Our contractor has attached the electrical panal against cinder blocks in our finished basement. We have noticed that around the panal the blocks will get a little damp once it has rained. It this something to cause concern?
Depends on your building codes. You have 3 code violations
right now where i live. Number one.You cannot use cinder blocks for a basement wall.( they leak ).You have no water
proofing between the blocks and the ground ( leaks ).
the panel cannot be connected directly to the wall. ( electrical leaks and corrosion.) The panel has to be mounted on a wood sub wall. If your code allows that type of install good luck. Live with it. This is not to sound offensive but you have problems and up here your electrical contractor could be in the can and out of business. Forgot about your actual question. YES this is something to be concerned about.
But the question is from a USA resident. Panels have raised bumps to create a small gap between the panel and the mounting surface to keep the panel separated from damp surfaces. I do not see a code violation in your installation.
It is more acceptable to have some 2x lumber on the wall under the panel.
This make attaching the cables close to the box (as required) far easier.
The rest sounds acceptable under the NEC (subject to local changes when adopted).