smear the inside of the glass and paint each other ' s faces with the phosphor. We explained that it was important that we perform some tests to identify if they had any internal exposure from the radiation, primarily for reassurance. Bioassay samples were taken from all the individuals involved and no internal exposure was identified.

Once all the radioactive materials had been cleaned up, wipes were taken and counted in a liquid scintillation counter in a local laboratory to confirm that the levels of tritium in the area and inside the hospital building were negligible.

This was an interesting job, where we had to adjust to living for a short time in a very small and remote community, relying on the supplies which we had brought, and had to gather and return all the low level radioactive material and generated waste via aeroplane. The air in the northern town was clean and beautiful, fortunately, the incident happened in the autumn when the weather was still a pleasant temperature in Northern Canada, although the nights still became dark quite early. With very little to do at the end of the work day, we watched the stars in the clear night skies and appreciated the quiet environment.

The incident made it very clear that, while radioactive materials can be safely handled when used correctly, they could easily be misused in the wrong hands. The tritium phosphor, while only mildly radioactive, was an appealing toy for the local youth looking to amuse themselves.

22 Radiation Protection Today www. srp-rpt. uk