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In May/June 2011, 30 experts (I was one of them) invited by the WHO International Agency for Research on Cancer (IARC), gathered in Lyon to discuss the scientific studies on radio-frequency electromagnetic fields (RF-EMF) and cancer.
After intense deliberations, to the great surprise of the world-at-large, experts decided to classify RF-EMF emitted by e.g. cell phones, cell towers and wi-fi networks, as a possible human carcinogen – in IARC scale “2B carcinogen”.
IARC has somewhat complicated but detailed set of rules that guide classification of carcinogenicity. The rules are in place to prevent “out of the blue sky” classifications. Protocols need to be followed and requirements fulfilled before carcinogen is classified.
Once the evidence from human studies is determined to be limited, and the same limited evidence is assigned to the evidence from experimental animal studies, classification of RF was automatically set as 2B possible carcinogen (for details see Preamble of IARC Monograph 102).
There are three possible scenarios that could change classification from 2B possible carcinogen to a higher group of carcinogenicity.
- The first scenario: if the evidence from human studies would be changed from limited to sufficient then, automatically, no matter what other evidence is, the classification would be – group 1 – carcinogenic to humans.
- The second scenario: if the evidence from experimental animal studies would be changed from limited to sufficient, and the evidence from human studies would remain as limited, the classification would change and become 2A – probable carcinogen.
- The third scenario: if the mechanistic evidence shows that the agent (RF) clearly belongs to a class of agents for which one or more members have been classified in group 1 or group 2A. This means that, in practice, mechanistic evidence for RF effects can be fully ignored by the IARC classification system because RF does not belong to a group of agents classified as group 1 or 2A carcinogens.
Something is, however, wrong with the third scenario option because, it would be possible, a priori, to “forget” the review of mechanistic studies related to RF because, no matter what, outcome of this evaluation cannot affect classification stemming from human and animal studies, even if these are evaluated as limited evidence. At the same time, the IARC Preamble says, “…the body of evidence is considered as a whole, to reach an overall evaluation of the carcinogenicity of the agent to humans”. Something is indeed wrong…
However, in 2011 in Lyon at the IARC experts meeting it was clearly spoken that if mechanistic studies provide a plausible mechanism by which cell phone radiation induces biological effects, this evidence will be sufficient to strengthen and even upgrade carcinogenicity classification. More on this topic, later, below.
What is the current situation? New evidence was published since 2011. How it plays with the old evidence – does it make it stronger or weaker?
The 2011 IARC classification of cell phone radiation as a possible carcinogen was based on the limited evidence from human studies and limited evidence from animal studies.
The limited human evidence was based on the results of two sets of epidemiological studies – European Interphone group and Hardell group in Sweden. After the IARC evaluation, in 2014, was published a new epidemiological study – the French CERENAT. This new study reached similar conclusions as Interphone and Hardell previously – long term avid use of cell phone increases a risk of developing brain cancer.
It means that now there are three replications of the same epidemiological type of study, the case-control study, that all suggest cell phone radiation might increase a risk of brain cancer.
It is important to consider, in context of these three results, that brain cancer latency is long and takes several tens of years for the cancer to develop and be diagnosed. Epidemiological studies showing that already little over ten years use of cell phone leads to an increased risk of brain cancer should be taken as a serious warning sign. These studies, due to intrinsic design bias, cannot be considered as a proof of brain cancer being caused by cell phone radiation, but they are a warning sign that such option might be not only “possible” but even “probable”. These are three replicates. These are what the WHO and the telecom industry always demands to get – independently replicated results – they now got it and should consider them as a potentially serious warning. A big red flag.
In respect of the large animal studies, nothing significant happened after 2011. The ongoing in the US a large National Toxicology Program (NTP) study is still in progress, and we need to wait for the results to be published.
In the area of mechanistic studies, both positive and negative studies are being continuously published and the arguing over the existence of the non-thermal effects is still not resolved. Or is this argument indeed still not resolved? Anyone, reading carefully the IARC Monograph Volume 102, may find the following quotes, coming from the deliberations of IARC experts in 2011 (p. 414 of the IARC Monograph Volume 102):
“The data to evaluate mechanisms by which RF radiation may cause or enhance carcinogenesis are extensive and diverse.”
Then there are comments concerning thermal and non-thermal effects:
“Many studies were confounded by significant increases in the temperature of the cells, leading to thermal effects that could not be dissociated from non-thermal RF-induced changes.”
