Masterbation is healthy and it's normal.
Believe it or not, 30 times in a month is nothing. All it means is that this person masterbates at least once a day equivalent to a whole calendar month or 2x a day which would be half of 30 days, meaning this person either masterbates 2x a day over the course of 15 days, consecutively or sporadically.
The real issue is when masterbation gets in control of your life to the point it causes you to not mentally function properly in handling your everyday life business such as work, school, relationships with people, sleeping habits, etc, etc where you are constantly horny and thinking about masturbating at odd times when your mind should be occupied with your daily activities (work, school, appointments, etc, etc).