Wednesday, June 24, 2020

IEEE Committee on Man and Radiation (COMAR)

Although no research has been published on the bioeffects or health effects from exposure to 5G radiation, the IEEE Committee on Man and Radiation (COMAR) has published an "expert statement" in the journal Health Physics that claims "(w)ithin current exposure limits, there appears to be little or no risk of adverse health effects related to radiofrequency (RF) exposure from 5G system."

According to the IEEE press release (below): 
"... COMAR is an organization composed of physicians, biologists, epidemiologists, engineers and physical scientists who are experts on health and safety issues related to electromagnetic fields who work voluntarily and collaboratively on a consensus basis."
Is COMAR qualified to issue an "expert statement" regarding health effects? By my count, the membership of COMAR consists of nineteen engineers, four physicists, two physiologists, one psychologist, and one M.D. Almost all of COMAR's members work for industry or rely on industry funding for their research. 

How many members of COMAR have published peer-reviewed research on the health effects of non-ionizing radiation? How many do not have conflicts of interest?

How can COMAR assume that current exposure limits ensure our safety when the International EMF Scientist Appeal claims these limits are inadequate? This appeal has been signed by more than 240 scientists who have published peer-reviewed research on the bioeffects or health effects of non-ionizing radiation, totaling more than 2,000 papers and letters in professional journals.

Finally, the 5G Appeal calls for a moratorium on the rollout of 5G "until potential hazards for human health and the environment have been fully investigated by scientists independent from industry." This appeal has been signed by more than 200 scientists and over 170 medical doctors (as of January 24, 2020).

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'Very low' risk of unknown health hazards from exposure to 5G wireless networks

Expert statement in health physics journal seeks to counter online misinformation

News Release, Wolters Kluwer Health, Jun 24, 2020

June 24, 2020 - Experts weigh in on recent online reports that warn of frightening health consequences from new fifth generation (5G) wireless networks. Within current exposure limits, there appears to be little or no risk of adverse health effects related to radiofrequency (RF) exposure from 5G systems, concludes an evidence-based expert review in the June issue of Health Physics, official journal of the Health Physics Society. The journal is published in the Lippincott portfolio by Wolters Kluwer.

"While we acknowledge gaps in the scientific literature, particularly for exposures at millimeter-wave frequencies, [we judge] the likelihood of yet unknown health hazards at exposure levels within current limits to be very low, if they exist at all," according to the statement by the Committee on Man and Radiation (COMAR) of the Institute of Electrical and Electronics Engineers (IEEE). As outlined by its Chair, Richard A. Tell, COMAR is an organization composed of physicians, biologists, epidemiologists, engineers and physical scientists who are experts on health and safety issues related to electromagnetic fields who work voluntarily and collaboratively on a consensus basis.

5G Networks Unlikely to Cause Exposure Above Current Safety Limits

The consensus statement seeks to counter the rise in alarming messages regarding mysterious health effects of 5G technology. "This misinformation together with activist websites expressing even more ominous consequences of 5G - ranging from cancer induction to being responsible for the current coronavirus pandemic - has created substantial and unnecessary public anxiety," comments Jerrold T. Bushberg of the University of California Davis School of Medicine and Vice-Chair of COMAR.

Fifth-generation wireless systems are expanding worldwide to meet the rapidly increasing demand for wireless connectivity. The new technology can transmit much greater amounts of data at much higher speeds, compared to previous 2G to 4G systems. That's in part because 5G uses the greater bandwidth available at higher frequencies, including the so-called millimeter-wave (MMW) band. Expansion of 5G "will produce a more ubiquitous presence of MMW in the environment," according to the report.

Because MMW do not penetrate foliage and building materials as well as lower-frequency signals, many lower-power "small cell" transmitters will be needed to provide effective indoor coverage. Some 5G systems will have "beamforming" antennas that transmit signals to individual users as they move around, which means that nonusers will have less exposure.

