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Medical Physicist here. The position isn't "non-ionizing radiation can't cause cancer". It's "There is no known mechanism by which non-ionizing radiation can ca

by mikekij 10y ago

Medical Physicist here. The position isn't "non-ionizing radiation can't cause cancer". It's "There is no known mechanism by which non-ionizing radiation can cause cancer." Maybe we'll discover a mechanism one day to explain this. But we seem to understand the processes by which cell mutations, and subsequently cancer, and produced. We should certainly research this area further. But the probability of this study having failed to control for some other variable is higher than the probability of an as of yet unknown process allowing microwaves to produce changes in the chemical bonds holding together DNA.

tryitnow 10y ago
"But the probability of this study having failed to control for some other variable is higher than the probability of an as of yet unknown process allowing microwaves to produce changes in the chemical bonds holding together DNA." I really like this sentence. I wish more science commentators would talk about probability like this.
donovanr 10y ago
I've always been curious: I understand that h.nu from cell phone radiation isn't big enough to ionize (say) DNA, but since the molecules in our body are in thermal equilibrium, can't h.nu + kT get it done every once in a while? [edited because using an asterisk to denote multiplication was a bad idea]
- tiplus 10y ago
  kT is very little energy compared to a chemical bond. Take for example [0], they give an excitation energy for water of about 8 electron Volts which is ~750 kJ/mol, whereas kT at room temp is about 2.5 kJ/mol. [0] http://scitation.aip.org/content/aip/journal/jcp/128/10/10.1063/1.2837827 http://scitation.aip.org/content/aip/journal/jcp/128/10/10.1...
  - donovanr 10y ago
    Right, but it's the 'every once in a while" part that I wonder about, i.e. the variance of that distribution. Maybe you could argue that since the Maxwell-Boltzmann distribution is narrower the lower its mean, if kT is small then it's an exponentially tiny effect.
    - tiplus 10y ago
      So yes, kT is small on average (does fluctuate) and it is also 1 kT per degree of freedom. So yes, in principle a few hundreds of atoms could randomly fluctuate in energy to create this effect. However, this is hyper unlikely. I would be suprisd if it happened once in the life time of the universe. Also consider that you cannot create Maxwell demons[1]. [1] https://en.m.wikipedia.org/wiki/Maxwell%27s_demon https://en.m.wikipedia.org/wiki/Maxwell%27s_demon
mangeletti 10y ago
Conjecture: There is no such thing as "non-ionizing" radiation. There is just a continuum that ranges from "barely a chance for this to ionize a molecule" to "this will ionize something in the first nanometer". I mean, what's the point of understanding EMR as a continuum of wavelength, if we're going to create arbitrary distinctions therein and presume to know everything about those distinctions. Another way to think about this is with an analogy: "non-lethal weapons"... but then see https://mic.com/articles/123410/nonlethal-weapons-are-much-more-lethal-than-police-want-you-to-think https://mic.com/articles/123410/nonlethal-weapons-are-much-m.... It would seem smarter to start thinking about things as "less" and "more" of something, rather than "non". If you find some wavelength in the middle that seems to be safe, perhaps it is safe in the near term, but when put in terms of "less ionizing than we can notice" it doesn't sound like something I want to hold next to my brain for the next 15 years. Also note, it's already known that Bluetooth and WiFi cause the blood brain barrier to become 10-100x more biologically leaky[1], letting more chemicals into your brain. Edit: apparently, this Bluetooth / WiFi point is moot. 1. http://www.ncbi.nlm.nih.gov/pubmed/8012056 http://www.ncbi.nlm.nih.gov/pubmed/8012056
- bittercynic 10y ago
  If a photon doesn't have enough energy to knock an electron out of it's orbital, then it won't. This is not a probabilistic thing. Do you have a source for the blood-brain barrier thing?
  - mangeletti 10y ago
    See update (added footnote).
  - tedsanders 10y ago
    It is a probabilistic thing. If your photon arrives at the same time as another photon, then you can have two-photon absorption (which wouldn't have occurred without your photon). Ditto if your photon arrives at the same time as a thermal vibration or any other carrier of energy. This is why semiconductors can still occasionally absorb photons with energy below their bandgap. Anything in a thermal environment has some chance of being excited, and adding extra radiation will only increase those chances. Furthermore, if we want to get really technical and into even lower probabilities, photons don't have single well defined energies. Wavelengths are not singularly defined for waves that don't extend to infinity. Therefore, even radiation that is emitted around, say, 500 nm, still has a small of chance of being absorbed by a 499 nm transition. Obviously these probabilities get tiny as the difference gets large, but they never drop to 0, technically. I'm not saying any of this is medically relevant, but practically everything that is quantum mechanical is probabilistic. (I have a PhD in physics, focusing on experimental quantum mechanics)
dragonwriter 10y ago
> But we seem to understand the processes by which cell mutations, and subsequently cancer, and produced. We certainly seem to understand many of the processes by which cell mutations are produced, but that's not the same as all of them, and, perhaps more importantly, what we do understand about how cancer is produced is that there are lots of factors besides cell mutation involved, and those of them that we do understand in general terms aren't understood in detail, and aren't sufficient to explain the entire process. > But the probability of this study having failed to control for some other variable is higher than the probability of an as of yet unknown process allowing microwaves to produce changes in the chemical bonds holding together DNA. That seems more like a statement of subjective plausibility than a supportable statement of quantitative probability, and, moreover, in order to be relevant to the result seems also to falsely assume that it is necessary to "produce changes in the chemical bonds holding together DNA" to alter the incidence of cancer. We already know that even when a potentially-cancer-inducing genetic mutation exists, various other non-genetic factors in the body (including qualities of the extracellular matrix around the cells which have the mutation) play significant roles in whether cancer actually develops. Its quite possible that if there is a cellphone-to-cancer link, that the mechanism doesn't involve changes in the frequency of genetic mutation at all, but affects on the body that affect the whether cancer manifests when a potentially-cancer-inducing mutation has arisen through other means.
- alevskaya 10y ago
  Cancer is complicated, but it emphatically is a _genetic_ disease, with inherited _genetic_ risk factors. Environmental influences are typically mediated by their ability to cause or promote mutation via cell stress (e.g. by promoting local inflammation) and cell proliferation, which in turn increases mutation load. There are subtler influences that could weaken the natural immunosurveillance of neopeptides by T-cells, but the importance of such surveillance in prevention is debated and perhaps more relevant in later-stage cancers. We may not fully understand such a complicated disease, but with modern sequencing we have a pretty good lens on the phenomenology of emergence of cancer, and that "subjective plausibility" is a working gut-bayesian framework that doesn't put a strong prior on ambient microwaves as a likely causative factor. Also, the field of RF- and microwave- induced cancer has been a long-running cottage industry producing bad science for many years now: i.e. studies with poor statistical power and poor replicability… so there’s a reason skepticism prevails on this point among biologists. It’s not just dogmatism: if anyone can get a replicable animal model we could dive into it to find new mechanisms… but these results always seem to sit at the edge of detection.
CorvusCrypto 10y ago
My first thought was "damn, those exposure powers are extremely high". Think about it... even the 0.5 W/kg treatment is still about 40W for average human adolescent male. That's a LOT of power from just a cell phone
psychometry 10y ago
Biostats grad student here. "But the probability of this study having failed to control for some other variable is higher than..." It was a randomized block experiment. You don't need to assume that there were no unmeasured confounders in order to make causal inferences. That assumption is only needed in cross-sectional and cohort studies.

