The monitoring of radiation doses released into the environment is required in some locations in the vicinity of nuclear or medical installations. In Belgium, special measuring poles with dosemeters are installed in the vicinity of nuclear installations. The SCK•CEN dosimetry service monitors environmental doses at several installations, for example around the nuclear power plant in Doel.
Environmental dosemeters are read out and exchanged every three months. The detectors are highly sensitive, and are not affected by strong fluctuations in the weather conditions. Based on the results of these measurements, the natural background radiation is determined and any deviating results are monitored.
The natural background radiation primarily consists of cosmic radiation and radiation originating from the earth. Human activities may increase this background level, but this usually represents only a minor increase.