Entrance for the National Institute of Environmental Health Sciences and the National Toxicology Program in Research Triangle Park, North Carolina Photo Source: National Institute of Environmental Health Sciences
Entrance for the National Institute of Environmental Health Sciences and the National Toxicology Program in Research Triangle Park, North Carolina. Photo Source: National Institute of Environmental Health Sciences

By Dr. Joel Moskowitz – 

On May 26, the National Toxicology Program (NTP) of the National Institutes of Health issued the first in a series of reports that contains partial findings from their long-awaited $25 million study of the cancer risk from cellphone radiation. This report summarizes the study of long-term exposure to cell phone radiation on rats. The report on mice will be issued at a later date.

According to the report:

“Given the widespread global usage of mobile communications among users of all ages, even a very small increase in the incidence of disease resulting from exposure to RFR [radiofrequency radiation] could have broad implications for public health.”

Overall, 30 of 540 (5.5%), or one in 18, male rats exposed to cellphone radiation developed cancer. In addition, 16 pre-cancerous hyperplasias were diagnosed. Thus, 46 of 540, or one in 12 male rats, exposed to cellphone radiation developed cancer or pre-cancerous cells as compared to none of the 90 unexposed male rats.

The two types of cancer examined in the exposed rats were glioma and schwannoma. Both types have been found in human studies of cellphone use.

In the group exposed to the lowest intensity of cellphone radiation (1.5 watts/kilogram or W/kg), 12 of 180, or one in 15 male rats developed cancer or pre-cancerous cells. In the highest exposure group (6 W/kg), 24 of 180, or one in 8 male rats, developed cancer or pre-cancerous cells.

This latter finding has policy implications for the FCC’s current cellphone regulations, which allow cellphones to emit up to 1.6 W/kg at the head or near the body (partial body Specific Absorption Rate or SAR).

The NTP study is likely a “game-changer” as it proves that non-ionizing, radiofrequency radiation can cause cancer without heating tissue.

The results of the study reinforce the need for more stringent regulation of radiofrequency radiation and better disclosure of the health risks associated with wireless technologies – two demands made by the International EMF Scientist Appeal – a petition signed by 220 scientists who have published research on the effects of electromagnetic radiation.

Along with other recently published studies on the biologic and health effects of cellphone radiation, the International Agency for Research on Cancer of the World Health Organization should now have sufficient data to reclassify radiofrequency radiation from “possibly carcingogenic” to “probably carcinogenic in humans.”

The risk of cancer increased with the intensity of the cellphone radiation whereas no cancer was found in the sham controls—rats kept in the same apparatus but without any exposure to cellphone radiation.

In contrast to the male rats, the incidence of cancer in female rats among those exposed to cellphone radiation was not statistically significant. Overall, 16 of 540 (3.0%), or one in 33 female rats exposed to cellphone radiation, developed cancer or a pre-cancerous lesion as compared to none of the 90 unexposed females. The NTP provided no explanation for the sex difference. The researchers pointed out that none of the human epidemiology studies has analysed the data by sex.

Why did cellphone radiation significantly increase cancer risk in male but not female rats? Perhaps because glioma and heart schwannoma are less common in females. According to Microwave News (6/1/2016), the NTP report shows that among controls from past toxicology studies, males were ten times more likely to develop glioma than female rats (11 of 550 vs. 1 of 540). Also, males were twice as likely to develop heart schwannoma than female rats (9 of 669 vs. 4 of 699).

The researchers believe that the cancers found in this experimental study were caused by the exposure to cellphone radiation as none of the control animals developed cancer. The researchers controlled the temperature of the animals to prevent heating effects so the cancers were caused by a non-thermal mechanism.

One of two types of second-generation (2G) cellphone technology, GSM and CDMA, were employed in this study. The frequency of the signals was 900 MHz. The rats were exposed to cellphone radiation every 10 minutes followed by a 10-minute break for 18 hours, resulting in nine hours a day of exposure over a two-year period. Both forms of cellphone radiation were found to increase cancer risk in the male rats.

For each type of cellphone radiation, the study employed four groups of 90 rats—a sham control group that was not exposed to radiation, and three exposed groups. The lowest exposure group had a SAR of 1.5 W/kg, which is within the FC’s legal limit for partial body SAR exposure (e.g., at the head) from cellphones. The other exposure groups had SARs of 3 and 6 W/kg.

Glioma is a common type of brain cancer in humans. It affects about 25,000 people per year in the US and is the most common cause of cancer death in adults 15-39 years of age. Several major studies have found increased risk of glioma in humans associated with long-term, heavy cellphone use.

In humans, schwannoma is a nonmalignant tumor that grows in Schwann cells that cover a nerve which connects to the brain. Numerous studies have found an increased risk of this rare tumor in heavy cellphone users. In the rat study, malignant schwannoma was found in Schwann cells in the heart.

For more information about the NTP study see http://bit.ly/govtfailure.

For references to the research that found increased risk of malignant and non-malignant tumors among long-term cell phone users see http://bit.ly/WSJsaferemr.

The NTP report is available at http://bit.ly/NTPcell1.


Dr. Joel Moskowitz is on the research faculty at the University of California, Berkeley, School of Public Health. He has conducted research on chronic disease prevention and health promotion for more than 30 years, authored dozens of peer-reviewed health publications, and is director of UC Berkeley’s Center for Family and Community Health.