Radiation Basics 6
In the course of the evolution of civilization, mankind has created a number of sources of radiation which contribute to radiation exposure of people. These include substances, medical equipments, consumer devices and building materials.
Sources of radiation that impact the average individual in industrialized countries include tobacco which contains thorium and uranium, televisions which emit x-rays, medical X-rays, smoke detectors which contain americium, and lantern mantles which contain thorium.
Modern medicine utilizes a large variety of radioactive isotopes which include: bismuth-213, cesium-137, carbon-11, chromium-51, cobalt-57, cobalt-60, copper-64, dysprosium-165, erbium-169, fluorine-18, gallium-67, gold-198, holmium-166, indium-111, iodine-123, iodine-125, iridium-192, iron-59, krypton-81, lutetium-177, nitrogen-13, oxygen-15, palladium-103, phosphorus-32, potassium-42, rhenium-188, rubidium-82, samarium-153, selenium-75, sodium-24, strontium-89, strontium-92, technetium-99, thallium-201, xenon-133 (5 d), ytterbium-169, and yttrium-90. These isotopes, with the exception of cesium, have half lives for seconds to days. They are used for diagnosis of many conditions, imaging of different parts of the body and treatment of a variety of disease.
Most building materials from natural sources contain small quantities of radium 226, uranium 238 and Thorium 232 as well as radionuclides which are the result of decay of these isotopes. Radon 22 and radon 220 are gases which are injected into the interior air of builds from the decay in the building materials.
Recycled industrial by-products contain radioactive isotopes which have been concentrated above normal background levels in industrial processes. These include coal ash from the burning of coal which is an additive in cement, coal slag is used in floors as an insulating fill, phosphogypsum which is a by-product of the production of phosphorous fertilizers and red mud which is a waste product in aluminum manufacture used in bricks, ceramics and tiles.
Some professions expose workers to radioactivity. Workers who mine uranium and process uranium are exposed to the natural radioactivity of uranium. Nuclear power plant workers and power plant inspectors can be exposed to uranium 235 and plutonium. Nuclear medicine technician can be exposed to any of the radioisotopes mentioned in the paragraph above on nuclear medicine. Radiography and X-ray technicians are exposed to x-rays.