Wednesday, October 23, 2019

NTP Cell Phone Radiation Study: Final Reports


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NTP Study: DNA damage found in rats and mice from 14-19 weeks of exposure to cellphone radiation

Smith-Roe SL, Wyde ME, Stout MD, Winters JW, Hobbs CA, Shepard KG, Green AS, Kissling GE, Shockley KR, Tice RR, Bucher JR, Witt KL. Evaluation of the genotoxicity of cell phone radiofrequency radiation in male and female rats and mice following subchronic exposure. Environ Mol Mutagen. 2019 Oct 21. doi: 10.1002/em.22343.

Abstract


The National Toxicology Program tested two common radiofrequency radiation (RFR) modulations emitted by cellular telephones in a 2-year rodent cancer bioassay that included interim assessments of additional animals for genotoxicity endpoints.

Male and female Hsd:Sprague Dawley SD rats and B6C3F1/N mice were exposed from gestation day 5 or postnatal day 35, respectively, to code division multiple access (CDMA) or global system for mobile (GSM) modulations over 18 hours per day, at 10 minute intervals, in reverberation chambers at specific absorption rates (SAR) of 1.5, 3, or 6 W/kg (Watts/kilogram) (rats, 900 MHz) or 2.5, 5, or 10 W/kg (mice, 1900 MHz). After 19 (rats) or 14 (mice) weeks of exposure, animals were examined for evidence of RFR-associated genotoxicity using two different measures. Using the alkaline (pH > 13) comet assay, DNA damage was assessed in cells from three brain regions, liver cells, and peripheral blood leukocytes; using the micronucleus assay, chromosomal damage was assessed in immature and mature peripheral blood erythrocytes.

Results of the comet assay showed significant increases in DNA damage in the frontal cortex of male mice (both modulations), leukocytes of female mice (CDMA only), and hippocampus of male rats (CDMA only). Increases in DNA damage judged to be equivocal were observed in several other tissues of rats and mice. No significant increases in micronucleated red blood cells were observed in rats or mice. In conclusion, these results suggest that exposure to RFR is associated with an increase in DNA damage.


Excerpts

The NTP bioassay was designed to evaluate non-thermal effects of cell phone RFR exposure, which meant that body temperature could not change more than 1 degree Centigrade under our exposure conditions .... Therefore, we consider it unlikely that thermal effects were a confounding factor for our genetic toxicity tests, although more work in general is needed to clarify the thermal effects of RFR on different tissues, and the degree to which increases in body or tissue temperature affect genomic integrity.

... our results and the results of other experiments suggest that non-thermal exposure of cells or whole organisms to RFR may result in measurable genotoxic effects, despite varied and weak responses across studies overall (Brusick et al., 1998; Ruediger, 2009; Verschaeve et al., 2010). Induction of oxygen radicals or interference with DNA repair processes have been proposed as possible mechanisms by which RFR could cause DNA damage (Ruediger 2009; Yakymenko et al. 2015).

... NTP Technical Reports on the results of the 2-year cancer bioassay for exposure to RFR for rats (TR 595) and mice (TR 596) were finalized, peer reviewed, and made publicly available in 2018. The NTP concluded that results demonstrated clear evidence of carcinogenic activity of cell phone RFR (both modulations) based on incidences of malignant schwannomas of the heart in male rats. Malignant gliomas in the brain were also observed in male rats exposed to cell phone RFR and were considered to be related to exposure. Female rats exhibited malignant schwannomas of the heart and malignant gliomas, but incidences of these tumors were considered equivocal. The observation that cell phone RFR affects heart and brain tissue in Sprague Dawley rats after long-term exposure was replicated in a similar study (that used only the GSM modulation) by the Ramazzini Institute (Falcioni et al., 2018). The gliomas and schwannomas observed in rats are similar to the tumor types reported in some epidemiology studies to be associated with cell phone use. The NTP bioassay findings in mice, in which different organs were affected compared to rats, were considered equivocal....

