Do it!
I know plenty of people in my program who are more research focused who reached out to faculty. Some, in fact, who made this a top criteria for selecting a school.
Absolutely 0 harm at all in you reaching out to faculty of schools you are considering and any faculty member who isn't a total curmudgeon should have no problem getting back to you. In fact, my UWashington application suggested that I reach out to a professor for a chat and I did and we had a wonderful conversation. Very nice guy. I didn't end up going there but I found this chat to be quite informative and certainly was something that I considered when it was time to choose.
Plus, its just more info for you to make a decision with. Don't you want to go somewhere where you know the faculty you want to work with are available and willing to work?
And from the most logical standpoint (i know its tough to be logical throughout the stress that is this procedure), do you think anyone is sitting there saying "wow, i wish the prospective student didn't contact me?" When you really think about it...probably not.
Just write a nice, professional and cordial letter along the lines of "Hello Professor (blank), I am considering (blank) for my MPH. I am very interested in your work in (blank). I was hoping you might be able to tell me a bit more about your work and what opportunities might be available for MPH students to work with you. Thanks!"
Ya know...something like that, only polished up.
So, to review...YES!
Good luck!