THPM-A - Special Session: Non-ionizing Radiation Centennial Ballroom 300D 13:30 - 17:50
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| Chair(s): Pete Sprenger and Ken Barat
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THPM-A.1
13:30 A review of the non-ionizing radiation topics and discussions from the first International Radiation Protection Agency’s North American Regional Congress. PJ Sprenger*, Naval Medical Research Unit San Antonio
Abstract: Cosponsored by the Health Physics Society, the International Radiation Protection Agency held their first North American Regional Congress in St. Louis, MO in February of 2022. The topic of non-ionizing radiation (NIR) is becoming more prevalent with advancements in magnetic fields, 5G for telecommunications, laser power and optics, microwaves, changes in regulation, and public misconceptions. The NIR section of the HPS provided assistance with organizing and chairing a special NIR session at the St. Louis congress to better inform health and safety personnel and increase dialogue on NIR subject matters. A summary of the topics and discussion is provided.
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THPM-A.2
13:50 Impact of Concomitant Electromagnetic Energy (EME) Hazards on the Radio-Frequency (RF) Safety Program DL Haes*, Consultant
Abstract: Impact of Concomitant Electromagnetic Energy (EME) Hazards
on the Radio-Frequency (RF) Safety Program
Donald L. Haes, Jr.
Consulting Radiation Safety Specialist
A Radio-Frequency (“RF”) safety program provides guidance for preventing exposures above applicable RF limits associated with RF sources that operate in an assigned frequency range (typically 3 kHz to 300 GHz). RF safety programs are initiated when there is potential for exposure to RF energy that exceeds relevant standards, guidelines, or regulations. However, workspaces unquestionably contain sources of Electromagnetic Energy (EME) which emit electric and/or magnetic fields below 3 kHz and may not be included in the current RF Safety Program, and are often not evaluated.
Concomitant EME hazards could exist at frequencies and/or power levels outside those covered by the RF Safety Program. The concomitant EME hazards included in the presentation are as follows: Interference with the operation of Implanted Medical Devices (IMD); Hazards to ordinance, Electro-Explosive Devices (EED), explosive atmosphere considerations and fuel; electrical power (60 + Hz) phenomena; and static magnetic field interactions. The presentation challenges safety practitioners to recognize the impact concomitant EME hazards could have on their RF safety programs. In addition, they should consider concomitant EME hazard assessments for equipment, the work environment, and the potentially exposed population. The RF Safety Program can then be revised as an EME Safety Program which includes recognition and mitigation of concomitant EME hazards.
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THPM-A.3
14:10 Revision of Ultraviolet Exposure Limits at Shorter Wavelengths - UV-C DH SLINEY*, Johns Hopkins University School of Public Health
Abstract: In 2022 the American Conference of Industrial Hygienists (ACGIH) adopted a change in the Threshold Limit Values (TLVs) for ultraviolet radiation - the first time in several decades. The COVID-19 pandemic has greatly heightened interest in
ultraviolet germicidal irradiation (UVGI) as an important
intervention strategy to disinfect air in medical treatment
facilities and public indoor spaces. However, a major drawback
of UVGI is the challenge posed by assuring safe installation
of potentially hazardous short-wavelength (UV-C) mercury
ultraviolet lamps. Questions arose regarding what appeared to be unusually conservative exposure limit values in the UV-C spectral band between 180 and 280 nm. The rationale for both the original limits and for the adjusted TLVs are discussed.
The new limits provide separate values for the eye and the
skin at wavelengths less than 300 nm and both the eye and
skin limits were increased in the UV-C spectral region below 250 nm.
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THPM-A.4
14:30 Safety Aspects of Germicidal Ultraviolet Radiation DH Sliney*, Johns Hopkins University School of Public Health
Abstract: Germicidal UV (GUV) – or ultraviolet germicidal irradiation (UVGI) – dates back more than a century and was widely used in hospitals and public places to reduce infections by inactivating airborne parthenogens throughout the 1930s – 1950s. Current experience with UVGI has largely been limited to TB clinics – particularly in some developing countries where some expertise on this technology has been retained. Sadly, misconceptions about UVGI, such as a perceived skin cancer risks remain and a lack of understanding of proper safety precautions continue to slow the wide acceptance of UVGI in North America and Europe. Today the COVID-19 pandemic has greatly accelerated development of traditional UV-C lamps and new lamp types such as the krypton-chloride (222-nm) lamp to augment the traditional use of low-pressure mercury (254 nm) lamp. Accidental exposure of skin and eyes in poorly installed UVGI installations can result in transient effects of the skin and eyes. The cornea is the most sensitive tissue to UV-C irritation: this is a transient injury – photokeratitis (“welder’s flash,” or “snow-blindness”) – with symptoms of “sand in the eyes.” Erythema – reddening of the skin can be severe if from the much more penetrating UV-B rays that produce “sunburn”, but erythema is mild from the very superficially penetrating UV-C. The delayed effects, such as skin cancer raise the greatest concern, but it is the UV-B in sunlight that penetrates to the basal (germinative) layer of the epidermis and is the recognized cause of most skin cancer. The “far UV-C” wavelengths (e.g., 222 nm) are even more heavily absorbed in the superficial epidermis & stratum corneum than longer UV-C wavelengths greater than ~ 230 nm, with the result that guidelines for human exposure can be much less restrictive below 230-240 nm. For this reason, whole-room, far-UV-C GUV appears practicable.
