You could just add all array variables to your foreach loop:

use warnings;
use strict;

my @array1=(1,2,3,4,8);
my @array2=(1,4,2,4,5);
my @array3=(1,6,1,7,5);
foreach my $element (@array1, @array2, @array3){
    if ($element == 1){
        ##do something;
    }
}
[download]

Perl has many tools for operating on arrays:

• grep
• map
• List::Util

Update: my solution was posted before the OP's UPDATE.