A few questions I've got: 1) What exactly does a MPH do on day-to-day basis? As far as I've been able to make out- a large part is biostatistics? 2) Can I study for an MPH degree after an undergrad degree in ANY field? Is a PhD necessary afterwards? 3) If I have a BS in biochemistry, then get a MPH, what are my job prospects? Are they good? 4) Some info on MD-MPHs would be good-what they do usually.