Answer: The goal of the Los Angeles County Department of Public Health is to protect health, prevent disease, and promote the health and well-being for all persons in Los Angeles County. Its focus is on the population as a whole. It conducts its activities through a network of public health professionals throughout the community. Public health nurses make home visits to families with communicable diseases; epidemiologists investigate the sources of disease outbreaks; environmental health specialists ensure safe food, water, and housing; and all work with community coalitions to protect and improve health.