(CBS Local) — A group of scientists are warning against the use of Apple Airpods, saying potentially dangerous radiation being beamed into your heads could pose a cancer risk.

As many as 250 experts from 40 countries signed a United Nations and World Health Organization petition warning against the use of Apple AirPods, back in 2015. They believe the earbuds pose possible cancer risks due to the Bluetooth technology, a type of electromagnetic frequency (EMF) radio wave that can transmit data.

Proximity to the user’s inner skull poses the greatest threat, the scientists said. The original report came back into the news recently after an article quoting the scientists earned renewed attention.

“My concern for AirPods is that their placement in the ear canal exposes tissues in the head to relatively high levels of radio-frequency radiation,” Jerry Phillips, a professor of biochemistry at the University of Colorado, told Medium.

An attendee wears an Apple AirPods during a launch event on September 7, 2016 in San Francisco, California. (Credit: Stephen Lam/Getty Images)

The experts also noted the International Agency for Research on Cancer recently determined EMF is “possibly carcinogenic” to humans. Along with cancer, genetic damage and neurological disorders are possibly linked to EMF exposure in humans.

Existing evidence “indicates potential concerns for human health and development from all technologies that operate at radio frequencies,” Phillips said.

Apple has previously responded to concerns about radiation risk but has yet to comment on the latest claims.

“Apple products are always designed and tested to meet or exceed all safety requirements,” Apple spokesperson Alex Kirschner said in 2016 when the devices first launched.