This article is a follow-up to another, dated November 14th last: What does the National Toxicology Program study reveal to us about radiofrequency fields?
On November 1st, 2018, the US government research programme NTP  issued a press release on  the release of “final reports on studies in rats and mice on radio frequency radiation of the type used in 2G and 3G cellular telephony technologies” where a link between certain cancers and exposure to radiofrequency radiation was observed in male rats. As can be seen from the media fallout , this wording suggests that using a mobile phone can lead to cancer. However, while the modulation signals used correspond to those used for the 2G and 3G telephony networks, the exposure conditions tested are not at all comparable with the use of mobile telephony. Levels are well above current safety standards and the animals’ entire bodies were exposed. The purpose of these standards is to limit exposure levels to well below the threshold for health effects resulting from warming up living tissues. This publication thus requires some further explanation.
The results of these studies (RF) in rats and mice were produced in January 2018 in two reports [1, 2]. These  were provisionally presented pending the opinion of a panel of reviewers appointed by the NTP and examined in March 2018. The striking result was an increase, only in male rats, in a particular heart tumour, malignant schwanomma (very rare in humans) at the highest levels of exposure. The NTP employs four categories to assess the level of evidence suggesting that the agent under consideration is the cause of an observed effect, in descending order: clear evidence, some evidence, equivocal evidence, and no evidence. For example, due to inconsistencies in observations between males and females (e.g. lower mortality in exposed rats), and with SAR levels (not dose response), the authors considered there to be “some evidence” for cardiac shwannomas, and at best “equivocal” evidence for other results indicating effects, including for glioma.
The final conclusions released on 1st November relate to the same data, but the assessment of the level of evidence was revised upwards following a vote from the reviewers , leading to the labelling of “clear evidence” for schwanommas and “some evidence” for gliomas and adrenal tumours, in male rats only.
The French Agency for Food, Environmental and Occupational Health & Safety (ANSES) summarised  the conclusions of the authors and those of the reviewers, pointing out the uncertainties related to the biases and weaknesses of the study. The International Commission for the Protection against Non-Ionizing Radiation (ICNIRP ) analysed this work alongside a study produced by the Ramazzini Institute in April 2018 , whose authors claimed to have confirmed the results of the NTP. It concluded “ICNIRP considers that the NTP and Falcioni et al. studies do not provide a consistent, reliable and generalizable body of evidence that can be used as a basis for revising current human exposure guidelines. Further research is required that addresses the above limitations.” Analyses by these reference bodies to assess the risk from radiofrequencies confirm that there is no cause for concern.
However, the NTP’s work, which has been widely publicised, has created a media storm, largely as a result of ambiguous communication. The NTP suggests, on its website and in its communications, that this work was aimed at studying the risk of mobile telephony at the request of the Food and Drug Administration (FDA), which is the authoritative public health authority in the USA and arbiter of the appropriateness of public exposure thresholds. It clarified that the exposures were not comparable with the use of a mobile phone , then explained that it had not studied Wifi and 5G, which would be the subject of future work.
For its part, the FDA indicated  as early as November 1st that it agreed that these results cannot be extrapolated to mobile phone use, but that it “disagreed with the conclusions of their final report regarding the “clear evidence” of carcinogenic activity in rodents,” pointing to weaknesses in the study. It also states that “we must remember the study was not designed to test the safety of cell phone use in humans, so we cannot draw conclusions about the risks of cell phone use from it. We also must thoroughly evaluate and take into consideration the totality of the data, and do so within the context of the complete body of evidence rather than drawing conclusions from the results of a single study.”
In the end we may well wonder what the purpose of this extensive study was. No alternative aims were mentioned by the NTP, either in its communication or in the reports. Now, Japan and Korea have announced their intention to conduct their own animal studies to verify these results , while the NTP plans to conduct studies on other technologies with new equipment. So, the show is very far from over!
 27 Nov18 News Release: “National Toxicology Program releases final reports on rat and mouse studies of radio frequency radiation like that used in 2G and 3G cell phone technologies” Nov. 1 2018
[“Study highlights clear link between telephone waves and cancer”]
  NTP report on 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. https://ntp.niehs.nih.gov/ntp/about_ntp/trpanel/2018/march/tr595peerdraft.pdf
 NTP report on Toxicology and carcinogenesis studies in B6C3F1/N MICE exposed to whole-body radio frequency radiation at a frequency (1,900 MHz) and Modulations (GSM and CDMA) used by Cell phones. https://ntp.niehs.nih.gov/ntp/about_ntp/trpanel/2018/march/tr596peerdraft.pdf
 Actions from Peer Review of the Draft NTP Technical Reports on Cell Phone Radiofrequency Radiation March 26-28, 2018
 Opinion of the National Agency for Food, Environment and Labour Safety on an Analysis of Interim Reports of the U.S. National Toxicology Program Study on Animal Exposure to Radiofrequency, 28 Sept. 2018.
 ICNIRP, Note on Recent Animal Carcinogenesis Studies. ICnirp.org, 4 Sep 2018
 Falcioni L. & al. Report of final results regarding brain and heart tumors in Sprague-Dawley rats exposed from prenatal life until natural death to mobile phone radiofrequency field representative of a 1.8 GHz GSM base station environmental emission. Environ Res. 2018 Aug; 165:496 -503. doi: 10.1016/d .envres.2018.01.037
 NTP Press Release, 1 Nov. 2018. National Toxicology Program releases final reports on rat and mouse studies of radio frequency radiation like that used in 2G and 3G cell phone technologies
Statement from Jeffrey Shuren, MD, J.D., Director of the FDA’s Center for Devices and Radiological Health on the National Toxicology Program’s report on radiofrequency energy exposure, For Immediate Release, November 1, 2018
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