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关于大气污染的作文

2020/03/17作文大全

大气污染小学生作文

大气污染小学生作文一:空气污染

空气污染是空气中某些物质的含量超过正常含量时,形成危害动、植物,影响其生存的现象。大气中C0、NH3、SO2、H2S、Cl2、03和N02等物质的正常含量均在百万分之一以下,对动、植物没有明显的不良影响。但19世纪以来,由于工业和交通运输的发展,那些物质大量排入大气,使空气污染日趋严重,影响到动、植物生命活动乃至人体健康。

污染物的来源,有的来自自然界(如火山喷出的烟灰),有的来自人类活动,其中工业、交通运输产生的废气是主要的污染源。空气污染可分为气体污染物和气溶胶状污染物两大类。气体污染物包括SO2,、03,、氮的氧化物以及碳氢化合物等;气溶胶污染物包括固体粒子(粉尘、烟尘气)和液体粒子(烟雾、雾气)两类。直接向空气中排放的污染物质,叫一次污染物。空气与污染物之间相互作用,产生反应,或空气中光化学反应引起的污染物变质所产生的新污染物,叫二次染物。

空气污染物种类很多,其中对农业威胁较大的约有十多种,如SO2、 HF、C12和光化学烟雾等。 气象条件对空气污染物的影响,水平风速和对流层高度是影响大气稀释空气污染物能力的两个气象要素。当农田上空主导风向来自污染源时,农田容易受有害气体的危害;风力强弱则影响空气污染物的扩散速度、污染物在空气中的浓度与平均风速成反比;通常午后湍流强,空气处于不稳定状态时,有利于扩散。夜间晴朗无风,近地面逆温层可使污染物在地面上停滞积聚,加剧空气污染的程度。另外,在准静止的高气压系统中,由于下沉逆温阻止下层排放的污染物扩散到大气上层,可形成近几百米厚的污染层。各国多次发生的严重空气污染事件大都是在低逆温层、风速小和无雨的气象条件出现几天之后形成的。

空气中一些污染物例,如SO2和悬浮于空气中的农药颗粒等,经雨水淋溶落到地面,又可污染土壤和植株。污染物对植物的危害,一般是通过气孔进入植物组织,干扰酶的作用,阻碍代谢机能,有的有毒物质在体内还可进一步分解或参与合成过程,产生新的有害物质,侵害细胞组织,抑制光合作用,使生长受阻、产量降低、品质变劣。其危害分为急性、慢性和不可见危害等。高浓度污染物造成急性伤害,引起产量显著下降,低浓度污染物,在长时间作用下,造成慢性危害,一般症状不明显。不可见危害只造成生理上的障碍,一般没有症状。

植物受空气污染危害的程度,主要受下列因素影响:污染物浓度和植物接触它的时间;植物本身的构造和所处的发育期以及环境条件的影响。如充足的光照,适宜的温度、良好的供水和空气湿润,较高的C02浓度等,都能导致叶片气孔开放,易受污染危害。 植物对大气的净化功能。不少植物具有一种以酶作催化剂的潜在解毒力,能够分解一些有毒物质,或形成一些大分子络合物,暂时可以降低毒性。1公顷森林,每年可吸滞灰尘30多吨,1公顷柳杉林,每年可吸收700多公斤S02,柑桔树的叶子可吸收储存硫达1%,青杨和桑树具有较强的吸收铅尘的能力,加拿大杨、银杏、榆树、梧桐、桉树等都是较好的“天然吸尘器”。草坪的吸附粉尘能力比裸露地面大几十倍。因此环境科学的任务之一,是要充分发挥植物净化大气的作用。选择吸收污染能力强的植物,扩大造林绿化面积,根据污染源位置、污染物汇集区的地形地势、风向和污染气体的季节分配,统一考虑构成一种包围式或隔离式的林带,使含尘气流在移动中途被树林吸收。另方面要研究采取控制或减少排放污染物的措施,以保证大气质量符合规定的标准。

