use CGI qw(:standard);

my %field;
for (@field) {
   my $param = param($_);
   die unless $param;     # do validation on $param here ...
   $field{$_} = $param;
}

# or validate specific pieces outside the loop:
die unless $field{rid} =~ /^\d+$/;
die unless is_valid_email($field{Email});

$insert_sth->execute(values %field);