Course: 18.46 空气污染 -- -- 高级

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空气污染 -- -- 高级

Why is the atmosphere important?
::为什么大气层很重要?

Well, it contains all of the air that we breathe. The atmosphere also has other roles and functions, so when we interfere with the atmosphere, we interfere with some important biological processes. And this can have consequences.
::它包含着我们呼吸的所有空气。大气层也有其他的角色和功能, 因此当我们干扰大气层时, 我们干扰一些重要的生物过程。这可能产生后果。

Air Pollution
::空气污染

The Atmosphere
::大气层

Air: so easy to take for granted. In its pristine state, we cannot see it, smell it, taste it, feel it, or hear it, except when the wind blows or clouds form. Yet its complex and dynamic mix of gases is essential for life. Nitrogen (78%) provides atoms which build and via the . Oxygen (21%) permits the production of the ATP through , to power life. Carbon dioxide (.04%) provides the carbon for fuels and carbon skeletons to build life’s bodies. (1-4% near the Earth’s surface) has so many unique properties ( adhesion , surface tension, cohesion , capillary action, high heat capacity, high heat of vaporization…and more) that it is difficult for us to imagine any form of life on any planet which does not depend on it. As a major component of the hydrologic cycle, the atmosphere cleans and replenishes Earth’s fresh water supply, and refills the lakes, rivers, and oceans habitats for life ( Figure ). The Earth’s atmosphere thins but reaches away from its surface for 100 kilometers toward space; between about 15 and 35 km lies the Ozone Layer – just a few parts per million which shields life from the sun’s damaging Ultra-Violet radiation. Earth’s atmosphere appears ideal for life, and indeed, as far as we know it is the only planetary atmosphere which supports life.
::空气:如此容易地被视为理所当然。在其原始状态下,我们看不到它,闻闻它,闻它,闻它,感觉它,或听到它,除非风吹或云体形成。然而,其复杂和动态的气体组合对于生命至关重要。氮(78 % ) 提供了构建和通过它创造的原子。氧(21 % ) 允许通过水循环生产ATP,生产动力生命。二氧化碳(0.04 % ) 提供了燃料和碳骨骼的碳,以建立生命体。 (靠近地球表面的1-4 % ) 具有许多独特的特性。 (靠近地球表面的1-4 % ) 。地球的大气层薄度、地表紧张度、凝聚度、毛细动作、高热能力、高蒸发热度等,对于我们很难想象任何不依赖它的星球上的任何生命形式。作为水文循环的一个主要组成部分,大气清洁和补充地球的淡水供应,以及生命的再填充充湖泊、河流和海洋生境(图示 ) 。地球的大气层从地球的表面到远方位值只有35公里处的地表层。

As we noted in the concepts, the Earth’s atmosphere has not always been this hospitable for life. Life itself is probably responsible for many dramatic changes, including the addition of oxygen by , and the subsequent production of ozone from accumulated oxygen. Changes in CO ₂ levels, climate , and sea level have significantly altered conditions for life, even since the addition of oxygen some 2 billion years ago. On a daily time scale, dramatic changes take place:
::正如我们在概念中所指出的,地球的大气层并不总是对生命如此友好。生命本身可能引发许多巨大的变化,包括由...增加氧气,以及随后从累积氧气中产生臭氧。二氧化碳水平、气候和海平面的变化已经大大改变了生命条件,即使自大约20亿年前增加氧气以来也是如此。每天发生的巨大变化包括:

most organisms remove O ₂ and add CO ₂ through cellular respiration
::大部分有机体除去O2,通过细胞呼吸添加CO2

most autotrophs remove CO ₂ and add O ₂ through photosynthesis
::多数自养成去除CO2, 通过光合作用添加O2

plants transpire vast quantities of water into the air
::植物在空气中产生大量的水

precipitation returns it, through gentle rains or violent storms, to the Earth’s surface
::降水通过温和的降雨或暴雨,使地球恢复到地球表面。

On a human time scale, the daily dynamics balance , and the atmosphere remains at equilibrium – an equilibrium upon which most life depends.
::在人类的时间尺度上,每天的动态平衡,大气保持平衡,这是大多数生命赖以生存的平衡。

