Air pollution
Claude Monet'sdrawing of London smog, whichis made because of air pollution. Sometimes
air pollution canbecomesodangerousthat people have to wear surgicalmaskswhenthey go
outside.
Air pollution is pollution of the air whichcan affect the health, survival, or activities of
manyorganisms, includinghumans. Many of the world's large citiestoday have bad air
quality.[1] Even 2,000 yearsago, the Romans werecomplaining about the bad air in theircities
(atthat time, the air wasthickwithsmokefromfires and the smell of sewers).[1] Air pollution
has been a danger to humanhealth and Earth'smanyecosystems for a long time.
Air quality
Even "clean" air is not really clean. It has manypollutants (thingsthatpollute the air)
fromnatural sources. Thesepollutantsincludedust, seasalt, volcanicashes and gases,
smokefromforestfires, pollen, and manyothermaterials.[1] In fact, there are many more
naturalpollutantsthanpollutantsthathumansmake.[1] However, humans have adapted to most
of thesenaturalpollutants.[1]
Types of air pollution
Mount St Helenserupting
Ashfromvolcaniceruptionsis an example of primarypollutants.
Air pollutions are usuallydescribed as eitherprimarypollutants or secondarypollutants.
Primarypollutants are pollutantsthat are put directlyinto the air by humans or natural sources.
Examples of primarypollutants are exhaust fumes (gas) from cars, sootfromsmoke,
duststorms and ashfromvolcaniceruptions (as seen in the picture on the left).[1]
Secondarypollutants are pollutantsthat are made fromchemicalreactionswhenpollutants mix
withotherprimarypollutants or natural substances like water vapor.[1]
Manysecondarypollutants are made when a primarypollutantreactswith sunlight. Ozone and
smog are secondarypollutants. Ozone is a gasthatishelpful and takes in harmful rays from the
sun. Whenitisnear the ground, though, ozone is a dangerouspollutantthat influences the
health of all organisms.[1]
Sources of human-made air pollution
There are manyproblemscaused by air pollution, likegreenhouseeffect and acidrain.
Human-made air pollution comesfrommanythings. Most air pollution made by
humanstodayisbecause of transportation. Cars, for instance, make about 60% of the human-
made air pollution in the United States. The gasesinside car exhaust, likenitrogenoxide, make
smog and acidrain.
Industrial air pollution
Manyindustrial power plants burnfossil fuels to gettheirenergy. However, burningfossil fuels
canmake a lot of oxides (chemicalcompoundsthat have oxygen and otherelementsinside). In
fact, the burning of fossil fuels makes 96% of the sulfuroxides in the atmosphere.
Some industries alsomakechemicalsthatmakepoisonous fumes (smoke).
Indoor air pollution
Air pollution is not only on the outside. Homes, schools, and buildings canalso have air
pollution. Sometimes the air inside a building isevenworsethan the air outside.[1]
Manythingswhichhumans use everydaycanpollute the air. Compounds insidecarpets, paints,
building materials and furniturealsopollute the air, especiallywhenthey are new.
In buildings where the windows are tightlyshut to stop air leaks, the air insidecanbepolluted
more than the air outside.[1]
Air pollution
Air pollution is a problemeverywhere in the world. Local air pollution usually affects
bigcities. Air pollution becomes a worldwideproblemwhen local pollution moves
awayfromwhereit came from. For example, winds carry air pollution made in the middle of
the western part of the United States to Canada, likeacidprecipitation.
Acidprecipitation
Acidprecipitationisprecipitation, likerain, sleet, or snow, thatcontainsacidsfrom air pollution.
Whenfossil fuels are burned, theylet outoxidesinto the air. Whentheseoxides mix with water
in the atmosphere, theymakeacid, whichfall as precipitation.[1] Acidprecipitationcankill
living things, likefish and trees, by making the place wherethey live tooacidic.
Acidraincanalso damage buildings made of limestone and concrete.
Ozone hole
Other global concernsbecause of air pollution include the greenhousegases and the hole in
the ozone layer in the stratosphere. The Earth's ozone layer issupposed to protect people from
the Sun'sharmful ultraviolet rays, but in the 1970s, scientistsfound out thatsomechemicalslet
outinto the atmospheremakes the ozone turnintooxygen, whichmeansthat more ultraviolet
rays reach the Earth. During the 1980s, scientistsfoundthat the ozone layerabove the South
Pole hadthinned by 50 to 98 percent.
Humanhealth
On March 17, 1992, in Mexico City, all childrenunder the age of 14 could not go to
schoolbecause of air pollution. This does not oftenhappen, but beingexposed to air pollution
everydaycanmake people have manyhealthproblems. Children, elderly (old) people, and
people with allergies especially, can have a lot of problemsbecause of air pollution.
Studiesfrom the University of Birmingham showedthatdeathsbecause of pneumonia and air
pollution frommotorvehicleslike cars are related.[2] The World HealthOrganizationsaidthat
2.4 million people diedbecause of the direct problems of air pollution.[3][4]Some of the
problemsinclude:[1]
Head
Dizziness
Headaches
Face
Burning, scratchyeyes
Runnynose
Coughing and hard breathing
Other
Lung cancer and lungdiseases
Sore throat
Chest pains, colds, and allergies