The highest exposure of 6 W/kg in rats and 10 W/kg in mice, for a total of 9 hours 10 minutes a day (achieved by cycling for 10 min on, 10 min off over 18 hours  20 minutes), produced higher exposures than experienced by humans under normal cellular phone use conditions. Thus, whether the findings in the NTP animal studies (e.g. malignant gliomas in the brain and malignant schwannomas in the hearts of male rats; increased levels of DNA damage in hippocampal cells of male rats and the frontal cortex of male mice) indicate a potential for adverse health outcomes in humans remains a question. Because one of the most important questions prompted by our results concerns the mechanism(s) by which RFR might induce biological effects, follow-up studies by the NTP to investigate mechanisms of genetic damage associated with RFR exposure are underway.

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The Significance of Primary Tumors in the NTP Study of Chronic Rat Exposure to Cell Phone Radiation

The following paper by Dr. James C. Lin, Professor of Electrical Engineering, Professor of Bioengineering, and Professor of Physiology and Biophysics at the University of Illinois at Chicago, was published in the November issue of the IEEE Microwave Magazine. Dr. Lin was one of the 14 scientists selected by the National Institute of Environmental Health Sciences to perform the expert review of the $30 million cell phone radiation study conducted by the National Toxicology Program.  Dr. Lin has received numerous professional awards and honors over the past four decades.


Lin JC. The Significance of Primary Tumors in the NTP Study of Chronic Rat Exposure to Cell Phone Radiation [Health Matters]. IEEE Microwave Magazine. 20(11):18-21. Nov 2019. DOI:10.1109/MMM.2019.2935361.

Abstract

Most media accounts of the U.S. National Toxicology Program's (NTP's) final report have understandably focused on the statistically significant finding of "clear evidence" that both GSM and code-division multiple access (CDMA)-modulated 900-MHz wireless RF radiation led to the development of malignant schwannoma, a rare form of tumor, in the hearts of male rats. In addition to this, unusual patterns of cardiomyopathy, i.e., damage to heart tissue, were observed in both RF-exposed male and female Sprague-Dawley rats compared with concurrent control animals, although the findings for female rats were deemed as providing only uncertain or "equivocal" evidence for schwannomas and malignant gliomas, compared to concurrent controls.


Excerpts

"A Closer Look at the NTP Findings

“In all fairness, the primary cancer or overall cancer rates detected in any organ or tissue inside the animal body do not appear to have been purposefully overlooked or unnoticed. Indeed, the results for total primary cancer or tumor occurrences in NTP animal studies can be found in the appendices of its final reports [1]. However, although the data may not have been purposefully disregarded or ignored, the NTP excluded them from its publicized report summaries. An independent analysis of the data showed that rats exposed to GSM and CDMA RF radiation had significantly higher overall or total primary tumor rates than did the concurrent control rats [4].

In particular, the highest overall cancer (or malignant tumors) rates were found in male rats exposed to whole-body SARs of 3 W/kg from 900-MHz cell phone RF radiation (42 and 46% for GSM and CDMA, respectively), and the lowest rate was found in the concurrent control group (27%). Thus, the RF-exposed groups had significantly higher overall or total primary cancer rates than did the concurrent control rats. Moreover, the highest overall tumor rates (either a benign or malignant tumor in any organ or tissue) were observed in male rats exposed to SARs of 3-W/kg (87 and 84% for GSM and CDMA, respectively) cell phone RF radiation. As stated previously, the lowest rate was seen in the concurrent control group (63%). The RF-exposed groups had significantly higher overall tumor rates than did the concurrent control rats. Male rats in the lowest RF-exposed groups (whole-body SARs of 1.5 W/kg) had significantly higher rates of benign primary tumors (76 and 73% for GSM and CDMA, respectively) than did concurrent or sham control groups (54%).”

