Modern Day Public Health
Modern Day Public Health

Modern Day Public Health

Lead Author(s): Leslie R. Hoglund

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Modern Day Public Health sets the vision for well-being and addresses the needs of a population. It responds to disease outbreaks, natural disasters, and environmental threats, and focuses on creating conditions where people can achieve their best possible health. The principles of public health are varied and inculcate aspects of many disciplines, professions, skills and knowledge. More than ever, public health is in the forefront of everything. Over 16 chapters, this textbook will give the student an expansive overview of the major issues and opportunities from epidemiology, health science communications, public health laboratories, and health informatics to public health careers, leadership, policy, systems, and resources. Each chapter includes five knowledge check questions, a discussion board, and an applied learning exercise assignment. The future of public health is the security of health equity and students using this textbook will be inspired to take action.

CH1: Introduction to Public Health

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At the end of this chapter, the student will be able to:

  • Describe the purpose of public health
  • Define key terms used in public health
  • Identify prominent events in the history of public health
  • Recognize the core public health functions and services
  • Describe the role of different stakeholders in the field of public health
  • List determinants of health and recognize how they affect population health
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Public health is “the totality of all evidence-based public and private efforts throughout the life cycle that preserve and promote health and prevent disease, disability, and death” (Riegleman & Kirkwood, 2019).

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[1] Image: National Health Corps (
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The Purpose of Public Health

What is public health? It’s a common question. All too often, the answer focuses on what it is not. It’s not healthcare. It’s not health insurance. Other times, the question may be answered with a list of examples — like vaccine awareness, car safety, or clean water campaigns. We may hear about the importance of public health on the news during emergencies or disasters, like a water crisis or a measles outbreak. 

Basically, while healthcare focuses on treating individuals who are sick, public health addresses the needs of a population — such as a community, a state, a nation, or even the world. And while public health responds to disease outbreaks, natural disasters, and environmental threats, its focus is on prevention — creating conditions where people can achieve their best possible health.

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Discussion 1

Why does public health interest you?

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It’s hard to describe work that encompasses the community conditions of health, and people often default to thinking about healthcare and individual responsibilities when they hear the term “public health.” But, public health is what we build together as a society when we shape our communities so everyone can achieve optimal health. The health of our community is like a building — it depends on a strong and stable foundation. Things like quality education, safe and affordable housing, safe drinking water, and access to healthy foods can lead to positive outcomes for health and well-being for everyone. A solid foundation gives everyone a chance to achieve their best possible health.

One example of this is that doctors and public health professionals are both concerned that heart disease is the leading cause of death in the United States. Doctors improve this by diagnosing heart disease early, prescribing drugs to lower cholesterol levels and blood pressure, and, possibly, performing surgeries to improve blood flow to the heart. Public health professionals use population health data and analysis to prevent and improve heart disease by passing and enforcing policies to improve nutrition standards, design walkable and bikeable communities, and creating health communication campaigns to help people from all walks of life quit smoking. Public health is strongly guided by the science and surveillance for disease prevention.

[2] Image: Kent State University (

We need to be prepared for emergencies and adhere to good public health practices and principles when outbreaks lead pandemics, contaminated water drips out of faucets in our homes, substance abuse leads to overdose fatalities, and gun violence becomes significant within communities. When a field is as interdisciplinary and evolving as public health, our focus is about protecting, promoting, and improving the health of populations and achieving that mission requires many disciplines, including math like biostatistics and epidemiology, social sciences like psychology, sociology, and anthropology, physical sciences like toxicology, environmental science, biology, chemistry, and engineering, politics and international relations, business and economics, and health sciences like occupational health, nutrition, and aspects of aging. The list goes on. Public health is a great field if you can’t decide what to major in. It brings together the best of everything!

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Image: Wisconsin Center for Health Equity (

Creative and innovative solutions to improve the health of all populations has changed where public health professionals can work; the field is expanding and incorporating elements of social justice to improve health equity. Salaries range between $45,000 to $65,000 for undergraduate public health graduates, depending on location, institution, and priority. Public health graduates are increasingly working outside of government, with more and more students securing jobs in the for-profit sector. So, what can you say when people ask you, “What can you do with a public health degree?” You tell your friends and family: “My degree in public health gives me almost limitless options. I could work in academia, government, non-profit, or for-profit sectors to improve health.”

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[3] Image: Walden University (

The projected growth of the public health workforce between2018-2028 is expected to increase by 1.2 percent. Positions related to data analysis, statistics, and computational sciences are expected to increase the most. Local government positions are expected to increase by 3.1 percent. The top public health generalizable skill sets most needed for new hires are interpersonal skills like collaboration and partnership, written communications, technology, management, finance, public speaking and making presentations.

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Public Health History

Public health in the US is characterized by three distinct periods of time, each marked by significant improvements to health and well-being in the US: Public Health 1.0, 2.0, and 3.0. Early records from the 1700s show the impact of public health practices during epidemics such as the plague, cholera, and smallpox by implementing ship quarantine and isolation in major East Coast port cities. Poor sanitation and hygiene, along with diseases associated with poor nutrition, maternal and infant health, unsafe workplaces and occupational injuries were most common in the 1800s and we define this time period Public Health 1.0.

