THE supposed link between cellphone radiation and cancer has long been dismissed by many experts. These scientists argue that mobile phones emit non-ionizing radiation that is too weak to set off the DNA damage known to cause cancer. There's no known biological mechanism to explain how non-ionizing radiation might lead to cancer. Recently, however, some researchers have suggested that just because science can't explain the mechanism doesn't mean one doesn't exist. "I think the safe practice is to use an earpiece so you keep the microwave antenna away from your brain," neurosurgeon Keith Black told CNN.