RD3.2 | ALARA Practice and AERB Regulatory Principles — Summary & Reflection

KEY TAKEAWAYS

ALARA Practice and AERB Regulation — Key Points

• Three radiation-protection principles (ICRP, adopted by AERB): Justification (net benefit before exposure) → Optimisation = ALARA (As Low As Reasonably Achievable; applies to patients AND workers) → Dose limitation (caps for workers and public only — NOT for a patient's own diagnostic dose).
• ALARA is a principle; the methods are the triad — time, distance, shielding:
• Time: short, pulsed screening; avoid repeats.
• Distance: inverse-square law (I ∝ 1/d²) — double the distance, quarter the dose; the cheapest, strongest lever.
• Shielding: lead aprons (0.25–0.5 mm Pb equivalent), thyroid shields, lead glasses, gonadal shields, structural lead barriers.
• Patient protection = justification + optimisation (collimation, low exposure factors, paediatric protocols, pregnancy care) — no patient dose limit.
• Regulator (India) = AERB (Atomic Energy Regulatory Board, Atomic Energy Act 1962, constituted 1983): licenses/registers X-ray & CT installations via eLORA, sets safety codes and dose reference levels, requires QA + RSO + dosimetry, inspects and enforces. ICRP = advisory (international); US NRC = American — neither is India's regulator.
• Dose limits: occupational 20 mSv/yr (averaged over 5 yr, ≤50 mSv any single year); public 1 mSv/yr; lens of eye 20 mSv/yr.
• The ordering clinician's role: justify every ionising request and give clinical detail so the lowest-dose protocol can be chosen.

REFLECT

Recall the last time you were present during an X-ray or fluoroscopy — a portable film on the ward, a theatre image-intensifier, or a contrast study. Ask yourself honestly: (1) Did you apply all three legs of the triad — did you step back (distance), keep the exposure brief (time), and wear or stand behind shielding — or did you rely on just one? (2) For any ionising study you have ordered recently, could you defend its justification ('it changed management') and was the protocol optimised for that patient, especially if they were a child or pregnant? (3) If you were asked tomorrow who regulates the X-ray equipment in your hospital, would you confidently answer 'the AERB' and know that the installation must be registered through eLORA? Turning these questions into reflexes is how RD3.2 becomes part of your clinical character rather than a fact recalled for an exam.