Nuclear Science and Technology and How It Influences Your Life http://www.aboutnuclear.org/ return to interactive version
	Radiation and Radioactivity : Sources of Radiation Most radiation comes to us from the sun and from cosmic radiation -- so that people at higher elevations like Colorado and adjacent Rocky Mountain States receive more than those who live at sea level.  However, a lot of radiation also comes from the soil and rocks around us.  Granite and marble have background levels of radioactivity.  A relatively small additional amount comes from our man-made technology.