[4] J. Moskowitz, “National toxicology program publishes final cell phone radiation study reports,” Electromagn. Radiation Safety, Nov. 2018. [Online]. Available: https://www.saferemr.com/2018/11/NTP-final-reports31.html

"IARC Assessment

The International Agency for Research on Cancer (IARC) assessed the then available scientific literature and concluded that the epidemiological studies on humans that had reported increased risks for malignant gliomas and acoustic neuromas among heavy or long-term users of cell phones were sufficiently strong to support a classification of 2B, i.e., possibly carcinogenic to humans [9]. With its classification of RF radiation as a 2B carcinogen, the IARC suggested that it also believed the available scientific evidence was incomplete and limited, especially with regard to results from animal experiments.

“The time is right for the IARC to upgrade its previous epidemiology-based classification of RF exposure to higher levels in terms of the carcinogenicity of RF radiation for humans. Recently, two relatively well-conducted RF and microwave exposure studies employing the Sprague–Dawley strain of rats—without, however, using any cancer-promoting agents (or cocarcinogens)—showed consistent results in significantly increased total primary cancer or overall tumor rates in animals exposed to RF radiation.”

It is important to note that the recent NTP and Ramazzini animal RF exposure studies presented similar findings in heart schwannomas and brain gliomas. The increased schwannomas and abnormal heart tissue development/damage to heart tissue are significant findings in RF-exposed animal research studies. In addition to this, the incidence of benign pheochromocytomas of the adrenal medulla was found to be higher in the exposed group than in the sham controls for the 2,450-MHz circular waveguide experiment [6]. Interestingly, in the recent NTP study, there was “some evidence” of carcinogenicity in the adrenal gland. The number of pheochromocytomas was significantly higher (p <0.05) in male rats at 1.5 and 3 W/kg, compared with the concurrent controls. Moreover, the increase in malignant tumor-like hyperplasia in the adrenal gland of female rats was significantly higher at 6 W/kg, relative to the concurrent controls (p <0.05)."

"Postscripts

... It is important to note that the recent NTP and Ramazzini animal RF exposure studies presented similar findings in heart schwannomas and brain gliomas. The increased schwannomas and abnormal heart tissue development/damage to heart tissue are significant findings in RF-exposed animal research studies....

A particular perspective to keep in mind is that, with the induction of cancer by a carcinogen, an agent is typically considered carcinogenic if it induces a significant response in a specific tissue.”


November 1, 2018 (Updated: Nov 16, 2018)

National Toxicology Program (NTP) cell phone radiation studies, the NTP press release, and a new NTP fact sheet can be found below along with the FDA press release that addresses these studies.

In 1999, the U.S. Food and Drug Administration (FDA) asked the NTP to conduct cell phone radiation studies on animals.The FCC's exposure guidelines for cell phone radiation adopted in 1996 and still in effect today were designed to protect humans from thermal (or heating) effects. However, scientists at that time were concerned that low level exposures could increase cancer risk through nonthermal mechanisms. This was the basis for the FDA's request to the NTP in 1999:

"The existing exposure guidelines are based on protection from acute injury from thermal effects of RFR exposure, and may not be protective against any non-thermal effects of chronic exposures. Animal exposure research reported in the literature suggests that low level exposures may increase the risk of cancer by mechanisms yet to be elucidated, but the data is conflicting and most of this research was not conducted with actual cellular phone radiation."
Nineteen years later on November 1, 2018, the NTP published the final reports on the effects of two-years of exposure to 2G (GSM and CDMA) cell phone radiation on rats and mice. Since these studies utilized radiation levels that would not induce significant heating (greater than one degree Centigrade), any observed effects would be due to nonthermal mechanisms (e.g., oxidative stress).

The NTP final reports found "clear evidence" of increased cancer risk in male rats from low level (i.e., nonthermal) exposures (c.f., heart schwannoma). Furthermore, many hundreds of peer-reviewed studies have found evidence of biologic and health effects from low level exposures to cell phone radiation. Hence, the FCC's exposure guidelines must be re-assessed as they are likely inadequate to protect human health. 

