National Toxicology Program Cell Phone Radiation Study: Dr. Ronald Melnick Answers Questions. – Environmental Health Trust


In 1996, when the FCC set human exposure limits for wireless exposures, these limits rested on the assumption that overheating was the primary way RF could be harmful. The idea that lower non heating levels could cause harmful biological effects was considered “in need of more research”. Equally importantly, the FCC’s limits were not based on health effects from long term exposures. Remember that the studies that underpin FCC’s human exposure thresholds are a handful of experiments where small animals- rats, mice and small monkeys- were briefly exposed to high intense levels of RF.  

By the mid nineties, media reports of brain cancer in cell phone users were making headlines. So in 1999, the U.S. Food and Drug Administration (FDA) nominated the National Toxicology Program to perform large scale animal studies on cell phone radiation because according to the agency, “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.”

The FDA’s nomination letter specifically referenced animal studies that had found a “potential carcinogenic effect” and asserted that:

“Over 80 million Americans currently use wireless communications devices (e.g., cellular phones) with about 25 thousand new users daily. This translates into a potentially significant public health problem should the use of these devices even slightly increase the risk of adverse health effects…”

The FDA specifically asked for animal studies stating, “There is currently insufficient scientific basis for concluding either that wireless communication technologies are safe or that they pose a risk to millions of users. A significant research effort, involving large well-planned animal experiments is needed to provide the basis to assess the risk to human health of wireless communications devices.”

NIH scientist Ronald Melnick PHD, was tapped to lead the study design. As he has explained in numerous publications, “The National Toxicology Program studies were conducted to test the widely-held assumption that cell phone radiofrequency radiation could not cause cancers or other adverse health effects (other than by tissue heating) because this type of radiation (non-ionizing) did not have sufficient energy to break chemical bonds.” 

n November 1, 2018, nearly two decades after the FDA nomination, the final NTP reports were released.  The NTP had accepted the peer reviewers conclusions. 

The NTP officially found:

  • “Clear evidence of an association with tumors in the hearts of male rats. The tumors were malignant schwannomas.
  • Some evidence of an association with tumors in the brains of male rats. The tumors were malignant gliomas.
  • Some evidence of an association with tumors in the adrenal glands of male rats. The tumors were benign, malignant, or complex combined pheochromocytoma.”

In addition to cancer, the NTP scientists had also examined a subset of animals for DNA damage after 19 (rats) or 14 (mice) weeks of exposure. The NTP final reports also documented how RFR exposure led to significant increases in DNA damage in the frontal cortex of the brain in male mice, the blood cells of female mice, and the hippocampus of male rats.” In 2020, the NTP published the DNA findings  in the journal Environmental and Molecular Mutagenesis concluding, “these results suggest that exposure to RFR is associated with an increase in DNA damage.” 

In addition,  the NTP also also found an unusual type of heart damage- cardiomyopathy of the right ventricle of the heart-  in both male and female rat groups. When the Environmental Working Group analyzed the NTP’s data on tumor and heart damage using current risk assessment guidelines and concluded that FCC limits should be strengthened by 200 to 400 times to protect children. 

A few months later, researchers of the renowned Ramazzini Institute in Italy published findings from their animal study designed to mimic the low level exposure from cell tower antennas and base stations. They used RF levels far lower than the NTP study. They found  increases in the very same tumors found by the NTP — schwannomas of the heart.  

Dr. Lennart Hardell’s team analyzed the NTP findings in the context of the Ramazzini and earlier animal and human studies.  He and his statistician Michael Carlberg concluded that:

“there is clear evidence that RF radiation is a human carcinogen, causing glioma and vestibular schwannoma (acoustic neuroma). There is some evidence of an increased risk of developing thyroid cancer, and clear evidence that RF radiation is a multi‑site carcinogen. Based on the Preamble to the IARC Monographs, RF radiation should be classified as carcinogenic to humans, Group 1.”

However immediately after the final reports were released, the FDA then released a statement by Dr. Jeffrey Shuren of the FDA rejecting the NTP findings. 

“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.” 

“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.” –2018 Statement by Dr. Jeffrey  Shuren


Once again, the headlines led with the controversy, quoting the FDA in their articles”

“Federal health agencies disagree over link between cell phone radiation and cancer” CNN November 1, 2018

Why You Shouldn’t Worry About the New Study Linking Cellphones to Cancer, Live Science november 1, 2018

“FDA officials say cell phone radiation causes brain tumors in rats but not humans.” Healthline News, November 11, 2018 

Melnick’s oped for the Hill entitled “There’s a clear cell phone-cancer link, but FDA is downplaying it” commented on the FDA statement discounting the NTP findings that: 

“Simply claiming that conclusions about human risk cannot be drawn from animal studies runs counter to standard practices of evaluating human cancer risks by public health agencies including the U.S. EPA, NTP, IARC and even the FDA. Every chemical known to cause cancer in humans is also carcinogenic in animals when adequately tested.”

“The next step would be for the FDA to perform a quantitative risk assessment of the data so that the FCC can develop health-protective exposure standards, ” stated Dr. Melnick. However, as far as we know, no quantitative risk assessment has been performed by the FDA. Instead, the FDA repeatedly attacked the study as irrelevant. Notably, Boice’s long list of criticisms were also repeated by the FDA. 

Melnick then published an article in Environmental Research on the scientific data showing that the FDA’s criticisms were unfounded concluding, “The expert peer-review panel clearly recognized the validity and biological significance of the adverse health effects produced in the NTP’s studies of cell phone RFR. The overall results from the NTP studies indicate that cell phone RFR is potentially carcinogenic to multiple organs of exposed people.”