LONDON — Danish researchers can offer some reassurance if you’re concerned about your cellphone: Don’t worry. Your device is probably safe.

The biggest study ever to examine the possible connection between cellphones and cancer found no evidence of any link, suggesting that billions of people who are rarely more than a few inches from their phones have no special health concerns.

The Danish study of more than 350,000 people concluded there was no difference in cancer rates between people who had used a cellphone for about a decade and those who did not.

Last year, a separate large study found no clear connection between cellphones and cancer. But it showed a hint of a possible association between very heavy phone use and glioma, a rare but often deadly form of brain tumor. However, the numbers of heavy users was not sufficient to make the case.

That study of more than 14,000 people in multiple countries, in addition to animal experiments, led the International Agency for Research on Cancer to classify electromagnetic energy from cellphones as ‘possibly carcinogenic,’ adding it to a list that also includes things such as coffee and gasoline engine exhaust.

But that designation does not mean the phones necessarily pose a risk. […]