Tissue heating is the main potential harmful effect of exposure to RF fields. Most countries, including the United States, have adopted exposure limits similar to those recommended by the recent standards (2019) published by IEEE International Committee on Electromagnetic Safety (ICES) or the International Commission on Non-Ionizing Radiation Protection (ICNIRP). These guidelines seek to avoid harmful effects by setting exposure limits far below the threshold at which any adverse human health effects would be expected to occur. These standards only allow for low levels of public RF exposures for which the energy is deposited in the form of thermal heating.

The COMAR statement provides perspectives to address concerns about possible health effects of 5G exposure:
  • In contrast to lower-frequency fields, MMW do not penetrate beyond the outer layer of the skin - and thus does not produce heating of deeper tissues.
  • The introduction of 5G is unlikely to change overall levels of RF exposure. As is currently the case, most exposure will be mainly due to "uplink" from one's own cell phone or other devices - not from transmission from base stations.
  • In nearly all publicly accessible locations, RF exposures from cellular base stations, including 5G stations will remain small - a fraction of current IEEE or ICNIRP exposure limits.
"[S]o long as exposures remain below established guidelines, the research results to date do not support a determination that adverse health effects are associated with RF exposures, including those from 5G systems," concludes the COMAR statement. The Committee acknowledges limitations of the current evidence on possible health and safety effects of 5G exposure and identifies key areas for further research, including high-quality studies of the biological effects of MMW.
###
"IEEE Committee on Man and Radiation--Comar Technical Information Statement: Health and Safety Issues Concerning Exposure of the General Public to Electromagnetic Energy from 5G Wireless Communications Networks." DOI: 10.1097/HP.0000000000001301

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IEEE Committee on Man and Radiation—Comar Technical Information Statement: Health and Safety Issues Concerning Exposure of the General Public to Electromagnetic Energy from 5G Wireless Communications Networks

Bushberg JT, Chou CK, Foster KR, Kavet R, Maxson DP, Tell RA, Ziskin MC.  IEEE Committee on Man and Radiation—Comar Technical Information Statement: Health and Safety Issues Concerning Exposure of the General Public to Electromagnetic Energy from 5G Wireless Communications Networks. Health Physics: June 22, 2020. doi: 10.1097/HP.0000000000001301.

Abstract

This COMAR Technical Information Statement (TIS) addresses health and safety issues concerning exposure of the general public to radiofrequency (RF) fields from 5G wireless communications networks, the expansion of which started on a large scale in 2018 to 2019. 5G technology can transmit much greater amounts of data at much higher speeds for a vastly expanded array of applications compared with preceding 2-4G systems; this is due, in part, to using the greater bandwidth available at much higher frequencies than those used by most existing networks. Although the 5G engineering standard may be deployed for operating networks currently using frequencies extending from 100s to 1,000s of MHz, it can also operate in the 10s of GHz where the wavelengths are 10 mm or less, the so-called millimeter wave (MMW) band. Until now, such fields were found in a limited number of applications (e.g., airport scanners, automotive collision avoidance systems, perimeter surveillance radar), but the rapid expansion of 5G will produce a more ubiquitous presence of MMW in the environment. While some 5G signals will originate from small antennas placed on existing base stations, most will be deployed with some key differences relative to typical transmissions from 2-4G base stations. Because MMW do not penetrate foliage and building materials as well as signals at lower frequencies, the networks will require “densification,” the installation of many lower power transmitters (often called “small cells” located mainly on buildings and utility poles) to provide for effective indoor coverage. Also, “beamforming” antennas on some 5G systems will transmit one or more signals directed to individual users as they move about, thus limiting exposures to non-users. In this paper, COMAR notes the following perspectives to address concerns expressed about possible health effects of RF field exposure from 5G technology. First, unlike lower frequency fields, MMW do not penetrate beyond the outer skin layers and thus do not expose inner tissues to MMW. Second, current research indicates that overall levels of exposure to RF are unlikely to be significantly altered by 5G, and exposure will continue to originate mostly from the “uplink” signals from one’s own device (as they do now). Third, exposure levels in publicly accessible spaces will remain well below exposure limits established by international guideline and standard setting organizations, including ICNIRP and IEEE. Finally, so long as exposures remain below established guidelines, the research results to date do not support a determination that adverse health effects are associated with RF exposures, including those from 5G systems. While it is acknowledged that the scientific literature on MMW biological effect research is more limited than that for lower frequencies, we also note that it is of mixed quality and stress that future research should use appropriate precautions to enhance validity. The authorship of this paper includes a physician/biologist, epidemiologist, engineers, and physical scientists working voluntarily and collaboratively on a consensus basis.

