Block Corrupted in Datafile

My DB is running with out Backup and also DB is in NO Archive log mode.How to find out the below issue. The following problem occured during DB operation: ORA-01115: IO error reading block from file 11 (block # 236928) ORA-27072: File I/O error Additional information: 4 Additional information: 236928 Additional information: 409600 ORA-01115: IO error reading block from file 11 (block # 236928) ORA-27072: File I/O error Additional information: 4 Additional information: 236928 Additional information: 409600