This is about mid range wireless charging [1] not Qi chargers. If something is charging your watch from across the room it's blasting your whole body.
The FCC limits RF exposure to 1.6 W/kg. [2] That's presumably the standard the authors argue is insufficient to prevent ~7MHz wireless chargers from inhibiting cell apoptosis.
[2] https://www.fcc.gov/consumers/guides/wireless-devices-and-he...