The science-based answer is that it depends on the frequency and effect on human tissue. So mounting a telco transmitter on your roof is probably bad for you,

The science-based answer is that it depends on the frequency and effect on human tissue. So mounting a telco transmitter on your roof is probably bad for you, similar to being inside a microwave oven. Holding it pressed against your ear while talking is also probably bad for you depending on duration, but mfgs. do tests at various distances from your ear. If you're a real estate agent using your mobile phone all day, I'd use an earpiece and put the phone on your desk away from your body.