A new study in the British Medical Journal concludes: In this update of a large nationwide cohort study of mobile phone use, there were no increased risks of tumours of the central nervous system, providing little evidence for a causal association. This has resulted in a sandstorm of criticism of the work. In general, the objections include sample size and who was studied.
You don’t have to know much about this issue to conclude that there’s not much here. People have been arguing about the relationship between cell phone use and brain tumors for many years. There either is no correlation between the two or it’s so remote as to be meaningless. It’s an inflexible rule of clinical investigation that if you have to do gigantic controlled studies to expose an effect that this effect is at best small or nonexistent. Were it large you wouldn’t need a big study to find it.
In fact, you don’t have to do any study to learn that penicillin cures syphilis or that morphine relieves pain or that diuretics increase urinary flow, etc. Similarly, you don’t need an army of epidemiologists to show that separating the drinking water from sewerage has major beneficial effects on health.
Also, you may show a statistically significant effect of a treatment or a behavior if a very large sample size is studied. But this statistically significant effect may have no clinical or practical meaning because it’s so small.
Even if cell phone use does cause brain tumors, it’s incidence is so low that it fades in comparison to your likelihood of suffering a brain injury every time you drive your car. We accept this risk because driving a car conveys much more benefit than risk. The same is true of cell phone use. People should stop kvetching about this and move on to something more important like eating a good hamburger.
Cell phone users of the world relax. You have nothing to lose but your minutes.