p. 1

pollution an environment is constantly changing sometimes the changes work together to keep the environment in balance in a balanced environment the size of the population remains about the same over time sometimes the balance in an environment is upset many times people upset the balance of nature by destroying the habitats of other living things for example people cut down forests for farms and towns they build dams and dig mines all of these human activities can be harmful to other organisms in the environment many species of animals are finding it hard to survive because of the ways people have upset the balance of nature people also upset the balance of nature by causing pollution you probably know that pollution is a major problem pollution is anything that harms the environment it occurs when harmful substances or pollutants are released into the environment pollution of the air land and water are all major problems today many different substances are poisoning the environment and upsetting nature s balance and we cannot think of just air pollution or just water pollution or just land pollution pollution may start out in one part of our environment but it does not remain there it s-p-r-e-a-d-s to all parts pollution is increasing daily like other organisms people also suffer from the effects of pollution in the form of illness birth defects respiratory diseases and many other problems therefore we must all work together to help reduce pollution.

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p. 2

as discussed high up in the atmosphere is a layer called the ozone layer this blocks harmful ultraviolet uv light coming from the sun which can cause skin cancer and eye problems these rays can also harm plants and animals humans have the largest impact on the ozone layer and the environment in general we put ozone-destroying chemicals like chlorine fluorine and hydrocarbons chlorofluorocarbons or cfc s into the atmosphere from things like air conditioners spray cans refrigerators and manufacturing processes humans pollute or contaminate the planet by sewage chemicals or bacteria this can occur on the surface or in the air air and water pollution respect no international boundary one country s pollution can affect other countries and can be damaging to ecosystems acid rain another human impact on the atmosphere is acid rain cars trucks planes trains power plants and industry spew sulphur and nitrogen into the air these combine with sunlight water vapour and oxygen to make acids and other toxins which fall to the earth as acid rain acid rain is most dangerous to plants and aquatic ecosystems.

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p. 3

what is conservation think about your pantry it contains many kinds of foods when they run low you replace them but what if you knew that you could not replace certain items what would you do you would try to make them last as long as possible you would use them sparingly or conserve them conserve means to protect from being used up earth is like a huge pantry it has all the things we need to stay alive it is also stocked with things that modern people use like ores for metals and fuels for energy all of the things we get from the environment are called natural resources there are two main groups of natural resources renewable resources and nonrenewable resources renewable resources are replaced by nature oxygen water soil and living things are renewable resources oxygen is made by plants during photosynthesis soil is made when rocks break up water is renewed through the water cycle living things reproduce themselves nonrenewable resources are not replaced by nature at least not in a reasonable period of time fossil fuels such as oil coal and natural gas are nonrenewable resources and so are minerals we get metals from mineral ores how would your life be different without fossil fuels and metals at one time our supply of natural resources seemed endless now we know differently the population of the world is increasing we are using more wasting more and polluting more natural resources than we did in the past earth s pantry is limited we must use our resources wisely if we do not there will not be enough resources left for future generations types of conservation

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p. 4

the wise use of our natural resources is called conservation conservation of all natural resources including renewable resources is important even though renewable resources are replaced their supply is limited people must be careful not to use them up faster than they can be replaced air conservation air pollution is very bad in most industrial areas and cities but air pollution spreads everywhere it reaches every place on earth polluted air can smell bad it can cause health problems like respiratory diseases lung cancer and allergies polluted air also kills trees and reduces food crops motor vehicles and factories are the major causes of air pollution strict laws concerning air pollution must be passed and enforced one of the least expensive ways to control air pollution is to walk instead of drive and use public transportation water conservation the average person drinks about 228 gallons of water each year but water is not only used for drinking we use it in many other ways for example we use water for bathing swimming cleaning cooking gardening and boating water is also vital for proper sewage disposal industry agriculture and aquaculture our water supply must be kept fresh and safe to drink we must stop dumping wastes and raw sewage into our water supply we can also conserve water by turning off the water when brushing teeth and taking showers instead of baths.

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p. 5

soil conservation it takes nature from 500 to 1000 years to produce about two and one-half centimeters one inch of topsoil soil can be carried away by the wind and moving water this removal of soil is called erosion erosion can be reduced to prevent too much soil erosion people must practice soil conservation some ways to conserve soil are a cover the soil with plants such as grass or shrubs the roots of plants help hold soil together b restrict the cutting down of forest trees act as windbreaks and help prevent soil from being blown away by the wind c plant crops across the slope of a hill instead of up and down the hill this helps prevent soil from being washed away by water running down the hill d add materials like humus or natural fertilizers to the soil.

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p. 6

wildlife conservation all natural plants and animals living in an area are called wildlife wildlife is part of nature they provide us with food clothes and many other products wildlife is also pretty to look at human activity can cause many forms of wildlife to become extinct die out we pollute and overhunt we destroy wildlife habitats with construction and mining these actions disturb nature s balance some methods for wildlife conservation are a b c d protecting habitats of organisms enforcing strict hunting and fishing laws setting aside refuges parks and other public lands for wildlife provide special breeding grounds for endangered species organisms in danger of becoming extinct forests are home for many plants and animals forests provide us with oxygen lumber wood pulp medicines and many other products wood pulp is used to make paper including the pages of this book tropical rain forests have more plant and animal species than any other place on earth many of the wildlife habitats are being lost in these forests.

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p. 7

fires caused by human carelessness destroy many forests public education about dangers of forest fires is one way to help conserve forests other methods of forest conservation include a planting new trees to replace those that have been chopped down for lumber or other products b chopping down only certain parts of a forest to allow seeds from remaining trees to provide replacements c removing only older or unhealthy trees from forest regions metal conservation to recycle means to use over again some resources like metals can be recycled aluminum cans glass bottles newspapers and some of the metals used to make cars can all be recycled they can be melted down and reused most can be recycled over and over again recycling is an important way to conserve minerals.

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p. 8

fuel conservation fuels are non-renewable resources once a fuel is used it is gone it cannot be recycled the best way to conserve a fuel is not to waste it use it sparingly use it as you would a non-replaceable item in your pantry here are some ways people can help conserve fuel a b c d use cars that get good gas mileage drive the speed limit walk bicycle or car pool when possible turn off lights when you leave a room to save the fuel used to produce electricity use electrical appliances that are energy saving go to assignment 15 in your student workbook.

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