A short Review of the ALARA Principle in Radiation Protection

Any activity involving radiation should be planned and conducted in such a way that the exposures to individuals are optimally low, taking into consideration the economic and cost aspects. This principle of optimization is called ALARA. ALARA stands for “As Low as Reasonably Achievable”. The ALARA principle states that the radiation exposures should be limited to a minimum level since the Ionizing radiation may produce biological effects in the exposed person. Background of ALARA Concept: The introduction of ALARA was a great philosophical change, as instead of working up to the permissible exposure limits, the idea was to keep exposures to levels as far below the limits as could reasonably be done, considering economic and technical factors. The linear-no-threshold (LNT) model, labeled is the basis of the ALARA protocol; if even small doses lead to slight increases in the risk of cancer than doses should be kept as low as possible. The concept of ALARA was first introduced in 1954 in the National Council on Radiation Protection & Measurements (NCRP) Report, and later in International Commission on Radiological Protection (ICRP) Publication 1 where it was initially called ALAP, the acronym for As Low As Practicable (ICRP 1959b). As per Atomic Energy Regulatory Board (AERB), Govt of India, all radiation work should be carried out in a preplanned and controlled manner so that the exposure to the workers and persons in and near sites of radiation use is kept as low as reasonably achievable (ALARA) and does not exceed the recommended limits. Suitable control measures shall be employed to minimize radiation exposure so that maximum benefits are derived with minimum radiological risk. Discussion: The ALARA principle appears simple but is often misinterpreted and inappropriately applied in radiation protection. It is often interpreted as “as low as possible” without taking into consideration the balancing factors. Considering radiation shielding requirements as an example excessive unnecessary shielding with materials such as lead, steel, or concrete is a waste of global resources. This in turn can cause other damages such as chemical harm and pollution to the environment, which have proven damages to human health. It is more meaningful to make use of the wasted resources for service improvements, such as reducing the charges to patients, investing in better medical technologies, and training of staff. Conclusion: The aims of radiation protection are (i) to avoid the occurrence of deterministic effects and (ii) to limit the risk of stochastic effects. ALARA protocol has successfully limited the exposure of radiation workers to impressively low levels of dose around 1 mSv. Since significant costs are incurred to comply with ALARA and the validity of the LNT model is unclear below doses of 100 mSv, more research on the health effects of low radiation doses is necessary before alternatives to ALARA can become viable.