The recent publication of the summary analysis of the Interphone project about the effect of mobile phone radiation on the development of glioma and meningioma has got the media and the public confused. The interpretation of the results and the language used in the article for the description of the final result were convoluted as if somewhat designed to “satisfy everyone” – those expecting no effect and those expecting an effect.
The conclusions of the study were as follows:
“…Overall, no increase in risk of glioma or meningioma was observed with use of mobile phones. There were suggestions of an increased risk of glioma at the highest exposure levels, but biases and error prevent a causal interpretation…”.
First of all, there was indeed no increase in cancer risk but in fact a decline, yet mention of that was omitted from the final conclusion. Explanation as to why, can be found from the article. The authors considered that the decline was an unlikely result and it was suggested that this observation must be caused by biases of the data. The same biases were also used to repeal the suggestion, which was part of the conclusions that the highest exposure might lead to an increased risk. However, the same biases seemed not to matter for the conclusion that: “Overall, no increase in risk of either glioma or meningioma was observed in association with use of mobile phones.” This so called “lack of association” should be and certainly is also weakened by the same biases. This “interpretation” of the results provided by the Interphone authors is what confuses the public and the media, and what allows interpretation of the study in whichever way it may fit the interpreter (for more details see e.g. Interphone resources at http://www.microwavenews.com/Interphone.Resources.html).
If we look at the results of Interphone as they are, without using “interpretation” provided by the authors, then it appears as if talking on mobile phone (= exposure to mobile phone radiation) for 30 minutes per day for 10 years might increase the risk of glioma by some 40%. Of course, this result is uncertain, as the data on which is based are, according to the authors, unreliable due to numerous biases. However, let us for a moment assume that this result is a rough indication of the potential trend. In such assumed case, the 40% increase in risk of glioma is, from the viewpoint of an individual phone user not a very “risky business” (unless someone is unlucky and gets the cancer). For example in Finland, the latest published statistics (years 2005-2007; (http://www.cancerregistry.fi/tilastot/image_67.pdf) of the cancer of brain and central nervous system (page 11, bottom tables) say that in men, the age-adjusted rate of brain cancer is 11.2 cases/100000 and women 13.3 cases/100000. The 40% increase would bring these numbers for men and women to 15.7/100000 and 18.6/100000, respectively. So, the increase of risk from the viewpoint of individual user is not very high.
However, from the viewpoint of the society and the financial burden caused by the additional cancer cases (costs of medical treatment, costs of lost productivity, monetary and non-monetary burden for the families) could be significant. According to the same source (http://www.cancerregistry.fi/tilastot/image_67.pdf; Table 3 on page 11 and Table 4 on page 12), the number of newly diagnosed brain and central nervous system cancer cases in men was in 2007 – 372 cases and among women – 561 cases. The 40% increase would mean that there would be additional 155 cases among men (total of 542 cases) and additional 220 cases among women (total of 771 cases). It means that there would be additional burden of 375 cancer cases to take care of for the health system and by the families. These are not small numbers and relate to only some 5.4 million of Finns. Also, let us remember that Interphone has dealt only with brain cancer and did not examine any other potential health risks.
Now, to the question: “Do our mobile phones indeed comply with the safety standards?”.
As we all know there are safety standards of how much radiation mobile phone may emit and how much radiation can be absorbed by our body. There are also, at least in some countries, testing mechanisms put in place to prevent sale of mobile phones that might, e.g. by manufacturing error, not meet these standards. So, we should be OK.
However, a review of the instruction booklets provided by the manufacturers with the mobile phones gives some puzzling information. For example Motorola advices “If you wear the mobile device on your body, always place the mobile device in a Motorola-supplied or approved clip, holder, holster, case, or body harness. If you do not use a body-worn accessory supplied or approved by Motorola, keep the mobile device and its antenna at least 2.5 centimetres (1 inch) from your body when transmitting”. Apple is even more straightforward in their statement: “iPhone’s SAR measurement may exceed the FCC exposure guidelines for body-worn operation if positioned less than 15mm (5/8 inch) from the body (e.g. when carrying iPhone in your pocket).” (for additional details on selected other phones see e.g. Environmental Health Trust at http://environmentalhealthtrust.org/content/read-fine-print).