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The NTP final reports indicate that the NTP staff has accepted the peer review committee’s recommendations about the carcinogenicity of cell phone radiation. A summary of these recommendations can be found at: http://bit.ly/NTP180330 

Information about the NTP study and the peer review process is available at:

National Toxicology Program (NTP) Finds Cell Phone Radiation Causes Cancer

Besides "clear evidence" (the highest category) of cancer in male rats from long term exposure to cell phone radiation, the NTP found degeneration in the hearts of male and female rats, decreased birth weights in rats exposed prenatally, and DNA damage in mice and rats as compared to sham controls.

Nonetheless, the NTP seems to be downplaying the significance of the results for public health of their $30 million cell phone radiation studies.

In my opinion, the results of the NTP cell phone radiation studies in conjunction with the results of the recent Ramazzini Institute study provide conclusive evidence that long term exposure to cell phone radiation causes DNA damage and cancer.

To follow up on the comments I submitted to the NTP in March, during the telebriefing yesterday, I asked whether the NTP conducted a statistical analysis of the overall tumor rates (across all organs) for each group. Dr. Bucher responded that there is a "philosophical difference" about whether to examine overall tumor risk in toxicology studies because the overall tumor rate is generally "driven by common tumors." Thus, such an analysis is usually overly conservative (i.e., biased toward the null).

However, there is a precedent for conducting such an analysis in the NTP cellphone studies since the entire body of the animals was exposed to cellphone radiation. A 5-year, $5 million Air Force study found low incidences of many types of tumors in male rats exposed to microwave radiation (Chou et al, 1992). In that study, the exposed rats were three times more likely to get cancer than the control rats. The study employed much lower intensity microwave radiation than the NTP studies. 

We should learn from our colleagues who study tobacco research. Early toxicology research on the effects of tobacco found low incidences of many types of tumors among animals exposed to tobacco smoke. Scientists dismissed this evidence because they assumed an agent could not cause cancer in different types of tissue. History later proved them wrong.

Dr. Wyde's response to my question was that the overall tumor rates appear in Appendices A through D of the NTP final reports. Unfortunately, these results remain buried in the appendices when in my opinion they should be featured as key results of the study.

The data in the following tables were extracted from Tables A2 and C2 in the NTP final report on the 2-year rat study (pp. 149-150 and 203-204). The tumor rates across all organs for the male rats are tabled by exposure condition for GSM and CDMA cell phone radiation for benign tumors, malignant tumors, and for either type of tumors.













































The above tables show that the highest overall tumor rates (i.e., the presence of either a benign or malignant tumor in any organ) were found in male rats exposed to 3 watts per kilogram of either GSM (87%) or CDMA (84%) cell phone radiation, and the lowest rate was found in the sham control group (63%). The exposed groups had significantly higher overall tumor rates than the sham controls even after adjusting for survival differences among the groups (see the Poly-3 test p values).

The highest cancer rates (i.e., malignant tumors) were found in male rats exposed to 3 watts per kilogram of either GSM (42%) or CDMA (46%) cell phone radiation and the lowest rate was found in the sham control group (27%). Here too, the exposed groups had significantly higher overall cancer rates than the sham controls.

Moreover, male rats in the lowest exposure groups (1.5 watts per kilogram) had significantly higher rates of benign tumors (76% for GSM; 73% for CDMA) than the sham control group (54%).

Is it justifiable to bury these results in the appendices to the final reports?

The results of the NTP and Ramazzini Institute studies reaffirm the concerns raised by the scientific community in the International EMF Scientist Appeal about the harm caused by chronic exposure to low-intensity electromagnetic fields (EMF). The Appeal, which has been signed by more than 240 EMF scientists who have published over 2,000 papers on EMF and biology or health in professional journals, calls for warning the public and strengthening EMF guidelines, especially to protect children and pregnant women.

We are guinea pigs in a massive technological experiment that threatens our health. Our government needs to fund the research needed to determine a safe level of long-term exposure to wireless radiation and then strengthen the FCC's radio frequency exposure limits.

In the meantime, the government should impose a moratorium on technologies that increase our exposure to wireless radiation, especially new forms of wireless radiation like 5G.

