total amount of aerosols in our atmosphere. Increased levels of fine particles in the air are linked to health hazards such as heart disease,[2] altered lung function and lung cancer.
Persistent free radicals connected to airborne fine particles could cause cardiopulmonary disease.[3][4]
Toxic metals, such as lead and mercury, especially their compounds.
Chlorofluorocarbons (CFCs) - harmful to the ozone layer emitted from products currently banned from use.
Ammonia (NH3) - emitted from agricultural processes. Ammonia is a compound with the formula NH3. It is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceuticals. Although in wide use, ammonia is both caustic and hazardous.
Odors — such as from garbage, sewage, and industrial processes Radioactive pollutants - produced by nuclear explosions, nuclear events, war explosives, and natural processes such as the radioactive decay of radon.
Pollution in the sky of Athens, Greece.
Secondary pollutants include:
Particulates created from gaseous primary pollutants and compounds in photochemical smog. Smog is a kind of air pollution; the word "smog" is a portmanteau of smoke and fog. Classic smog results from large amounts of coal burning in an area caused by a mixture of smoke and sulfur dioxide. Modern smog does not usually come from coal but from vehicular and
industrial emissions that are acted on in the atmosphere by ultraviolet light from the sun to form secondary pollutants that also combine with the primary emissions to form photochemical smog.
Ground level ozone (O3) formed from NOx and VOCs. Ozone (O3) is a key constituent of the troposphere. It is also an important constituent of certain regions of the stratosphere commonly known as the Ozone layer. Photochemical and chemical reactions involving it drive many of the chemical processes that occur in the atmosphere by day and by night. At abnormally high concentrations brought about by human activities (largely the combustion of fossil fuel), it is a pollutant, and a constituent of smog.
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 particulates. Persistent organic pollutants (POPs) are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes. Because of this, they have been observed to persist in the environment, to be capable of long-range transport, bioaccumulate in human and animal tissue, biomagnify in food chains, and to have
potential significant impacts on human health and the environment. Sources[edit]
Dust storm approaching Stratford, Texas
Controlled burning of a field outside of Statesboro, Georgia in preparation for spring planting
Sources of air pollution refer to the various locations, activities or factors which are responsible for the releasing of pollutants into the atmosphere. These sources can be classified into two major categories which are: Anthropogenic sources (man-made sources) mostly related to burning different kinds of fuel
"Stationary Sources" include smoke stacks of power plants, manufacturing facilities (factories) and waste incinerators, as well as furnaces and other types of fuel-burning heating devices. In developing and poor countries, traditional biomass burning is the major source of air pollutants; traditional biomass includes wood, crop waste and dung.[5][6] "Mobile Sources" include motor vehicles, marine vessels, aircraft and the effect of sound etc.
Chemicals, dust and controlled burn practices in agriculture and forestry
management. Controlled or prescribed burning is a technique sometimes used in forest management, farming, prairie restoration or greenhouse gas abatement. Fire is a natural part of both forest and grassland ecology and controlled fire can be a tool for foresters. Controlled burning stimulates the germination of some desirable forest trees, thus renewing the forest.
Fumes from paint, hair spray, varnish, aerosol sprays and other solvents Waste deposition in landfills, which generate methane. Methane is highly flammable and may form explosive mixtures with air. Methane is also an asphyxiant and may displace oxygen in an enclosed space. Asphyxia or suffocation may result if the oxygen concentration is reduced to below 19.5% by displacement.
Military, such as nuclear weapons, toxic gases, germ warfare and rocketry Natural sources
Dust from natural sources, usually large areas of land with little or no vegetation
Methane, emitted by the digestion of food by animals, for example cattle Radon gas from radioactive decay within the Earth's crust. Radon is a colorless, odorless, naturally occurring, radioactive noble gas that is formed from the decay of radium. It is considered to be a health hazard. Radon gas from natural sources can accumulate in buildings, especially in confined areas such as the basement and it is the second most frequent
cause of lung cancer, after cigarette smoking.
Smoke and carbon monoxide from wildfires
Vegetation, in some regions, emits environmentally significant amounts of VOCs on warmer days. These VOCs react with primary anthropogenic pollutants—specifically, NOx, SO2, and anthropogenic organic carbon compounds—to produce a seasonal haze of secondary pollutants.[7] Volcanic activity, which produce sulfur, chlorine, and ash particulates Emission factors[edit]
Main article: AP 42 Compilation of Air Pollutant Emission Factors
Industrial air pollution emissions
Air pollutant emission factors are representative values that people attempt to relate the quantity of a pollutant released to the ambient air with an activity associated with the release of that pollutant. These factors are usually expressed as the weight of pollutant divided by a unit weight, volume, distance, or duration of the activity emitting the pollutant (e.g., kilograms of particulate emitted per tonne of coal burned). Such factors facilitate estimation of emissions from various sources of air pollution. In most cases, these factors are simply averages of all available data of acceptable quality, and are generally assumed to be representative of long-term averages.
