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This preprint presents results from a 2-year National Toxicology Program study on the effects of cell-phone radiation in rats. On page 8 of the PDF, survival results are presented. The presentation of the results is complicated by the fact that some treatment groups experienced significantly different effects when compared to the control group, while in other groups the effect was small but not significant. However, the gist is that rats treated with phone radiation lived longer, and that the effect is stronger in male rats.

I was confused by the fact that this result is presented in the "Results" section on page 8, while the seemingly less significant finding - that treated rats had higher rates of cancer or tumors - was presented in the "Summary" section on page 4. Obviously the study was funded to address concerns we have about observed relationships between cell-phone use and cancer, but when an effect on longevity was discovered, shouldn't this have become the primary result?

The plots on page 11 (Figure 3) and 12 (Figure 4) show some more interesting relationships between the survival of the various groups. Figure 4A shows the high-dose (6W/kg) CDMA male group overtaking the control males only towards the end of the study. With the GSM males (Figure 3A), as well as the low-dose CDMA males, the control group does worse almost from the beginning.

I'm curious to know why more people haven't commented on this result in news outlets. My opinion is that controlled experiments in animals aren't perfect, but they're much better than cheap "longitudinal" studies in humans. As far as I can tell, this is the best evidence we have to date, and it says that cell phone radiation promotes longevity. So why aren't we being required to sleep with phones next to our heads?

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    $\begingroup$ I don't think it is useful or relevant to discuss preprints. Wait until they have appeared in peer-reviewed journals. $\endgroup$
    – David
    Jan 11, 2017 at 19:43
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    $\begingroup$ @David There are actually a bunch of reviews at the end of that document. Most take (quite negative) issue with the study design and power. $\endgroup$
    – kmm
    Jan 11, 2017 at 21:52

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If you read the discussion, and also the full contents of the PDF which include some reviewer comments, there is concern about the control group:

The survival of the control group of male rats in the current study (28%) was relatively low compared to other recent NTP studies in Hsd:Sprague Dawley® SD® (Harlan) rats (average 47%, range 24-72%).

Specifically, the control group had an abnormally high mortality rate for that strain of rat. There is no increase in longevity if you compare to historical data.

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  • $\begingroup$ Yes, I read that. Is your argument that we should (a) do away with control groups and just compare with non-randomized controls from historical rat populations used in different studies in other parts of the world? Or that we should (b) use control groups but ignore the results when we disagree with them, falling back on historical statistics? $\endgroup$
    – Metamorphic
    Jan 9, 2017 at 22:15
  • $\begingroup$ Because a randomized trial gives us a p-value, which, although not reported by the authors of this study, tells us that the in case of the null hypothesis, where the treatment is not doing anything, the observed differences between groups must indicate that a e.g. 1 in 20, or a 1 in 1000, event happened. And I thought the point of statistical analysis was not to fall back on explaining our results as due to extreme randomness. $\endgroup$
    – Metamorphic
    Jan 9, 2017 at 22:17
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    $\begingroup$ @Metamorphic don't look for conspiracy where there likely is none. I personally applaud the researchers for publishing mixed results - that's not done often enough, and skews the literature (and our understanding) to a potentially large degree. Not every study will give perfect, absolutely clear-cut results. We don't know a lot of things, but that doesn't mean they're being covered up intentionally. Maybe it was a poorly-trained grad student. Maybe it was disease, or the animal facility staff, or the facility itself, or the supplier, or a million other possibilities. Don't be paranoid. $\endgroup$
    – MattDMo
    Jan 10, 2017 at 5:55
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    $\begingroup$ @Metamorphic I don't think MattDMo meant any harm. You are coming here and saying "Why aren't people taking this study more seriously?" and we are giving you a very good reason: because the data are suspect. That doesn't mean you throw out the results. I don't think the researchers are incompetent, as you suggest, I think they are pragmatic and reasonable: something in their results looks funny, so they aren't putting much stock in it until it gets confirmed. That's responsible research. I also wouldn't say the NTP's funding is dependent on finding particular things toxic. $\endgroup$
    – Bryan Krause ♦
    Jan 10, 2017 at 16:20
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    $\begingroup$ @MattDMo makes a great point as well about the skew in the literature: that many studies go unpublished when the results are suspect or borderline. That's actually a big problem. It's much better to publish the results, with the appropriate caveats noted, so that future studies can take it into consideration. If you zap two more studies worth of rodents with cell phone radiation and their control groups suffer again, we can start to conclude that the radiation is making telekinetic rats that suck the life force out of their kin to prolong their lives. Until then, let's be cautious. $\endgroup$
    – Bryan Krause ♦
    Jan 10, 2017 at 16:23
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"I'm curious to know why more people haven't commented on this result in news outlets"