Related posts:




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NTP Final Reports

National Toxicology Program. NTP technical report on the toxicology and carcinogenesis studies in Hsd:Sprague Dawley SD rats exposed to whole-body radio frequency radiation at a frequency (900 MHz) and modulations (GSM and CDMA) used by cell phones. NTP TR 595. Research Triangle Park, NC. November, 2018. https://www.niehs.nih.gov/ntp-temp/tr595_508.pdf


SUMMARY

Background

Cell phones utilize a specific type of radio waves, or radio frequency radiation (RFR), to transmit between the devices and the network. Exposure of people to RFR occurs primarily through use of cell phones and other wireless devices. We studied the effects of nearly lifetime exposures to two different types, or modulations, of RFR (GSM and CDMA) used in cellular telephone networks in the United States in male and female rats and mice to identify potential toxicity or cancer-related hazards.

Over the years, cell phone technology has evolved from the original analog technology (1G) commercially introduced in the 1980s to digital networks that supplanted analog phones. The digital network, referred to as 2G or the 2nd generation of technology, was commercially launched in the 1990s, with 3G and 4G subsequently deployed in the intervening years. When the current studies were being designed, 2G technology was the industry standard, and 3G technologies were under development. While newer technologies have continued to evolve, it is important to note that these technologies have not completely replaced the older technologies. In fact, today’s phones are very complex in that they contain several antennas, for wi-fi, GPS, 2G/3G bands, etc. Thus, the results of these studies remain relevant to current exposures, although the power levels of the exposures were much higher than typical patterns of human use.

Methods

We exposed groups of 90 male and 90 female rats to 1.5, 3, or 6 W/kg RFR that was modulated in the same manner in which signals are emitted from cell phones and other similar wireless communication devices. Other groups of male and female rats housed in the same type of chambers without any exposure to RFR were used as the controls. Animals were exposed to RFR in utero, postnatally, and during adulthood for approximately 9 hours a day, 7 days per week, for 2 years. Tissues from more than 40 sites were examined for every animal.

Results

Exposure to RFR caused decreased body weights of pregnant rats during gestation and lower birth weights in their offspring. However, a few weeks after birth body weights returned to normal and were similar to non-exposed rats. In general, RFR-exposed male rats lived longer than non-exposed rats. The higher survival of exposed males was attributed to a lower severity of a natural, age-related kidney disease typically observed in male rats at the end of these types of studies, which may have been related to the RFR exposure. In both studies (GSM and CDMA), exposure to RFR in male rats resulted in higher numbers of animals with tumors of the heart and brain. In the GSM study, increased numbers of animals with tumors of the adrenal gland were also observed in exposed males. In both studies, there were tumors that occurred in several organs that we were unable to clearly determine whether these resulted from exposure or were just incidental findings. For the GSM studies, these lesions included tumors of the prostate gland, pituitary gland, and pancreas in males and of the heart in females. For the CDMA studies, these equivocal lesions included tumors of the pituitary gland and liver in males and of the heart, brain, and adrenal gland of females.

Conclusions

In males for both GSM- and CDMA-modulated RFR, we conclude that exposures increased the number of animals with tumors in the heart. Tumors of the brain were also considered to be related to exposure; and increased numbers of male rats with tumors of the adrenal gland were also related to exposure. We are uncertain whether occurrences of prostate gland, pituitary gland, and pancreatic islet tumors in male rats exposed to GSM-modulated RFR and pituitary gland and liver tumors in male rats exposed to CDMA-modulated RFR were related to RFR exposures. This was also the case with female rats, where we conclude that exposure to GSM- or CDMA-modulated RFR may have been related to tumors in the heart. For females exposed to CDMA-modulated RFR, occurrences of brain and adrenal gland tumors may have been related to exposure.

