Also, be sure to check: sys.sql_expression_dependencies.
And not just in its own db but in other dbs, esp. on the same instance.
And the usual disclaimer: even that isn't guaranteed to be every reference, of course. But it's probably the best list of references to that column you can get.
SQL DBA,SQL Server MVP(07, 08, 09) Prosecutor James Blackburn, in closing argument in the Fatal Vision murders trial:
If in the future, you should cry a tear, cry one for them [the murder victims]. If in the future, you should say a prayer, say one for them. And if in the future, you should light a candle, light one for them.