Pollution

Question 1

what is happening to the global human population

Answer 1

it is increasing

Question 2

why is the global human population increasing

Answer 2

number of babies born is greater than the number people who die

Question 3

what will happen to pollution if population increases

Answer 3

pollution will increase unless we find ways to reduce the amount of pollutants we produce.

Question 4

what is a pollutant

Answer 4

a substance that can damage the environment and the organisms that live in it.

Question 5

give 2 examples of pollutants

Answer 5

1. sulfur dioxide gas released from factories and power stations, which pollutes the air
2. phosphates and nitrates from sewage and fertiliser, which can pollute water.

Question 6

what is eutrophication

Answer 6

it is when fertilisers, which contain phosphates and nitrates, get into streams and rivers

Question 7

explain the process of eutrophication

Answer 7

1. eutrophication causes water plants and grow algae to grow more quickly.
2. plants and algae cover the water surface, and block light to deeper water.
3. deeper plants cannot get light, so they die.
4. bacteria decompose dying plants and take oxygen from the water.
5. there is not enough oxygen left in the water for fish, so the die