Date: ………………………..

Chapter three

Man and the environment

E nvironmental problems include:

*Air, water pollution, soil, food & noise pollution.

*Population explosion

*Food & energy problem

*Drought problem and desertification

*Coastal decay and dam problems

Pollution: is the presence of any substance or energy in the wrong place quantity or

time.

Classification of pollutants

Biological	Chemical	Physical
P ollen grains	P esticides	N oise
B acteria	Products of burning petroleum	Temperature

Air pollution

Air pollutant	Source	Effect
Fine particles of carbon, oil or metals	F actory chimneys power station furnaces	Light particles decrease vision, irritate the respiratory system . Fall on the plant leaves and block stomata, decrease photosynthesis and kill plants.
Rubber in soot	B urning garbage	Pneumonia
Lead particles	E xhaust of cars	Affect the nervous system
Cadmium particles		Heart diseases
Phosphate particles	Phosphate mines,
Cotton dust	Spinning and weaving cotton
Radioactive pollution	Outer space Radioactive rocks	Man is adapted to such radiations
	N uclear explosions	Cause cancer & congenital deformities.
Freon	R efrigerators , air conditioners and aerosols	The ozone hole
CO2	Product of burning organic fuel such as petroleum and coal.	Gradual increase of the Earth's temperature

G.R.

1. Nuclear wastes are stored in thick steel containers mixed with cement and buried deeply in the ground.

To avoid the pollution with radioactive remains which cause cancer and congenital deformities?

2. Ozone is an important component of the atmosphere but it's also a source of pollution. a. In the lower layers of the atmosphere, ozone reacts with air pollutants forming smog.

b. In the upper layers of the atmosphere, ozone protects us from the harms of UV radiation.

3. Freon is a harmful air pollutant.

It damages the ozone and therefore more ultraviolet radiation reaches the Earth.

Explain the effect of the accumulation of carbon dioxide on the temperature of the atmosphere.

Two opposing theories explain the effect of increased carbon dioxide ratio in the atmosphere.

1. Increased carbon dioxide gas increases the temperature of the atmosphere & therefore polar ice melts & coastal cities are flooded.

2. Substances which pollute the air reflect thermal radiation & therefore the temperature of the atmosphere decreases & new ice age occurs.

Controlling air pollution:

• Fix filters for smoke coming out from chimneys.

• Use solar energy which is a clean source of energy.

• Construct factories out of towns and cities.

Water pollution

It is any change in the physical properties of water that makes it unfit for use.

Sources and effect :

1. Pollution with microbes, viruses, parasites, and organic compounds which decay

oxygen in water, and therefore kill fish. Dead fish release toxins which prevent the

hatching of fish eggs.

2. Inorganic compounds from factory wastes are difficult to get rid of.

3. Oily substances that result from searching for petroleum under the sea,

or oil leaking from tankers which float on the water reduce the amount of

oxygen in the water and harms the fish.

4. Fertilizers dissolve in water of irrigation canals & increase the reproduction & growth of aquatic plants.

5. Industrial wastes (minerals and poisonous chemicals)

cause the death of living organisms.

6. Thermal pollution resulting from the release

of waste water from factories in rivers and seas

cause the death of living organisms.

7. Polluted water is frozen & is used in cooling drinks & therefore transmits serious

diseases. That's why it's better to put ice outside the container when cooling drinks.

8. People who use irrigation canals for bathing & ablution may become infected with

Bilharzias.

C holera, typhoid, hepatitis infantile paralysis, dysentery are transmitted by water contaminated with microbes.

Controlling water pollution:

1. Avoid throwing industrial and house

wastes into the river or sea .

2. Treat sewage water and industrial

wastes to purify it and use it.

3. Periodic examination of water.

4. Researches on the precipitation of pollutants & getting rid of them.