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THPM-A.5
14:50 BREAK
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THPM-A.6
15:05 Review of case studies for radiofrequency exposures in stadiums, on small cells, towers and rooftops AH Thatcher*, Thatcher Consulting LLC
; D Ludick, Alphawave Mobile Network Products (Pty) Ltd; J Nell, Alphawave Mobile Network Products (Pty) Ltd
Abstract: The proliferation of wireless antennas has resulted in a number of compliance challenges. Wireless antennas are in stadiums, on street utility poles, on towers and on buildings. Over time, the equipment and antennas have been swapped out to keep up with demand, the result of which has been a steady increase in the number of locations, frequency bands and transmitters used to handle traffic. Concerns over worker exposure requires compliance evaluation of both the spatial average and peak spatial exposure close to the antennas. For other sites the evaluation of accessible spaces on rooftops, adjacent building’s rooftops and balconies requires further analysis. Using recently completed projects we’ll walk through a number of interesting sites and the results.
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THPM-A.8
15:25 NIR Hazards Mitigation for ISS and Lunar Missions R Gaza*, Leidos, Exploration & Mission Support 2NASA Johnson Space Center
; B Hayes, Leidos, Exploration & Mission Support 2NASA Johnson Space Center; A Castro, Leidos, Exploration & Mission Support 2NASA Johnson Space Center
Abstract: Human space exploration is paramount for mankind’s advances in science and technology. The National Aeronautics and Space Administration (NASA) was directed through the presidential Space Policy Directive-1 to ‘‘Lead an innovative and sustainable program of exploration with commercial and international partners to enable human expansion across the solar system and to bring back to Earth new knowledge and opportunities.’’ The lunar exploration program, named Artemis, will use the return to the Moon as a testbed for exploring and potentially inhabiting other planets, such as Mars. The Artemis Program will include a habitable Gateway station orbiting the Moon and capabilities to reach and explore the lunar surface via the Human Landing System (HLS) and robotic activities.
There is a multitude of health risks associated with space exploration, ranging from microgravity and radiation effects on the human body to long-term isolation impacts. With technology advancements over the last decade, stronger lasers and radio antennas are now available to use for routine operations (e.g., space communications, vehicle docking, etc.). Therefore, exposure to non-ionizing radiation (NIR) sources is one of the major concerns in human space exploration. The main NIR sources of interest for crew protection include lasers, natural and artificial incoherent light sources (e.g., sunlight, LEDs, lamps, etc.) and radiofrequency emitters (e.g., antennas, RFID, etc.). The NASA Safety program at the Johnson Space Center (JSC) uses agency-developed standards and risk-specific developed requirements by the agency’s subject matter experts (SMEs) for all human space flight programs, such as: International Space Station (ISS), Orion Multi-Purpose Crew Vehicle (MPCV), Commercial Crew (CC), Artemis, Gateway Station, Human Landing System (HLS), Exploration Extravehicular Mobility unit (xEMU), Axiom Station, and International Habitation module (I-Hab).
The need for dedicated requirements for each of the human spaceflight risks is dictated by the unique challenges associated with space operations that often result in dedicated safety procedures and risk mitigation approaches. These requirements are developed in-house at JSC by the discipline SMEs, approved by the NASA Health Medical Technical Authority (HMTA) office, NASA Safety, and concurred with by NASA’s international partners. This process requires a proactive, flexible, and highly adaptive risk management approach for NIR that is unique compared to more traditional terrestrial NIR safety processes.
This presentation will provide an overview of the non-ionizing radiation safety process for human spaceflight, including requirements overview, challenges, and safe operational implementation techniques.
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THPM-A.9
15:45 Health Physicists’ duty to fight misinformation and disinformation. BE Edwards*, None
Abstract: “Professional statements made by members shall have sound scientific basis. Sensational and unwarranted statements of others concerning radiation and radiation protection shall be corrected, when practical” (HPS Code of Ethics). In the current post-truth world, it’s more important than ever for health physicists honor this item in our Society’s Code of Ethics. While correlation does not equal causation, correlations can indicate the potential existence of a causal link. Conversely, a proposed causal link between uncorrelated variables is not credible. This presentation illustrates two claims of radiation-related causality, and hence risk, that persist despite the effect’s lack of correlation to the implicated radiation exposures. Microwave radiation from cell phones is widely assumed to cause brain cancer. Some individuals assert that most of the increase in atmospheric CO2 concentration in recent decades is due primarily to an increase in solar radiation (insolation) levels during the same period. In both cases the data fail to show a correlation between the purported causes and effects. These examples demonstrate real world opportunities to correct “…unwarranted statements of others concerning radiation."
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THPM-A.10
16:05 BREAK
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THPM-A.11
16:35 Business Meeting
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