Artificial Light and Health


Glossary over Artificial Light and Health


A class of natural or man-made substances, such as penicillin, that kill or inhibit the growth of some micro-organisms. (Source: GreenFacts, based on CoRIS, Glossary  )













A clouding of the natural lens of the eye most frequently caused by ageing that can severely blur vision. (Source: GreenFacts)


The basic subunit of any living organism; the simplest unit that can exist as an independent living system. There are many different types of cells in complex organisms such as humans, each with specific characteristics. (Source: GreenFacts)


Cell Nucleus

The center of a cell, where [most] of the DNA, packaged in chromosomes, is contained. (Source: GreenFacts, based on Genetics Glossary  )



Occurring over a long period of time, either continuously or intermittently; used to describe ongoing exposures and effects that develop only after a long exposure. (Source: US EPA Thesaurus  )

Chronic actinic dermatitis

Chronic actinic dermatitis is a rare skin disease that mainly affects middle-aged and elderly men. It is characterised by severely itchy, red, inflamed, and thickened dry skin due to exposure to ultraviolet radiation and frequently also visible light from the sun or artificial lighting. The cause remains unknown. Treatment consists in avoiding exposure to sunlight. (Source: GreenFacts, based on DermNet NZ  )

Circulatory system





Collagen is the main structural protein of the skin. (Source: GreenFacts)


Compact fluorescent lamps (CFLs)

Compact Fluorescent Lamps (CFLs) are energy-saving light bulbs, which last longer and use far less energy than traditional (or incandescent) light bulbs for the same level of light intensity. (Source: GreenFacts )



A transparent membrane covering the eyeball and the inner surface of the eyelid. (Source: GreenFacts)


Dyspraxia is a disability that affects body movements and co-ordination. It often leads to clumsiness, and problems with language, perception and thoughts. The causes are unclear, but it can be acquired via a stroke, accident, illness, weak trauma, momentary lack of oxygen at birth or during pregnancy. The condition can be treated via early intervention, using physical and occupational therapy to improve motor skills. (Source: GreenFacts )

Electromagnetic fields (EMF)

Electromagnetic fields (EMF) are a combination of invisible electric and magnetic fields of force. They occur both naturally and due to human activity. (Source: GreenFacts)


Electromagnetic spectrum

The electromagnetic spectrum is the entire range of wavelengths of all known electromagnetic radiations. It includes:

Gamma rays have the smallest wavelengths and highest frequencies known. They are high energy waves capable of travelling long distances through air and are the most penetrating waves.

X-rays have longer wavelengths than gamma rays but smaller wavelengths and therefore higher energy than ultraviolet radiation. They have been used in various applications in science and industry and are primarily used in medicine for instance in radiography. They are a form of ionizing radiation and as such can be dangerous. X-rays are emitted by electrons outside the nucleus, while gamma rays are emitted by the nucleus.

Ultraviolet (UV) radiation is defined as the portion of the electromagnetic spectrum between X-rays and visible light. More...

Visible light – also known as the visible spectrum – is the portion of the electromagnetic spectrum that human eyes can detect. It covers all colours from blue at 400 nm to red at 700 nm, with blue light having more energy than red light.

Infrared (IR) radiation – also referred to as thermal radiation – is the portion of the electromagnetic spectrum lying between visible light and microwaves. The most important natural source of infrared radiation is the sun.




An electron is a particle that carries a negative electrical charge. Electrons form the outer "reactive" shell of atoms which interacts with other atoms and form the chemical bonds that hold molecules together. Flow of electrons between two points generates an electric current. (Source: GreenFacts )

Elemental mercury

Hg. Mercury in its elemental (pure) form, that is, as a metal; hence the synonym metallic mercury. A shiny, silver-gray metal that is a liquid at room temperature. (Source: GreenFacts)



In humans and animals, epidermis refers to the thin outermost layer of the skin.

This tissue constantly renews itself. (Source: GreenFacts)


Epilepsy is a brain disorder that causes people to have recurring seizures. These happen when clusters of nerve cells in the brain undergo a sudden surge of electrical activity, resulting in strange sensations, emotions or behaviour. Epileptics may have violent muscle spasms or lose consciousness.

Epilepsy has many possible causes, including illness, brain injury and abnormal brain development. In many cases, the cause is unknown. There is no cure for epilepsy, but medicines can control seizures for most people. (Source: GreenFacts )



Superficial reddening of the skin due to the dilatation of blood vessels. Erythema is often a sign of infection or inflammation and may be caused by sunburn. (Source: GreenFacts)


Main components of the human eye include:

The retina - Light-sensitive layer at the back of the eyeball onto which incoming light is focused. It contains cells that respond to colours, different shades of grey, and movement. These cells trigger nerve impulses that are carried by the optic nerve to the brain, where a visual image is formed.

