NTP RF Microwave Radiation Study Update

From the National Toxicology Program’s Director of Communications:

Ms. Christine Bruske Flowers bruskec@niehs.nih.gov
Director, Office of Communications and Public Liaison
National Institute of Environmental Health Sciences (NIEHS)
National Toxicology Program (NTP)
111 T.W. Alexander Drive
Durham, N.C. 27709
Tel 919-541-3665
Fax 301-480-2978

Note: According to Ms. Bruske Flowers in our telephone conversation on 12/20/17, The NTP anticipates that complete study findings from the Carcinogenesis Studies of Cell Phone Radiofrequency Radiationwill be available for peer review and public comment in early February 2018.

The full release of data was made available for public review at Noon on Feb 2, 2018


Findings from the National Toxicology Program for
Carcinogenesis Studies of Cell Phone Radiofrequency Radiation
in Hsd: Sprague Dawley® SD rats (Whole Body Exposures)


In 1999, the U.S. Food and Drug Administration (FDA) nominated the National Toxicology Program (NTP) to study possible adverse health effects Wireless pulsed, data-modulated, Radiofrequency Microwave Radiation (RF Microwave Radiation) exposures from cell phones and Wireless infrastructure: cell phone towers and other microwave transmitters.

The RF Microwave Radiation Exposure studies were undertaken for the following reasons:

  1. There is widespread human exposure to Wireless pulsed, data-modulated, Radiofrequency Microwave Radiation in America.

  2. Current exposure RF Microwave Radiation guidelines only protect from acute injury from the heating of tissue (thermal effects).

  3. Scientific data from tens of thousands of peer-reviewed studies have linked adverse health effects from exposures to RF Microwave Radiation at power levels below what would heat living tissue.

Over 16 years, at a cost of $25+ million, the NTP completed toxicology and carcinogenicity studies in laboratory animals. These studies were designed to simulate the exposures of US cell phone users to RF Microwave Radiation from their cell phones and from the Wireless infrastructure. Rats and mice were exposed to RF Microwave Radiation that used data modulation schemes common in the Wireless industry’s 2G Wireless service: Code Division Multiple Access (CDMA) and Global System for Mobile (GSM) at frequencies of 900 and 1900 megahertz.

Michael Wyde, Ph.D., NTP Toxicologist

919-316-4640 | wyde@niehs.nih.gov

Comprehensive nature of the NTP studies

We’ve conducted comprehensive studies in laboratory animals to determine the potential toxic and carcinogenic effects of radio frequency radiation that’s emitted from cell phones and other similar wireless devices [and infrastructure]. Exposures in our studies start during gestation while animals are in utero and are carried through the lifetime of the animals. This study is the largest study that the NTP has ever conducted — it’s the largest of this kind on cell phone radio frequency radiation that’s been done to date. Our studies are targeted not just at brain cancer, as many other studies have been targeted; our studies also address effects in other parts of the body.

How the NTP studies will be applicable to humans:

The studies at the National Toxicology Program are complete [and will be available for public comment in late January 2018]. Our studies are designed specifically to mimic the human exposure scenario. The NTP studies are looking at [RF Microwave Radiation] exposures for 9 hours a day. There’s heavy cell phone users that may approach the 9 hour mark, but it allows us to fully investigate whether or not there is an effect of cell phone [RF Microwave Radiation]. Our studies are designed to look at the frequencies that are currently in use in the United States centering around 900 megahertz and 1900 megahertz, as well as the two modulations that are currently in use in the US, which are CDMA (Code Division Multiple Access) and GSM (Global System for Mobile communications).

How NIST and others helped in the study design:

There’s been a lot of leg work leading up to the exposure studies. We’ve pulled together some of the world’s experts on RF Microwave Radiation. We’ve specially designed chambers [in which] to expose the animals. Engineers from NIST, the National Institute of Standards and Technology, have come in to validate the [reverberation] chambers. So, we have third-party validation of the [RF Microwave Radiation] exposures. Additionally, there was a lot of architectural construction that needed to be done at the lab – these chambers are rather large. And they had to be shipped from where they were constructed and designed in Switzerland to our laboratory in Chicago, Illinois.