大气污染小学生作文二:空气的自述

有人说我是看不见摸不着的,也有人说我是地球的面纱,其实啊,我的名字大家非常熟悉——叫空气。我住在地球的最外面,我把地球轻轻地抱在怀里,与你们形影不离。

在广漠的宇宙中,我们的家庭可算是历史悠久的大家庭。我们推选出氧气、氨、氮、碳这三位成员作为家族中的核心,千百年来,我们在宇宙中默默无闻地生活。

说起我的岁数,可是你们长者中的长者了,若要我说出来,恩——少说也有十亿年了。

我算不上高尚伟大,但对地球上的生灵,我可以自豪地说:“我是无愧的。”我给了鲜花娇艳的姿态,我给了呱呱坠地的婴儿顽强的生命力……总之地球的生灵都要靠我,它的生命都是我给予的。早晨,当太阳女神初升之时,阳光透过我射进千家万户,生灵们呼吸着我,人们向我点头微笑……就这样,过了好多年。

我是地球上赖以生存的物质,俗话说:“远亲不如近邻”,因而人类对我非常地友好。但近几年来,人们的生活水平提高了,工业生产越来越发达了,却忽视了我,他们认为我是无足轻重的,使纯洁的我受到了污染。大约在两百年前,一些工业的废气排放出来,它们混杂在我的中间,天然的“过滤器”森林也被人们大批大批的砍伐掉了,鸟儿们无处安家。什么粉尘、烟灰全都寄托在我的身上,我好象成了天然的垃圾箱。人们呼吸了我而发生疾病,这使我万分痛苦,但人们却把“凶手”的帽子戴在我头上,什么害人精了。地球上的生灵请你们听听我的哀诉。

蓝天上笼罩了尘烟,小河里的水不再清澈见底了,工厂里排放出的废气张牙舞爪地向我扑来。天长日久,你们呼吸着不干净的我,生出了各种疾病,它们时时威胁着你们的健康,虽然“环保”工作人员做了不少环保工作,但我需要更多的人来保护我……

有人说,当世界上最后一只老虎在孤独中寻求配偶,最后一只雄鹰从天空坠向大地,最后一只鸟儿发出悲惨的鸣叫时,人类也就失去了自己的未来。这真是警世之言!

我希望我的自述能在地球上得到正确的回答,希望你们能帮助我摘掉“凶手”的帽子,保护你们赖以生存的环境。同学们,行动起来吧,做个环保小卫士!

大气污染小学生作文三:空气污染危害大

空气污染不管是对我们还是对植物危害都很大,为什么这么说?这是我通过一次研究发现的,至于是什么研究,就听我慢慢跟大家说。

在庭园里种些花草,不仅能美化我们的家,还能净化我们四周的空气,让我们呼吸的空气更清新。因此有人说,一个具有一定规模的庭园就像一个不停工作的天然“氧吧”,能提供我们所需的清新空气。但近几天我发现我家的天然“氧吧”“罢工”了,每天清早我到院子里,再也呼吸不到以前那种清新的空气了。这是怎么回事呢?是什么令到我家的天然“氧吧”停止工作呢?我下定决心,一定要把那个“凶手”揪出来!

针对上述事件,我查阅了大量资料,综合我对花草、树叶的连日观察,发现嫌疑最大的是近日车辆的频繁来往,造成了严重的空气污染,加上附近的一些食店排放出来的油烟因近日风势不强,得不到有效的散解,被花草、树叶过量地吸收,造成叶片表面气孔被尘粒堵塞,以至它们不能“工作”。我咨询了自然老师,老师认为这种可能性很高,让我回家去试验一下。于是我回去采了一些花草样本,把它们栽在室内,定期让它们照射阳光,浇水次数加密,几天后,和其他的比较一下,发现经我“悉心照顾”的那些花草比外面的生长得好多了。根据我的实验结果,我把每天浇水的次数加密到每天3次,经过我一个多星期“苦心经营”,“天然氧吧”终于又恢复了正常的工作,每天为我们提供着清新的空气。

综合以上所述,我得出了结论:“天然氧吧”的停止工作,是因为周围空气污染的日趋严重,使花草过量地吸收了空气中的一氧化碳、碳氢化合物、氮氧化物以及空气中的悬浮粒子,以至花草、树叶中用于进行光合作用的气孔被堵塞,机能超荷,停止工作。我终于把这个“凶手”揪了出来!