Conclusion

The emergence of 5G cellular networks into widespread usage has attracted public attention. This development is due in part to the necessary reliance of 5G sources of MMW on many small cells installed near subscribers (densification), as well as to the introduction into the environment of RF fields from a part of the spectrum to which the public has not previously been exposed to any significant extent. Though research efforts have begun, the effect of 5G networks on population exposures to RF signals has not been as thoroughly researched as have RF exposures at lower frequencies. However, we anticipate that in all cases, exposure levels will remain well below major international exposure limits and that network operators will be aware of their obligation to maintain their systems within compliant operating parameters. When exposure levels are maintained below current exposure limits, neither health agencies nor guideline/standards setting organizations have identified hazards from exposure to millimeter waves or RF signals in lower frequency bands used in previous generation technologies. Given the limited bioeffects literature on millimeter wave exposure, however, COMAR recommends more high-quality research on MMW, together with ongoing surveillance by health agencies of relevant scientific developments. This effort should result in systematic reviews of the literature done under established protocols, with appropriate selection and evaluation criteria for research papers. Such efforts will serve the public interest and assist our society's adaptation to 5G with minimal, if any, disruption. Finally, COMAR is comprised of career professionals who deal with environmental and health issues associated with electromagnetic exposures from across the non-ionizing spectrum, including power delivery, RF broadcast, and wireless technologies. The advent of 5G technologies has been accompanied by a steady stream of media pieces expressing various opinions on 5G ranging from the ominous to the exculpatory. Given the background and commitment of its members, we feel a unique responsibility to provide an objective assessment of where 5G technologies stand with respect to health and safety issues. COMAR concludes that while we acknowledge gaps in the scientific literature, particularly for exposures at millimeter wave frequencies, the likelihood of yet unknown health hazards at exposure levels within current exposure limits is considered to be very low, if they exist at all.

Acknowledgments—This statement was prepared by the IEEE EMBS Committee on Man and Radiation (COMAR) with significant contributions from the following: Jerrold T. Bushberg, C-K Chou, Kenneth R. Foster, Robert Kavet, David P. Maxson, Richard A. Tell, and Marvin C. Ziskin. It was revised and approved by COMAR, the IEEE Engineering in Medicine and Biology Society's Committee on Man and Radiation. It represents a consensus of COMAR, a committee that is composed of experts on health and safety issues related to electromagnetic fields, from power line through microwave frequency ranges. The mission of COMAR is to disseminate authoritative information to the public relating to the safety of nonionizing electromagnetic fields and to correct misinformation that relates to public health on this topic.

COMAR

(Committee on Man and Radiation)

IEEE Engineering in Medicine and Biology Society

The Committee on Man and Radiation (COMAR) is a group of experts on health and safety issues related to electromagnetic fields, from powerline through microwave frequency ranges.

COMAR is a Technical Committee of the Engineering in Medicine and Biology Society (EMBS) of the Institute of Electrical and Electronics Engineers (IEEE). It reports to the EMBS President and Administrative Committee.

COMAR's primary area of interest is biological effects of non-ionizing electromagnetic radiation. It examines and interprets the biological effects and presents its findings in an authoritative manner, usually in Technical Information Statements (TIS's) or Position Papers.  
These papers are subject to an extensive review process within the Committee and represent the consensus of the Committee.

COMAR does not establish safety standards, but it has an interest in the standards activity within its scope.


Saturday, June 13, 2020

Mobilize: A Film About Cell Phone Radiation

Aug 1, 2016   (Updated Jun 13, 2020)



Mobilize: A Film About Cell Phone Radiation, an award-winning, feature-length documentary, explores the long-term health effects from cell phone radiation including cancer and infertility.

The film examines recent scientific research, follows state and national legislative efforts, and illuminates the influence that technology companies have on public health. The film was selected as the best documentary film at the California Independent Film Festival in 2014. 

