Could be either one or both.
RF from cell phones are microwave. Over exposure to that can cause damage to the body.
My wife has started using blue tooth ear buds to use her cell phone.
She has a stint and family history of heart trouble. She is wise.
Sounds like the lady made bad choices.
“My wife has started using blue tooth ear buds to use her cell phone”
Bluetooth is RF.
And they say exposure to the EMF does not cause brain cancer? I have several friends that have died from brain cancer. And it seems to be more frequent now- WHY? Some people are on their phones several hours a day.