The NTP studies found that high exposure to RFR used by cell phones was associated with:
- Clear evidence of tumors in the hearts of male rats. The tumors were malignant schwannomas.
- Some evidence of tumors in the brains of male rats. The tumors were malignant gliomas.
- Some evidence of tumors in the adrenal glands of male rats. The tumors were benign, malignant, or complex combined pheochromocytoma.
- DNA damage: Specifically, they found RFR exposure was linked with significant increases in DNA damage in:
- the frontal cortex of the brain in male mice,
- the blood cells of female mice, and
- the hippocampus of male rats.