Mobilize features interviews with scientists, doctors, politicians, cancer patients, and technology experts. 

The film was directed by Kevin Kunze and produced by Amir Zeev Kovacs, Ellie Marks, Devra Davis, and Joel Moskowitz. For more information see the official Mobilize web site.

The film is now available for free to Amazon Prime members and can be rented for $1.99 or purchased for $7.99 by non-members:   https://www.amazon.com/gp/video/detail/B07M639C2B

The film may also be available for free streaming via Bitchute:  https://www.bitchute.com/video/sh14sQ4ASydK/

The DVD can still be purchased through Amazon:  https://www.amazon.com/gp/product/B00M58FRQM/.

Note: I have no financial interest in the film.

KPFA Interview 
of Joel Moskowitz about Mobilize on September 11, 2014.   https://www.youtube.com/watch?v=qgde8u9mBmw

KALW panel on Mobilize, Joel Moskowitz and Kevin Kunze. September 16, 2014. 
  https://www.youtube.com/watch?v=01YB1ShpNWY


Movie reviews
Mobilize: A Film about Cell Phone Radiation
Distributed by TDC Entertainment, 220 East 23rd St., Suite 405, New York, NY 10010
Produced by Devra Davis, Ellen Marks, and Joel Moskowitz
Directed by Kevin Kunze
DVD, color, 88 min.

General Adult
Health Care, Public Health, Sociology, Psychology, Telecommunications
Date Entered: 07/01/2015
Reviewed by Rodney Birch, Reference Librarian, George Fox University
Mobilize investigates the claims around the question of whether the radiation from cell phones is harmful to human health. While the question dates back to the early 1990s, it has been revived as a result of the World Health Organization has stated that, “the electromagnetic fields produced by mobile phones are . . . possibly carcinogenic to humans,” as well as an increasing number of scientific studies showing the effects of cell phone radiation on human health, personal claims, and our increasing dependence on these personal communication devices. The producers go beyond the hype to get to the root of the issue, often exposing inconsistencies in statements by the cell phone industry regarding the current research, and statements made by the Federal Communications Commission and public health organizations. The producers process the information gained through scientific research, Congressional Hearings, and interviews with cell phone industry executives, politicians, public health professionals, and other individuals to provide a balanced and thorough discussion and investigation. Other countries have created legislation around the public health concerns related to the radiation from cell phones. The producers of the film claim the U.S. is slower to adopt such legislation due to the lobbying efforts of the cell phone industry. One of the few cases mentioned is when the city of San Francisco adopted a policy regarding the health concern of cell phone radiation, the cell phone industry filed a lawsuit against the city. This film would be a useful resource for persons exploring the impact of technology on health and behavior, including sociology, psychology, health care and public health.  http://emro.lib.buffalo.edu/record/index.html?id=5807



Mobilize 3 1/2 stars (2014) 84 min. DVD: $19.98. ISBN: 978-1-939517-25-8.
What are the long-term health consequences from daily use of cellular phones? No one really knows, since widespread cell phone use is fairly new. Still, filmmaker Kevin Kunze’s documentary Mobilize makes a strong case that persuasive evidence has emerged regarding the potential for damage to the human body through heavy cell phone usage. Buried in the fine print of the manuals that accompany new cell phones are warnings about keeping the devices a short distance from a user’s head. But studies outlined here make it clear that such precautions aren’t enough: radiation from phones causes heat that, over time, can injure the brain, while a phone’s constant radio interactions with mobile device towers can alter brain chemistry. The problems don’t end there: cell phones carry a potential threat to pregnant women and their babies, and have been linked to cancer, low sperm count, and attention deficit disorder (the industry is also marketing to toddlers, assuring that future generations will be exposed to this radiation). Despite the concerns, Mobilize illustrates how the lobbying and legal powers of the telecommunications industry have been able to shut down any legislative or judicial attempts to curb emissions (or even educate consumers). An alarming documentary with unquestionably controversial findings, this is highly recommended. Aud: C, P. (T. Keogh)

Monday, June 8, 2020

Cellphone use may be harmful for people with dental braces

Electric Field and SAR Distribution in the Vicinity of Orthodontic Brace Exposed to the Cell Phone Radiation

Jovanovic DB, Krasic DD, Stankovic VB, Cvetkovic, NN, Vuckovic DD. Electric Field and SAR Distribution in the Vicinity of Orthodontic Brace Exposed to the Cell Phone Radiation. Applied Computational Electromagnetics Society Journal 34(12):1904-1914. Dec 2019.

