Electromagnetic radiation and health
Part of a series on |
Pollution |
---|
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).[5]
Hazards
The heating effect varies with the power and the
Workplace exposure
Radio frequency (RF) energy at power density levels of 1–10 mW/cm2 or higher can cause measurable heating of tissues. Typical RF energy levels encountered by the general public are well below the level needed to cause significant heating, but certain workplace environments near high power RF sources may exceed safe exposure limits. which guard against thermal damage.
Industrial installations for induction hardening and melting or on welding equipment may produce considerably higher field strengths and require further examination. If the exposure cannot be determined upon manufacturers' information, comparisons with similar systems or analytical calculations, measurements have to be accomplished. The results of the evaluation help to assess possible hazards to the safety and health of workers and to define protective measures. 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.[10]
Low-level exposure
The World Health Organization (WHO) began a research effort in 1996 to study the health effects from the ever-increasing exposure of people to a diverse range of EMR sources. In 2011, the WHO/International Agency for Research on Cancer (IARC)[11] has classified radiofrequency electromagnetic fields as possibly carcinogenic to humans (Group 2B), based on an increased risk for glioma, a malignant type of brain cancer, associated with wireless phone use.
Epidemiological studies look for statistical correlations between EM exposure in the field and specific health effects. As of 2019, much of the current work is focused on the study of EM fields in relation to cancer.[12] There are publications which support the existence of complex biological and neurological effects of weaker non-thermal electromagnetic fields (see Bioelectromagnetics), including weak ELF electromagnetic fields[13][14] and modulated RF and microwave fields.[15][16]
Effects by frequency
While the most acute exposures to harmful levels of electromagnetic radiation are immediately realized as burns, the health effects due to chronic or occupational exposure may not manifest effects for months or years.[17][18][4][19]
Extremely low frequency
Extremely low frequency EM waves can span from 0 Hz to 3 kHz, though definitions vary across disciplines. The maximum recommended exposure for the general public is 5 kV/m.[20]
ELF waves around 50 Hz to 60 Hz are emitted by
Overhead power lines range from 1kV for local distribution to 1,150 kV for ultra high voltage lines. These can produce electric fields up to 10kV/m on the ground directly underneath, but 50 m to 100 m away these levels return to approximately ambient.[20] Metal equipment must be maintained at a safe distance from energized high-voltage lines.[21]
Exposure to ELF waves can induce an electric current. 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] In scientific tests, only about 10% of people could detect a field intensity in the range of 2-5 kV/m.[22] Such voltage differences can also create electric sparks, similar to a discharge of static electricity when nearly touching a grounded object. When receiving such a shock at 5 kV/m, it was reported as painful by only 7% of test participants and by 50% of participants at 10 kV/m.[22]
The International Agency for Research on Cancer (IARC) finds "inadequate evidence" for human carcinogenicity.[23]
Shortwave
Studies have been performed on the use of shortwave radiation for cancer therapy and promoting wound healing, with some success. However, at a sufficiently high energy level, shortwave energy can be harmful to human health, potentially causing damage to biological tissues, for example by overheating or inducing electrical currents.[26] The FCC limits for maximum permissible workplace exposure to shortwave radio frequency energy in the range of 3–30 MHz has a plane-wave equivalent power density of (900/f2) mW/cm2 where f is the frequency in MHz, and 100 mW/cm2 from 0.3 to 3.0 MHz. For uncontrolled exposure to the general public, the limit is 180/f2 between 1.34 and 30 MHz.[7]
Radio and microwave frequencies
The designation of mobile phone signals as "possibly carcinogenic to humans" by the World Health Organization (WHO) (e.g. its IARC, see below) has often been misinterpreted as indicating that some measure of risk has been observed – however the designation indicates only that the possibility could not be conclusively ruled out using the available data.[27]
In 2011,
Since 1962, the microwave auditory effect or tinnitus has been shown from radio frequency exposure at levels below significant heating.[31] Studies during the 1960s in Europe and Russia claimed to show effects on humans, especially the nervous system, from low energy RF radiation; the studies were disputed at the time.[32][33]
In 2019, reporters from the Chicago Tribune tested the level of radiation from smartphones and found that certain models emitted more than reported by the manufacturers and in some cases more than the U.S. Federal Communications Commission exposure limit. It is unclear if this resulted in any harm to consumers. Some problems apparently involved the phone's ability to detect proximity to a human body and lower the radio power. In response, the FCC began testing some phones itself rather than relying solely on manufacturer certifications.[34]
Microwave and other radio frequencies cause heating, and this can cause burns or eye damage if delivered in high intensity,[35] or hyperthermia as with any powerful heat source. Microwave ovens use this form of radiation, and have shielding to prevent it from leaking out and unintentionally heating nearby objects or people.