Upsetting the Equilibrium of the Atmosphere: Air Pollution
::建立大气平衡:空气污染

lesson content

Despite the atmosphere’s apparent vastness, human activities have significantly altered its equilibrium in ways which threaten its services for life. Chemical substances, particulate matter, and even biological materials cause air pollution if they modify the natural characteristics of the atmosphere. Primary pollutants are directly added to the atmosphere by processes such as fires or combustion of fossil fuels ( Figure ). Secondary pollutants, formed when primary pollutants interact with sunlight, air, or each other, can be equally damaging. The chlorine and bromine which threaten the Ozone Layer are secondary pollutants , formed when refrigerants and aerosols (primary pollutants) decompose in the stratosphere ( Figure ).
::化学物质、微粒物质,甚至生物材料,如果能改变大气的自然特性,就会造成空气污染。初级污染物通过燃烧或燃烧化石燃料等过程直接添加到大气中(图 ) 。当初级污染物与阳光、空气或相互之间发生相互作用时形成的次要污染物同样会造成损害。威胁臭氧层的氯和溴是次要污染物,当制冷剂和气溶胶(主要污染物)在平流层中分解时形成(图 ) 。

The majority of air pollutants can be traced to the burning of fossil fuels. We burn fuels in power plants to generate electricity, in factories to power machinery, in stoves and furnaces for heat, in airplanes, ships, trains, and motor vehicles for transportation, and in waste facilities to incinerate waste. Since long before fossil fuels powered the Industrial Revolution, we have burned wood for heat, fireplaces, and campfires and vegetation for and land management. The resulting primary and secondary pollutants and the problems to which they contribute are included in Table .
::大部分空气污染物可以追溯到化石燃料的燃烧,我们燃烧发电厂的燃料,以发电、工厂、发电厂、炉灶和热炉、飞机、船舶、火车和机动运输车,以及废物设施,以焚化废物。早在化石燃料为工业革命提供动力之前,我们就已经烧焦了柴火、火炉、营火和植被以及土地管理。由此产生的主要和次要污染物及其造成的问题都列在表格中。

Pollutant	Example/Major Source	Problem
Sulfur oxides (SO _x )	Coal-fired power plants
Nitrogen oxides (NO _x )	Motor vehicle exhaust	Acid Rain
Carbon monoxide (CO)	Motor vehicle exhaust	Poisoning
Carbon dioxide (CO ₂ )	All fossil fuel burning
Particulate matter (smoke, dust)	Wood and coal burning	Respiratory disease, Global Dimming
Mercury	Coal-fired power plants, medical waste	Neurotoxicity
Smog	Coal burning	Respiratory problems; eye irritation
Ground-level ozone	Motor vehicle exhaust	Respiratory problems; eye irritation

Beyond the burning of fossil fuels, other anthropogenic (human-caused) sources of air pollution are shown in Table .
::除燃烧矿物燃料外,表内还列出了其他人为(人为)空气污染源。

Activity	Pollutant	Problem
Agriculture: Cattle Ranching Fertilizers Herbicides and Pesticides Erosion	Methane (CH ₄ ) Ammonia (NH ₃ ), Volatile Organic Chemicals(VOCs) Persistent Organic Pollutants(POP): DDT, PCBs, PAHs* Dust	Global Warming Toxicity, Global Warming Global Dimming
Industry (solvents, plastics) Refrigerants, Aerosols	VOCs, POPs CFCs	Cancer, Global Warming
Nuclear power and defense	Radioactive waste	Cancer
Landfills	Methane (CH ₄ )	Global Warming
Mining	Asbestos	Respiratory problems
Biological Warfare	Microorganisms	Infectious Disease
Indoor Living	CO, VOCs, asbestos, dust, mites, molds, particulates

DDT = an organic pesticide; PCB = poly-chlorinated biphenyls, used as coolants and insulators; DDT and most PCBs are now banned at least in the U.S., but persist in the environment; PAHs = polycyclic aromatic hydrocarbons – products of burning fossil fuels, many linked to health problems
::DDDD = 有机杀虫剂;PCB = 用作冷却剂和绝热剂的多氯联联苯;DDT和大多数多氯联苯现在至少在美国受到禁止,但长期存在于环境中;PAHs = 多环芳烃,这是燃烧化石燃料的产品,许多与健康问题有关。

