TUE-J - Non-Ionizing Radiation Tuesday 10/13/20 2:00 PM - 5:00 PM
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| Chair(s): Fred McWilliams, Donald Haes, Peter Sprenger
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TUE-J.
2:00 PM Introduction FF McWilliams, Massachusetts Institute of Technology
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TUE-J.1
2:10 PM Management of Outside Laser Devices RP Harvey*, Roswell Park Comprehensive Cancer Center
Abstract: Many institutions bring in outside lasers for use at their facility. These laser devices may be used for demonstrations, or as loaners or rentals. Laser Safety Programs should include compliance assessments of these lasers in order to assure adequate laser safety for patients and staff. In addition, outside lasers should be inspected and outside eyewear should be evaluated as part of your Laser Safety Program. Without the appropriate oversight, your organization may compromise it's laser safety and put individuals at risk for injuries.
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TUE-J.2
2:35 PM Beyond the Door Interlock: Considerations in Design of Interlocks for High-Powered Lasers MA Spencer*, Massachusetts Institute of Technology
; JM Reilly, Massachusetts Institute of Technology; FF McWilliams, Massachusetts Institute of Technology
Abstract: Interlocks are a class of control measure used to prevent access to hazardous levels of laser radiation. The most common variety of interlock cuts power to the laser or closes a shutter when a door or enclosure is opened. This type of interlock is may not be suitable for high energy laser systems as an interlock will not trigger instantaneously, which may allow a hazardous condition to persist between initiation and activation of the interlock. In addition, the interlock system may result in damage to equipment or cause a fire. Several cases are presented of customized interlock designs that prevent access to radiation levels above the Maximum Permissible Exposure (MPE), while optimizing research priorities and protecting expensive equipment.
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TUE-J.
3:00 PM BREAK
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TUE-J.3
3:10 PM Radio-Frequency Safety – What a Health Physicist Needs to Know. GR Komp*, NASA GSFC
; Gregory komp
Abstract: Most of us health physicists spend our entire careers focusing on Ionizing Radiation Safety. Our work lives are submersed in Nuclear Regulatory Commission, Department of Energy, or another similar regulatory structure. Other than answering the common question about the safety of cell phones, we seldom cross that line into the non-ionizing radiofrequency (RF) realm. This talk will discuss why RF safety is important to health physicists, the regulatory (or non-regulatory) structure and how to apply the recent changes to IEEE C95.1, IEEE Standard for Safety Levels with Respect to Human Exposure to Electric, Magnetic, and Electromagnetic Fields, 0 Hz to 300 GHz.
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TUE-J.4
3:35 PM The RF Relative Risk Index; A Novel Approach for Assessment and Comparison of the Relative Risk of Sources of Radio-Frequency (RF) Energy. D Haes*, Consultant
Abstract: Sources of radio-frequency (RF) energy are ubiquitous in the populated environment. What was once a landscape dotted with tall towers hosting high-power transmitting antennas (principally broadcast systems), is now a complex of tall and short towers supporting multiple transmit and receive antennas. Many building roof-tops are now sites for Personal Wireless Services (PWS) providing both voice and data connectivity with the Internet. So-called “micro-cells” and “pico-cells” are installed indoors. Current Federal regulations require compliance with RF exposure guidelines for both members of the general public and workers. Guidance in the mitigation of RF exposures through the implementation of RF safety programs (RFSP) is available through documents such as IEEE Std.C95.7-2014. Although IEEE Std.C95.7-2014, through a hierarchy of categories, provides for categorizing sites based on RF exposure conditions, there is no “score” per se, that allows for ranking of dissimilar sites/sources, nor tracking over time. The Radio-Frequency Relative Risk Index (RF RRI) allows the user to rank RF sources (sites) in terms of their relative importance for implementing appropriate RFSP exposure mitigation strategies. The RF RRI applies across all population categories based on outcome(s) of applied exposure controls, and not simply by power or frequency. This unique approach consists of determination of an “index”, or ranking score, based upon evaluation of exposed population considerations, RF exposure conditions, the anticipated severity of outcomes, and the application of alternative mitigating controls. The final “score” does not represent an absolute risk but rather a relative risk for that RF source or site. This tool provides a numerical metric for quick evaluation, ranking, and tracking of RF sources or sites such that the score values can then be compared to those determined for other sources or sites. An especially useful feature of the RF RRI is its value for identifying existing “troublesome” sites, triaging necessary renovations, and affording the user a protocol for optimizing the use of scarce resources in addressing RF compliance activities.
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TUE-J.
4:00 PM BREAK
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TUE-J.5
4:10 PM What health physicists should know about 5G BE Edwards*, Cree Inc.
Abstract: As with any “new” technology, some people are understandably concerned about the potential health effects of exposure to radiofrequency (microwave) radiation from 5G devices. Health physicists are uniquely positioned to provide science-based information regarding what is known about such potential hazards. The biological effects of exposure to microwave radiation are very well understood and stem primarily from tissue heating. Exposure limits are well-established, and both current cellular networks and new 5G equipment operate well within those exposure limits. Other mechanisms of interaction have been proposed, but despite occasional tantalizing indications, no converging or compelling scientific evidence of significant non-thermal mechanisms have emerged. Epidemiological evidence does not support a link between cell phone radiation exposure and increased incidence of brain cancer, despite decades of exposure to very large cohorts. While current cellular networks operate in the ~800 MHz – 8 GHz frequency range, 5G network radiation would use different parts of the microwave spectrum (mostly >24GHz, though one carrier plans a 600 MHz 5G network). The tissue penetration depth of microwave radiation decreases with increasing frequency, so the higher frequency 5G emissions would not go as far into tissue as current cell phone radiation. 5G technology also features a variety of new frequency modulation patterns. Modulation does not change the total energy deposited, and hence would not modify thermal effects. Some authors hypothesize possible non-thermal effects due to new 5G frequency modulation structures.
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TUE-J.6
4:35 PM 5G Network Overview AP Miaullis*, USAF
Abstract: The Verizon telecommunications company became the first to introduce the 5G network in April 2019, bringing the technology to both Chicago and Minneapolis. By the end of 2019, 5G was activated in 27 cities and 13 National Football League stadiums within the United States. 5G is the fifth generation of cellular network technology that will transform the way we use our phones and has the potential to revolutionize other technological applications. However, the rapid progression has also raised public concern about health and aesthetic effects of 5G antennas in addition to data security. This cursory overview of the 5G Network will compare the characteristics of Sub6 (600 MHz to 6 GHz) vs millimeter (6 to 110 GHz) waves, the need for massive Multiple-Input Multiple Output antennas and portable miniature base stations, public concerns, advantages and limitations, beamforming, splat charts, Department of Defense use, cybersecurity, and the Institute of Electrical and Electronics Engineers standards for military workplaces (IEEE Std C95.1-2345-2014) and safety levels with respect to human exposure (IEEE Std C95.1-2019).
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