10 December 2021
The Radiation Health Committee has recently noted a number of incidents of personal radiation monitoring devices (PRMD) that have recorded false high doses. On investigation, these doses were attributable to radiation exposure of the PRMD during airport hand luggage security screening.
Security screening is used to exclude prohibited items from sensitive venues (e.g. at embassies, airports, courts and on board aircraft) and helps to ensure the safety and security of guests, clients and personnel who enter these areas. X-ray-based technology is well-suited for screening because it is rapid, accurate and non-destructive.
X-ray-based security scanners have the potential to produce a dose that is detectable by PRMD. This means that a PRMD can record an exposure event if it passes through a security scanner. For radiation workers who may transit multiple security screening points (e.g. airports for interstate work), the cumulative exposure can generate false high dose reports. This is especially problematic as technology is evolving toward higher energy CT-based screening.
Doses associated with security screening exposure to the PRMD – and not the wearer – can make personal dose records unreliable for a monitoring period and could ultimately impact a worker’s ability to perform their duties because of dose constraints applied by their employer that are well below the annual occupational dose limits. In addition, investigating false high dose reports is unproductive for employers and regulators.
Because they are effective for security detection, the adoption of x-ray-based scanners is expected to increase, and therefore false high dose reports may also increase if PRMDs are scanned at security screening points. Considering this, the Committee issues the following guidance to all security providers who use x-ray-based scanners and affected radiation workers:
To maintain the integrity of dose records of radiation workers who frequently require hand baggage security screening, PRMDs should not be scanned by x-ray-based scanners. Radiation workers should be permitted to carry their assigned PRMD on their person after declaring the possession of their PRMD to security screening points and be checked by alternative screening processes.