Millimeter waves
In 2009, the US TSA introduced full-body scanners as a primary screening modality in
Infrared
Exposing skin to infrared radiation near visible light (IR-A) leads to increased production of free radicals.[38] Short-term exposure can be beneficial (activating protective responses), while prolonged exposure can lead to photoaging.[39]
Another important factor is the distance between the worker and the source of radiation. In the case of arc welding, infrared radiation decreases rapidly as a function of distance, so that farther than three feet away from where welding takes place, it does not pose an ocular hazard anymore but, ultraviolet radiation still does. This is why welders wear tinted glasses and surrounding workers only have to wear clear ones that filter UV.[citation needed]
Visible light
Moderate and high-power lasers are potentially hazardous because they can burn the retina of the eye, or even the skin. 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.[41][42] Regulations prescribe required safety measures, such as labeling lasers with specific warnings, and wearing laser safety goggles during operation (see laser safety).
As with its infrared and ultraviolet radiation dangers, welding creates an intense brightness in the visible light spectrum, which may cause temporary flash blindness. Some sources state that there is no minimum safe distance for exposure to these radiation emissions without adequate eye protection.[43]
Ultraviolet
Sunlight includes sufficient ultraviolet power to cause
Ultraviolet light, specifically UV-B, has been shown to cause
Prolonged exposure to
Ultraviolet radiation of wavelengths shorter than 300 nm (actinic rays) can damage the corneal epithelium. 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. UV generated by a welding arc can similarly cause damage to the cornea, known as "arc eye" or welding flash burn, a form of photokeratitis.[49]
Regulation
In the United States, nonionizing radiation is regulated in the
See also
- Background radiation
- Bioinitiative Report
- Biological effects of radiation on the epigenome
- Central nervous system effects from radiation exposure during spaceflight
- Cosmic ray
- COSMOS cohort study
- Directed energy weapon
- Electromagnetic hypersensitivity
- Electromagnetism
- EMF measurement
- Health threat from cosmic rays
- Light ergonomics
- Magnetobiology
- Microwave
- Wireless device radiation and health
- Personal RF safety monitor
- Specific absorption rate
References
- ^ Cleveland Jr RF, Ulcek JL (August 1999). Questions and Answers about Biological Effects and Potential Hazards of Radiofrequency Electromagnetic Fields (PDF) (4th ed.). Washington, D.C.: OET (Office of Engineering and Technology) Federal Communications Commission. Archived (PDF) from the original on 30 June 2019. Retrieved 29 January 2019.
- ISBN 978-92-822-2272-0, archivedfrom the original on 18 October 2021
- PMID 31912902.
- ^ ISBN 1-55009-113-1. Archivedfrom the original on 4 September 2015. Retrieved 31 January 2011.
- ^ Gaudin, Ph.D., Nicolas (31 May 2011). "IARC Classifies Radiofrequency Electromagnetic Fields As Possibly Carcinogenic to Humans" (PDF). International Agency for Research on Cancer. Archived (PDF) from the original on 4 April 2012. Retrieved 20 November 2021.
- ISBN 978-1420009460. Archivedfrom the original on 4 January 2021. Retrieved 29 January 2019.
- ^ a b c Cleveland Jr RF, Ulcek JL (August 1999). "Questions and Answers about Biological Effects and Potential Hazards of Radiofrequency Electromagnetic Fields" (PDF). OET Bulletin 56 (Fourth ed.). Office of Engineering and Technology, Federal Communications Commission. p. 7. Archived (PDF) from the original on 30 June 2019. Retrieved 2 February 2019.
- ^ "Standard for Safety Level with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3KHz to 300GHz". IEEE STD. C95.1-2005. IEEE. October 2005. Archived from the original on 7 May 2015. Retrieved 23 May 2015.
- PMID 9525427. Archived from the original(PDF) on 13 November 2008.
- ^ Institute for Occupational Safety and Health of the German Social Accident Insurance. "Electromagnetic fields: key topics and projects".
- ^ [1]
- ^ "What are electromagnetic fields? – Summary of health effects". World Health Organization. Archived from the original on 16 October 2019. Retrieved 7 February 2019.
- PMID 7107514.
- from the original on 16 December 2019. Retrieved 29 June 2019.
- PMID 16495939.
- PMID 26300312.
- ^ ISBN 0203311825. Archivedfrom the original on 15 December 2019. Retrieved 31 January 2019.
- ^ S2CID 8242055.
- ^ a b "UV Exposure & Your Health". UV Awareness. Archived from the original on 2 May 2019. Retrieved 10 March 2014.
- ^ a b c World Health Organization (4 August 2016). "Radiation: Electromagnetic fields - Q&A". Archived from the original on 18 January 2022. Retrieved 21 January 2022.
- ^ Ubong Edet (6 December 2017). "How to identify powerline voltage level and safe clearance level". Archived from the original on 12 May 2021. Retrieved 21 January 2022.