How results will be used:

Currently, RF Microwave radiation from cell phones is regulated by the FDA – the Food and Drug Administration. Certain aspects of the particular phones are regulated by the FCC – Federal Communications Commission . So, the data that we’ll generate will primarily be used by the Food and Drug Administration, but also, the data will be available and be highly used by consumers and the public.

The Carcinogenesis Studies of Cell Phone Radiofrequency Radiation are the largest and most complete toxicology studies ever completed on the subject.

Dr. Ronald L. Melnick, the lead designer of the NTP study stated on 6/26/16:

So, what’s the message from all of this? We tested the hypothesis that [RF Microwave] radiation could not cause health effects and we feel that the hypothesis has now been disproved because these results clearly show that that [radio-frequency] radiation can cause adverse health effects. . .

The finding of increases of gliomas and schwannomas of the heart in rats exposed to the radio-frequency radiation provides consistency with the epidemiological reports of increases of gliomas and acoustic neuromas, which are tumors of Shwann cells among humans exposed to [radio-frequency] radiation. Those were the findings that provided the basis for the IARC evaluation of 2011, because the same cells that became cancerous in rats are the cells that have been reported to develop into tumors in [human] epidemiological studies . . .

The incidence of tumors is not the measurement of risk alone. Risk is determined from both the dosimetry, which is the absorbed power [multiplied by] time [of exposure], versus the tumor response . . . because of the large number of [exposed human] users worldwide, even a small increase in risk at exposure propensities that may be close to what humans experience, could result in a large number of people developing a RF-radiation-induced tumor with long-term exposure.

Listen to the scientists who designed and executed the $25 Million NTP/NIEHS Radiofrequency Radiation study:

  • 5/27/16 audio recording of NTP/NIEHS RFR Study Results conference call

    • John Bucher, Ph.D., Associate Director, National Toxicology Program (NTP)
    • Michael Wyde, Ph.D., National Toxicology Program NTP/NIEHS RFR Study Director
  • 6/01/16 audio recording of NTP/NIEHS RFR Study Results conference call

    • Ronald L. Melnick, PhD., Retired, Former lead designer of the NTP/NIEHS RFR Study


  • The animals were exposed for approximately nine hours spread over the course of the day.

  • Due to the technical complexity of studying specific RF Microwave Radiation of cell phone modulations and frequencies (CDMA at 900 MHz, CDMA at 1900 MHz, GSM at 900 MHz and GSM at 1900 MHz), the NTP staff worked closely with RF Microwave Radiation experts from the National Institute of Standards and Technology (NIST). NIST scientists developed an exposure system of unique reverberation chambers that were used by both the test and control animals.

  • These reverberation chambers were carefully designed Faraday cages that shielded the test and control animals from any ambient RF Microwave Radiation exposures from any Wireless antennas near the research labs where these animals were housed. The chambers for the test animals delivered to test rodents uniform RF Microwave Radiation exposures in specific frequencies and modulations by employing a series of rotating RF Microwave Radiation reflectors — to simulate exposures from the Wireless infrastructure — the cell towers/microwave transmitters of all sizes that saturate many communities in America with 24/7/365 RF Microwave Radiation exposures.

The NTP cell phone RF Microwave Radiation studies were conducted in three phases:

Phase 1: A series of pilot studies to establish field strengths that do not raise body temperature. Data from this phase helped identify the maximum RF Microwave Radiation power levels that could be used for the second phase of studies.

Phase 2: Short-term toxicology studies, where the rodents were exposed to various low-level RF Microwave Radiation field strengths for two months. Data from this phase helped determine the appropriate power levels for each strain and species of rodent for the third phase of the studies.

Phase 3: Long-term, chronic toxicology and carcinogenicity studies where the rodents were exposed to RF Microwave Radiation for 24 months. This third phase was designed to determine if chronic RF Microwave Radiation exposures are hazardous to test animals and, therefore, to humans. These chronic studies were started in utero and continued for two years through adulthood.

Intended Use of The NTP Data

These data could help the FDA, EPA or other health agency determine RF Microwave Radiation exposures guidelines that actually protect public health and safety. The studies may also be used by the FCC, an agency that regulates interstate and international communications via radio, television, wire, satellite, and cable.