The cornea - The dome-shaped, transparent layer that forms the front of the eyeball. It bends light entering the eye into the lens, and hence helps to focus images onto the retina. It contains no blood vessels and is extremely sensitive to pain.

The lens - Transparent elastic structure situated behind the pupil of the eye that focuses incoming light onto the retina. Muscles in the eye can adjust the shape of the lens and make it more flattened to focus on distant objects, or make it more rounded to focus on near objects.

The vitreous humour - The transparent jelly-like substance that fills the eyeball between the lens and the retina. (Source: GreenFacts)



Fibromyalgia is a chronic pain disorder characterized by widespread pain of the muscles and bones, stiffness, general fatigue, and sleep disturbances. The underlying cause remains unknown, yet most researchers agree that it is related to the nervous system. There are several suggested explanations for fibromyalgia, such as genetic predisposition, stress, trauma, psychological problems. Treatment includes pain and sleep management and psychological support. (Source: GreenFacts )

Free radical

A free radical is an atom or molecule that is highly reactive because it contains an unpaired electron in the outer shell.

Free radicals are formed as necessary intermediates in a variety of normal biochemical reactions, but can damage important cellular molecules such as DNA or lipids.

Radicals can have positive, negative or neutral charge. (Source: GreenFacts)


Genophotodermatoses are rare inherited skin diseases induced by light. They include Xeroderma Pigmentosum, Cockayne’s, Bloom’s and Rothmund-Thomson Syndromes. (Source: SCENIHR  Opinion on Light Sensitivity (2008) )

Immune system

The immune system is a network of cells, tissues, and organs that work together to defend the body against attacks by “foreign” invaders. (Source: NIAID Immune System   )


Incandescent light bulbs

An incandescent light bulb is an electric light bulb in which an electric current passes through a filament, heating it up until it becomes incandescent, producing light. (Source: GreenFacts )


Inflammation is the reaction of living tissues to infection, irritation or other injury. (Source: GreenFacts)


Infrared radiation

Electromagnetic radiation with wavelengths longer than visible light, but shorter than microwave radiation, i.e. from approximately 750nm to 1mm. The name means "below red", red being the color of visible light of longest wavelength. (Source: GreenFacts)



A chronic inflammatory connective tissue disease marked by skin rashes, joint pain and swelling, inflammation of the kidneys, inflammation of the fibrous tissue surrounding the heart (i.e. the pericardium), as well as other problems. Not all affected individuals display all of these problems. (Source: Rare Cancer Alliance Cancer Dictionary  )


Cancer that begins in cells of the immune system (the lymphatic system).

The most common type of lymphoma is called Hodgkin's lymphoma or Hodgkin's disease.

All other lymphomas are grouped together under the term non-Hodgkin's lymphoma. (Source: GreenFacts)


Cancerous. Progressive and uncontrolled growth. Malignant neoplasms or tumours can invade and destroy other tissues and spread to other parts of the body via the bloodstream or lymphatics (metastasis). (Source: GreenFacts )


A reddish to dark-brown to black pigment occurring in the hair, skin, and parts of the eye.

It helps protect skin from ultraviolet radiation from the sun.

The amount of melanin determines skin colour. Absence of melanin results in an albino.

Melanin production is responsible for tanning of skin exposed to sunlight. (Source: GreenFacts)


Melatonin is a hormone formed by the pineal gland (which is located in the center of the brain). Melatonin regulates the sleep-wake cycle and is stimulated by darkness and inhibited by light. Melatonin is also available in some countries as a drug or a dietary supplement which acts against insomnia and jet-lag. (Source: GreenFacts)


Migraine is a severe headache, often accompanied by nausea and visual disturbances such as blurred or loss of vision, light flashes and abnormal sensitivity to light. Its cause could be genetic or related to changes of blood flow and certain chemicals. Medicines can help prevent attacks or relieve symptoms. For many people, treatments to relieve stress can also help. (Source: GreenFacts )

Multiple sclerosis

A disorder of the central nervous system marked by weakness, numbness, a loss of muscle coordination, and problems with vision, speech, and bladder control. Multiple sclerosis is thought to be an autoimmune disease in which the body's immune system destroys myelin. Myelin is a substance that contains both protein and fat (lipid), serving as a nerve insulator and helping in the transmission of nerve signals. (Source: NCI dictionary   )




Photochemical reaction

Refers to any chemical reaction which occurs as a result of light energy from the sun.

