ALARA / ALARP / ALATA

The aim of radiological protection must be to prevent unnecessary exposures and to keep the exposures below the internationally accepted ICRP dose limits. It is not possible to control the exposures lower than the background radiation dose levels and hence zero or even close to zero exposures to occupational radiation workers is neither possible or justifiable. Due to its acceptance of LNT theory for radiological protection, and use of As Low As Reasonably Achievable (ALARA) approach, ICRP is over-cautious in its recommendation of ALARA. However, over the years, ALARA has become a regulatory requirement!

The recommendation of ALARA is based on the optimization of the protection taking into account the socio-economic considerations and should remain as the best possible level of protection under the prevailing circumstances. This statement makes ALARA a very uncertain requirement which is difficult to quantify.  

Risk must be averted unless there is gross disproportion between the cost in terms of averting the risk and the benefits of averting such a risk. A proportionate approach - ALARP is the term used in UK legislation, as a requirement that risks to health must be reduced to a level that is As Low As Reasonably Practicable (ALARP). It is the tolerable risk level, which is in- between normally unacceptable and broadly acceptable levels.

 

The “As Low As Technically Achievable (ALATA)” approach is to take the protection level to a level that may be achieved using “World’s Best Practice” utilizing grossly disproportional amount of resources (manpower, money and technology) to reduce exposures which has trivial amount of risk. 

Comment: One sensible and practical approach is to get away from the ALARA, ALARP and ALATA, and ensure that the occupational exposures are strictly maintained below the scientifically derived ICRP dose limits. This will be uniformly in line with the chemical industry where the exposures to chemicals, including carcinogens are regulated by the Threshold Limit Values (TLVs) / Permissible Exposure Limits (PELs). The TLV/PEL of a chemical substance is an exposure level to which a work worker can be exposed for a working lifetime without adverse health effects. The regulation will be through use of SOPs, regular monitoring, periodic review and ensuring compliance.