Non İyonizan Radyasyonun Nörolojik Etkileri
Özet
Gelişen teknoloji, sanayileşme ve küreselleşmenin getirdiği yenilikler, insanların günlük yaşamda yapay kaynaklardan yayılan non-iyonizan radyasyona (NIR) sürekli maruz kalmasına yol açmaktadır. İyonizan radyasyon gibi kimyasal bağları koparma gücü olmayan NIR, atomları uyararak daha hızlı titreşmelerine ve dolayısıyla termal etkilere sebebiyet veren bir ışınım enerjisidir. Cep telefonları, baz istasyonları, elektrikli ev aletleri, yüksek gerilim hatları ve MRG gibi tıbbi cihazlar hayatımızın her alanında yer alan yapay NIR kaynaklarıdır. Elektriksel bir sinyal iletim sistemine sahip olan insan sinir sisteminin bu çevresel elektromanyetik alanlardan etkilenmesi kaçınılmazdır. Laboratuvar ortamında ve deneysel hayvan çalışmalarında, NIR maruziyetinin beyinde ödem, vasküler yapıların bozulması, nöron membran parçalanması ile miyelin kılıf hasarı gibi morfolojik değişikliklere zemin hazırladığı saptanmıştır. Ayrıca kortikal eksitabiliteyi artıran bu dalgalar; dopamin, norepinefrin, glutamat ve asetilkolin gibi nörotransmitter seviyelerini değiştirerek bellek problemlerine, kognitif disfonksiyona, anksiyete ve öğrenme güçlüklerine yol açabilmektedir. İnsanlar üzerindeki epidemiyolojik veriler kalıcı biyolojik hasarı tam olarak kanıtlayamasa da, IARC radyofrekans dalgalarını olası karsinojen kategorisine dahil etmiştir. Bu doğrultuda ICNIRP ve Dünya Sağlık Örgütü, kümülatif biyolojik riskleri en aza indirmek ve halk sağlığını korumak amacıyla özgül soğurma hızı (SAR) kapsamında güvenli limit değerler belirlemiş olup maruziyetin minimuma indirilmesini önermektedir.
Technological advancements, industrialization, and globalization have inevitably increased human exposure to non-ionizing radiation (NIR) emitted from human-made devices in daily life. Unlike ionizing radiation, which breaks chemical bonds, NIR possesses lower energy that excites atoms and causes thermal effects through molecular vibration. Mobile phones, base stations, household appliances, power lines, and medical imaging systems like MRI are ubiquitous artificial sources of NIR. Given that the human nervous system functions as an electrical system, it is highly susceptible to these environmental electromagnetic fields. In vitro and animal studies indicate that NIR exposure induces morphological alterations in the brain, including edema, vascular degradation, neuronal membrane fragmentation, and myelin sheath damage. Furthermore, it enhances cortical excitability and alters vital neurotransmitter levels such as dopamine, norepinephrine, glutamate, and acetylcholine, leading to cognitive dysfunction, memory impairment, anxiety, and learning difficulties. Although human epidemiological studies lack conclusive evidence regarding definitive biological damage, the International Agency for Research on Cancer (IARC) has classified radiofrequency fields as possibly carcinogenic. Consequently, international bodies like the WHO and ICNIRP have established strict exposure guidelines and Specific Absorption Rate (SAR) limits to protect public health from potential cumulative biological risks, advising individuals to minimize their overall daily exposure.
Referanslar
Understanding radiation: What is non-ionising radiation?. Available from: https://www.arpansa.gov.au/understanding-radiation/what-radiation/what-non-ionising-radiation.
Moulder JE. Power-frequency fields and cancer. Critical Reviews in Biomedical Engineering. 1998; 26 (1-2):1-116.
Martin CJ, Sutton DG. Practical Radiation Protection in Health Care, 2nd edition. Oxford University Press; 2002.
International Commission on Non-Ionizing Radiation Protection. Guidelines for limiting exposure to time-varying electric, magnetic, and electromagnetic fields (up to 300 GHz). Health Physics. 1998; 74: 494-522.
Repacholi MH. A History of the International Commission on Non-Ionizing Radiation Protection. Health Physics. 2017;113(4):282-300.
Ng KH. Non-ionising radiations – sources, biological effects, emissions and exposure. In: Proceedings of the International Conference on Non-Ionising Radiation at UNITEN (ICNIR 2003). Electromagnetic Fields and Our Health; 2003. Available from: http://www.who.int/peh-emf/meetings/archive/en/keyno te3ng.pdf.
