Is it secure to enable debug using an environmental variable?

I'm used to using environment variables with MAMP but I wanted to ask are there any security concerns when doing this with something like Perch?

e.g. I might have this in my config.php:

    if ( isset( $_SERVER["DEVELOPER_ENV"]) && $_SERVER["DEVELOPER_ENV"] == 'development' ) {
    define('PERCH_DEBUG', true);
    }

and then I might have this in the footer:

    <?php if ( isset( $_SERVER["DEVELOPER_ENV"]) && $_SERVER["DEVELOPER_ENV"] == 'development' ) {
        PerchUtil::output_debug();
    }?>

I appreciate this is maybe not Perch specific but I'm trying to configure my Perch install so that I get helpful information when working locally, without having to switch things on and off all the time.