你看,这就是空气污染的危害。空气污染其实伤害的不仅仅是我们自己,也伤害了地球上的许许多多的生物,还有我们的地球母亲……让我们一起行动起来,减少空气污染,一起保护我们的生存环境吧!

大气污染小学生作文四:我发现空气被污染了

今天早上起床,我洗漱了一下,吃了饭,到了中午我去楼下玩。

一下午我看到我的朋友们在放鞭炮,我也闻到了浓浓的火药味,那味可真是呛啊!我们玩的周围都是火药味。尽管有那么呛,但还是有许多人下去玩,继续放鞭炮。我因为感到太呛,所以就跑上楼写作业去了。连续好几天都是那样,只有朋友叫我的时候我才下去玩一会。他们问我:“你这几天怎么不下去玩呢?”我说:“难道你们这几天在楼下玩都感觉不到很呛吗?我是因为你们这样放鞭炮把空气污染了,我感到很呛,所以不想下去。”

我想我如果少放一些鞭炮,空气就是会少一些污染了吧!

大气污染小学生作文五:对大气污染的调查

我的家乡大连是一个美丽的城市,气候宜人,有蓝色的天,蓝色的海,处处充满美丽的风光。从我家大厅向外望就能看见大连一处著名的风景——绿山上的电视塔。每逢节日晚上,电视塔灯火通明,使美丽的家乡看起来更加明亮,有魅力。但是白天看电视塔就不觉得那么夺目了,它显得灰乎乎的没有生气。有时候干脆躲在雾里面不见踪影。我问爸爸为什么雾天那么多?爸爸说那是因为大气污染物越来越多使空气质量下降,因此雾天就多了。我又查阅资料知道大气污染物已经有1000多种。它们有自然原因形成的,比如火山爆发,森林大火等。还有人为原因形成的比如工业废气,生活燃煤,汽车尾气等。电视里常说的温室效应,酸雨和臭氧层破坏就是大气污染物破坏环境造成的后果。它还会给人类带来急性中毒、慢性中毒、致癌三种危害。中国已经制定了《环境保护法》来保护人民的健康,大连市也制定了相关的法规。作为一个小学生我们能做到哪些事情来减轻大气污染物的破坏呢?我认为第一是要保护植物,加强绿化。让绿色植物来帮助我们过滤空气;二是减少使用私家车,出门多做地铁和公交车。另外车多了噪音也是一种对环境的污染。我相信在大家知道了大气污染的巨大危害以后,都会从自己的角度去想办法来减少大气污染。相信在不久的将来大连必定还是蓝蓝的天,蓝蓝的海,处处充满美丽的风光。

大气污染小学生作文六:大气污染

所谓“大气污染”是指有害物质进入大气,对人类和生物造成危害的现象。如果对它不加以控制和防治,将严重的破坏生态系统和人类生存条件。

大气污染有的是由于森林火灾、火山爆发等自然因素造成的;有的则是由汽车尾气、工业废气、烟尘、爆炸等人为因素造成的,其中人为因素对大气的污染是主要的,尤其是现代交通运输和工业生产对城市大气造成的污染更为严重。因此人们对大气污染问题越来越关切。

造成大气污染的物质有:一氧化炭CO、二氧化硫SO2、一氧化氮NO、臭氧O3以及烟尘、盐粒、花粉、细菌、苞子等。

距地面几十米的近地面层大气,是人类和生物的生存空间。这一层空气质量的好坏直接影响着人类的生产和生活。近年来,由于交通运输业的发展,排放出的大量汽车尾气与空气中的一些物质成分发生化学反应,生成对人体十分有害的一氧化氮、臭氧 、乙醛等新物质。

悬浮在大气中的各种气溶胶粒子,按其大小可分为降尘和飘尘。其中降尘的粒子较大,直径大于10微米,它的自然沉降率较快。它与人类支气管炎的死亡率和农业减产有很大关系;飘尘粒子较小,直径一般在0·1—1·0微米。其自然沉降率很小,故悬浮在大气中的生命史较长。随着粒子的减小有毒元素的浓度将增加。通常小于0·3微米的飘尘能直接吸入肺泡,如长期积累,会损害呼吸机能,引起哮喘、 肺气肿、 矽肺和肺癌等不治之症。由于飘尘的污染期长和毒性强,因此它的危害性大。当大气中气溶胶粒子增加到一定程度以后,就会出现烟雾弥漫,能见度降低,太阳辐射减弱等现象。