- ^ a b c d Extremely Low Frequency Fields Environmental Health Criteria Monograph No.238, chapter 5, page 121, WHO
- ^ "Power Lines, Electrical Devices, and Extremely Low Frequency Radiation". Archived from the original on 11 April 2020. Retrieved 22 April 2020.
- ISBN 978-0781768276. Archivedfrom the original on 18 August 2021. Retrieved 1 February 2019.
- ISBN 978-0781757447. Archivedfrom the original on 15 December 2019. Retrieved 1 February 2019.
- PMID 28729909.
- PMID 21795667.
- ^ "IARC classifies radiofrequency electromagnetic fields as possibly carcinogenic to humans" (PDF). press release N° 208 (Press release). International Agency for Research on Cancer. 31 May 2011. Archived (PDF) from the original on 1 June 2011. Retrieved 2 June 2011.
- ^ "Electromagnetic fields and public health: mobile phones – Fact sheet N°193". World Health Organization. October 2014. Archived from the original on 6 August 2016. Retrieved 2 August 2016.
- ^ Limits of Human Exposure to Radiofrequency Electromagnetic Fields in the Frequency Range from 3 kHz to 300 GHz Archived 29 October 2013 at the Wayback Machine, Canada Safety Code 6, p. 63
- S2CID 12359057.
- ^ Bergman W (1965), The Effect of Microwaves on the Central Nervous System (trans. from German) (PDF), Ford Motor Company, pp. 1–77, archived from the original (PDF) on 29 March 2018, retrieved 19 December 2018
- ^ Michaelson SM (1975). "Radio-Frequency and Microwave Energies, Magnetic and Electric Fields" (Volume II Book 2 of Foundations of Space Biology and Medicine). In Calvin M, Gazenko OG (eds.). Ecological and Physiological Bases of Space Biology and Medicine. Washington, D.C.: NASA Scientific and Technical Information Office. pp. 409–452 [427–430]. Archived (PDF) from the original on 7 March 2017. Retrieved 19 December 2018.
- ^ Sam Roe (21 August 2019). "We tested popular cellphones for radiofrequency radiation. Now the FCC is investigating". Chicago Tribune.
- ^ "Microwaves, Radio Waves, and Other Types of Radiofrequency Radiation." American Cancer Society, http://www.cancer.org/cancer/cancer-causes/radiation-exposure/radiofrequency-radiation.html Archived 2 May 2020 at the Wayback Machine
- ^ Khan FN (18 December 2017). "Is That Airport Security Scanner Really Safe?". Scientific American. Archived from the original on 17 December 2019. Retrieved 28 March 2020.
- ^ "Characterization of 60GHz Millimeter-Wave Focusing Beam for Living-Body Exposure Experiments, Tokyo Institute of Technology, Masaki KOUZAI et al., 2009" (PDF). Archived (PDF) from the original on 1 February 2014. Retrieved 18 January 2014.
- PMID 14535893.
- PMID 28441605.
- ISBN 978-0683080278.
- ^ "Laser Standards and Classifications". Rockwell Laser Industries. Archived from the original on 8 April 2017. Retrieved 10 February 2019.
- ^ "An Overview of the LED and Laser Classification System in EN 60825-1 and IEC 60825-1". Lasermet. Archived from the original on 12 February 2019. Retrieved 10 February 2019.
- ^ "What is the minimum safe distance from the welding arc above which there is no risk of eye damage?". The Welding Institute (TWI Global). Archived from the original on 10 March 2014. Retrieved 10 March 2014.
- ISBN 978-1437736199.
- PMID 16087845.
- PMC 1298891.
- ^ Komarnitsky. "Case study of ultraviolet vision after IOL removal for Cataract Surgery". Archived from the original on 9 February 2014. Retrieved 17 January 2014.
- S2CID 45178405.
- ^ "Ultraviolet keratitis". Medscape. Archived from the original on 1 November 2015. Retrieved 31 May 2017.
- S2CID 2626216.
- PMID 23026199.
- ISBN 978-1468407600. Archivedfrom the original on 14 December 2019. Retrieved 30 January 2019.
Further reading
- U.S. Congress, Office of Technology Assessment (May 1989). Biological Effects of Power Frequency Electric & Magnetic Fields—Background Paper, OTA-BP-E-53 (PDF). Washington, DC: U.S. Government Printing Office. Archived (PDF) from the original on 1 August 2014. Retrieved 2 May 2010. (over 100 pages)ju
External links
- Information page on electromagnetic fields at the World Health Organization web site
- CDC – Electric and Magnetic Fields – NIOSH Workplace Safety and Health Topic
- Dunning, Brian (30 October 2007). "Skeptoid #72: Electromagnetic Hypersensitivity: Real or Imagined?". Skeptoid.
- Biological Effects of Power Frequency Electric and Magnetic Fields (May 1989) (110 pages) prepared for US Congress Office of Technology Assessment by Indira Nair, M.Granger Morgan, Keith Florig, Department of Engineering and Public Policy Carnegie Mellon University