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National Toxicology Program. NTP technical report on the toxicology and carcinogenesis studies in B6C3F1/N mice exposed to whole-body radio frequency radiation at a frequency (1900 MHz) and modulations (GSM and CDMA) used by cell phones. NTP TR 596.  Research Triangle Park, NC. November, 2018. https://www.niehs.nih.gov/ntp-temp/tr596_508.pdf

SUMMARY

Background

Cell phones utilize a specific type of radio waves, or radio frequency radiation (RFR), to transmit voice and data between the devices and the network. Exposure of people to RFR occurs primarily through use of cell phones and other wireless devices. We studied the effects of nearly lifetime exposure to two different types, or modulations, of RFR (GSM and CDMA) used in cellular telephone networks in the United States in male and female rats and mice to identify potential toxic or cancer-related hazards.

Over the years, cell phone technology has evolved from the original analog technology (1G) commercially introduced in the 1980s to digital networks that supplanted analog phones. The digital network, referred to as 2G or the 2nd generation of technology, was commercially launched in the 1990s, with 3G and 4G subsequently deployed in the intervening years. When the current studies were being designed, 2G technology was the industry standard, and 3G technologies were under development. While newer technologies have continued to evolve, it is important to note that these technologies have not completely replaced the older technologies. In fact, today’s phones are very complex in that they contain several antennas, for Wi-Fi, GPS, 2G/3G bands, etc. The results of these studies remain relevant to current exposures, although the power levels of the exposures were much higher than typical patterns of human use.

Methods

We exposed groups of 90 male and 90 female mice to 2.5, 5, or 10 W/kg RFR that was modulated in the same manner in which signals are emitted from cell phones and other similar wireless communication devices. Other groups of male and female mice housed in the same type of chamber without any exposure to RFR were used as the controls. Animals were exposed to RFR for approximately 9 hours a day, 7 days per week, for 2 years. Tissues from more than 40 sites were examined for every animal.

Results

There were higher rates of survival in males at the low (2.5 W/kg) and mid (5 W/kg) exposures to CDMA- and GSM-modulated RFR, respectively. Body weights in the exposed groups of animals were similar to their controls. In both studies (GSM and CDMA), there were higher incidences of malignant lymphoma in all groups of female mice exposed to RFR compared to controls. However, the incidences in all of the exposed females were within the range historically observed in this strain of mouse in other NTP studies. There were higher incidences of skin and lung tumors in males exposed to the highest two levels of GSM-modulated RFR (5 and 10 W/kg), and of liver tumors at the mid-dose (5 W/kg) of CDMA-modulated RFR.

Conclusions

For GSM-modulated RFR, we conclude that exposure to RFR may have caused tumors in the skin and lungs of male mice and malignant lymphomas in female mice. For CDMA-modulated RFR, we conclude that exposure to RFR may have caused tumors in the liver of male mice and malignant lymphomas in female mice.

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NTP Press Release (November 1, 2018)

High exposure to radio frequency radiation associated with cancer in male rats

National Toxicology Program releases final reports on rat and mouse studies of radio frequency radiation like that used in 2G and 3G cell phone technologies

Press Release, National Toxicology Program, Nov 1, 2018

The National Toxicology Program (NTP) concluded there is clear evidence that male rats exposed to high levels of radio frequency radiation (RFR) like that used in 2G and 3G cell phones developed cancerous heart tumors, according to final reports released today. There was also some evidence of tumors in the brain and adrenal gland of exposed male rats. For female rats, and male and female mice, the evidence was equivocal as to whether cancers observed were associated with exposure to RFR. The final reports represent the consensus of NTP and a panel of external scientific experts who reviewed the studies in March after draft reports were issued in February.

“The exposures used in the studies cannot be compared directly to the exposure that humans experience when using a cell phone,” said John Bucher, Ph.D., NTP senior scientist. “In our studies, rats and mice received radio frequency radiation across their whole bodies. By contrast, people are mostly exposed in specific local tissues close to where they hold the phone. In addition, the exposure levels and durations in our studies were greater than what people experience.”

The lowest exposure level used in the studies was equal to the maximum local tissue exposure currently allowed for cell phone users. This power level rarely occurs with typical cell phone use. The highest exposure level in the studies was four times higher than the maximum power level permitted. 

“We believe that the link between radio frequency radiation and tumors in male rats is real, and the external experts agreed,” said Bucher. 