Abstract

The aim of this study is to investigate the impact of orthodontic brace on the electric field distribution and amount of the absorbed energy from the cell phone within the teeth. A comparative analysis of the models (child and adult) with and without brace has been carried out due to different morphological and tissue characteristics of child's and adult's head. The 3D realistic models of the child's and adult's head, with the jaw having the orthodontic brace, have been designed. The shapes and features of the child and adult head model, as well as the distance between the electromagnetic source and the exposed object, have an important role in the evaluation of the Specific Absorption Rate (SAR). The applied procedure is based on the numerical solution of the electromagnetic waves propagation equations. The numerical analysis has been performed at the frequency of 3G (0.9GHz). The obtained results are represented within the teeth positioned on the side of the electromagnetic radiation source. Based on the obtained results, one can conclude that the presence of orthodontic brace affects the increase of electric field and SAR within the teeth.

Excerpts

"According to previous studies, one can find that the metal objects can significantly increase the amount of absorbed energy. The authors in [1] have found that the SAR values can be several times greater in the presence of metal object. The effect of electromagnetic radiation from mobile phone on nickel release from orthodontic brackets has been taken into consideration in study [2]. It is found that the concentration of nickel in the artificial saliva in the exposure group was significantly higher than that of the control group. The level of the nickel released in this investigation was far below the toxic level but maybe enough that can lead to allergic reaction in humans. One of the previously studies [3] reported the involuntary movements of the subjects, which had gold (metal) alloy dental inlay, caused by electromagnetic waves."

"It is evident that the value of the electric field is significantly greater in the presence of an orthodontic brace for both models. Based on the results shown in Figs. 6-8, as well as the results given in Table 3, the overall conclusion is that the presence of an orthodontic brace increases the electric field strength within the teeth.

Also it is noticeable that the electric field strength in the case of a child is higher comparing to the adult case."

"Since the referent value for the electric field, prescribed by adequate standards at 0.9 GHz, is 41 V/m, comparing the results obtained by numerical calculation with values prescribed by safety standards, it is evident that obtained results exceed the referent levels inside all teeth in both models (with and without the orthodontic brace). However, it should be kept in mind that in the case of model with orthodontic brace the values are many times greater than the allowable values."

"Regarding the obtained results for SAR within the teeth, in the presence of an orthodontic brace, a significant increase in the amount of absorbed energy can be observed. The maximum of SAR1g occurs in the tooth No. 6 in the case of a child (2.46 W/kg). This value is about 65% higher comparing to the adult with orthodontic brace and 45% higher comparing to the results obtained for a child without orthodontic brace. In this tooth and tooth No. 5, the SAR1g overcomes the safety values but only in the case of child in the presence of the orthodontic brace. The amount of absorbed energy inside the other teeth satisfies basic restriction. However, the increase in the amount of absorbed energy in the presence of an orthodontic brace is not negligible."

"Based on the obtained results, one can conclude that the presence of orthodontic brace causes increase of electric field and SAR within the teeth. In some cases, those values overcome referent limits for electric field strength, i.e., safety limits for SAR values."

"Because of the mentioned before and the fact that each standard contains specific safety limits of exposure to electromagnetic fields but they have been developed based on the research for adults, it should be established if they are sufficiently valid also in case of children.

The future researches should be focused on the impact of orthodontic brace on the electric field strength and amount of absorbed energy at the frequency of LTE-4G, and the latest generation of mobile networks – 5G."



Note: The FCC radio frequency radiation exposure limit (i.e., SAR1g) for cell phones is 1.6 W/kg.

