Effective dose from different sources

Problem

Consider four exposures: (A) an intercontinental Rome–Tokyo flight ($\sim 0{,}1\ \text{mSv}$); (B) a chest CT scan ($\sim 7\ \text{mSv}$); (C) living in Cortina, with enhanced natural background ($\sim 5\ \text{mSv/year}$); (D) a dental X-ray ($\sim 0{,}005\ \text{mSv}$). Rank the exposures from smallest to largest acute dose (per single event, not annual).

Solution

We must compare the dose received in a single event. Exposures A, B and D are discrete events (a flight, an examination), and are therefore directly comparable. Exposure C, on the other hand, is a chronic dose spread over an entire year of residence: it does not correspond to a single event and should not be placed on the same footing as the others.

Ranking A, B, D by increasing dose in a single event:

$D\ (0{,}005\ \text{mSv}) < A\ (0{,}1\ \text{mSv}) < B\ (7\ \text{mSv})$

The dental X-ray is the lightest, the flight is intermediate, the chest CT scan is the most demanding. Living in Cortina (C) stays outside the acute ranking because it is a chronic annual dose.

$\ev{D < A < B\quad(\text{C: chronic annual})}$

Collegamenti

Argomenti: Fisica nucleare Concetti: Decadimento radioattivo Competenze: Ragionamento di ranking