Hazards of Contamination & Irradiation (AQA GCSE Combined Science: Trilogy: Physics): Revision Note

Hazards of Contamination & Irradiation

• Irradiation is the process of exposing a material to alpha, beta or gamma radiation

• Contamination is where small amounts of the radioactive isotope leak onto the material

• The only way a material can become radioactive is if that material becomes contaminated

• Although irradiation can cause harm, contamination has the potential to cause far more harm, due to the continuous exposure to radiation that it will produce

• Contamination is particularly dangerous if a radioactive source gets into the human body

  • The internal organs will be irradiated as the source emits radiation as it moves through the body

Comparison of Irradiation and Contamination Table

Protecting against Irradiation and Contamination

• It is important to reduce the risk of exposure to radiation

• Radiation can mutate DNA in cells and cause cancer

• Shielding is used to absorb radiation

  • Lead lined suits are used to reduce irradiation for people working with radioactive materials

  • The lead absorbs most of the radiation that would otherwise hit the person

• To prevent contamination an airtight suit is used by people working in an area where there may have been a radiation leak

  • This prevents radioactive atoms from getting inside the person

Lead shielding is used when a person is getting an x-ray, as well as for people who work with radiation. Contamination carries much greater risks than irradiation

Chernobyl Nuclear Disaster

• Chernobyl Nuclear Power Plant is in Ukraine

• In 1986 an incident at the plant caused an explosion

• A large amount of radioactive material was released from the plant and went into the air

• Hundreds of thousands of people were evacuated from the surrounding area to protect them from being contaminated

• An exclusion zone of around 2,600 square kilometres is still in place around the power plant

  • This is because the level of radiation in the area is still very high

The Chernobyl Disaster is probably the worst nuclear disaster in history