On March 26 – 28, 2018, the National Institute of Environmental Health Sciences (NIEHS) conducted an intense 3-day peer review of the two recently published draft technical reports of the results of the National Toxicology Program (NTP) study. The review process was open to the public and was broadcast live from the NIEHS campus in Research Triangle Park, North Carolina, USA. A panel of 13 invited well-established experts were charged with the task to scrutinize all aspects of the reports. In addition to the panel, the scientists who were responsible for the studies, together with representatives of the US Food and Drug Administration (FDA), the Federal Communications Commission (FCC), non-governmental organizations (NGO), the media, and industry representatives, as well as private citizens, attended the meeting. Some of those attending took the opportunity to add valuable comments to the review process, the results of which have been reported in the media, e.g., Scientific American.
During the first day of the meeting, the exposure system, the dosimetry, and the thermal pilot study were reviewed. Niels Kuster and Myles Capstick of the IT’IS Foundation – who had been tasked with the development, installation and maintenance of the exposure systems – provided an overview about the rationale of the exposure protocols, the differences and similarities of the selected exposure for the study to actual human exposure scenarios at the beginning of 2000 and now, and details about the exposure systems, the dosimetry, and verification and validation, before answering questions related to technical aspects of the exposure. The day concluded with a panel discussion and recommendations for how to report on the chamber design and performance, as well as dosimetry considerations. It was agreed that the rationales of selected exposures must be provided in the beginning of the report, along with hyperlinks to Myles’s presentations to provide the additional details of the exposure systems and dosimetry that are not described in the report or the published papers.
The second and third days were focused on the NTP studies of rats. The expert panel, which included top pathologists from the pharmaceutical industry, reviewed details of the histopathology data and the classification of the findings. The decision of the panel to upgrade the evidence of carcinogenic activity for seven categories of tumors in rats described in the draft reports was very surprising. A complete list of the reported tumor types summarizing the evidence classification according to both the draft report and the expert panel is available for download.
Although the panel upgraded the classification of the results for heart schwannoma to “clear evidence” and for brain glioma and adrenal gland tumor to “some evidence” of an association with exposure to cell phone RFR, it will be difficult for health agencies to translate the findings into an appropriate risk assessment for exposure on the basis of these results. Clearly, carefully conducted and effective high-quality follow-up studies are required. Such studies have already been initiated by the NTP or are currently being planned in other parts of the world.
The NIEHS online news channel, Environmental Factor, published an analysis of the peer review of the NTP draft reports on 04.04.2018, and additional information and testimonials were reported by Microwave News on 09.04.2018.