my $sql = 'select page_title, page_touched
           from   proadvpag
           where  page_namespace = 0
           and    page_is_redirect = 0
           and    page_touched < 
                  NOW() - INTERVAL 100000000 SECOND';

my $sth = $dbh->prepare($sql);
$sth->execute($then);

while (my $row = $select->fetchrow_hashref) {
  # all rows returned are ones you want to send an
  # email about
}