近地面层大气污染程度与气象条件密切相关,存在着明显的季节变化和日变化。一般冬季的早晨和傍晚在无风的天气条件下空气污染最为严重。夏季由于空气层结不稳定,污染物易向高空扩散,因此一般污染不会太严重。

大气污染小学生作文七:大气污染

“嘟嘟嘟!有电话!”原来是青蛙探长正在吃早饭,放在一旁的手机响了。青蛙探长接通电话,把手机拿到耳边:“喂,这里是青蛙侦探所。请问,有什么是吗?”“是青蛙探长吗?”手机里传来了急促声,“我是某市的兔小姐,我们这里有妖魔作怪!”“妖魔作怪?”青蛙探长还是第一次接到这种电话,“兔小姐,请你不要激动,慢慢讲不用着急。”“我们没法不激动呀!”电话里传来了另一个人的声音。“你是谁?”青蛙探长疑惑道。“我是哈巴先生。”我们这里真的出现了妖怪,不信你过来看看。”

“真的有那么严重?那好,我们马上就到!”青蛙探长紧张了起来。“某市已经到了。这大概就是蓝色烟雾了吧!”青蛙探长十分镇定地说。

青蛙探长刚从机舱里出来,一个带着防毒面具的猫警察就向他走来。说:“你怎么不带防毒面具呀?”“我刚来到这里。”

青蛙探长捂着鼻子说,“是来调查这蓝色的烟雾……咳……咳咳……”

这时,神犬博士来了他拿出一个大玻璃瓶,把蓝色烟雾进行化验。原来这些烟雾是无色的,成分却很复杂,主要是醛类、臭氧等有毒化合物的混合体。还说:“这里大气污染相当严重,各种工厂的烟囱不停地排放着废气。这些废气中所含的氮氧化合物和碳氢化合物等,在太阳光线的照射下,会产生一系列的化学反应,这样就形成了蓝色的烟雾。我想我们应该想个办法!”神犬博士一说完,就开始行动了起来。

不一会,某城的上空中,出现了一个庞大的“怪物”:“我是妖魔,名字叫大气污染。当所有的人和动物都看到了这个漂浮在空中的“怪物”——大气污染,而且知道了他的名字叫大气污染。

大气污染小学生作文八:大气污染

我们生活在钢筋水泥的森林里,我们对生机勃勃的树木远离了。现在的交通工具、建筑物或复杂的机械都给空气带来极大的污染,它们虽然都给我们带来方便,但大家有没有想到,它们也会污染空气对人体有害的。

此时此刻某些科学家已经研制发明出许多可以净化空气的物品和机器,人们可以利用这些东西将空气中的有害物体吸走,然后将新鲜空气排出,让空气更加清新。可我们人类不能依赖这些工具,并不是有了这些工具就可以乱砍滥伐树木。因为每一棵树木都是对我们很重要的,没有大树保护土壤,泥土就会被河流冲走;没有大树美化环境,人们就生活在乌烟瘴气的地球里;没有大树维持生态环境,动物就会渐渐稀少……这样一来再多机器也没用。大家看,现在空气污染这么厉害,大家也听说过“空气污染,全球变暖”吧!如果空气污染得太厉害的话,地球就会逐渐暖和,那时南极和北极的冰川就会融化,我们的家园会被淹没,这样整个地球都是茫茫大海,我们就会像神话一样,乘坐着“诺亚方舟”在海上漂流。所以说净化空气对我们很重要,我们要多植树让空气更清新。

让我们共同去植树,保护美好的大自然,爱护一草一木,让沙漠中的绿洲增加,大家行动起来吧!

大气污染英语作文

大气污染英语作文一:Air pollution

Air pollution is one of the major problems of the modern world. A great deal of energy is needed to run the factories of modern industrial nations. Automobile, trains, planes and busses need energy, too. Nearly all of this energy is produced by burning fuels. The burning produces wastes, some of which remain in the air, causing air pollution.

