Radiation is all around you.Your lifetime’s dose of radiation.

What is responsible for each of the segments?

Everyone is exposed to radiation from radioactive materials. What sources do you think contribute most to your radiation dose?

Lesson 2a

Radioactive Cornflakes

Learning Outcomes • You will be successful if you can:

• Describe sources of background radiation and the potential risks it can pose.

• Describe the effect of radiation on human (or other) tissues.

• Explain the difference between irradiation and contamination.

• Analyse newspaper reports to identify facts and opinions.

What does radiation do to you?

500 000 cosmic rays pass through you each hour.

From the air: 30 000 radon atoms decay each hour in your lungs.

From our food: 15 million atoms of potassium-40 decay inside you each hour.

From rocks and building materials: 200 million gamma rays pass through you each hour.

Most people live their lives without being harmed by this background radiation.

Radioactive materials emit ionizing radiation, which can damage living cells.

nucleus

cloud of electrons

Radiation can damage DNA. But that damage rarely leads to cancer, because DNA can repair itself.

Radiation-damaged DNA in a sperm or ovum can produce genetic defects.

This shows the average radiation exposure for a person in the UK. Radiation exposure depends on where you live and what you do.