Science: Section 5

Pollution and the Environment

Poor air quality not only harms human health, it can also harm the environment.   The main adverse effects are acid rain, nutrient enrichment and the greenhouse effect.

Experiment - Acid Rain

Download the CERC Guidelines for the Acid Rain Experiment here.

When we burn fossil fuels such as petrol and coal they release gases containing sulphur and nitrogen into the air.  These gases are carried up high into the sky and can be carried by the wind over other countries a great distance away. Once in the air, the gases dissolve in water in the atmosphere and are changed into different chemicals called acids.

Acid Rain

When it rains or snows these chemicals fall back to earth. This is called acid rain. The chemicals are deposited in rivers, on land and on buildings, and over time they can cause problems. Some of the air pollution produced in the UK can end up in countries in northern Europe including Sweden, Norway and Denmark.

Acid rain can cause many problems such as:

  • Corrosion of iron bridges
  • Corrosion of limestone buildings
  • Damage to plants and the soil they require
  • Damages wildlife especially fish

Nutrient Enrichment

Nutrients are the things that all living things need in order to grow and nourish. Plants require the 3 essential nutrients, nitrogen, potassium and phosphorus in order to grow however too much of any one of these nutrients can be harmful.

Nitrogen gas released into the air from burning fuels can cause an excess of nutrients in soil and water. 

In soil, nutrient enrichment can cause some plants such as grass to grow well, but others to grow less well. The plants that grow well however can eventually stop the other plants from growing at all. 

In water, this excess can lead to the growth of microorganisms such as algae.  These microorganisms can use up the oxygen in the water and stop sunlight getting to the plants that live there. This can be harmful to both plants and fish in the water.

Nutrient Enrichment

Greenhouse effect

Carbon Dioxide
Carbon dioxide is produced when any hydrocarbon burns completely in air. It contributes to the greenhouse effect which in turn leads to global warming.

Greenhouse Effect

There is also a Homework Sheet you can download that supports and develops further the ideas from this section.