A set of updated, evidence-based guidelines defining safe levels of exposure to radiofrequency electromagnetic fields (EMF) has been published in Health Physics, official journal of the Health Physics Society. The journal is published in the Lippincott portfolio by Wolters Kluwer.
The report by an expert Project Group of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) seeks “to establish guidelines for limiting exposure to EMFs that will provide a high level of protection for all people against substantiated adverse health effects from exposures to both short- and long-term, continuous and discontinuous radiofrequency EMFs.” After a public consultation period, the guidelines were approved by ICNIRP earlier this year.
Report outlines evidence-based recommendations for safe exposure to EMFs
Electromagnetic fields in the radiofrequency range – 100 kilohertz (kHz) to 300 gigahertz (GHz) – are widely used in technologies including communications (such as cell phones and Wi-Fi networks) and home appliances (microwave ovens). They are also used in medical devices, such as magnetic resonance imaging (MRI) scanners, as well as radiofrequency ablation equipment used in medical and surgical treatments.
Replacing previous ICNIRP documents, the new guidelines make recommendations for safe exposure to EMF fields in the radiofrequency range. Exposure limits are based on independently verified reports “of sufficient scientific quality and consistent with current scientific understanding.” For each substantiated effect identified, the “adverse effect threshold” – the lowest exposure level known to cause the health effect – was identified.
Tissue heating is the main potential harmful effect of radiofrequency EMF exposure. Electromagnetic fields can penetrate the body, causing vibration of charged or polar molecules thus leading to kinetic energy and heat. The new guidelines seek to avoid any possible harmful effects by setting limits below the threshold at which any EMF-induced adverse effect can occur. The adverse effects with the lowest thresholds are increased deep body temperature, and excessive local heating. Separate exposure limits are recommended for the whole body, as well as for the head and torso region, and the limbs.
The guidelines include a set of “basic restrictions” on EMF exposure at differing frequencies and times, based on the thresholds known to cause harmful effects. To further protect the general public, the basic restrictions are reduced by factors ranging from 10 to 50. The guidelines also include a set of more easily-assessed “reference levels,” calculated to ensure that threshold levels for radiofrequency EMF exposure are never exceeded.
The document also includes guidance for “contact currents” which can potentially cause harm when a person touches a conducting object within an electric or magnetic field. It also addresses guidance related to mitigating the risk of harmful exposure to EMF in occupational settings – emphasizing the need for an appropriate workplace health and safety program.
The revised guidelines come at a time of public reports of concerning but generally unsubstantiated harmful health effects of radiofrequency EMF exposure – below the exposure thresholds that could cause body or tissue heating effects. As stated in an ICNIRP public information page, “Acute and long-term effects of HF exposure below the thermal threshold have been studied extensively without showing any conclusive evidence of adverse health effects.”
The report acknowledges gaps in the currently available research evidence concerning substantiated heat-induced health effects of EMF exposure. Periodic reviews are planned to ensure that the guidelines reflect the latest scientific knowledge.
About Health Physics
Health Physics, first published in 1958, provides the latest research to a wide variety of radiation safety professionals including health physicists, nuclear chemists, medical physicists, and radiation safety officers with interests in nuclear and radiation science. The Journal allows professionals in these and other disciplines in science and engineering to stay on the cutting edge of scientific and technological advances in the field of radiation safety. The Journal publishes original papers, technical notes, articles on advances in practical applications, editorials, and correspondence. Journal articles report on the latest findings in theoretical, practical, and applied disciplines of epidemiology and radiation effects, radiation biology and radiation science, and radiation ecology, to name just a few.
About the Health Physics Society
The Health Physics Society (HPS), formed in 1956, is a scientific organization of professionals who specialize in radiation safety. Its mission is to support its members in the practice of their profession and to promote excellence in the science and practice of radiation safety. Today its members represent all scientific and technical areas related to radiation safety, including academia, government, medicine, research and development, analytical services, consulting, and industry in all 50 states and the District of Columbia. The Society is chartered in the United States as an independent nonprofit scientific organization and, as such, is not affiliated with any government or industrial organization or private entity.