Nuclear Radiations Flashcards
What is ionizing radiation
Too much radiation exposure can cause free radical DNA (cancer) when it kills it damages living cells
Describe UVA vs UVB
UVA is absorbing and penetrates deeper into the skin (indirect DNA damage)
UVB is burning and penetrates just the first layer of the skin (direct DNA damage)
What is SPF
The sun protection factor, used as an index of the protective effect of sunscreen (indicates how long it takes for UVB rays to redden the skin)
Difference between chemical sunscreen and physical sunscreen
Chemical sunscreens are chemical based and works by absorbing UV radiation
Physical sunscreen protects the skin by reflecting or scattering the UV radiation
4 steps for selecting a good sunscreen
- Broad spectrum protection (UVA and UVB protection)
- SPF of 15 or greater
- Good photo stability
- Good water resistance
List the 4 background ionizing radiations
Cosmic radiation
Terrestrial radiation
Inhalation
Ingestion
Describe radon
Is an odourless, colourless radioactive gas produced by the decay of uranium, the half life is 3.8 days and can cause cancer
What happens during radioactive decay
Radioactive elements continue to decay into other isotopes until they are stable (uranium-238 undergoes 14 decays = into lead-206)
Describe alpha radiation
Won’t penetrate much (not even paper) but if it gets inside your body, from a gas it cannot get out and is very harmful
What is beta radiation
Can penetrate air and paper but tinfoil will stop it, can damage skin but is hazardous when swallowed it inhaled
What is gamma radiation
Can pass through everything other than thick concrete, lead or steel. Similar to x-rays, travels at the speed of light, can be very hazardous
What is background ionizing radiation
People are constantly exposed to small amounts of ionizing radiation from the environment
Radon, cosmic rays, our own bodies