Scientists are finding ways to stop air pollution especially in big industrial areas and densely-populated cities. They are studying new ways of generating electricity that may be less damaging to the environment. In the meantime, many power plants are being modernized to give off less polluted material. Also, engineers try to design and locate new power plants to do minimum damage to the environment.

However, it may be that we still have a long way to go before we have a "clean" world. Nearly all of the countries are trying hard to prevent and control air pollution. There indeed seems to be no end to tasks that environmentalists will be required to do. People will continually find new ways to control pollution.

大气污染英语作文二:Air pollution

Pollution is becoming more and more serious all over the world. As is shown in the cartoon, two cars are giving off waste gas and three people are trying to avoid breathing in the poisonous gas by masking their face with their hands. The poisonous gas sent off by factories, domestic appliances and automobiles has made the air unhealthy for people to breathe.

There is no denying that automobiles are indications of civilization, progreand development; neverthele, automobiles cause the serious problem of air pollution. Scientists have warned that unleeffective measures are taken, the problem of pollution will eventually get out of hand. Actually, people are showing a real concern over the problem. For example, there is an increasingly loud voice from the public for firm action against pollution from automobiles.

Indeed, the earth is our home and we have the duty to take care of it for ourselves and for our descendants. In my opinion, we should work out concrete solutions to the problem of pollution from poisonous gas given off by automobiles. For example, the automobiles should be equipped with a device which can dispose of waste gas so as to prevent it from polluting air. Only in this way can we really solve the problem of air pollution caused by automobiles.

The cartoon presents the Earth with a personified human face that seems quite unhappy. A examination of the picture immediately reveals that the source of its mood is the air pollution resulting from a huge number of automobiles spread around its surf-ace.

The cartoon, no doubt, aims at alarming humans of the heavy load we have exerted on Earth by our insatiable production and usage of automobiles. However, the majority of people merely indulge in the celebration of the convenience brought by cars, while forgetting or simply neglecting their harmful impact on the atmosphere. Admittedly, there are various factors contributing to the current worldwide air pollution, but it is undeniable that the exhaust from automobiles is categorized as one of the major elements.

I would like to make the following proposals to solve this problem: firstly, we should apply the most cutting-edge technologies in order to adopt new forms of energy as substitutes for fossil fuels. It should also be guaranteed that the clean energy be inexpensive so that it can be widely accepted. Besides, there should be attempts to develop possible transportation means, so that citizens can be diverted from dependence on cars. In short, it is humans' responsibility to resume clean air for Earth.

大气污染英语作文三:Air pollution

Today the quality of our natural environment has become an important issue.

The world population is rising so quickly that the world has become too crowded.

We are using up our natural resources and at the same time polluting our environment with dangerous chemicals. If we continue to do this, life on earth cannot survive. Concerned people have made some progress in environmental protection. Governments of many countries have established laws to protect the air, forests and sea resources and to stop environmental pollution.

Still more measures should be taken to solve environmental problems. People should be further educated to recognize the importance of the problems, to use modern methods of birth control, to conserve our natural resources and recycle our products. We are sure that we can have a better and cleaner place in the future.

大气污染英语作文四:Air pollution

We all know that clean air is important to good health. Wherever you go and whatever you do, you are always surrounded by a sea of gases that we call air. If there are impurities in the air, they may be absorbed by our bodies and make us ill. We need clean air, but unfortunately , air pollution is globally present , especially in cities.

Many large cities are anything but pollution-free. Our cities have many factories, which we need to make food, clothing and other things. Every year these factories pour millions upon millions of tons of smog into air. Power plants and houses that burn coal add greatly to air pollution. Besides , there are more cars in cities now. Once out on the streets, they will take in fresh air and replace it with poisonous gases.

Our country is trying hard to prevent and control air pollution. As long as every citizen also realizes its importance and makes join efforts, the day will come soon when people will take in only clean air. Then , the sunlight will no longer be blackened out by smoke and soot.

大气污染英语作文五:Air pollution

As you know,there's no enough clean water for people. So many of them lose their lives because of water. In a lot of countries, people have to cut trees for living. So there's nothing to keep water from running away. Also we have polluted the land, the river and the air. So we have to face more and more floods and droughts .