International Commission on Non-Ionizing Radiation Protection (ICNIRP). ICNIRP Statement on Diagnostic Devices Using Non-ionizing Radiation: Existing Regulations and Potential Health Risks. Health physics. 2017;112(3):305–321.
Hansson Mild K, Lundström R, Wilén J. Non-Ionizing Radiation in Swedish Health Care-Exposure and Safety Aspects. International journal of environmental research and public health. 2019; 16(7): 1186.
Polk C, Postow E. Handbook of Biological Effects of Electromagnetic Fields. Second Edition, CRC Press; 1996.
Leach V, Weller S, Redmayne M. A novel database of bio-effects from non-ionizing radiation. Reviews on Environmental Health. 2018;33(3):273-280.
O'Hagan JB, Driscoll CMH, Pearson AJ. Occupational Exposure to Optical Radiation in the Context of a Possible EU Proposal for a Directive on Optical Radiation, NRPB-W35. National Radiological Protection Board, Didcot,UK. 2003.
McKinlay AF, Driscoll CMH, Meara JR et al. Documents of the NRPB. Advice on Protection Against Ultraviolet Radiation. National Radiological Protection Board, Didcot, UK. 2002;13 (3).
International Commission on Non-Ionizing Radiation Protection (ICNIRP). Health Issues Related to the use of Hand-Held Radiotelephones and Base Station Transmitters. Health Physics. 1996;70:587-593.
Mobile Phones and Health Independent Expert Group on Mobile Phones. The Stewart Report. National Radiological Protection Board. 2000. Available from: http://www.iegmp.org.uk/report/text.htm.
The Royal Society of Canada. A Review of the Potential Health Risks of Radio-frequency Fields from Wireless Telecommunication Devices.1999. Available from: https://rsc-src.ca/sites/default/files/RFreport-en.pdf.
Ng KH. Radiation, Mobile Phones, Base Stations and Your Health. Malaysian Communications and Multimedia Commission publication; 2003.
International Agency for Research on Cancer (IARC). IARC Classifies Radiofrequency Electromagnetic Fields as Possibly Carcinogenic to humans. Press Release; 2011. Available from: https://www.iarc.who.int/wp-content/uploads/2018/07/pr208_E.pdf.
Chou CK. Ph.D. Dissertation. Department of Electrical Engineering; College of Engineering, University of Washington, Seattle, DC, USA: 1975. The Effects of Electromagnetic Fields on the Nervous System.
Carrubba S, Marino AA. The effects of low-frequency environmental strength electromagnetic fields on brain electrical activity: a critical review of the literature. Electromagnetic Biology and Medicine. 2008;27:83–101.
Aboul Ezz HS, Khadrawy YA, Ahmed NA et al. The effect of pulsed electromagnetic radiation from mobile phone on the levels of monoamine neurotransmitters in four different areas of rat brain. European Review for Medical and Pharmacological Sciences. 2013;17:1782–1788.
Lai H, Carino MA, Horita A, Guy AW. Low-level microwave irradiation and central cholinergic systems. Pharmacology Biochemistry and Behaviour. 1989;33:131–138.
Hu C, Zuo H, Li Y. Effects of Radiofrequency Electromagnetic Radiation on Neurotransmitters in the Brain. Frontiers in Public Health. 2021;9:691880.
Lai H. Neurological effects of non-ionizing electromagnetic fields. In: Sage C, Carpenter DO, editors. The bioinitiative report 2012, a rationale for a biologically-based public exposure standard for electromagnetic fields (ELF and RF); 2012. Available from: http://www.bioinitiative.org.
World Health Organization (WHO). The Internatıonal EMF Project. 2016. Available from: https://www.who.int/initiatives/the-international-emf-project/docs/default-source/radiation-international-emf-project-reports/emf-iac-2016-progress-report.
International Commission on Non-Ionizing Radiation Protection. Guidelines on limits of exposure to static magnetic fields. Health Physics. 1996;66:100-106.
International Commission on Non-Ionizing Radiation Protection. Guidelines on Limits of Exposure to Broad-Band Incoherent Radiation (0.38 to 3mm). Health Physics. 1997;73:539-554.
International Commission on Non-Ionizing Radiation Protection. Revision of the Guidelines on Limits of Exposure to Laser radiation of wavelengths between 400nm and 1.4μm. Health Physics. 2000; 79: 431-440.
