Dangers of Nuclear Radiation

• Some materials absorb ionising radiation and it can then enter living cells and interact with molecules causing ionisation
• Lower doses of ionising radiation can cause mutations in DNA, which can lead to cancer
• Higher doses tend to kill cells completely, which causes radiation sickness
• OUSIDE the body, beta and gamma sources r the mot dangerous, because they can pass thru the skin to delicate organs
• Alpha sources can't penetrate the skin
• INSIDE the body, an alpha source is the most dangerous because it's the most ionising and it does all of it's damage in a very localised area
• Beta and Gamma r less dangerous inside the body because they r less ionising. Gamma will mostly pass straight through the body
• Low-level radioactive waste (clothing, syringes) is disposed in special containers, which r buried in secure landfill sites
• High-level waste has a long half-life
• After being cooled in special pools for a few years, high level waste is sealed into glass blocks, then sealed in canisters deep underground
• The site for high level waste has to be geologically stable, since big movements can cause leakage contaminating the soil and water
• Waste can be injected into porous rock underground, but some countries have ended up dropping waste onto sea beds
• Disposal in outer space is an option, but is too expensive and risky
• Radioisotopes are used as tracers to track how substances move through ecosystems or human bodies
• They need a relatively short half-life, so that the source becomes relatively safe quite quickly but long enough that it still emits enough radiation by the time it reaches the correct place
• Medical tracers r Gamma sources, as it can penetrate tissue, pass out the body and be detected. Alpha and Beta cause more damage to the body than Gamma does, so they r not used
• Radioactive tracers can be joined to molecules that will be absorbed by cancerous cells. The cancerous regions can be detected and seen on a screen