We all know how we use and keep with us mobile phones. Today’s devices are small, thin and light. Thus, most of us who do not carry handbags keep our phone in the back or front pocket of our trousers or in a shirt breast pocket. Then, according to the booklets provided by the manufacturers, emission of our phones does not meet the safety standards and we are exposing locally our bodies (predominantly skin) to higher radiation levels than permitted (especially when we use earpiece or Bluetooth with the pocketed phone). And even when we use e.g. Motorola provided clip for keeping the phone on trousers belt we most likely expose ourselves to higher radiation dose than permitted, too. At least it might be so for those of us who might have few extra pounds and little bit of an “extra muscle” hanging over our belt and directly touching the phone.
Certainly the manufacturers must be aware of the exact ways how we keep and use our phones and must be aware that, in practice, when keeping phones as we do, in pockets, users expose themselves to more radiation than it is permitted by the safety standards.
Also, when keeping the phone during conversation next to ear some areas of our body are likely exposed more than the safety standards permit. Our brain is “fine” and is exposed in accordance with the safety standard because our ears work as “spacers” that keep the phone ca. 1 inch from the skull. However, our ears are likely overexposed. This “permission” of overexposing ears is thanks to the definition of the ear as an “extremity” – part of the body where radiation effects would be not so detrimental to the health because there are not located any essential internal organs. However, this natural “spacer” consists of cartilage with its cells and skin. We do not know at all whether radiation has any effects on these tissues. In fact there is only a single study that suggests that it might be that the mobile phone radiation affects human skin (http://www.biomedcentral.com/1471-2164/9/77). Results of this study are of course still uncertain because it was a pilot study with only a small number of analyzed volunteers. Unfortunately, continuation of this study was prevented due to lack of funding. However, this study was pretty popular and was viewed since its publication in 2008 by 28760 readers (as of June 8, 2010) and it makes it the most viewed study in the history of the journal BMC Genomics (http://www.biomedcentral.com/bmcgenomics/mostviewedalltime/). It means to me that there is an interest and a need for such research and information.
Based on the manufacturers’ own information provided in the instruction booklets, one can come to the conclusion that, locally, our skin might be exposed to higher radiation levels than these permitted by the current safety standards. Is it really so? And, if it is so, why some unrealistic “1-inch-distance” models are used to determine compliance of the phones with the safety standards instead, as in real life, using model of “pocket storage” of mobile phone? It would be nice to get come answers from MMF, GSMA, ICES and ICNIRP.
To wrap-up, when considering:
- the uncertain results of Interphone (however uncertain but suggesting potential increase in risk),
- the long time before the next epidemiology study (Cosmos) will provide more reliable answers,
- the likely higher than allowed exposures of skin to mobile phone radiation when the phones are used and stored as in everyday life they are,
the conclusion can be only one – we should advice people to minimize the exposure to mobile phone radiation for the time being, before we know more whether there is or is no risk of any disease developing from the mobile phone radiation exposures. Furthermore, we should conduct not only epidemiological studies, which likely are not sensitive enough to prove or to disprove possibility of health risk. We should conduct human volunteer studies that would determine if our bodies react to mobile phone radiation and in which way.
Finally, I am against changing safety standards without sound scientific evidence, which is for now missing. I am also against forcing people to limit their use of mobile phones (e.g. ban on phones for children) because solid scientific basis for such action is still missing. But I am for phones that, in real life situation, comply with the safety standards. And, in the current situation of scientific uncertainty, I fully support the precautionary approach and advice of limiting exposures whenever possible and feasible. And, of course, further research is the only way to solve this puzzle.
More of my opinions about the Interphone and epidemiological evidence in my earlier posts: