It could be mission related.

same issue on capture the island.
players take random dammage and die even when running in a field or just staying at the main respawn doing nothing. this happens more and more often the longer you stay on a same server.

reproduce by going in a server playing capture the island when the round is almost won by a side then go in the military base near the airfield.

It is not mission related.
Some ruins can even throw you in the air.

It's note mission related, as I've experienced the same problem today on a PvP server.
1st death was at respawn location and 2nd while running across a field.
In both cases nobody shot at me from a tank or 12.7 mm sniper rifle or arty) nor was I kill by a vehicles that rolled over me. I simply died for no apparent reason.

My guess is that since collapsing buildings deal damage, there is a glitch where destroyed buildings deal damage. Similar to those infamous burned out helicopter wrecks from alpha. I experienced this in longer MP missions, when arty has destroyed many buildings in a town and you move through it.
However it's not limited to near a building but quite random in the surrounding area. Very annoying but also rare and not easy to reproduce.

The ruins at 229188 on Altis seem to be doing that to me consistantly

happends mostly in Kavala and other towns surounding it

Known issue with destroyed buildings