Public health is the science and clinical practice of population and community-based efforts to prevent disease and disability, and promote physical and mental
- environmental health
- nutrition and food safety
- immunization and infectious diseases
- injury and violence prevention
- maternal, infant, and child health
- substance abuse
- chronic disease prevention and treatment
- access, availability, and affordability of health care
- education, screening, and outreach services
The science of public health is called epidemiology. It is the study of the occurrence of disease in such naturally existing populations as nations, cities, or communities. The term "epidemiology" comes from the Greek word epidemic, which means "upon the people." The earliest epidemiologists (public health scientists) worked to prevent the spread of epidemics.
Today, epidemiologists gather and analyze information about populations to manage and prevent disease. Epidemiologists are trained in highly specialized research methods: surveillance, investigation, analysis, and evaluation. Surveillance refers to systematic data collection and analysis; it enables the epidemiologists to detect changes that may require investigation. Epidemiological investigation involves observation, detailed descriptions of the problem, documentation of data, and analysis. Evaluation is the process that helps to answer such a question as "How often should men between the ages of 40 and 60 be screened for hypertension (high blood pressure)?"
By analyzing population data, epidemiologists also are able to describe diseases and determine the factors that cause them. Epidemiology is a quantitative science; it measures rates and proportions. Two commonly used rates are prevalence and incidence rates. Prevalence describes the characteristics of a given population at a specific moment in time; it is like a snapshot.
Incidence describes the rate of development of a disease in a given population over a specified time interval. Incidence offers a longer view of population dynamics, like a video, as opposed to the snapshot offered by the prevalence rate. Epidemiologists also analyze such other rates as morbidity (disease-related illness) and mortality (death).
Public health practitioners rely on the findings of epidemiologists to develop health services, allocate resources, and determine standards of care. The results of epidemiological studies also influence health policy. For example, epidemiological research helps to determine how many health care professionals are needed based on population; the effectiveness of various treatments; and schedules for immunization or screening.
Historically, public health disease prevention activities focused primarily on sanitation (also referred to as environmental health) and hygiene. Public health measures aimed to ensure the safety of food and water supplies, and to prevent transmission of communicable (capable of being transmitted) diseases. In some developing countries, these same basic public health problems, such as adequate food supplies and potable (fit to drink) water, continue to threaten health and longevity.
During and after World War II, such advances in medicine as the development of antibiotics, cardiac surgery, and physical rehabilitation changed the emphasis of public health in the United States. Federal, state, and local governments enacted legislation to protect public health. Federal laws aimed at safeguarding public health. Major regulations passed during the twentieth century include:
- the 1938 Food, Drug and Cosmetic Act, which bans distribution of unsafe products and prohibits false advertising
- the 1972 Clean Water Act, which forbids release of pollutants into rivers, streams, and waterways
- the 1974 Safe Drinking Water Acts, which established standards for safe drinking water
- the 1976 Resource Conservation and Recovery Act, which stipulates the safe storage, transport, treatment and disposal of hazardous waste materials
- the 1990 Clean Air Act, which reduced industrial discharge or emission of pollutants into the air and set standards for vehicular emissions
Today, public health practitioners continue to work to prevent disease. However, their efforts are often directed to addressing such social issues as access to health care, and promoting such lifestyle changes as smoking cessation, responsible sexual behavior, and violence prevention.
Frequently, public health professionals must work cooperatively with persons in other disciplines to achieve health promotion objectives. For example, public health practitioners may work with educators and schools to
Communicable—Capable of being transmitted.
Epidemiology—The study of disease occurrence in human populations.
Incidence—The rate of development of a disease in a given population over time.
Potable—Safe to drink.
Prevalence—The rate describing the characteristics of a given population at a specific moment in time.
help combat illiteracy, since persons unable to read may be less able to obtain needed health care services. Similarly, they may work with urban planners and housing specialists to identify such health hazards as lead-based paints or asbestos.
The Healthy People 2010 initiative is a national plan to assist states, communities and professional associations to develop programs to improve health. Coordinated by the Office of Disease Prevention and Health Promotion (ODPHP) of the Department of Health and Human Services, the program's goals are to: increase quality and years of healthy life; and eliminate health disparities. Healthy People 2010 targets ten areas for improving health standards in the United States. They are:
Medical, nursing and allied health professionals and practitioners work in the field of public health. Public health professionals are employed by hospitals, health plans, managed care organizations, clinics, medical relief organizations (e.g., American Red Cross, American Heart Association, American Cancer Society) and schools as well as federal, state, and local government health departments. Careers in public health include:
- public health nursing
- environmental health technologists and specialists
- restaurant and food safety inspectors
- community health educators
- epidemiologists, biostatisticians, and researchers
- patient and consumer health advocates
Public health nursing began in the United States during the late 1800s. Public health nurses helped to prevent and manage outbreaks of smallpox, cholera, typhoid, tuberculosis, and other communicable diseases. The profession continues to attract nurses interested in community health education and preventive services. Public health nurses (also called community health nurses) work in clinics, schools, voluntary agencies, and provide skilled nursing assessments, visiting nurse services, and home care.
Federal government agencies that belong to the U.S. Department of Health and Human Services provide many vital public health services. The agencies devoted to health care include the Health Care Financing Administration (HCFA), Office of Development Services, Food and Drug Administration (FDA), National Institutes of Health (NIH) and the Centers for Disease Control and Prevention (CDC).
HCFA administers Medicare and Medicaid, programs that finance health care services for older adults, persons with disabilities and those unable to afford medical care. The FDA is the agency responsible for ensuring food, drug, and cosmetic safety. It also enforces labeling practices, so that consumers receive accurate, truthful information about the content, benefits, and risks of products).
Each of the 13 institutes of the NIH is involved in organ or disease-specific research activities. The seven centers of the CDC research and track infectious and other diseases in order to identify sources of disease and prevent their spread.
Wallace, Robert B., ed. Public Health & Preventive Medicine Stamford, CT: Simon & Schuster, 1998.
Clark, Noreen M., and Elizabeth Weist. "Mastering the New Public Health." American Journal of Public Health 90, no. 8 (August 2000): 1208-1211.
Meyer, Ilan H., and Sharon Schwartz. "Social Issues as Public Health: Promise and Peril." American Journal of Public Health 90, no. 8 (August 2000): 1189-1191.
American Public Health Association. 800 I. Street, NW Washington, DC 20001-3710. (202) 777-2532. <http://www.apha.org>.
Centers for Disease Control and Prevention. 1600 Clifton Rd. Atlanta, GA 30333. (800) 311-3435. <http://www.phppo.cdc.gov>.
Partners in Information Access. <http://www.nnlm.nlm.nih.gov/partners/index.htm>.