The $30 million NTP studies took more than 10 years to complete and are the most comprehensive assessment, to date, of health effects in animals exposed to RFR with modulations used in 2G and 3G cell phones. 2G and 3G networks were standard when the studies were designed and are still used for phone calls and texting.

“A major strength of our studies is that we were able to control exactly how much radio frequency radiation the animals received — something that’s not possible when studying human cell phone use, which has often relied on questionnaires,” said Michael Wyde, Ph.D., lead toxicologist on the studies.

He also noted the unexpected finding of longer lifespans among the exposed male rats. “This may be explained by an observed decrease in chronic kidney problems that are often the cause of death in older rats,” Wyde said.

The animals were housed in chambers specifically designed and built for these studies. Exposure to RFR began in the womb for rats and at 5 to 6 weeks old for mice, and continued for up to two years, or most of their natural lifetime. The RFR exposure was intermittent, 10 minutes on and 10 minutes off, totaling about nine hours each day. RFR levels ranged from 1.5-6 watts per kilogram in rats, and 2.5-10 watts per kilogram in mice.

These studies did not investigate the types of RFR used for Wi-Fi or 5G networks.

“5G is an emerging technology that hasn’t really been defined yet. From what we currently understand, it likely differs dramatically from what we studied,” said Wyde.

For future studies, NTP is building smaller RFR exposure chambers that will make it easier to evaluate newer telecommunications technologies in weeks or months, rather than years. These studies will focus on developing measurable physical indicators, or biomarkers, of potential effects from RFR. These may include changes in metrics like DNA damage in exposed tissues, which can be detected much sooner than cancer.


The U.S. Food and Drug Administration nominated cell phone RFR for study by NTP because of widespread public use of cell phones and limited knowledge about potential health effects from long-term exposure. NTP will provide the results of these studies to FDA and the Federal Communications Commission, who will review the information as they continue to monitor new research on the potential effects of RFR.

NTP uses four categories to summarize the evidence that a substance may cause cancer:

·      Clear evidence (highest)
·      Some evidence
·      Equivocal evidence
·      No evidence (lowest) 


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NTP Cell Phone Radiation Fact Sheet (November, 2018)






https://www.niehs.nih.gov/health/materials/cell_phone_radiofrequency_radiation_studies_508.pdf

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FDA contradicts NTP

According to NTP Report (NTP TR 595, p. 25):

"The FDA does not currently regulate the use of wireless communications devices or the devices themselves. The FDA also does not require safety evaluations for radiation-emitting wireless communication devices. It does maintain the authority to take regulatory action if it is demonstrated that exposure to the emitted cell phone RFR from these devices is hazardous to the user."
Dr. Bucher, an NTP senior scientist and former associate director, stated in the NTP's press release (Nov 1, 2018), "We believe that the link between radio frequency radiation and tumors in male rats is real, and the external experts agreed.” 

Nonetheless, the FDA dismissed the NTP results in its press release. FDA Center Director, Dr. Shuren, stated “these findings should not be applied to human cell phone usage ... we believe the existing safety limits for cell phones remain acceptable for protecting the public health.” 

This is rather odd since the FDA requested that the NTP conduct these animals studies in 1999 because the agency was concerned that the FCC's cell phone "safety limits" did not protect human safety since the limits were based on a thermal model. Now that we have hundreds of animal studies demonstrating non-thermal biologic effects and several major epidemiologic studies demonstrating increased cancer risk in heavy cell phone users, FDA should be more concerned than ever that the FCC exposure guidelines are inadequate.

