A radio telescope is a receive-only device. It is incapable of rendering
anything sterile.

A radar telescope--using a dish--can be dangerous and the EIRP can be
megawatts. In this case, a number of health dangers apply. Fortunately those
most likely to be exposed are the best informed, and I am not familiar with a
single case of dangerous exposure.

SETI has nothing to do with this.

73,
Chip N1IR