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August 3, 2015

A new peer-reviewed study found that cell phone use significantly increased nickel concentration in the saliva of 50 adult patients who wore dental braces (i.e., fixed orthodontic appliances) as compared to when they did not use their cell phones for a week. Moreover, patients who spoke more on their cell phone had a greater increase in salivary nickel concentration. 

The “adverse effect of radiation on the release of nickel was more prominent in women” because they spoke more on their cell phones. The females averaged 53 minutes during the week they used their cell phones whereas the males averaged 23 minutes.

Nickel is a known toxic and carcinogenic metal. It is also a common cause of metal-induced contact allergic dermatitis. Nickel-containing alloys are often used in orthodontics for metallic brackets, arch wires, and bands.

Previous research either found no increase in salivary nickel concentration after a fixed orthodontic appliance was inserted or a significant increase that tapered off within three weeks after insertion.  The patients in the current study had orthodontic appliances for 2-4 months before they participated to control for this potential confounding effect of time.

The Federal Communications Commission (FCC) requires all cell phone models be tested for their Specific Absorption Rate (SAR), a measure of the maximum amount of microwave radiation absorbed by the head and the body. SAR is measured in a laboratory using an artificial model of a large adult male with different fluids to simulate human tissue. The SAR testing procedure, adopted in 1996, was criticized by the Government Accountability Office in 2012 because it does not simulate today’s typical user or the way cell phones are typically used. The artificial head does not contain any metal (e.g., dental fillings, dental braces, metallic earrings or eyeglass frames) which could increase the radiation absorption beyond that measured in the laboratory. The artificial body test makes the unrealistic assumption that  consumers will carry their cell phones in manufacturer-approved holders that keeps the phones a minimum distance away from their bodies. 

Today many children are cell phone users.  The young child’s brain absorbs twice the radiation as the adult’s brain. The SAR testing procedure does not take this into account.  

Although the current study was conducted on young adults who had fixed orthodontic appliances, the results should have relevance for children who are more likely to be fitted for dental braces than adults.

The paper did not describe the specific types of fixed orthodontic appliances the patients had.

The abstract for the study and excerpts from the paper appear below.

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Saghiri MA, Orangi J, Asatourian A, Mehriar P, Sheibani N. Effect of mobile phone use on metal ion release from fixed orthodontic appliances. Am J Orthod Dentofacial Orthop. 2015 Jun;147(6):719-24. doi: 10.1016/j.ajodo.2015.01.023.

Abstract

INTRODUCTION:  The aim of this study was to evaluate the effect of exposure to radiofrequency electromagnetic fields emitted by mobile phones on the level of nickel in saliva.

METHODS:  Fifty healthy patients with fixed orthodontic appliances were asked not to use their cell phones for a week, and their saliva samples were taken at the end of the week (control group). The patients recorded their time of mobile phone usage during the next week and returned for a second saliva collection (experimental group). Samples at both times were taken between 8:00 and 10:00 pm, and the nickel levels were measured. Two-tailed paired-samples t test, linear regression, independent t test, and 1-way analysis of variance were used for data analysis.

RESULTS:  The 2-tailed paired-samples t test showed significant differences between the levels of nickel in the control and experimental groups (t [49] = 9.967; P <0.001). The linear regression test showed a significant relationship between mobile phone usage time and the nickel release (F [1, 48] = 60.263; P <0.001; R(2) = 0.577).

CONCLUSIONS:  Mobile phone usage has a time-dependent influence on the concentration of nickel in the saliva of patients with orthodontic appliances.


Highlights

•  Radiofrequencies from mobile phones and nickel concentrations in saliva were examined.
•  Mobile phone radiation is positively correlated with nickel concentration in saliva.
•  Nickel concentrations in saliva were different in men and women.

Excerpts

An integral part of modern telecommunication is the mobile phone, which may have negative effects on different organs and cells. These negative impacts culminate from radiofrequency electromagnetic radiation (RFER) emitted from mobile phones. From 1990 to 2011, worldwide mobile phone subscriptions grew from 12.4 million to over 5.6 billion, and the global pandemic usage of mobile phones was about 70% as of 2011.  Insufficient understanding of the potential adverse health effects of mobile phones have raised concerns among health care professionals.