There are 12 compounds in the list of POPs. Dioxins and furans are two of them and are intentionally created by combustion of organics, like open burning of plastics. The POPs are also endocrine disruptor and can mutate the human genes.
The United States Environmental Protection Agency has published a compilation of air pollutant emission factors for a multitude of industrial sources.[8] The United Kingdom, Australia, Canada and many other countries have published similar compilations, as well as the European Environment Agency.[9][10][11][12]
Indoor air quality (IAQ)[edit]
Main article: Indoor air quality
Air quality monitoring, New Delhi, India.
A lack of ventilation indoors concentrates air pollution where people often spend the majority of their time. Radon (Rn) gas, a carcinogen, is exuded from the Earth in certain locations and trapped inside houses. Building materials including carpeting and plywood emit formaldehyde (H2CO) gas. Paint and solvents give off volatile organic compounds (VOCs) as they dry. Lead paint can degenerate into dust and be inhaled. Intentional air pollution is introduced with the use of air fresheners, incense, and other
scented items. Controlled wood fires in stoves and fireplaces can add significant amounts of smoke particulates into the air, inside and out.[13] Indoor pollution fatalities may be caused by using pesticides and other chemical sprays indoors without proper ventilation.
Carbon monoxide (CO) poisoning and fatalities are often caused by faulty vents and chimneys, or by the burning of charcoal indoors. Chronic carbon monoxide poisoning can result even from poorly adjusted pilot lights. Traps are built into all domestic plumbing to keep sewer gas and hydrogen sulfide, out of interiors. Clothing emits tetrachloroethylene, or other dry cleaning fluids, for days after dry cleaning.
Though its use has now been banned in many countries, the extensive use of asbestos in industrial and domestic environments in the past has left a potentially very dangerous material in many localities. Asbestosis is a chronic inflammatory medical condition affecting the tissue of the lungs. It occurs after long-term, heavy exposure to asbestos from asbestos-containing materials in structures. Sufferers have severe dyspnea (shortness of breath) and are at an increased risk regarding several different types of lung cancer. As clear explanations are not always stressed in non-technical literature, care should be taken to distinguish between several forms of relevant diseases. According to the World Health Organisation (WHO), these may defined as; asbestosis, lung cancer, and Peritoneal Mesothelioma (generally a very rare form of cancer, when
more widespread it is almost always associated with prolonged exposure to asbestos).
Biological sources of air pollution are also found indoors, as gases and airborne particulates. Pets produce dander, people produce dust from minute skin flakes and decomposed hair, dust mites in bedding, carpeting and furniture produce enzymes and micrometre-sized fecal droppings, inhabitants emit methane, mold forms in walls and generates mycotoxins and spores, air conditioning systems can incubate Legionnaires' disease and mold, and houseplants, soil and surrounding gardens can produce pollen, dust, and mold. Indoors, the lack of air circulation allows these airborne pollutants to accumulate more than they would otherwise occur in nature.
Health effects[edit]
See also: Neuroplastic effects of pollution
Air pollution is a significant risk factor for multiple health conditions including respiratory infections, heart disease, and lung cancer, according to the WHO. The health effects caused by air pollution may include difficulty in breathing, wheezing, coughing, asthma 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.[citation needed]
The most common sources of air pollution include particulates, ozone, nitrogen dioxide, and sulfur dioxide. Both indoor and outdoor air pollution have caused approximately 3.3 million deaths worldwide. Children aged less than five years that live in developing countries are the most vulnerable population in terms of total deaths attributable to indoor and outdoor air pollution.[14]
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.[15] "Epidemiological studies suggest that more than 500,000 Americans die each year from cardiopulmonary disease linked to breathing fine particle air pollution. . ."[16] A study by the University of Birmingham has shown a strong correlation between pneumonia related deaths and air pollution from motor vehicles.[17] Worldwide more deaths per year are linked to air pollution than to automobile accidents.[18] A 2005 study by the European Commission calculated that air pollution reduces life expectancy by an average of almost nine months across the European
Union.[19] Causes of deaths include aggravated asthma, emphysema, lung and heart diseases, and respiratory allergies.[20] 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.[citation needed]
The US EPA estimates allowing a ground-level ozone concentration of 65 parts per billion, would avert 1,700 to 5,100 premature deaths nationwide in 2020 compared with the current 75-ppb standard. The agency projects the stricter standard would also prevent an additional 26,000 cases of aggravated asthma, and more than a million cases of missed work or school.[21][22]
The worst short term civilian pollution crisis in India was the 1984 Bhopal Disaster.[23] Leaked industrial vapours from the Union Carbide factory, belonging to Union Carbide, Inc., U.S.A., killed more than 25,000 people outright and injured anywhere from 150,000 to 600,000. 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.[citation needed] 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.[citation needed] The worst single incident of air pollution to occur in the US occurred in Donora, Pennsylvania in late October, 1948, when 20 people died and over 7,000 were injured.[24]
A new economic study of the health impacts and associated costs of air pollution in the Los Angeles Basin and San Joaquin Valley of Southern California shows that more than 3800 people die prematurely (approximately 14 years earlier than normal) each year because air pollution levels violate federal standards. The number of annual premature deaths is considerably higher than the fatalities related to auto collisions in the same area, which average fewer than 2,000 per year.[25][26][27]
Diesel exhaust (DE) is a major contributor to combustion derived particulate matter air pollution. In several human experimental studies, using a well validated exposure chamber setup, DE has been linked to acute vascular dysfunction and increased thrombus formation.[28][29] This serves as a plausible mechanistic link between the previously described association between particulates air pollution and increased cardiovascular morbidity and mortality.
