delete bdump alert log?

Hi everyone,
I am new to the database realm and I'm hoping that I can resolve this issue I'm having. I inherited this database (oracle 10g) and I noticed that the space summary said that the dump area had 98% used. So i checked the cdump, adump, udump and the bdump directories. They were full of old logs dating back to 2006. I read some of them but they basically had the same error repeated. That issue was resolved a long time ago. I save the audit and trace files off of the server and deleted them. But the OEM still says that it has 98% used in the dump areas????
I noticed that there is an alert.log that is also there. It also has old entries dating March 2006! Is it ok to delete this log? Will it be recreated if I delete it?
I saw an article about truncating the alert log but will that do the trick.

Your suggestions are most welcomed.

Thanks