Electromagnetic radiation and health
[1] Extreme ultraviolet and higher frequencies, such as X-rays or gamma rays are ionizing, and these pose their own special hazards: see radiation poisoning.
[2] The most common health hazard of radiation is sunburn, which causes between approximately 100,000 and 1 million new skin cancers annually in the United States.
[3][4] In 2011, the World Health Organization (WHO) and the International Agency for Research on Cancer (IARC) have classified radiofrequency electromagnetic fields as possibly carcinogenic to humans (Group 2B).
Industrial installations for induction hardening and melting or on welding equipment may produce considerably higher field strengths and require further examination.
Since electromagnetic fields may influence passive or active implants of workers, it is essential to consider the exposure at their workplaces separately in the risk assessment.
In 2011, the WHO/International Agency for Research on Cancer (IARC) has classified radio frequency electromagnetic fields as possibly carcinogenic to humans (Group 2B), based on an increased risk for glioma and acoustic neuroma associated with wireless phone use.
Typical household exposure to ELF waves ranges in intensity from 5 V/m for a light bulb to 180 V/m for a stereo, measured at 30 centimetres (12 in) and using 240V power.
Because the human body is conductive, electric currents and resulting voltages differences typically accumulate on the skin but do not reach interior tissues.
[22] People can start to perceive high-voltage charges as tingling when hair or clothing in contact with the skin stands up or vibrates.
[22] Associations between exposure to extremely low frequency magnetic fields (ELF MF) and various health outcomes have been investigated through a variety of epidemiological studies.
[25] Shortwave (1.6 to 30 MHz) diathermy (where EM waves are used to produce heat) can be used as a therapeutic technique for its analgesic effect and deep muscle relaxation, but has largely been replaced by ultrasound.
[7] The classification of mobile phone signals as "possibly carcinogenic to humans" by the World Health Organization (WHO) — "a positive association has been observed between exposure to the agent and cancer for which a causal interpretation is considered by the Working Group to be credible, but chance, bias or confounding could not be ruled out with reasonable confidence"[29]— has been interpreted to mean that there is very little scientific evidence as to phone signal carcinogenesis.
[31] The WHO concluded in 2014 that "A large number of studies have been performed over the last two decades to assess whether mobile phones pose a potential health risk.
Microwave ovens use this form of radiation, and have shielding to prevent it from leaking out and unintentionally heating nearby objects or people.
Cataract-like changes can occur in workers who observe glowing masses of glass or iron without protective eyewear for prolonged periods over many years.
[17] Exposing skin to infrared radiation near visible light (IR-A) leads to increased production of free radicals.
[citation needed] Photic retinopathy is damage to the macular area of the eye's retina that results from prolonged exposure to sunlight, particularly with dilated pupils.
To control the risk of injury, various specifications – for example ANSI Z136 in the US, EN 60825-1/A2 in Europe, and IEC 60825 internationally – define "classes" of lasers depending on their power and wavelength.
As with its infrared and ultraviolet radiation dangers, welding creates an intense brightness in the visible light spectrum, which may cause temporary flash blindness.
The UV-B flux is 2–4 times greater during the middle 4–6 hours of the day, and is not significantly absorbed by cloud cover or up to a meter of water.
[47] Ultraviolet light, specifically UV-B, has been shown to cause cataracts and there is some evidence that sunglasses worn at an early age can slow its development in later life.
This is most commonly the result of exposure to the sun at high altitude, and in areas where shorter wavelengths are readily reflected from bright surfaces, such as snow, water, and sand.
When the film is cracked by mishandling or faulty manufacturing then UV may escape at levels that could cause sunburn or even skin cancer.