Effects on cardiovascular health[edit]
A 2007 review of evidence found ambient air pollution exposure is a risk factor correlating with increased total mortality from cardiovascular
events (range: 12% to 14% per a 10 microg/m3 increase). PMID 19235364. Air pollution is also emerging as a risk factor for stroke, particularly in developing countries where pollutant levels are highest.[30] A 2007 study found that in women air pollution is associated not with hemorrhagic but with ischemic stroke.[31] Air pollution was also found to be associated with increased incidence and mortality from coronary stroke in a cohort study in 2011.[32] Associations are believed to be causal and effects may be mediated by vasoconstriction, low-grade inflammation or autonomic nervous system imbalance or other mechanisms. [33] [34]
Effects on cystic fibrosis[edit]
Main article: Cystic fibrosis
A study from around the years of 1999 to 2000, by the University of Washington, showed that patients near and around particulates air pollution had an increased risk of pulmonary exacerbations and decrease in lung function.[35] Patients were examined before the study for amounts of specific pollutants like Pseudomonas aeruginosa or Burkholderia cenocepacia as well as their socioeconomic standing. Participants involved in the study were located in the United States in close proximity to an Environmental Protection Agency.[clarification needed] During the time of the study 117 deaths were associated with air pollution. Many patients in the study lived in or near large metropolitan areas in order to be close to medical help. These same patients had higher
level of pollutants found in their system because of more emissions in larger cities. As cystic fibrosis patients already suffer from decreased lung function, everyday pollutants such as smoke, emissions from automobiles, tobacco smoke and improper use of indoor heating devices could further compromise lung function.[36]
Effects on COPD and asthma[edit]
Main article: Chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease (COPD) includes diseases such as chronic bronchitis and emphysema.[37]
Researches have demonstrated increased risk of developing asthma [38] and COPD[39] from increased exposure to traffic-related air pollution. Additionally, air pollution has been associated with increased hosptializations and mortality from asthma and COPD.[40][41]
A study conducted in 1960-1961 in the wake of the Great Smog of 1952 compared 293 London residents with 477 residents of Gloucester, Peterborough, and Norwich, three towns with low reported death rates from chronic bronchitis. All subjects were male postal truck drivers aged 40 to 59. Compared to the subjects from the outlying towns, the London subjects exhibited more severe respiratory symptoms (including cough, phlegm, and dyspnea), reduced lung function (FEV1 and peak flow rate), and increased sputum production and purulence. The differences were more pronounced for subjects aged 50 to 59. The study controlled for age
and smoking habits, so concluded that air pollution was the most likely cause of the observed differences.[42]
It is believed that much like cystic fibrosis, by living in a more urban environment serious health hazards become more apparent. Studies have shown that in urban areas patients suffer mucus hypersecretion, lower levels of lung function, and more self diagnosis of chronic bronchitis and emphysema.[43]
Links to cancer[edit]
A review of evidence regarding whether ambient air pollution exposure is a risk factor for cancer in 2007 found solid data to conclude that long-term exposure to PM2.5 (fine particulates) increases the overall risk of nonaccidental mortality by 6% per a 10 microg/m3 increase.PMID 19235364
Exposure to PM2.5 was also associated with an increased risk of mortality from lung cancer (range: 15% to 21% per a 10 microg/m3 increase) and total cardiovascular mortality (range: 12% to 14% per a 10 microg/m3 increase). PMID 19235364
The review further noted that living close to busy traffic appears to be associated with elevated risks of these three outcomes (increase in lung cancer deaths, cardiovascular deaths, and overall nonaccidental deaths. PMID 19235364
The reviewers also found suggestive evidence that exposure to PM2.5 is。