Monitoring of the public and responders


First responder monitor
When to apply:
When a first responder monitor or radiological assessor is available and there is an indication that people may be contaminated (possible presence of radioactive smoke, liquid or dust) and conducting monitoring is feasible.

Caution: Do not delay medical treatment or transport for registration or monitoring. If you do not understand how to perform the operational steps or to use units below, another qualified person should conduct monitoring.

Some instruments can be saturated (be overwhelmed) by very high radiation levels and show a low or "0" reading in very dangerous areas.


  1. Approach the scene with an instrument that can read at least 100 mSv/h switched on and do not enter areas with ambient dose rates >100 mSv/h
  2. If terrorism/criminal activity is suspected, ensure law enforcement searches the people for weapons before being monitored and emergency workers are protected from potentially armed suspects
  3. Perform an operational check of the monitoring instrument(s) in an area away from the scene:
    • Check the battery
    • Confirm that the instrument can measure ambient dose rates in the range of local background (typically between 0.05–0.2 µSv/h). Make sure you understand units displayed and how ranges are changed
    • Open beta window if available
    • Wrap instrument in plastic bag
    • Record instrument number and the background level in an area not close to the scene
  4. Keep one check instrument in a "clean area" and do not use it for routine monitoring
  5. Establish monitoring location in an area with ambient dose rates below 0.3 µSv/h that is close to the decontamination area
  6. To ensure that any objects with an ambient dose rate >100 µSv/h at 1 metre are identified and isolated before members of the public are entering monitoring area, have the public screened away from the monitoring area (walk within 2 metres of an instrument measuring in a range of 100 µSv/h or more). Isolate identified objects with an ambient dose rate >100 µSv/h
  7. Instruct people to be monitored not to eat, drink or smoke until hands are washed; to shower and change clothing as soon as possible and after release to listen for and to follow official instruction given over the media (TV or radio).
  8. When monitoring:
    • Wear gloves and protective clothing as available, change gloves regularly
    • Follow personnel protection guidelines
    • Periodically get monitored and if contaminated >0.3 µSv/h , get decontaminated
    • Periodically confirm the instrument is operational and not contaminated (it can measure background). If contaminated, replace the plastic bag, and re-check
  9. Monitor a person's hair, hands, pockets, dirty parts of clothes, feet and face holding the monitor about 10 cm from the monitored surface
  10. Record the results of contamination survey using a registration form
  11. Perform the following actions depending on the results of survey. If the personal survey measurements of gamma dose rate at 10 cm from body surface (clothes) show:
    <1 µSv/h
    • Remind those monitored to:
      • shower and change clothing as soon as possible
      • listen for official instructions
    • Send them home (release).
    >1 µSv/h
    • Send those monitored for immediate decontamination (see instructions for public decontamination)
    • If immediate decontamination is not available, remind them to:
      • shower and change clothing as soon as possible
      • listen for official instructions
    • Send them home (release).

| Last update: Tuesday, 09 December, 2014.