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The turn of the 20th century evidenced smallpox, typhus, tuberculosis, and infant mortality were the leading causes of disease. Public agency for the population’s health became paramount and in over 40 states and cities, local health departments and boards of health were established. Modern public health became an essential function of government. Sanitation and social reform were the focus and environmental improvements led to reservoirs and municipal water supplies, improved food inspections and immediate disease case reporting. Public health labs got their start to control bacteria in community water sources and epidemiology launched into disease detection, mitigation and control. Public health as a science of knowledge and expertise formed into a disciplined field of study and practice to reduce the impact of infectious and chronic diseases like cancer within the population.

As the 1900s unfolded, major national policy initiatives were undertaken to prolong life and promote health and well-being. The U.S. Public Health Service was created and funding for federal-state partnerships were developed and expanded. Government’s role in public health took on a greater authority in health and welfare of individuals. The National Institute of Health became the research hub for the study of all diseases and related conditions. Data became a priority and the National Center for Health Statistics was formed alongside the Center for Disease Control during World War II. Expansion of governmental agency capacity at state and local departments of health aimed funding at maternal and child health, family planning, immunizations, sexually transmitted diseases, and tuberculosis control. By the 1970s, individual health care expenditures began to significantly increase and uneven access to care became an issue. And for the first time, “this scientific and organizational progress mean that comprehensive public health protection – from effective primary prevention through science-based medical treatment and tertiary prevention – was possible for the general populations” (DeSalvo et al., 2017).

[4] Image: Preventing Chronic Disease (

A turning point occurred in 1988 with the publication of The Future of Public Health by the Institute of Medicine (IOM), as it described US public health as a system of disarray and lost goals. The report outlined a new framework of core functions and 10 essential services of public health, and delineated how these functions would be performed at the national, state, and local levels. This was Public Health 2.0 – assessment, policy development, and assurance.

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[5] Image: Community Tool Box (


Which of the following is NOT a core function of public health?








Policy Development

Being responsible as the safety-net clinical care for poor people was demanding and public health was not able to address the rising prevalence of chronic diseases and greater levels of disability. Differences in life expectancy and disease incidence were beginning to surface among people of color and lower socioeconomic status when compared to other racial or economic groups. Governmental public health became “professionalized” in that it set core functions, established target capabilities, launched performance measures at every level of federal, state, and local levels. The Tenth Amendment positions public health activities under the delivery of state direction. There are approximately 2,800 local health departments in the US and most exist in a city or county, or are organized into districts or regions. All health is local and local health departments have considerable ability to lead policy change.

Public Health 2.0 saw 10 significant achievements in public health by 2000, specifically:

  1. Vaccination
  2. Motor-vehicle safety
  3. Safer workplaces
  4. Control of infectious diseases
  5. Decline in deaths from coronary heart disease and stroke
  6. Safer and healthier foods
  7. Healthier mothers and babies
  8. Family planning
  9. Fluoridation of drinking water
  10. Recognition of tobacco use as a health hazard

During the recession and at the onset of the Affordable Care Act, a new era of public health emerged beyond the traditional and limited scope of public health department services and functions. A new vision, Public Health 3.0, was born and centers on key components: cross-sectoral collaboration, actionable and timely data, full funding for public health, and focusing on changing the outcomes from social determinants or influences of health. These require a leader – called the Chief Health Strategist (or Catalyst) – to drive collective action and impact in ways public health has never considered before. This era of public health is one of innovation and transformation – we need strong leaders to disrupt and dismantle systems of chronic oppression and disadvantage that result in poor health outcomes. The goal is to build an equitable, health-promoting system – that provides safety, stability, and sustainability to all communities in the way they need to improve the population’s health; read: For the Public’s Health: Investing in a Healthier Future.

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Public Health 3.0 is characterized by all of the following except:


Led by a Chief Health Strategist


Focusing on the health of individuals


Cross-sector collaboration


Actionable and timely data


Adequate funding

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Population Health

Population health is a term that has grown in prominence over the past decade but has been familiar to public health practitioners for a long time. A population and its health status can be defined in many different ways: race, gender, geography, age, and those with disease, impacted by social and environmental factors, or constrained by health disparities or inequities. Health is more than what happens inside of a clinician’s office; it is about where you live, learn, work, play, and age, and the influences and capacities that exist within a given community. The “health outcomes of a group of individuals, including the distribution of such outcomes within the group” defines population health (Kindig & Stoddart, 2003).

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Chronic diseases are the leading causes of death in the United States. Heart disease and cancer are the top two.

