The risk of damage comes from ESD (static discharge) and EMF (inductive coupling from nearby circuits).
You can guard in two ways:
- shielded cables, with appropriately grounded connectors
- surge suppression diodes
You will still experience data loss during ESD/EMF events, but will be able to avoid catastrophic damage.
To minimize data loss, you have two possibilities:
- transceivers which typically incorporate protection, as well as transmit the signal over a differential connection to eliminate common-mode transients.
- lower data rates in the 100Kbps range or less