Speed Reads

Evidence-based medicine

Why it's very unlikely that cell phones cause cancer

A possible link between mobile phone use and cancer is one of those perennial worries that crops up every few months. But as Aaron Carroll explains below, there are a couple of simple heuristics that give strong reason to think that cell phones will not cause cancer.

The first has to do with the type of radiation emitted by cell phones. All objects above absolute zero emit some electromagnetic radiation. Very hot objects emit radiation we can see, that is, visible light. Electromagnetic radiation that is strong enough to blow the electrons off neutral atoms or molecules is called ionizing radiation. That kind is much more dangerous, because molecules missing electrons tend to break down or react with others. Broken DNA can mean a cancerous mutation.

But cell phones only emit weak, nonionizing radiation — too weak to break DNA.

The second is that any hypothesized cancer effect would have to be extremely rare. The use of cell phones has exploded across the world, yet studies have shown no consistent growth of cancer associated with cell phone use (as compared to lung cancer and cigarettes). Even a small cancer risk would result in millions of cases given the billions using phones every day; the fact that we don't see this suggests there is no such risk.

Check it out. --Ryan Cooper