01-15-2016, 10:57 PM
The clock hands don't glow as well because of radiation damage to the zinc sulfide coating that illuminates. Radium hasn't been used on clock hands since the '70's. Radium has a half-life of 1600 years so the radium on the hands is still dangerous to ingest or inhale. The radioactive paint could flake off and become airborne. My recommendation is to leave it alone! Otherwise, remediation could be expensive.