Because for once the news outlets appear to be behaving responsibly, and waiting until the results are published in a peer-reviewed journal. You could do worse than follow their example.

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  • $\begingroup$ @AliceD — I am sorry but it answers the part of the question I quoted. It is not a request for clarification nor a critique (in the correct or incorrect usage of the word), and it is in no sense suitable for a comment. In any case this is an old question that has only resurfaced because someone has dug it up. Not worth a flame war now. $\endgroup$
    – David
    Mar 15, 2017 at 20:26
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I'm curious to know why more people haven't commented on this result in news outlets.

This is an easy point: nobody is interested in publishing this. A quick scan of my (not that bad) local newspaper shows stories in a few categories:

  • Photogenic stuff. About the moon, Antarctica, animals etc.
  • Male/female stuff, why we are not the same, or why women are better at something
  • Everything about food, medicine and vitamins
  • Climate change

Besides that, the story has to be news. It has to have some actuality, fit in with previous/further stories people are talking about, and people have to want to read it.

This story has none of that. Nobody is talking about cell phone radiation, and people are already convinced that it's not dangerous. 15 years ago this would definitely be on science pages everywhere.

Then there's also the science. Apart from what people are saying in the comments, you just cherry picked a single data point from a single study. The study was not designed and powered to show that cell phones increase survival, the authors don't focus on it (rightfully so), and there's also no plausible mechanism how this should work.

You can have a theoretical discussion about whether or not this fact is a reliable fact, and about whether or not the authors did everything right. However, I would put all my money on future research showing no enhanced survival, because circumstantial evidence is pointing in that direction and there's no mechanism.

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  • $\begingroup$ Good first half, but... "you just cherry picked a single data point from a single study" - What are the other studies? I mean, other studies that would provide evidence about survival effects. "The study was not designed and powered to show that cell phones increase survival" - not designed in what way? "circumstantial evidence is pointing in that direction" - good if true, but can you elaborate? Thanks $\endgroup$
    – Metamorphic
    Jan 12, 2017 at 19:31
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    $\begingroup$ It's highly likely there are other studies where animals are exposed to cell phone radiation. Probably there this effect is absent or not significant. Not designed / powered: if there is an effect it's likely that it's (extremely) small. By doing the study with low power, you're very likely to get either nothing (expected) or, if you get a statistically significant effect, the effect size will be overestimated. The circumstantial evidence is that similar mice in identical control groups that usually live longer. $\endgroup$
    – VonBeche
    Jan 12, 2017 at 21:50
  • $\begingroup$ See #3 in my question. If you think another study is relevant, I need you to track down the citation. Otherwise you're asking anyone who disagrees with you to cite every study ever published and show that it doesn't meet your advertised criteria. Some estimate that a total of 50 million journal articles have been published to date. It's much easier if you just tell us where to look. $\endgroup$
    – Metamorphic
    Jan 13, 2017 at 3:08
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    $\begingroup$ You were interested enough to look this up in the first place, why would you stop looking when you find one number that fits what you want to think? $\endgroup$
    – VonBeche
    Jan 13, 2017 at 8:10
  • $\begingroup$ I don't appreciate your condescension. I made a simple request. Please back up your claims, or don't participate here. $\endgroup$
    – Metamorphic
    Jan 13, 2017 at 20:16

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