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[6] Image: Statista (

It is not enough to attempt to reduce or “fix” what kills us through individual interventions like lifestyle behavior changes, medication, and health education. Research demonstrates consistently that “no matter how social status is determined in a society, whether by age, caste, race/ethnicity, or income, health will be strongly associated with status” (Michener et al., 2016). The top of the social ladder typically has better health than those at a lower status. Imagine living in a stress- or trauma-inducing environment where food is scarce and you have no transportation and childcare. This is the space in which public health excels, advances broad population health improvement, and advocates for upstream, collaborative action. Through strong health leadership and strategy and cross-sector partnership, organizing to improve health can be done by “1) increasing a group’s collective capacity to work effectively toward a common aim, 2) enhancing belief in collective self-efficacy and thereby the willingness to fight longer, harder battles, and 3) exposing the role of social determinants in health as well as the limitations that existing circumstances place son the group’s ability to effect desired changes” (Michener et al., 2016).

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Moving Upstream on Social Determinants and Social Needs

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[7] Image: DeBeaumont Foundation (

Taking an upstream approach is more critical than ever before. Policies, system, and environmental (PSE) changes are how we improve health of populations, communities, and our nation. It’s about changing the conditions in which people can be healthy. If your doctor tells you that you are pre-diabetic and you should walk a mile every day for exercise, but you live in a place that does not have sidewalks or street lamps for safety – how much do you think you are going to walk a mile each day? Would you feel supported by your environment and community to follow the doctor’s strategy as a means to prevent developing diabetes?

In public health, we use the socio-ecological model to describe the levels of intervention, and when strategies connect across the framework, there is mutually-reinforcing effort toward health improvement. Most prevention activities are focused on the individual which fail to consider the impacts of their relationships and social networks, housing, transportation, poverty, employment, education, health insurance, food environment and scarcity, etc. Public health works at the societal (i.e., policy) and community levels to keep healthy people health first, and to make healthy choices easy by default; this is about positive health impact. Former CDC Director, Dr. Thomas Frieden, published a similar framework for public health action called The Health Impact Pyramid. These two models align well together and prioritizes where public health and policymakers can be most effective in moving the trend lines on disease and disability toward improved outcomes. As you move up the pyramid, it becomes more individually focused and therefore, less population impact. Focusing on improvement of socioeconomic factors in a community will reap the widest population health impacts. 

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[8] Image: Social Ecological Model (
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Based on the socioecological model, where does public health focus its efforts?










A and B


C and D

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[9] Image: Health Impact Pyramid (

Why does all of this matter to public and population health? Unfair distribution of advantages causes poor health outcomes. Variance in social status in a community or population is directly related to their quality and length of life. Social justice becomes central to the mission of public health. Public health began improving the needs of the most disadvantaged and has grown to advance human well-being by improving health. Health emergencies like COVID-19 put a strain on life-saving resources and shortages often impact groups of people who are considered non-essential, further disenfranchising them. “Justice requires public health officials to devise plans and programs with particular attention to the disadvantaged” (Gostin and Powers, 2006). Government at all levels must challenge the systematic disadvantage and take action through political and social coordination. Commitment to social justice is the core of public health so that equal respect to all individuals and groups who make up the community achieves advances the common good.

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What is the health of your city or county?  The County Health Rankings provide an overview or snapshot of where you live, learn, work and play and the conditions and factors that lead to quality and length of life. Knowing the health status of your community is critical to becoming grounded in the principles of public health. 

CH1 Assignments

Locate your city or county profile on the County Health Rankings website, answer the following prompts and questions for your essay assignment. The goal is to describe your community, the place where you live, based on the determinants of health. Use the four sections below to outline your essay. 1) Demographics - Describe your city or county in terms of the composition of the population. 2) Health Outcomes - How does the premature death rate compare to the state and US? Describe the quality of life in your city or county. What measures are surprising or concerning to you? What measures indicate that your city or county is doing well? Do the numbers match what you believe and experience about your city or county's quality of life? Explain your perspective of the rankings for Length of Life and Quality of Life. 3) Health Factors - Review the measures under each subsection, i.e., Health Behaviors, Clinical Care, Social and Economic, Physical Environment. Describe at least three (3) measures that your city or county is doing well or is better than the state. Share and explain at least three (3) measures where your city or county is performing poorly and public health should take action. 4) Summary - Close your essay with a summary statement about the overall snapshot of your city or county in regards to the determinants of health.

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DeSalvo KB, Wang YC, Harris A, Auerbach J, Koo D, O’Carroll P. Public Health 3.0: A Call to Action for Public Health to Meet the Challenges of the 21st Century. Prev Chronic Dis 2017;14:170017. DOI:

Gostin, LO, Powers, M. What Does Social Justice Require For The Public’s Health? Public Health Ethics And Policy Imperatives. Health Affairs 2006 25:4, 1053-1060.

Kindig, D., & Stoddart, G. (2003). What is population health? American Journal of Public Health, 93(3), 380–383.

Michener, J, Koo, D, Castrucci, B, & Sprague, J. (Eds.), The Practical Playbook: Public Health and Primary Care Together. Oxford, UK: Oxford University Press. Retrieved 14 Jul. 2020, from

Riegelman, RK, & Kirkwood, B. (2019). Public health 101: Improving community health.