So, if I have read this right I may need to change my Database structure.
At the moment a user registers with the website, then a check box is used by an admin to indicate that a person is a member of a department (as people can be in more than 1 department). So instead of having value 1, 2, 3 etc in one column, they will have a 1 in each dept column.
The next table that holds emails is one that is entered about a committee, they enter contact details into a form of key positions within that committee and are simply an email address associated to a committee position.
Can I create a search as you described but have multiple criteria so that in the case of table 1 multiple columns are chosen to find items with a value of 1?
With regard to the second table, could i set up multiple criteria that selected all email addresses in each column?