Hi Kenny
I'm afraid I don't know anything about chemicals causing nerve damage but Carpal Tunnel Syndrome is usually (but not always) caused by a thickened ligament trapping a nerve at the wrist & that's what causes the tingling & numbness. The median nerve is the one affected in cts & this supplies your thumb, index, middle & part of ring finger. The ulnar nerve comes down your arm to supply the other half or the ring finger & pinky. It does sound like you have some kind of nerve entrapment but it's cause may need to be found out by the help of an emg & nerve conduction tests. Hope you get it sorted out soon as 10 years is a long time before doing anything about it. I'd say don't hesitate any longer as nerve damage sometimes can't be corrected after being left for many years.
Good luck & best wishes.
Lidia