Ultraviolet radiation (UV radiation) accompanies us throughout our lives as part of solar radiation. As part of the electromagnetic spectrum, it lies between X-rays and visible optical radiation (light). The wavelength of UV radiation ranges from 100 nanometres to 400 nanometres. 

UV radiation was discovered in 1801 by Johann Wilhelm Ritter. By splitting sunlight with a prism and observing the reaction of silver chloride, which darkens when exposed to light, he noticed a strong colour change just beyond the violet range of light. So there must also have been radiation in this spectral range that is not visible and that we now call ultraviolet radiation.

In addition to the sun as a natural source of UV radiation, there are many ways to encounter artificial UV radiation. The best known is probably the sunbed, but UV radiation also plays an important role in technology, medicine and research, e.g. in fluorescent dye analysis, phototherapy, disinfection, curing of plastics and paints, as well as an unwanted by-product in welding processes.

Today it is well understood that UV radiation, whether natural or artificial, can damage the skin and eyes and cause cancer. The number of skin cancer cases has risen dramatically in recent decades. One of the groups particularly affected are employees who regularly work outdoors as part of their job. In Germany, the occupational disease ‘squamous cell carcinoma or multiple actinic keratoses of the skin caused by natural UV radiation’ was added to the list of recognised occupational diseases in 2015. In order to protect the population from the effects of UV radiation in their private and professional lives, it is therefore necessary to provide well-founded information on individual exposure to UV radiation as well as easily understandable information on possible protective measures and their application. 

UV radiation is therefore not only a natural phenomenon, but also an important factor in science, medicine and technology – with both opportunities and risks.

FS Poster "Radiation of the Year 2026"

Radiation of the Year 2026 -  UV-Radiation
Note: This poster is free to use. If you use it, please send a short message to the FS Executive Director fs-gf@fs-ev.org

Gamma radiation (rays)
is a particularly penetrating electromagnetic radiation that is produced after the radioactive decay of an atomic nucleus, e.g. via alpha or beta decay. It was discovered in 1900, 125 years ago, by the French physicist and chemist Paul Ulrich Villard (28.09.1860-13.01.1934).

While investigating the properties of radium, he discovered that there is a magnetically non-deflectable part of the radiation emitted by radium. As this component was also able to penetrate aluminum and thin lead plates, he presented this radiation as a new radiation, in addition to the alpha and beta radiation already described by Becquerel, Mr. and Mrs. Curie and Mr. and Mrs. Rutherford. Although Villard correctly interpreted the results of his experiments and thus discovered the new rays, his discovery was initially largely ignored by the scientific community. It was not until 1903 that these new rays were first named “gamma rays” by Rutherford.

Gamma radiation is used in industry, e.g. for testing weld seams, measuring fill levels or sterilizing objects and products, mostly in medicine or pharmacy. In medicine, gamma radiation is used for diagnostics and in some cases for tumor therapy. Radionuclides are often detected via their gamma radiation.

For a detailed article on the history of the discovery of gamma radiation, its origin, formation, properties, effects, use, measurement, and reams, as well as protection against it, see The decay of radionuclides in the ground also produces gamma radiation, which, together with cosmic radiation, is an essential component of radiation exposure to humans.sem document.

The decay of radionuclides in the ground also produces gamma radiation, which, together with cosmic radiation, is an essential component of radiation exposure to humans.

A detailed article on the history of the discovery of gamma radiation, its origin, formation, properties, effect, use, measurement, and risks as well as protection against it can be found --> here

Further interesting information

• example of gamma radiation in medicine

• FS Poster “Radiation of the Year 2025 Gamma Radiation”
  Note: This poster is free to use. If you use it, please send a short message to the FS Executive Director fs-gf@fs-ev.org

   

   

Reasons for the radiation of the year 2024

We live in a world where many artificial light sources outdoors, such as street lights, sky beamers, stadium lighting, and large-scale outdoor advertising, are increasingly illuminating the natural night sky. Protection from “light pollution” has thus far been only a marginal issue within the historically developed field of radiation protection.
However, our future-oriented approach to radiation protection considers the protection of the environment to be just as important as the protection of human beings.

The Professional Association for Radiation Protection has therefore named light pollution “Radiation of the Year 2024” in order to draw attention to this often overlooked radiation problem.

Light pollution is inextricably linked to urbanization. It not only causes the stars to fade in the sky but also has a wide range of effects on humans and nature. In many places, the conversion to LED street lighting has led to excessive luminous flux with a high proportion of blue light, which penetrates homes. Unnecessary and incorrectly installed or designed lights also cause artificial brightening of the immediate surroundings in commercial areas, as well as scattering and reflection on clouds and particles. This affects a variety of physiological processes. The sleep-wake cycle can be disrupted and the production of the hormone melatonin can be reduced. Sleep deprivation and other health problems may result.

Disturbance of the nocturnal environment also affects animal behavior. Numerous insects, a major food source for birds, are attracted to artificial light and often die on contact with light sources. Birds circle around illuminated office towers and die from exhaustion, and fireflies can no longer reproduce because the males can no longer see the glowing females.

As the World Atlas of Night Sky Brightness (https://www.science.org/doi/10.1126/sciadv.1600377) shows, light pollution is a global problem. Large parts of Europe, North America, the Middle East, and Asia are particularly affected.

Further interesting information

•   Wenn die Nacht zum Tag wird: Lichtverschmutzung - eine gesellschaftliche Herausforderung (When night becomes day: light pollution – a social challenge) (Joint press release by the Professional Association for Radiation Protection, the German Society for Lighting Technology and Lighting Design, and the Association of Star Friends (December 2024))

•   Lichtverschmutzung: Was Kunstlicht für das Leben im Meer bedeuten kann  (Lightpollution: What artificial light can mean for marine life)
(NDR News Schleswig-Holstein; November 17, 2024)

In February 1923, its discoverer Wilhelm Conrad Röntgen died. However, awarding the title is not just a symbolic act to mark the 100th anniversary of his death.
X-rays were the type of radiation whose effects, in the first few decades after their discovery, made it clear that protection from this radiation was necessary. To this day, X-rays are the form of ionising radiation that reaches practically everyone and has a wide range of applications. From simple X-rays at the dentist to computer tomography, where patients (if medically justified) can receive a dose that is within the occupational exposure limits, hardly anyone would want to forego the knowledge that an X-ray provides in an emergency.
Modern technology also often requires information from inside devices, materials or packaging, and X-ray fluorescence (XRF) makes the chemical composition of substances visible quickly and easily.

Further interesting information

• Wikipedia: Röntgen und Röntgenstrahlung
• Welt der Physik
• Röntgenmuseum Lennep
• Wilhelms Kurs „Blended-Learning-Angebot für Schulen“