FREE - use it even after you graduate! "Helping the public health workforce find and use information effectively to improve and protect the public's health." Use a specialized search or the general search box at this site.
CINAHL, the Cumulative Index to Nursing and Allied Health Literature, draws information from more than 3000 journals, including publications within public health and others covering various topics relevant to public health.
This is a very large business database that cross-searches numerous journals, magazines, trade publications and more. With the economic/business impacts of public health, you can find much relevant content in this database.
"The Cochrane Library is a collection of six databases that contain different types of high-quality, independent evidence to inform healthcare decision-making......" (About Cochrane). A central database within Cochrane Library is the Cochrane Database of Systematic Reviews, providing high-level evidence on effectiveness of treatments or interventions.