Many pollutants travel indoors in building materials, furniture, carpeting, paints and varnishes, contributing to indoor air pollution. In 2002, the World Health Organization estimated that 2.4 million people die each year as a consequence of air pollution – more than are killed in automobile accidents. Respiratory and cardiovascular problems are the most common health effects of air pollution, but accidents which release airborne poisons (the nuclear power plant at Chernobyl, the Union Carbide explosion in Bhopal, and the “Great Smog of 1952” over London) have killed many people – and undoubtedly other – with acute exposure to radiation or toxic chemicals.
::许多污染物在建筑材料、家具、地毯、油漆和清漆等内部活动,导致室内空气污染。 2002年,世界卫生组织估计每年有240万人死于空气污染 — — 超过死于汽车事故的人数。呼吸和心血管问题是空气污染最常见的健康影响,但释放空生毒物的事故(切尔诺贝利核电厂、博帕尔的碳化物联合爆炸以及伦敦的“1952年大烟雾 ” ) 已经导致许多人死亡 — — 无疑还有其他人 — — 严重暴露于辐射或有毒化学品。

If you study the problems caused by air pollution (third column in the tables, above), you will note that beyond human health, air pollution affects entire , worldwide. Acid Rain , Ozone Depletion , and Global Warming are widespread and well-recognized global concerns, so we will explore them in detail in independent sections. Effects of toxins, which poison wildlife and plants as well as humans, were addressed in discussions of soil and water pollution in the last chapter. Before we move on to the “Big Three,” let’s take a brief look at the problems caused by particulates and aerosols, since these are unique pollutants of air, rather than soil or water.
::如果你研究空气污染引起的问题(上表第三栏),你就会注意到,除了人类健康之外,空气污染影响整个世界。酸雨、臭氧消耗和全球暖化是普遍和公认的全球关注问题,因此我们将在独立章节中详细探讨这些问题。上一章关于土壤和水污染的讨论中讨论了毒害野生动物和植物以及人类的毒素的影响。在我们开始讨论“大三 ” 之前,让我们简要审视微粒和气溶胶造成的问题,因为这些是独特的空气污染物,而不是土壤或水污染物。

“Global dimming” refers to a reduction in the amount of radiation reaching the Earth’s surface. Scientists observed a drop of roughly 4% between 1960 and 1990, and attributed it to particulates and aerosols (in terms of air pollution, aerosols are airborne solid particles or liquid droplets). These pollutants absorb solar energy and reflect sunlight back into space. The consequences for life are many:
::“全球稀释”是指降低到达地球表面的辐射量。科学家观察到1960年至1990年间下降了大约4 % , 并归因于微粒和气溶胶(在空气污染方面,气溶胶是空气传播的固体颗粒或液体滴子 ) 。这些污染物吸收了太阳能并将阳光反射回太空。对生命的影响有很多:

Less sunlight means less photosynthesis.
::少阳光意味着少光合作用

Less photosynthesis means less food for all .
::光合作用少意味着人人享有的食物少。

Less sunlight means less energy to drive evaporation and the hydrologic cycle.
::较少阳光意味着较少能驱动蒸发和水文循环。

Less sunlight means cooler ocean temperatures, which may lead to changes in rainfall, drought and famine.
::阳光较少意味着海洋温度更低,这可能导致降雨、干旱和饥荒的变化。

Less sunlight may have cooled the planet, masking the effects of Global Warming.
::日光减少可能使地球冷却,掩盖了全球变暖的影响。

Recent measurements of sunlight-absorbing particulates show a decline since 1990, which corresponds to a return to normal levels of radiation ( Figure ). These data suggest that Clean Air legislation enacted by developed nations may have improved air quality and prevented most of the above effects, at least for now. Two caveats remain:
::最近对日光吸收颗粒的测量显示,自1990年以来下降,相当于恢复到正常辐射水平(图)。这些数据表明,发达国家颁布的清洁空气立法可能改善了空气质量,防止了上述大部分影响,至少目前是这样。

If “Global Dimming” did indeed mask Global Warming for 30 years, predictions about future climate change may be too conservative. Keep this in mind when we address Global Warming in an additional concept.
::如果“全球降温”确实掩盖了30年的全球升温,那么对未来气候变化的预测可能过于保守。当我们在另一个概念中处理全球升温问题时,记住这一点。

and industrialization of developing countries continues to increase levels of pollution .
::发展中国家工业化和发展中国家的工业化继续增加污染水平。

