Natural Sources of Radiation

Abstract

The term radiation is commonly used to describe charged or neutral heavy particles (e.g. electrons, protons, neutrons, nuclei and nuclear fragments) and massless neutral particles (X-rays, \(\gamma \)-rays). However, strictly speaking and throughout this text all elementary particles, including neutrinos and any electromagnetic wave, can be thought of as a form of radiation. The sources of radiation in the Universe are many, but can be grouped for simplicity in natural and man-made. Natural radiation is radiation whose source can be traced to be of either terrestrial, solar or astronomical nature and as such is typically found in our everyday life. This chapter presents an account of only a handful of the most common natural radiation sources: the cosmic background radiation, the cosmic and solar radiation and the natural radioactivity. Despite being mostly invisible to our eye, radiation permeates the natural environment in which we live.