National Toxicology Program Final Reports on Rat and Mouse Studies of Radio Frequency Radiation: Summaries and Full Texts

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. Research Triangle Park, NC. November, 2018.

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.

Full text:
https://www.niehs.nih.gov/ntp-temp/tr595_508.pdf

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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. Research Triangle Park, NC. November, 2018.

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.

Full text:
https://www.niehs.nih.gov/ntp-temp/tr596_508.pdf