Massive waves of pollution from Asian industry have blown across the Pacific by prevailing winds ( Figure ). On some days, atmospheric physicists at the Scripps Institution of Oceanography have traced nearly one-third of the air over Los Angeles and San Francisco directly to Asian sources. The waves are made of dust from Asian deserts combined with pollution from increasing industrialization, making the level of particulates and aerosols in Beijing, for example, reach levels 7 times World Health Organization standards. Scientists estimate that the clouds may be blocking 10% of the sunlight over the Pacific. By seeding clouds, the aerosols and particulates may be intensifying storms. In addition to direct effects on the global atmosphere (such waves can circle the Earth in three weeks), these pollution clouds can, as we stated above, mask Global Warming.
::亚洲工业的大规模污染波浪被大风吹过太平洋(图 ) 。几天后, 海洋史学会的大气物理学家们将洛杉矶和旧金山的近三分之一的空气直接追踪到亚洲的源头。这些波浪是由亚洲沙漠的尘埃组成的,加上工业化不断增强的污染,例如北京的微粒和气溶胶达到世界卫生组织标准的七倍。科学家们估计,云层可能阻挡了太平洋的10%的阳光。通过播种云,气溶胶和微粒可能加剧风暴。除了对全球大气的直接冲击(这种波浪可以在三个星期内环绕地球 ) , 这些污染云可以遮盖全球暖气。

One additional topic relates to atmospheric change. Light pollution ( Figure ) results from humans’ production of light in amounts which are annoying, wasteful, or harmful. Light is essential for safety and culture in industrial societies , but reduction in wasteful excess could mitigate its own harmful effects, as well as the amounts of fossil fuel used to generate it. Astronomers – both amateur and professional – find light interferes with their observations of the night skies. Some studies show that artificial spectra and excessive light exposure has harmful effects on human health. Life evolved in response to natural cycles and natural spectra of light and dark, so it is not surprising that our changes in both of those might affect us and other forms of life. Light pollution can affect animal navigation and and predator/ prey interactions. Because many migrate by night, Toronto, Canada has initiated a program to turn out lights at night during spring and fall migration seasons. Light may interfere with sea turtle egg-laying and hatching, because both happen on coasts at nighttime. The behavior of nocturnal animals from owls to moths can be changed by light, and night-blooming flowers can be affected directly or through disruption of pollination . Zooplankton normally show daily vertical migration, and some data suggests that changes in this behavior can lead to algal blooms .
::另一个主题是大气变化。光污染(Figure ) 是由人类生产令人烦恼、浪费或有害的光量产生的光源。光是工业社会的安全和文化的关键,但减少浪费过剩可以减轻其自身的有害影响,以及用于生成它的化石燃料的数量。无论是业余还是专业的天文学家都发现光会干扰其对夜间天空的观察。一些研究表明,人工光谱和过度光照射会给人类健康带来有害影响。自然循环和光和黑暗的自然光谱使生活演变,因此,我们这两种变化的变化都会影响我们和其他生命形式,这并不奇怪。光污染会影响动物航行和食肉动物/食肉动物的相互作用。由于许多人在夜间迁移,多伦多,加拿大启动了一个计划,在春季和秋天的迁徙季节关灯。光可能会干扰海龟蛋的繁殖和孵化,因为两者都在夜间发生。夜幕动物从猫头到黄蜂的不夜行行为可以因光和夜深层运动而改变。高温的传动行为通常会影响着花的流传。

Solutions to problems caused by light pollution include
::解决光污染引起的问题的办法包括:

reducing use
::减少使用

changing fixtures to direct light more efficiently and less harmfully
::将固定装置改变为更高效、更无害的直光

changing the spectra of light released
::改变释放的光谱

changing patterns of lighting to increase efficiency and reduce harmful effects
::改变照明模式以提高效率和减少有害影响

Many cities, especially those near observatories, are switching to low-pressure sodium lamps, because their light is relatively easy to filter.
::许多城市,特别是靠近天文台的城市,正在改用低压钠灯,因为灯光相对容易过滤。

Preventing Air Pollution
::防止空气污染

Throughout this concept, we have discussed solutions to specific problems for our atmosphere. A quick recap of ways to maintain our atmosphere and its ecosystem services from this chapter includes:
::在整个概念中,我们讨论了解决大气层具体问题的办法。

