Several radiation sources worldwide contribute to the delivered dose to the human population. This
radiation also acts as a natural background when detecting radiation, for instance from radioactive
sources. In this work a medium-sized 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.