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FDA. Press Release: Statement from Jeffrey Shuren, M.D., J.D., Director of the FDA’s Center for Devices and Radiological Health on the National Toxicology Program’s report on radiofrequency energy exposure. FDA, Nov 1, 2018.
"We know that cell phones are an important, everyday tool to most Americans. We use them now for much more than just talking—from booking travel on an app to using mobile wallets to pay for groceries. Our ubitquitious use of cell phones inevitably means that we must continue to review and ensure their safety.
The Food and Drug Administration is charged with ensuring cell phones— and any radiation-emitting electronic product—are safe for the public to use. Our scientific expertise and input, along with other health agencies, are used by the Federal Communications Commission (FCC) to set the standards for exposure limits of radiation from cell phones, called radiofrequency energy.
We have relied on decades of research and hundreds of studies to have the most complete evaluation of radiofrequency energy exposure. This information has informed the FDA’s assessment of this important public health issue, and given us the confidence that the current safety limits for cell phone radiofrequency energy exposure remain acceptable for protecting the public health.
When new studies or information becomes available, the FDA conducts thorough evaluations of the data to continually inform our thinking. We reviewed the recently finalized research conducted by our colleagues at the National Toxicology Program (NTP), part of the National Institute of Environmental Health Sciences within the National Institutes of Health, on radiofrequency energy exposure. After reviewing the study, we disagree, however, with the conclusions of their final report regarding “clear evidence” of carcinogenic activity in rodents exposed to radiofrequency energy.
In the NTP study, researchers looked at the effects of exposing rodents to extremely high levels of radiofrequency throughout the entire body. This is commonly done in these types of hazard identification studies and means that the study tested levels of radiofrequency energy exposures considerably above the current whole body safety limits for cell phones. Doing this was intended to help contribute to what we already understand about the effects of radiofrequency energy on animal tissue. In fact, we only begin to observe effects to animal tissue at exposures that are 50 times higher than the current whole body safety limits set by the FCC for radiofrequency energy exposure.
Our colleagues at NTP echoed this point in a statement earlier this year about their draft final report, including the important note that “these findings should not be directly extrapolated to human cell phone usage.”
We agree that these findings should not be applied to human cell phone usage.
NTP hosted a three-day peer review of this study in March, as part of their normal process for issuing scientific reports. The FDA was not a participant in that process, but was invited to observe the panel discussions, which included an assessment of the study methods and data by a panel of 15 peer reviewers to determine the basis of evidence for the final report. Based on their assessment, the panel voted to upgrade the conclusions from some evidence to clear evidence for malignant heart schwannomas in male rats, and from equivocal (ambigious) to some evidence for malignant gliomas of the brain and benign tumors of the adrenal gland in male rats. It’s important to note that the vote does not mean new data or findings were reported in the final assessment.
In addition, as we’ve noted previously, there were unusual findings in the study, such as: the rats exposed to whole body radiofrequency energy lived longer than rats that were not exposed to any radiation (control group); only male rats exposed to the highest radiofrequency energy dosage developed a statistically significant number of heart schwannomas, which are very rare in humans, when compared to the control group in this experiment. There was also no true dose response, or a lack of a clear relationship between the doses of radiation administered to the animals and their subsequent tumor rate.
Researchers will need to consider all of the findings when exploring future human epidemiological studies.
As scientists, we welcome new studies. Animal studies like this one contribute to our discussions on this topic, but we must remember the study was not designed to test the safety of cell phone use in humans, so we cannot draw conclusions about the risks of cell phone use from it. We also must thoroughly evaluate and take into consideration the totality of the data, and do so within the context of the complete body of evidence rather than drawing conclusions from the results of a single study.
As part of our commitment to protecting the public health, the FDA has reviewed, and will continue to review, many sources of scientific and medical evidence related to the possibility of adverse health effects from radiofrequency energy exposure in both humans and animals and will continue to do so as new scientific data are published.
Based on our ongoing evaluation of this issue, the totality of the available scientific evidence continues to not support adverse health effects in humans caused by exposures at or under the current radiofrequency energy exposure limits. We believe the existing safety limits for cell phones remain acceptable for protecting the public health.
The FDA, an agency within the U.S. Department of Health and Human Services, protects the public health by assuring the safety, effectiveness, and security of human and veterinary drugs, vaccines and other biological products for human use, and medical devices. The agency also is responsible for the safety and security of our nation’s food supply, cosmetics, dietary supplements, products that give off electronic radiation, and for regulating tobacco products."