Exposure - in the area of the radiation
Contamination- directly contacted with radiation such as touching a material
Risk benifit analysis- used to ensure the benifts outweigh the risks
- Cosmic radiation - Sun releases large amounts of charged sub atomic particles
- Gamma rays from lithosphere- Isotopes which penetrate through the ground
- Internal radiation from the body- from upper atmospher via food and water decay inside body
- Radon from the ground- rocks decay producing gas radionuclide radon. Pass through buildings
- Medical exposure- X rays and MRI radiotheraphy
- Occupational exposure- Nuclear industry, manufacturing, mining and medical radiographers, air craft crew
- Weaponas fall out- testing of nuclear weapons contaminatng earths surface
- Consumer products - Smoke detors and electrical devices
- Industrial effluent disharges- Use radioactive nuclides release radioactive waste such as heavy metals.
Risk benifit analysis and critical pathway analysi
Made difficult by:
- We do not understand all risks associated with ionising radiation
- Geographical separation- those who benift and those who take the risk could be in different places
- Time separation- May cause long term health effects we are not aware of
- Redcution of other risks- Without an X ray is less problematic that invasive surgery
Must be taken into account:
effluent discharges and half lives Effect of PH and oxygen levels
State - solid liquid or gas and bioccumulations Geology - permable rock
Wind speed and direction River flow and currents
Methods to reduce exposure
Close sources- put in a container ensuring workers do not come into any direct contact. Prevents them picking up a radioactive material.
Use of protective clothing and washing to remove all waste
Alpha emitters may be reduced to zero in a container as the box absorbs the radiation
Barriers should prevent the radiation from reaching workers
Distance from source can recuce exposure
Reducing the time workers are exposed to such radiation
Monitoring workers using badges which calculate how much radiation they have been exposed to, long term measures, air monitorts to detect atmospheric particles and contamination monitors to detect contamination.
Critical pathway analysis- finding the different ways radioactive materials can get into the environment.
Enviornmental sampling- environment monitored to check whether radionuclides released in the effluent are becoming concentrated in which places and what threat that poses to humans.
Critical group analysis- a method of monitoring radiactive disharges by looking at those members of the public most at risk.