It's time that we must do something useful to protect our environment. We can plant trees and take good care of them. We can save the water and ask our parents to do so. We can't throw any litter onto the ground and we should collect them for recycling.

If we take good care of our earth today,it will be more beautiful tomorrow.

大气污染英语作文六:Air pollution

Once man did not have to think about the protection of his environment. There were few people on the earth, and natural resources seemed to be unlimited.

Today things are different. The world has become too crowded. We are using up our natural resources,and polluting our environment with dangerous chemicals. If we continue to do this, human life on earth will not survive.

We realize that if too many fish are taken from the sea, there will soon be none left. Yet,with modern fishing methods, more and more fish are caught.We know that if too many trees are cut down, forests will disappear. Yet, we continue to use powerful machines to cut down more and more trees. We see that if rivers are polluted with waste products, we will die. Yet, waste products are still put into rivers.

We know that if the population continues to rise at the present rate, in a few years, there won't be enough food.What can we do to solve these problems?

If we eat more vegetables and less meat, there will be more food available. Land for crops feeds five times more people than land where animals are kept.

Our natural resources will last longer if we learn to recycie them.

The world population will not rise so quickly if people use modern methods of birth control.

Finally, if we educate people to think about the problems we shall have a better and cleaner planet in the future.

大气污染英语作文七:Air pollution

The cartoon presents the Earth with a personified human face that seems quite unhappy. A examination of the picture immediately reveals that the source of its mood is the air pollution resulting from a huge number of automobiles spread around its surface.

The cartoon, no doubt, aims at alarming humans of the heavy load we have exerted on Earth by our insatiable production and usage of automobiles. However, the majority of people merely indulge in the celebration of the convenience brought by cars, while forgetting or simply neglecting their harmful impact on the atmosphere. Admittedly, there are various factors contributing to the current worldwide air pollution, but it is undeniable that the exhaust from automobiles is categorized as one of the major elements.

I would like to make the following proposals to solve this problem: firstly, we should apply the most cutting-edge technologies in order to adopt new forms of energy as substitutes for fossil fuels. It should also be guaranteed that the clean energy be inexpensive so that it can be widely accepted. Besides, there should be attempts to develop possible transportation means, so that citizens can be diverted from dependence on cars. In short, it is humans' responsibility to resume clean air for Earth.

大气污染英语作文八:Air pollution

Air pollution comes from factories, power stations and cars. Chemicals in the smoke from power stations cause a lot of damage.

They can travel hundreds of miles in the wind before falling to the ground in the rain. But this "chemical rain" gradually destroys trees in the forests and kills fish in the lakes. In Germany, over 50% of the country's trees had been damaged by the year 1986.

Time and time again there are serious accidents that pollute the air.

In 1986 there was a bad accident at a nuclear power station in Russia.

A cloud of radiation crossed the whole of Europe. It is said that 125,000 people died in Russia as a result of illnesses caused by this accident.In 1984 there was a serious accident at a factory in India and a cloud of dangerous gas covered the town of Bhopal. Over 2,500 people were killed that night, and hundreds of thousands of people were injured. Many of the injured lost their sight.

大气污染事例

大气污染事例一:四日事件

1955年以来,以石油联合企业为主的日本四日市工业迅速发展,每年排到大气中的粉尘和SO2总量达13万吨,使城市终年烟雾弥蔓,严重污染了空气,并蔓延到其它城市。人们由于吸入了有害气体而患支气管炎、支气管哮喘、肺气肿及肺癌等呼吸道疾病,称为“四日市哮喘病”。截止到1972年,患四日市哮喘病患者高达6376人。

大气污染事例二:

兰州空气污染 ,天下第一 。

因大气污染严重,兰州曾被称为“看不见的城市”,洛杉矶时报曾报导说,兰州的 200万市民天天忍受著恶劣的环境,吸口气就像抽了一包烟似的,连洛杉矶當年污染最严重時都沒這么厉害,因为里头含有太多的煤灰、汽车废气和尘土,「世界资源协会」的一项调查显示,兰州市是全球空气污染程度最严重的城市。

