  Worldwide several radiation sources contribute to the delivered dose to the
human population. This radiation also acts as natural background when detecting
radiation, for instance from radioactive sources. In this work a medium-size
plastic scintillation detector is used to evaluate the dose delivered by
natural radiation sources. Calibration of the detector involved the use of
radioactive sources and Monte Carlo simulation of the energy deposition per
disintegration. A measurement of the annual dose due to background radiation to
the body was then estimated. A dose value compatible with the value reported by
the United Nations Scientific Committee on the Effects of Atomic Radiation was
obtained.