by mikekij 10y ago

tryitnow 10y ago

"But the probability of this study having failed to control for some other variable is higher than the probability of an as of yet unknown process allowing microwaves to produce changes in the chemical bonds holding together DNA." I really like this sentence. I wish more science commentators would talk about probability like this.

donovanr 10y ago

I've always been curious: I understand that h.nu from cell phone radiation isn't big enough to ionize (say) DNA, but since the molecules in our body are in thermal equilibrium, can't h.nu + kT get it done every once in a while? [edited because using an asterisk to denote multiplication was a bad idea]

tiplus 10y ago
kT is very little energy compared to a chemical bond. Take for example [0], they give an excitation energy for water of about 8 electron Volts which is ~750 kJ/mol, whereas kT at room temp is about 2.5 kJ/mol. [0] http://scitation.aip.org/content/aip/journal/jcp/128/10/10.1063/1.2837827 http://scitation.aip.org/content/aip/journal/jcp/128/10/10.1...
- donovanr 10y ago
  Right, but it's the 'every once in a while" part that I wonder about, i.e. the variance of that distribution. Maybe you could argue that since the Maxwell-Boltzmann distribution is narrower the lower its mean, if kT is small then it's an exponentially tiny effect.
  - tiplus 10y ago
    So yes, kT is small on average (does fluctuate) and it is also 1 kT per degree of freedom. So yes, in principle a few hundreds of atoms could randomly fluctuate in energy to create this effect. However, this is hyper unlikely. I would be suprisd if it happened once in the life time of the universe. Also consider that you cannot create Maxwell demons[1]. [1] https://en.m.wikipedia.org/wiki/Maxwell%27s_demon https://en.m.wikipedia.org/wiki/Maxwell%27s_demon