According to the proximity of mobile phones to the oral cavity during the conversation period and the metallic orthodontic appliances in the mouth, there might be a serious risk in exposure of these appliances to the mobile phone radiation. Archwires, headgear, bands, and brackets used in orthodontics mainly consist of nickel. The harmful effects of nickel have been systematically investigated at the levels of the cells, tissues, organs, and organisms.  According to the International Agency for Research on Cancer, nickel compounds are classified as carcinogenic to humans, but it is still unclear which forms of nickel pose the greatest risk. Nickel complexes in the form of arsenides and sulphides are carcinogenic, allergenic, and mutating substances even at nontoxic concentrations. Nickel might induce DNA alterations mainly through basic damage and DNA-strand scission in G12 cultured cells. Empirically, a biologic limit of 30 μg per gram has been proposed for nickel in the urine of workers exposed to soluble nickel compounds at the end of their shifts.

Nickel is a common metal that can cause allergic contact dermatitis more than all other metals. Previous studies have indicated that approximately 10% of the population is sensitive to nickel, and this sensitivity is more commonly seen in female patients.

The anatomic location of the parotid gland (at the anterior border of the external ear and between the mandibular ramus and the sternocleidomastoid muscle, 4- to 10-mm deep under the skin surface) makes it a conceivable candidate to be influenced by exposure to RFER on the side of the head where the mobile phone is held. Some researchers, in both human and animal studies, have confirmed that mobile phones cause significant increases in salivary oxidative stress, salivary flow, total proteins, and albumin, whereas amylase activity was decreased. In a nationwide case-control study, Sadetzki et al examined the correlation between parotid gland tumors and mobile phone usage and indicated a positive dose-dependent response trend. Thus, the RFER emitted from mobile phones may influence the amount of nickel released from the fixed orthodontic appliances.

… the aim of this study was to test the hypothesis that exposure to RFER emitted by mobile phones can affect the level of nickel in saliva. In addition, the effect of different times of exposure to the RFER was evaluated on the concentration of nickel in saliva.

Fifty healthy patients (25 men, 25 women; average age, 25.2 years; range, 23-26 years) who had fixed orthodontic appliances were selected for the study. Candidates needed placement of full orthodontic appliances for at least 2 months and no more than 4 months to satisfy the inclusion criterion.

During the regular checkups, the patients were asked not to use their cell phones for 1 week, and saliva samples were taken from them at the end of the week (this was considered the control group). For the next visit, a chronometer was given to the patients to calculate how many minutes they used their cell phone during the second week of the experiment. At the end of the second week, saliva samples were again collected, and the sexes, ages, and cell phone usage times were also recorded; this was considered the experimental group. The saliva samples were sent to the laboratory for further analysis.

The main outcome of the study was a significantly higher concentration of nickel ions in patients' saliva after using their mobile phones compared with the control group. The mobile phones used in this study had emissions of radiation in the normal range of 800 to 2200 MHz, as mentioned above.

The concentrations of salivary calcium, magnesium, and phosphate were lower in the mobile user group.  Our results showed that the concentrations of nickel ions after using a cell phone for 1 week were significantly higher than the concentrations in the control group. This might be attributed to the greater flow rate and the lower concentration of the components in saliva, which in turn result in more nickel released from fixed orthodontic appliances into the saliva.

The linear regression test showed a positive significant increase in nickel concentration with mobile phone usage time. In other words, the longer the exposure to the RFEF emitted by a mobile phone, the greater the concentration of nickel in saliva.

According to results of our study, mobile phone radiation might cause DNA damage indirectly by influencing the release of nickel from fixed orthodontic appliances. Thus, the necessity of studying the effects of this radiation on metal ions released from fixed orthodontic appliances in adjacent tissues seems to be undeniable.

Conclusions
According to the outcomes of this study, it can be concluded that mobile phone radiation, regardless of the type of phone, can influence the concentration of nickel in saliva in a time-dependent manner. In addition, this adverse effect of radiation on the release of nickel was more prominent in women because of longer usage times. Future large-scale studies, which should include more parameters such as the effects on the parotid glands or the saliva flow rate, are needed.