Public health is the work of individuals, groups and organizations that look for ways to help people lead healthy lives. The field’s professionals use science, research, advocacy and community involvement to identify and address health hazards in communities. Their work contributes to the development of policy and practices that reduce the spread of illness, disability and death.
As public health has evolved over time, so too have the tools available to protect and promote individual and community wellbeing. The emergence of the modern healthcare system and the growth of the public health profession in the 19th century led to the formation of state-level public health agencies, as well as local government departments such as county and city public health. The field was further consolidated after the U.S. Civil War with the creation of the first state boards of health and the advancement of the germ theory of disease, leading to increased responsibilities for regional and local agencies.
Today, funding for public health comes primarily from governmental sources, including federal appropriations passed through to state governments, funds from county, city and district governing bodies and private, philanthropic or corporate granting. Public health also depends on the voluntary participation of individual citizens in activities such as vaccination, blood donation and cancer screenings.
Public health has a unique role in tackling some of the world’s biggest challenges, such as climate change adaptation, global biosecurity, rising violence and migration crises. As new health threats emerge, the need for creativity and interdisciplinary thinking amongst public health professionals has never been more critical.