And in the next sentence is the most important statement:
“The conclusions presented in this section [of the Monograph] for results in vivo and in vitro pertain only to those studies for which the Working Group concluded that thermal confounding did not occur.”
This statement clearly suggests that any RF effects described in the mechanistic studies part of the IARC Monograph Volume 102 are non-thermal effects.
These non-thermal effects, effects not having thermal confounding, are as follows:
- p. 415 “Overall, the Working Group concluded that there was weak evidence that RF radiation is genotoxic…”
- p. 416 “…the Working Group concluded that data from studies of genes, proteins and changes in cellular signaling show weak evidence of effects from RF radiation…”
- p. 417 “…Overall, the Working Group concluded that there was weak evidence that exposure to RF radiation affects oxidative stress and alters the levels of reactive oxygen species.”
- p. 417 “The evidence that exposure to RF radiation alters the blood-brain barrier was considered weak.”
- p. 417 “The evidence that exposure to RF radiation alters apoptosis was considered weak.”
- p. 417 “The evidence that RF radiation alters cellular replication was considered weak.”
- p. 417 “There was weak evidence from in vitro studies that exposures to RF radiation alters ornithine decarboxylase activity.”
- p. 417 “The evidence that exposure to RF radiation, at intensities below the level of thermal effects, may produce oxidative stress in brain tissue and may affect neural functions was considered weak.”
Consistently, the mechanistic group found all mechanistic evidence to be weak. This, however, does not fully reflect the opinions presented in Lyon. In most of the cases, when the consensus was impossible to reach, the group members had to vote, and… voting went along the certain, predetermined lines. Consistently, the same members voted down the opinions of the differently thinking minority.
The composition of the experts of the mechanistic group:
- Igor Belyaev
- Carl Blackman
- Rene De-Seze
- Jean-Francois Dore
- Jukka Juutilainen
- Dariusz Leszczynski
- James McNamee,
- Junji Miyakoshi,
- Chris Portier (Chair)
- Stanislaw Szmigielski
- Luc Verschaeve
The weak evidence of mechanistic studies reflected the opinions of the majority. Democracy might be not the best way to deal with scientific evidence.
Was there, during Lyon’s deliberations, presented mechanistic evidence that could be considered as plausible mechanism for the cell phone radiation-induced effects? My answer is yes. There was evidence from six different research groups using six different experimental models and six different exposure conditions, but all of them arrived at the same result – cell phone radiation activated stress response in living cells. This means that the radiation is recognized by the living cells and an agent who might cause harm, and it is necessary to protect from this harm by the launch of the stress response. I have presented this option in my talk in London at the meeting on Childhood Cancer 2012. Slide from this talk is presented below.
Already at the IARC meeting in 2011, using the mechanistic evidence, it was possible to classify cell phone radiation as a probable carcinogen (2A). However, in my observation, the sole “shock” of the probable carcinogen classification making it through, against all expectations, prevented any reasonable debate over the classification of this radiation as a probable carcinogen.
The third replicate of the epidemiological evidence, published in 2014, makes the evidence from human studies clearly stronger. Some might say that the human evidence is now sufficient, what automatically means that the cell phone radiation is a human carcinogen, category 1 in IARC scale.
Others, like myself, might be more moderate and consider that three replicates of epidemiological evidence are a strong indication of a probability that cell phone radiation is a probable carcinogen. This is not, however, a definite proof because a variety of bias is involved in the case.control studies. Furthermore, the epidemiological evidence is supported by the limited evidence from animal studies and by the mechanistic evidence showing activation of stress response – a major set of pathways regulating, among others, development of cancer.
For those dismissing scientific evidence of probable carcinogenicity – a memento. Thus far we focused on whether cell phone radiation alone causes cancer. We did not study whether cell phone radiation in combination with chemicals or other radiation could enhance carcinogenicity. Hints of such a possibility come from the animal studies used as evidence during IARC 2011 deliberations.
Any person, scientist or non-scientist, before claiming that there is no risk from cell phone radiation and dismissing the science as a bogus, should remember that it is necessary to study all possible options of effects before making such statements – option of co-effects of cell phone radiation and chemicals was not studied yet…
In conclusion, I consider that currently the scientific evidence is sufficient to classify cell phone radiation as a probable human carcinogen – 2A category in IARC scale. Time will show whether ‘the probable’ will change into’ the certain’. However, it will take tens of years before issue is really resolved. In the mean time we should implement the Precautionary Principle. There is a serious reason for doing so.