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Letter to FDA From Scientists on the FDA Rejection of NTP Study and FCC Limits 

Aug 10, 2019


Letter to FDA From Scientists on the FDA Rejection of NTP study and FCC Limits

Note: This letter was sent December 17, 2018 , sent again in April 2019 and as of August 2019, scientists have received no response from the FDA. 

To: Jeffrey Shuren, MD, JD,Director of the FDA’s Center for Devices and Radiological Health Food and Drug Administration 10903 New Hampshire Ave Silver Spring, MD 20993-0002

Sent: December 17, 2018  

Questions RE:  FDA’s Rejection of the Cancer Association Found in the National Toxicology Program Radiofrequency Cell Phone Research Studies


Dear Dr. Jeffrey Shuren; 

As you are aware, the National Toxicology Program (NTP)/National Institute of Environmental Health Sciences (NIEHS) released their final reports on their $30 million animal study on long-term exposure to wireless radiofrequency electromagnetic (RF-EMF) radiation. They found statistically significant increases in DNA damage, heart damage, malignant glioma tumors of the brain, and malignant schwannomas of the heart. The increased incidence of heart tumors was considered by the expert peer-reviewers and staff of the NTP to demonstrate “clear evidence of carcinogenic activity” of modulated cell phone radiofrequency radiation. Similarly, studies by the Ramazzini Institute of RF-EMF at levels below FCC limits (Falcioni, 2018) found increases in malignant schwannomas of the heart in exposed rats. 


Importantly, these animal study findings support published case control studies in humans which found increases in tumors of the same types—schwannomas and gliomas. In 2011, RF-EMF was classified as a Group 2B possible carcinogen by the World Health Organization’s International Agency for Research on Cancer based on published research that found tumor increases in humans using cell phones long term. Now, in 2018, these animal studies substantially strengthen the scientific evidence that RF-EMF causes cancer, and scientists have concluded that there is now sufficient evidence to classify RF-EMF as a human carcinogen (Hardell and Carlberg, 2017, Peleg et al., 2018, Miller et al., 2018).


However, in response to the NTP final reports, the FDA stated, “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.”


We ask these questions to the FDA:


  1. Are there technical comments by the FDA that substantiate the FDA’s conclusions that NTP’s study did not find “clear evidence” of carcinogenicity for RF-EMF. Please provide copies. 


  1. Specifically what are the FDA’s conclusions regarding the schwannomas of the heart in male rats, the brain gliomas in the male rats, the DNA damage, and the cardiomyopathy of the heart?


  1. The FDA states, “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.” Please provide the documentation of the FDA’s “ongoing evaluation.” We respectfully request that you indicate the specific review process through which such an evaluation was undertaken and share with us the FDA evaluation, which we expect is in a report with citations for the research that was analyzed.


  1. The FDA stated of the March 2018 peer review, “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.” However, two FDA officials came to the National Toxicology Program’s peer review of the study and had an opportunity to speak and offer comments. Yet the FDA did not provide official comments on the NTP study at that time. FDA scientists did agree with the design of the NTP studies, which were presented to the Radiofrequency Interagency work group in 2003. Did the FDA ever share their disagreements or concerns with the NTP at any time—before and/or after the peer review? If so, please provide the comments of the FDA to the NTP.


  1. The FDA nominated cell phone radiation emitted from wireless communication devices to the NTP in 1999 and specifically stated that “animal experiments are crucial because meaningful data will not be available from epidemiological studies for many years due to the long latency period between exposure to a carcinogen and the diagnosis of a tumor” and that such studies would “provide the basis to assess the risk to human health.”  


Did the FDA inform the NIEHS/NTP at any time over the last 20 years since this nomination that animal research would not be sufficient to determine risk to public health from cell phone radiation? Further, please clarify if it is now the FDA’s position that animal research is no longer relevant to human health? If this is the case, will animal studies no longer be used to assess cancer risks from food contaminants, and how does the FDA propose to treat pharmacological testing of animals in support of pharmaceutical registration processes?


  1. The FDA states, “We believe the existing safety limits for cell phones remain acceptable for protecting the public health.” However, the FCC limits on allowable radiofrequency exposures are based on the assumption that only thermal RF levels can cause harm. The NTP studies were carefully controlled to minimize any potential thermal effects of RF on exposed animals, yet cancers and other adverse health effects were found at these nonthermal levels. Please provide the FDA’s scientific documentation that evaluates the current FCC limits in light of the NTP and Ramazzini studies to understand how the FDA can state FCC limits are adequate to protect human health.


  1. Kindly provide copies of FDA-submitted recommendations, reports, or opinions to the FCC regarding the radiofrequency human exposure exposure limits and policies. This could be either to the FCC Dockets 13-84, 03-137 or directly to the Commission. 


  1. Will the FDA be performing a quantitative risk assessment? If so, please provide a timeline. If not, please explain how and why that decision was made.




Ron Melnick, PhD

Senior Toxicologist and Director of Special Programs in the Environmental Toxicology Program at the National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health, now retired.


Anthony B. Miller, MD, FACE

Professor Emeritus Dalla Lana School of Public Health

University of Toronto


Lennart Hardell, MD, PhD

Department of Oncology

University Hospital

SE-701 85 Örebro, Sweden (retired)

Cancer Research Foundation

Örebro, Sweden


Devra Davis, PhD, MPH

President and Founder Environmental Health Trust

Visiting Professor of Medicine

Hebrew University Hadassah Medical Center 


David O. Carpenter, MD

Director, Institute for Health and the Environment

A Collaborating Centre of the World Health Organization

University at Albany


Theodora Scarato MSW

Executive Director, Environmental Health Trust 


Lloyd Morgan

Senior Research Fellow, Environmental Health Trust

Response as of August 10, 2019

Theodora –

Yes, this letter to Dr. Shuren has been received and I’ve asked it to be official logged and assigned for reply.



Lindsay Lloyd
Office of the Center Director
Center for Devices and Radiological Health

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