Initial results of a U.S. government-sponsored National Toxicology Program (NTP) study released last Friday point to “low incidences” of two types of cancerous tumors in male rats exposed to non-ionizing radiofrequency radiation (RFR) emitted from cell phones built on the third-generation GSM and CDMA mobile standards.  In a press statement addressing the NTP report, however, wireless association CTIA emphasized that various U.S. and international organizations “have determined that the already existing body of peer-reviewed and published studies shows there are no established health effects from radio frequency signals used in cell phones.” 

The preliminary NTP study results stand in contrast to an Australian study which was published early last month and which depicts no increase in national brain cancer rates since mobile phones were introduced in Australia three decades ago.  Nevertheless, the NTP indicated that the partial results of its peer-reviewed study “appear to support the International Agency for Research on Cancer conclusions regarding the possible carcinogenic potential of RFR.”  While acknowledging that “much works remains to be done to understand the implications, if any, of these findings on the rapidly-changing cellular technologies that are in use today,” NTP associate director John Bucher told reporters: “we felt it was important to get the word out.”

Under the NTP study, more than 2,500 rats were subjected to 900 MHz GSM- or CDMA-modulated RFR over the course of their lives for a two-year period.  These animals were exposed in 10-minute on/10-minute off intervals over a period of 18 hours per day. In four of six groups consisting of 90 rats each (and which were compared to a 90-rat control group), the study found a 2.2% to 3.3% increase in malignant brain tumors.  Six groups of 90 rats each exhibited a 1.1% to a 6.6% increase in cancerous heart tumors.  All of the tumors were detected in male rats, and females in the group showed no increase in tumor activity. 

NTP officials anticipate that the full study results will be issued by the end of 2017.  A spokesman for the FCC, which was briefed on the preliminary findings, told reporters: “we will continue to follow all recommendations from federal health and safety experts.”