Reducing use of fossil fuels
::减少使用矿物燃料

Switching to cleaner fuels, such as nuclear power
::转用更清洁的燃料,例如核能

Switching to renewable energy sources
::转向可再生能源

Increasing fuel efficiencies
::提高燃料效率

Supporting legislation for fuel efficiencies
::支持提高燃料效率的立法

Supporting national and international agreements to limit emissions
::支持旨在限制排放的国家和国际协定

Utilizing pollution control technologies: e.g., scrubbers on smokestacks and catalytic converters for motor vehicles
::利用污染控制技术:例如,烟囱洗涤器和机动车辆催化转换器

Creating and supporting urban planning strategies
::制定和支持城市规划战略

As always, costs are high and tradeoffs must be considered. The classic example is nuclear power, whose effects on the atmosphere are less than those of fossil fuels. Unfortunately, it has high potential for health damage and high costs – both economic and environmental – for storage and transport of nuclear waste.
::与往常一样,成本高昂,权衡平衡必须加以考虑。典型的例子就是核能,其对大气的影响比化石燃料的影响要小。不幸的是,核能对健康损害和核废料储存和运输成本高 — — 包括经济和环境成本 — — 的可能性很大。

Because fossil fuel use is the cause of so many atmospheric as well as water and soil pollutants, the solutions mentioned in the other concepts apply here, as well. The Preventing Climate Change concept relates directly to both fossil fuel combustion and atmospheric change, so more pollution solutions, specific to climate change, will be presented. You should also review the individual responses at the end of the concept, because that list focuses on ways you can change your own life to help protect the environment.
::由于化石燃料的使用是造成许多大气以及水和土壤污染物的原因,其他概念中提到的解决办法也适用这里。防止气候变化的概念与矿物燃料燃烧和大气变化直接相关,因此将提出更多的污染解决办法,具体针对气候变化。你也应该在概念结尾处审查个别对策,因为清单的重点是如何改变自己的生活以帮助保护环境。

Summary
::摘要

Earth’s atmosphere, as we understand it today, provides ideal conditions and essential raw materials for life.
::正如我们今天所理解的那样,地球大气层为生命提供了理想的条件和基本原材料。

Throughout Earth’s history, the atmosphere has changed dramatically, and life caused some of the changes.
::在整个地球历史上,大气层发生了巨大变化,生命引起了一些变化。

Within human history, the atmosphere had been in a dynamic equilibrium: balancing photosynthesis, respiration, evaporation, and precipitation.
::在人类历史上,大气层一直处于动态平衡:平衡光合作用、呼吸、蒸发和降水。

Primary pollutants are directly added to the atmosphere by processes such as fires or combustion of fossil fuels. Secondary pollutants are formed when primary pollutants interact with sunlight, air, or each other.
::初级污染物通过燃烧或燃烧化石燃料等过程直接添加到大气中,当初级污染物与阳光、空气或相互之间发生相互作用时,形成次级污染物。

The majority of air pollutants can be traced to the burning of fossil fuels for heat, electricity, industry, transportation, and waste disposal.
::大多数空气污染物可追溯到燃烧化石燃料用于热、电、工业、运输和废物处理。

Worldwide, air pollution causes as many as 2.4 million deaths each year.
::在世界范围内,空气污染每年造成240万人死亡。

Aerosols (particulates and liquid droplets) cab cause global dimming, or reduction in sunlight reaching the Earth.
::气溶胶(片段和液滴)计程车造成全球二极分光,或减少到达地球的阳光。

Light pollution can interfere with bird migrations, sea turtle reproduction, nocturnal animal behavior, and human activity.
::轻污染会干扰鸟类迁徙、海龟繁殖、夜间动物行为和人类活动。

Review
::回顾

Summarize the importance of the gaseous “life support system” which Earth’s atmosphere provides, and describe the ecosystem services provided by Earth’s atmosphere.
::概述地球大气层提供的气体 " 生命支持系统 " 的重要性,并描述地球大气层提供的生态系统服务。

Distinguish between acid rain, ozone depletion and global dimming. What causes these problems?
::区分酸雨、臭氧消耗和全球稀释。是什么原因导致这些问题?

Distinguish between primary and secondary pollutants, and give an example of each.
::区分主要污染物和次要污染物,并举例说明每一种污染物。

Section outline

General

空气污染 -- -- 高级

Air Pollution ::空气污染

The Atmosphere ::大气层

Upsetting the Equilibrium of the Atmosphere: Air Pollution ::建立大气平衡:空气污染

Preventing Air Pollution ::防止空气污染

Summary ::摘要