I was trying to understand it. Do you mean to suggest there is a required amount of radiation for a person?
If not (and likely not what you meant) what do you mean by min and max?
What I meant is that there are min. levels people can tolerate for a specific amount of time before it causes damage to your body. Maximum levels are when you begin to experience illness or long term effects.
Perhaps a misunderstanding, I am not having a good day.