Air pollution and smog are the prob

Air pollution and smog are the problems of modern cities
The word smog comes from smoke and fog. Smog is a sort of fog with other substances mixed in. Smog has been here a long time. Billions of years ago, volcanoes sent millions of tons of ash and smoke into the air. Winds whipped up dust clouds. Animal and vegetable matter decayed, adding polluting gases.
When people came along, they began to produce their own kind of air pollution. They discovered fire. In the Middle Ages, people in cities such as London used soft coal to heat their homes. The smoke from these fires, combined with moisture in the air, produced dense lavers of smog. The smog would blanket the city for days, particularly in winter. The heat generated in large cities tends to circulate air within a dome-like shape. This traps the smog and holds it over the city.
Smog, and the chemicals and other substances in it, can be harmful, even deadly. Smog blurs vision. It irritates the eyes, the throat, and the lungs. Eyes water, throats get sore, people cough. Smog can make people ill. And it can make sick people sicker. Air pollution has been linked to eczema, asthma, emphysema, cardiovascular difficulties, and lung and stomach cancer. It also has a harmful effect on the environment. Food crops and animals suffer. Paint may peel from houses. It is obvious that we must do everything possible to reduce man-made atmospheric pollutants and smog.
Smog, along with smoke, is the most visible evidence of atmospheric pollution. But some atmospheric pollution is not visible and may not become visible until it is mixed with moisture. Lead compounds from leaded gasoline, hydrocarbons (unburned gasoline), carbon monoxide, and other gases may pollute the air without being seen. All air is polluted to some extent. That is, all air carries some polluting substances. Much of it is natural: smoke and ash from volcanoes, dust stirred up by the wind, compounds given off by growing vegetation, gases given off by rotting animal and vegetable matter, salt particles from the oceans, and so on.
Man adds to these pollutants by burning coal, oil, gas, gasoline, and many other things.
Before we get to the automobile, however, let us review what we know about combustion. Most fuels, such as coal, gasoline, and wood, contain hydrogen and carbon in various chemical combinations. During combustion oxygen unites with the hydrogen and carbon to form water, carbon monoxide, and carbon dioxide.
In addition, many fuels contain sulfur; this burns to produce sulfur oxides. Also, in the heat of combustion, some of the nitrogen in the air combines with oxygen to form nitrogen oxides. Some of the fuel may not burn completely, so that smoke and ash are formed. Smoke is simply particles of unburned fuel and soot, called particulates, mixed with air.
Altogether, it is estimated that 200 million tons of man-made pollutants enter the air every year in the United States alone. This is about a ton for every man, woman, and child in the country!
This man-made pollution is what clean-air laws are aimed at.
Consider Los Angeles a large city set in basin with about 7,000,000 inhabitants. It is surrounded on three sides by mountains and on the fourth by the Pacific Ocean. When the wind blows out over the ocean, it sweeps away pollutants. But at other times, the air is stagnant. Smoke and other pollutants from industry and automobiles do not blow away. They just build up into a thick, smelly, foggy layer of smog. The location of Los Angeles, plus all the people and industry there, make it one of the biggest “smog centers” in the country. And it is Los Angeles which has led in measures to reduce smog.
Los Angeles has banned unrestricted burning, for example, burning trash. Incinerators without controls were outlawed. Industry was forces to change combustion processes and add controls to reduce pollutants coming from their chimneys. Laws were passed that required the addition of emission controls on automobiles. All these measures have significantly reduced atmospheric pollution in the Los Angeles area.
If not controlled, the automobile can give off pollutants from four places. Pollutants can come from the fuel tank, the carburetor, the crank-case, and the tail pipe. Pollutants fro the fuel tank and carburetor consist of gasoline vapors. Pollutants from the crankcase consist of partly burned air-fuel mixture that has blown by the piston rings. Pollutants from the tail pipe consist of partly burned gasoline, carbon monoxide, nitrogen oxide, and- if there is sulfur in the gasoline – sulfur oxides.

Результаты (узбекский) 1:

Havo ifloslanishi va chang zamonaviy shaharlar muammosidir
so'z chang tutun va tuman keladi. Chang aralashgan boshqa moddalar bilan tuman xil bo'ladi. Smog bu erda uzoq vaqt bo'ldi. Milliard yil oldin, vulqonlar havoga kul va tutun millionlab tonna yubordi. Shamollar chang bulutlarni up ko'pirtirilgan. Hayvon va o'simlik nazar, chirigan ifloslantiruvchi gazlar qo'shib.
kishi birga kelganida, ular havo ifloslanishi o'z turdagi ishlab chiqarishni boshladi. Ular olovni kashf qilgan. O'rta asrlarda, London kabi shaharlarda odamlar uylarini isitish uchun yumshoq ko'mir ishlatiladi. havoda namlik bilan birga, bu yong'in, tutun, tutun zich Lavers ishlab chiqarilgan. chang, ayniqsa qishda, kun davomida shaharni adyol edi. katta shaharlarda hosil issiqlik bir gumbaz kabi shakl ichida havo tarqatdi istagi. Bu tutun narsalarni va shahar. Ustidan ushlab
chang, va unda kimyoviy va boshqa moddalar, hatto halokatli, zararli bo'lishi mumkin. Chang ko'rish, odatda bulanıklaştırır. Bu ko'zlarini, tomoq, va o'pka noqulay. Eyes suv, og'iz og'iz olish, odamlar yo'tal. Chang odamlar kasal qilishi mumkin. Va u sodda kasal odamlarni mumkin. Havo ifloslanishi ekzema, astma, amfizem, yurak-qon tomir qiyinchiliklar va o'pka va oshqozon saratoni bilan bog'liq bo'ldi. Bundan tashqari, atrof-muhit bilan bog'liq bo'lgan zararli ta'sir ko'rsatadi. Oziq-ovqat ekinlari va hayvonlarni azob chekadilar. Uylaridan pulni mumkin bo'yoq. Biz sun'iy Atmosferani ifloslantiruvchi va tutun kamaytirish mumkin, har bir narsani kerak, deb ochiq-oydin emas.
tutun, tutun bilan birga, atmosfera ifloslanishining eng aniq dalil hisoblanadi. Lekin ayrim atmosfera ifloslanish aniq emas va u namlik bilan aralash qadar aniq bo'lib mumkin emas. Qo'rg'oshinlangan benzin, uglevodorodlar (zarar etmagandi benzin), uglerod oksidi va boshqa gazlar dan Qo'rg'oshin aralashmalar ko'rgan holda havoni ifloslaydi mumkin. Barcha havo bir darajada ifloslangan. Bu barcha havo ba'zi ifloslantiruvchi moddalar oshiradi, deb. U ko'p tabiiy: tutun va vulqonlardan kul, shamol bilan aralashtiriladi, tuproq, aralashmalar o'sayotgan o'simlik tomonidan off berilgan, gazlar shunga okeanlardan hayvon va o'simlik masalani, tuz zarralar chirigan, va off berilgan.
Man bu qo'shimchalar yonib ko'mir, neft, gaz, benzin, va boshqa bir qancha narsalar bilan ifloslantiruvchi moddalar.
Biz avtomobil olish oldin, ammo, bizga yonish haqida bilish nima ko'rib chiqaylik. Bunday ko'mir, benzin, va yog'och kabi eng yonilg'i, turli kimyoviy birikmalarning vodorod va uglerod o'z ichiga oladi. Yonish paytida kislorod, vodorod va suv hosil qilish uchun uglerod, uglerod oksidi va uglerod dioksid bilan birlashtiradi.
Bundan tashqari, bir qancha yonilg'i oltingugurt; bu oltingugurt oksidi ishlab chiqarish uchun yoqadi. Bundan tashqari, yonish issiqlik, havo azot ba'zi azot oksidi hosil qilish uchun kislorod bilan birlashtiradi. Tutun va ash shakllanadi, shuning uchun yoqilg'i, ayrim, butunlay yondirib mumkin emas. Tutun havo bilan aralashgan zarar etmagandi yonilg'i va muassasa, deb nomlangan zarrachalar shunchaki zarralar hisoblanadi.
Umuman, u sun'iy ifloslantiruvchi 200 million tonna yolg'iz Qo'shma Shtatlarda har yili havo kiritish, deb taxmin qilinadi. Bu mamlakatda har bir odam, ayol va bola uchun bir tonna haqida!
Bu sun'iy ifloslanish toza-havo qonunlar qaratilgan nima bo'ladi.
Los Anjeles haqida 7.000.000 aholisi bilan havzasida belgilangan katta shahar ko'rib chiqaylik. Bu Tinch okeani tomonidan tog'lar va to'rtinchi kuni uch tomondan o'rab turadi. Shamol, okean ustida zarba bo'lsa, u ifloslantiruvchi moddalarni yuz supurmoqda. Lekin boshqa vaqtlarda, havo sokin bo'ladi. Tutun va sanoat boshqa ifloslantiruvchi moddalar va mashina sovurib emas. Ular faqat tutun bir qalin, hidlash, noaniq qatlami ichiga qurish. Los Anjeles joy, shuningdek, u erda barcha odamlar va sanoat, mamlakatda eng yirik "chang markazlari" biri qiling. Va u tutun kamaytirish. Tadbirlari olib keldi Los Anjeles bo'lgan
Los Anjeles cheksiz yonib man qildi, masalan, axlat yoqib. Nazorat holda incinerators noqonuniy edi. Sanoat yonish jarayonlari o'zgartirish va ularning oyoq kelgan ifloslantiruvchi moddalarni kamaytirish boshqaruvlari qo'shish kuchlar edi. Qonunlar avtomobil emissiya nazorat qo'shilishi zarur, deb qabul qilindi. Bu barcha chora-tadbirlar sezilarli darajada Los Anjeles hududida atmosfera ifloslanishi kamayadi qilgan.
nazorat yo'q bo'lsa, avtomobil to'rt joylardan ifloslantiruvchi moddalarni off berishi mumkin. Ifloslantiruvchi yonilg'i tank, karbüratör, krank-holda, va quyruq quvur kelishi mumkin. Yonilg'i tank va karbüratör fro ifloslantiruvchi benzin bug'lari iborat. Karterine dan ifloslantiruvchi piston halqalarni bilan o'rtangan qisman yondi havo-yonilg'i aralashmasi iborat. Quyruq quvur ifloslantiruvchi qisman yondi benzin, uglerod oksidi, azot oksidi iborat, ustaxonalarda amaliy benzin oltingugurt bo'lsa, - oltingugurt oksidi.