According to EMWatch, there is evidence to suggest that these towers are dangerous to human (and animal) health, and that proximity to a tower increases certain negative health conditions.
People report headaches, sleep disorders, poor memory, mental excitation, confusion, anxiety, depression, appetite disturbance and listlessness. In other words, a whole slew of potential mental issues may be caused by a lot of radio wave exposure.
As far as the real elephant in the room goes, no, there is no evidence to suggest cell towers cause cancer. Not even 5G. Though, further research into that is ongoing.