Books are shelved in general subject categories using the Library of Congress classification system. You may want to supplement your use of the catalog with browsing shelf areas for your topic. Below is a brief listing of some of the subject locations relevant to public health.
BF -- Psychology
HQ -- Family; marriage; women; sexuality; children
Q -- Science - General
QD -- Chemistry
QP -- Physiology
QR -- Microbiology
R -- Medicine - General
RA -- Public aspects of medicine
RB -- Pathology
RC -- Internal medicine
RM -- Therapeutics; pharmacology
RT -- Nursing
RX -- Homeopathy
Introduction to Public Health by 
Community and Public Health Nursing by 
Ten Lessons in Public Health by 
Oxford Handbook of Public Health Practice by 
