Where to start with SOP for public health

[ravens13]

I have recently started completing my SOPHAS application for several schools, and I am stuck on how to write the statement of purpose. My background:

 

BS in Biology, graduated 2010

study aborad in India for a winter semester, budhhist philosophy

undergraduate research in plant population genetics

currently employed for 3+ at a molecular diagnostics laboratory as a lead tech

 

I am interested in global health, specifically India, and I am looking to get an MPH with an Epidemiology concentration. However, I don't know how to zone in on any specific research goal. I also don't know if I have the appropriate background in Public health, even though working in a clinical genetics lab could possibly be applicable (thoughts?). I have also been out of school for a WHILE, so I may only be able to contact my one research porfessor to be an acedemic reference, even thoguh SOPHAS suggests getting mostly acedemic ones. I will mostly have professional references from my current employer. Is that an issue as well? Does anyone have any suggestions on where to get started? Are there popular public health journals that I can peruse for current research to give me some ideas? Thank you!