兰州地处黄土高原的河谷盆地,周边地区生态环境脆弱,人口、机动车辆和耗煤量不断增加,大气中污染物不易稀释扩散,有人称兰州是个“只冒烟却没有窗户的黑房子”,当地顺口溜则说“太阳和月亮一个样;白天和晚上一个样;麻雀和乌鸦一个样”。

大气污染事例三:伦敦烟雾事件

1952年12月初的一天,本来就污染严重的英国伦敦,突然出现阴雨天气,天空中灰黑色烟雾缭绕,并有浓重的生葱头似的辛辣味,伦敦上空的能见度太低,飞往世界各地的班机全部取消。浓雾中,粒径小米般大小的黑色晶体纷纷扬扬地降落着,撒落在街道上、建筑物上、人们的衣服上,天地之间仿佛降了场黑雪。整个伦敦开始了一场集体性烟气中毒。医院里咳嗽、呕吐声不绝于耳,4天之后,伦敦城死去4000多人;2个月后,伦敦市统计部门统计,这次黑色浩劫共夺去了8000位无辜市民的生命。这就是震惊世界的英国伦敦烟雾事件。

大气污染事例四:

美国洛杉矶光化学烟雾事件是世界有名的公害事件之一,40年代初期发生在美国洛杉矶市。

洛杉矶是美国西部太平洋沿岸的一个海滨城市,前面临海,背后靠山。原先风景优美,常年阳光明媚,一年只有几天下雨,气候温和。美国电影中心——好莱坞就设在它的西北郊区。洛杉矶南郊约100公里处的圣克利门蒂是美国西部白宫。

但是,自从1936年在洛杉矶开发石油以来,特别是二次世界大战后,洛杉矶的飞机制造和军事工业迅速发展,洛杉矶已成为美国西部地区的重要海港,工商业的发达程度仅次于纽约和芝加哥,是美国的第三大城市。

随着工业发展和人口剧增,洛杉矶在40年代初就有汽车250万辆,每天消耗汽油1600万升。市内高速公路纵横交错,占全市面积的30%,每条公路通行的汽车每天达16.8万次。由于汽车漏油、汽油挥发、不完全燃烧和汽车排气,每天向城市上空排放大量石油烃废气、一氧化碳、氧化氮和铅烟(当时所用汽油为含四乙基铅的汽油)。这些排放物,在阳光作用下,特别是在5月份至10月份的夏季和早秋季节的强烈阳光作用下,发生光化学反应,生成淡蓝色光化学烟雾。这种烟雾中含臭氧、氧化氮、乙醛和其他氧化剂,滞留市区久久不散。

洛杉矶地处太平洋沿岸的一个口袋形盆地地带之中,只有西面临海,其他三面环山。

该地区天气的一个重要特点是持续性的反气旋。洛杉矶处于被称为太平洋高压反气旋的的东端。下沉的空气往往并不一直降到地面,使得逆温层在约600米的高度上形成了。

还有另一个因素促使逆温层的形成——加利福尼亚寒流。在春季和初夏,来自太平洋上空的比较温暖的空气,越过海岸向洛杉矶地区移动,经过这一寒冷水面上空变冷。这就出现了接近地面的空气变冷,同时高空的空气由于下沉运动而变暖的态势,于是便形成了洛杉矶上空强大的持久性的逆温层。它们犹如帽子一样封盖了地面的空气,并使大气污染物不能上升到越过山脉的高度。

洛杉矶的光化学烟雾在这种特殊的气象条件下,扩散不开,停滞在市内,毒化空气,形成污染。洛杉矶已经失去了它美丽、舒适的环境,有了“美国的烟雾城”称号。

大气污染事例五:马斯河谷烟雾事件

比利时马斯河谷工业区。在这个狭窄的河谷里有炼油厂、金属厂、玻璃厂等许多工厂。12月1日到5日的几天里,河谷上空出现了很强的逆温层,致使13个大烟囱排出的烟尘无法扩散,大量有害气体积累在近地大气层,对人体造成严重伤害。一周内有60多人丧生,其中心脏病、肺病患者死亡率最高,许多牲畜死亡。这是本世纪最早记录的公害事件。