Radiation

                                  Overview

                                  Radiation is energy that travels in the form of waves or particles and is part of our everyday environment. People are exposed to radiation from cosmic rays, as well as to radioactive materials found in the soil, water, food, air and also inside the body.

                                  Human-made radiation sources are widely used in medicine, industry, and research. There are two types of radiation: ionizing and non-ionizing radiation.

                                   

                                  Ionizing radiation

                                  Ionizing radiation is a type of energy released by atoms that travels in the form of electromagnetic waves (gamma or X-rays) or particles (neutrons, beta or alpha). Ionizing radiation can remove electrons from the atoms, i.e. they can ionize atoms. In terms of natural radiation sources, there are more than 60 different naturally occurring radioactive materials present in the environment, with radon gas being the highest contributor to people’s exposure.

                                  Artificial radiation sources are used for nuclear power generation and many other industrial and research applications, with the medical use of ionizing radiation being today the highest contributor to people’s exposure (e.g. diagnostic radiology, image-guided interventions, nuclear medicine and radiotherapy).

                                  Non-ionizing radiation

                                  Non-ionizing radiation is radiation in the part of the electromagnetic spectrum where there is insufficient energy to cause ionization. It includes electric and magnetic fields, radio waves, microwaves, and optical radiation, which consists of infrared, visible, and ultraviolet radiation.

                                  Non-ionizing radiation encompasses both natural and human-made sources of electromagnetic fields. Electrical power supplies and appliances are the most common sources of low frequency electric and magnetic fields in our living environment. Everyday sources of radiofrequency electromagnetic fields include telecommunications, broadcasting antennas and microwave ovens.

                                  Optical radiation technologies, such as lasers, light bulbs and UV lamps, are used in industry, research and medicine. Non-ionizing radiation also encompasses mechanical waves such as infrasound and ultrasound.

                                   

                                  Over 84 000

                                  deaths

                                  from lung cancer caused by residential radon in 2019

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                                  Over 60 000

                                  skin melanoma

                                  -related deaths caused by solar ultraviolet radiation yearly

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                                  20 000

                                  thyroid cancers

                                  caused by the Chernobyl accident (up to 2015)

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                                  Highlights

                                  Featured

                                  Publications

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                                  Compendium of WHO and other UN guidance on health and environment

                                  This compendium provides a systematic compilation of published guidance from WHO and other UN organizations on health and environment. Guidance on policies...

                                  Portable digital radiography system: technical specifications

                                  This WHO-IAEA joint publication takes its origin from a substantial and increased need from Member States, donor agencies and NGOs to use “portable”...

                                  Technical specifications of radiotherapy equipment for cancer treatment

                                  The purpose of this publication is to provide guidance on the specification of technical equipment utilized in the practice of radiotherapy. The publication...

                                  A framework for mental health and psychosocial support in radiological and nuclear emergencies

                                   The health impact of radiological and nuclear emergencies can last for decades. Lessons learned from past radiological and nuclear accidents have...

                                  Documents

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                                  The electronic newsletters (e-Newsletters) of the WHO REMPAN network provide a communication platform to share the information and to advocate for the...

                                  The electronic newsletters (e-Newsletters) of the WHO REMPAN network provide a communication platform to share the information and to advocate for the...

                                  The virtual Inter-Agency Task Force (IATF) meeting on Chernobyl was chaired by Mr. Achim Steiner, UNDP Administrator and UN Coordinator of International...

                                  The WHO’s Radiation Emergency Medical Preparedness and Assistance Network (REMPAN) was established in 1987 in order to fulfill WHO’s mandate...

                                  Infographics