For example, ozone is formed through a photochemical reaction involving nitrogen dioxide and reactive organic compounds. (Source: DNREC online   A history of air pollution events )



Photophobia is an abnormal sensitivity or intolerance to light leading to intense eye discomfort, tearing and blinking and other reactions aimed at avoiding light. It can be due to eye inflammation, trauma to the outer surface of the eye, migraine or the use of certain eye drops. (Source: GreenFacts )


Porphyrias are a group of rare blood disorders caused by a mixture of inherited and environmental factors. They are due to the accumulation in the body of a substance called porphyrin, which is normally used as a component to make blood cells. Symptoms include blisters, itching, and swelling of the skin when it is exposed to sunlight. Other factors such as the use of certain medicines, smoking, alcohol, infections and stress can also trigger symptoms. Each type of porphyrias has a different treatment (Source: GreenFacts )

Scientific Committee on Emerging and Newly Identified Health Risks

The Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) was set up in 2004 by the European Commission to provide the Commission with unambiguous scientific advice on the safety of a series of issues requiring a comprehensive assessment of the risks, such as new technologies, medical devices, etc.

The SCENIHR advice is intended to enable risk managers to take the adequate and required actions in order to guarantee consumer safety or public health.

The SCENIHR addresses questions concerning emerging or newly-identified risks and on broad, complex or multi-disciplinary issues requiring a comprehensive assessment of risks to consumer safety or public health and related issues not covered by other Community risk- assessment bodies.

The Scientific Committee on Emerging and Newly Identified Health Risks is composed of a maximum of 13 members, but for any specific question may enlist the support of up to six associated members selected on the basis of their expertise. There is also a reserve list made up of candidates found suitable for a position in a Scientific Committee but not appointed. The members of the SCENIHR are appointed on the basis of their skills and experience in the fields in question, and consistent with this a geographical distribution that reflects the diversity of scientific problems and approaches in the European Union (EU). The experts' term of office is three years and is renewable for a maximum of three consecutive times. In agreement with the Commission, the Scientific Committees may turn to specialised external experts.

The SCENIHR complies with the principles of independence, transparency and confidentiality. The members therefore make a declaration of commitment to act in the public interest and a declaration of interests; requests for opinions, agendas, minutes and opinions are published; work and publications are done with regard to the need for commercial confidentiality. (Source: SCENIHR pages  )

Skin cancer

A tumour that grows from skin cells and which can have different causes, including repeated severe sunburns or long-term exposure to the sun. (Source: GreenFacts, based on EcoHealth; Glossary   )


Solar urticaria

Solar urticaria is a stinging, itchy rash which develops within minutes of exposure to sunlight or artificial light emitting ultraviolet radiation. The cause of solar urticaria is not clearly defined but may be due to an immune reaction between a chemical created in the body (photoallergen) reacting with ultraviolet radiation to cause the allergic reaction. (Source: GreenFacts, based on DermNet NZ  )

Stem cell

An undifferentiated type of body cell found in bone marrow, growing tissues, and embryonic tissue. The physical location of the stem cell, and the hormonal or growth influences that surround it, will determine what type of adult cell it will become. (Source: Queensland Institute of Medical Research, Glossary )


Ultraviolet radiation

Electromagnetic radiation of shorter wavelength than visible light but of longer wavelenght than x-rays, i.e. ranging from approximately 400 nm to 100 nm.

The most common source of ultraviolet radiation is the sun, but it can also be produced artificially by UV lamps.

UV radiation is divided into three bands: UVA, UVB, and UVC. All three bands are classified as a probable human carcinogen.

UVA – Long-wavelength UVA covers the range 315–400 nm. Not significantly filtered by the atmosphere. Approximately 90% of UV radiation reaching the Earth’s surface. UVA is again divided into UVA-I (340 nm - 400 nm) and UVA-II (315 nm - 340 nm).

UVB – Medium-wavelength UVB covers the range 280–315 nm. Approximately 10% of UV radiation reaching the Earth’s surface.

UVC – Short-wavelength UVC covers the range 100–280 nm. All solar UVC radiation is absorbed by the ozone layer. (Source: GreenFacts based on WHO  Artificial tanning sunbeds: risks and guidance )



A virus is a small organism which can infect other biological organisms.

Viruses can only reproduce by invading and taking over cells as they lack the cellular machinery for self reproduction.

They cause diseases in human beings, animals, plants and bacteria.

Examples of human diseases caused by viruses include the common cold, influenza, small pox, AIDS, and cold sores. (Source: GreenFacts)






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