Human Population

The main cause of human population changes is the change in birth rate and death rate. The human population growth is caused by a natural increase that occurs when the number of births in the population exceeds the number of deaths in the population. 

There are some factors that effecting the human population: 

• Birth rate is the number of live babies born in a year for every 1000 people. A high birth rate may be caused by:

                         
     

- early marriages.     - lack of knowledge of birth control.

• Death rate is the number if people dying in a year for every 1000 people. A high death rate may be caused by:

        

- Diseases               - famine        - natural disasters 

Life expectancy becomes higher and death rate decreases.

Decreases in population size           

                                    

                                         

A low birth rate together with an ageing population may on the other hand result in a decrease in population size. A population is considered ageing when:

• people under the age of 15 make up less than 30% of the population .
• people above the age of 65 make up more than 6% of the population.

The human population may be describe by its population density. Population density refers to the number of people in given amount of space. Population density is an average value. One of the factor that affects the population density of a place is migration.

Human migration is human movement from one area to another. People who migrate are called migrants. Human migration may occur in the form of immigration or emigration.

Immigration takes place when people move into a country permanently. People who immigrate are called immigrants. A population growth may occur in an area when the amount emigration.

Emigration takes place when people move out of the country permanently. People who emigrate are called emigrants. The population density of a country can decrease as a result of emigration.

The picture on the right side is showing an area that have a low population density.

Area that have low population means that it is the healthy place..

The picture on the left side is showing a  place that have too much population density. That place is not healthy and it is not  a good place to live in.

FROM THIS ARTICLE WE CAN START LIVING HEALTH IS GOOD FROM NOW SO THAT WE CAN MAKE ALL THE WORLD IS FREE FROM ANY POLLUTION !! 

Pollution

Air pollution occurs when harmful substances or pollutants are released into the air.

The causes of air pollution is :

• Burning of fuels, rubbish and forests                      
• Dust and dirt in the air 
• Smoke from cigarettes                                       

The effects of air pollution are :

• Health problems 
• Haze 
• Acid rain                                                                                   

Water pollution occurs when pollutants are released into the water. These pollutants include:

* Harmful chemicals from factories and farms.

* Rubbish                                                                                      

* Human waste 

*Oil spills

The effects of water pollution are:\

* Harms organisms in water

* Harms people

Soil pollution occurs when pollutants are released into the soil. These pollutants include:

- Rubbish

- Harmful chemicals from farms

The effects of soil pollution are :

-Air pollution                                                                         

- Water pollution

- Deterioration of soil condition

-Growth of germs and pests

Picture on the side that is one example of images showing that it is a picture of eachstate of pollution contained in the above. If you wanna save the world you can read the picture that I put down.