mangeletti 10y ago

Conjecture: There is no such thing as "non-ionizing" radiation. There is just a continuum that ranges from "barely a chance for this to ionize a molecule" to "this will ionize something in the first nanometer". I mean, what's the point of understanding EMR as a continuum of wavelength, if we're going to create arbitrary distinctions therein and presume to know everything about those distinctions. Another way to think about this is with an analogy: "non-lethal weapons"... but then see https://mic.com/articles/123410/nonlethal-weapons-are-much-more-lethal-than-police-want-you-to-think https://mic.com/articles/123410/nonlethal-weapons-are-much-m.... It would seem smarter to start thinking about things as "less" and "more" of something, rather than "non". If you find some wavelength in the middle that seems to be safe, perhaps it is safe in the near term, but when put in terms of "less ionizing than we can notice" it doesn't sound like something I want to hold next to my brain for the next 15 years. Also note, it's already known that Bluetooth and WiFi cause the blood brain barrier to become 10-100x more biologically leaky[1], letting more chemicals into your brain. Edit: apparently, this Bluetooth / WiFi point is moot. 1. http://www.ncbi.nlm.nih.gov/pubmed/8012056 http://www.ncbi.nlm.nih.gov/pubmed/8012056

bittercynic 10y ago
If a photon doesn't have enough energy to knock an electron out of it's orbital, then it won't. This is not a probabilistic thing. Do you have a source for the blood-brain barrier thing?
- mangeletti 10y ago
  See update (added footnote).
- tedsanders 10y ago
  It is a probabilistic thing. If your photon arrives at the same time as another photon, then you can have two-photon absorption (which wouldn't have occurred without your photon). Ditto if your photon arrives at the same time as a thermal vibration or any other carrier of energy. This is why semiconductors can still occasionally absorb photons with energy below their bandgap. Anything in a thermal environment has some chance of being excited, and adding extra radiation will only increase those chances. Furthermore, if we want to get really technical and into even lower probabilities, photons don't have single well defined energies. Wavelengths are not singularly defined for waves that don't extend to infinity. Therefore, even radiation that is emitted around, say, 500 nm, still has a small of chance of being absorbed by a 499 nm transition. Obviously these probabilities get tiny as the difference gets large, but they never drop to 0, technically. I'm not saying any of this is medically relevant, but practically everything that is quantum mechanical is probabilistic. (I have a PhD in physics, focusing on experimental quantum mechanics)

dragonwriter 10y ago

> But we seem to understand the processes by which cell mutations, and subsequently cancer, and produced. We certainly seem to understand many of the processes by which cell mutations are produced, but that's not the same as all of them, and, perhaps more importantly, what we do understand about how cancer is produced is that there are lots of factors besides cell mutation involved, and those of them that we do understand in general terms aren't understood in detail, and aren't sufficient to explain the entire process. > But the probability of this study having failed to control for some other variable is higher than the probability of an as of yet unknown process allowing microwaves to produce changes in the chemical bonds holding together DNA. That seems more like a statement of subjective plausibility than a supportable statement of quantitative probability, and, moreover, in order to be relevant to the result seems also to falsely assume that it is necessary to "produce changes in the chemical bonds holding together DNA" to alter the incidence of cancer. We already know that even when a potentially-cancer-inducing genetic mutation exists, various other non-genetic factors in the body (including qualities of the extracellular matrix around the cells which have the mutation) play significant roles in whether cancer actually develops. Its quite possible that if there is a cellphone-to-cancer link, that the mechanism doesn't involve changes in the frequency of genetic mutation at all, but affects on the body that affect the whether cancer manifests when a potentially-cancer-inducing mutation has arisen through other means.

alevskaya 10y ago
Cancer is complicated, but it emphatically is a _genetic_ disease, with inherited _genetic_ risk factors. Environmental influences are typically mediated by their ability to cause or promote mutation via cell stress (e.g. by promoting local inflammation) and cell proliferation, which in turn increases mutation load. There are subtler influences that could weaken the natural immunosurveillance of neopeptides by T-cells, but the importance of such surveillance in prevention is debated and perhaps more relevant in later-stage cancers. We may not fully understand such a complicated disease, but with modern sequencing we have a pretty good lens on the phenomenology of emergence of cancer, and that "subjective plausibility" is a working gut-bayesian framework that doesn't put a strong prior on ambient microwaves as a likely causative factor. Also, the field of RF- and microwave- induced cancer has been a long-running cottage industry producing bad science for many years now: i.e. studies with poor statistical power and poor replicability… so there’s a reason skepticism prevails on this point among biologists. It’s not just dogmatism: if anyone can get a replicable animal model we could dive into it to find new mechanisms… but these results always seem to sit at the edge of detection.

CorvusCrypto 10y ago

My first thought was "damn, those exposure powers are extremely high". Think about it... even the 0.5 W/kg treatment is still about 40W for average human adolescent male. That's a LOT of power from just a cell phone

psychometry 10y ago

Biostats grad student here. "But the probability of this study having failed to control for some other variable is higher than..." It was a randomized block experiment. You don't need to assume that there were no unmeasured confounders in order to make causal inferences. That assumption is only needed in cross-sectional and cohort studies.