PH 1

Public Health Overview

• Module: Public Health

• Definition:

  • Public health is the science and art of preventing disease, prolonging life, and promoting human health.

  • Achieved through organized efforts and informed choices of individuals and society as a whole.

  • Involves contributions from public and private organizations, communities, and individuals.

  • Analyzes population health and associated threats.

Study Materials

• Textbooks/Study Materials:

  • Prescott’s Microbiology (Willey, Sherwood, Woolverton, 8-13th Edition)

  • Brock Biology of Microorganisms (Madigan, Martinko, Dunlap and Clark, 12th or 13th Edition)

• Study eGuide/Module Outcomes:

  • Learning outcomes available on eFundi.

Module Outcomes Expected from Students

• Understand and know:

  • Epidemiology and public health surveillance.

  • Major products of industrial pollution (air and water).

  • Major microorganisms responsible for biodegradation and bioremediation.

  • Waterborne and airborne diseases and their implications.

Lesson 1: Industrial Air Pollution Outcomes

• At the end of this lesson, you should be able to:

  • Describe industrial air pollution.

  • Describe the two National Ambient Air Quality Standards (NAAQS).

  • Explain primary and secondary air pollutants.

  • Identify and describe the six conventional air pollutants.

  • Define epidemiology and public health.

Lesson 2: Air Pollution Implications

• Outcomes:

  • Identify the six greenhouse gases and explain their roles.

  • Provide types of Hazardous Air Pollutants (HAP), their classification, and list six examples.

  • Describe diseases caused by air pollution.

Lesson 3: Biodegradation Outcomes

• Outcomes:

  • Define biodegradation and explain its three stages.

  • Describe the two types of reductive dehalogenation.

  • List and explain the three genera and species that perform reductive dehalogenation.

  • Discuss the effectiveness of soil degradation processes and toxicity reduction with examples.

  • Describe the application of microbial fuel cells in the oxidation of toluene by Geobacter metallireducens.

Lesson 4: Bioremediation Outcomes

• Outcomes:

  • Define bioremediation and its difference from biodegradation.

  • Discuss glucose use in bioremediation.

  • Discuss requirements for stimulating hydrocarbon degradation in oil spills.

  • Define and exemplify phytoremediation and rhizoremediation.

  • Define bioaugmentation and explain briefly.

  • Describe metal bioleaching.

Industrial Pollution Overview

• Definition:

  • Refers to harmful by-products and waste from factories and industrial plants, including air emissions and water pollution.

• Impact:

  • Contributes to environmental degradation and public health issues.

Global Air Pollution Issues

• Countries of Concern:

  • Rapid growth in India, China, and South Africa leading to severe air pollution challenges.

  • Legal enforcement improved but some cities still struggle, such as those near ports and oil extraction.

• Health Effects:

  • Air pollution harms human health, crops, ecosystems, and infrastructures.

• Consequences:

  • Greenhouse gas pollutants are changing the climate.

  • Aesthetic issues include odors and reduced visibility.

Natural Contributors to Air Quality Degradation

• Sources:

  • Volcanic ash, desert dust, volatile organic compounds (VOCs) emitted by trees, and methane from decaying vegetation.

  • Other contributors include methane from termites and ruminants, and forest fires producing particulate matter and nitrogen oxides.

• Human Impact:

  • Human-caused emissions are the primary concern in pollution discussions.

Clean Air Act Overview

• Historical Context:

  • Numerous efforts to control smoke and odors, culminating in the 1963 Clean Air Act established by the EPA.

• Amendments:

  • The 1970 amendments focused on six major pollutants: sulfur dioxide, nitrogen oxides, carbon monoxide, ozone and its precursors, lead, and particulate matter.

• Sources of Pollution:

  • Transportation and power plants are key sources of conventional pollutants.

National Ambient Air Quality Standards (NAAQS)

• Definition:

  • Establish maximum allowable limits for six conventional pollutants in ambient air.

• Polling Designing:

  • Primary standards protect human health, while secondary standards protect crops, materials, climate, visibility, and comfort.

NAAQS Table of Pollutants

Additional Pollutant Regulations

• The Clean Air Act also regulates unconventional pollutants produced in smaller volumes but are toxic or hazardous (e.g., asbestos, benzene, mercury, PCBs, and vinyl chloride), most of which have no natural sources.

Primary vs Secondary Pollutants

• Primary Pollutants:

  • Released directly from sources in harmful forms (e.g., emissions from coal-burning power plants).

• Secondary Pollutants:

  • Formed by chemical reactions in the air, becoming hazardous through solar radiation-induced reactions (e.g., photochemical oxidants, atmospheric acids).

Point Source Pollution

• Definition:

  • Emissions originating from identifiable sources, like smokestacks.

• Fugitive Emissions:

  • Emissions that do not pass through a smokestack, including dust and leaks from oil-processing facilities contributing about 90% of hydrocarbons and VOCs.

Specific Conventional Pollutants

• Sulfur Dioxide (SO₂):

  • Colorless, corrosive gas damaging to plants and animals, mainly from combustion of sulfur-containing fuels and industrial processes.

  • Converts to sulfuric acid in presence of oxygen and water, contributing to acid rain.

• Nitrogen Oxides (NOx):

  • Highly reactive gases from combustion heating nitrogen in fuel or air.

• Carbon Monoxide (CO):

  • Colorless, odorless toxic gas mainly produced by incomplete fuel combustion, critically affecting hemoglobin's function on oxygen transport.

• Ozone (O₃):

  • Beneficial in the stratosphere, detrimental at ground level by damaging vegetation and building materials; a product of photochemical reactions in the air.

• Volatile Organic Compounds (VOCs):

  • Organic chemicals that evaporate into the air, primarily from human activities.

• Lead:

  • Toxic air pollutant, phased out in the U.S. due to successful pollution control measures.

• Particulate Matter (PM):

  • Suspended solid particles or liquid droplets in air, with smaller particles posing the most severe health risks.

Epidemiology Overview

• Definition:

  • The science investigating diseases to understand their origins, assess the risks, and prevent future outbreaks.

• Epidemiologists' Roles:

  • Monitor public health, respond to disease outbreaks, and develop prevention methods.

Key Terminology in Epidemiology

• Sporadic:

  • Occasional disease occurrence at irregular rates (e.g., bacterial meningitis).

• Endemic:

  • Steady but low-frequency disease occurrence; e.g. common cold.

• Hyperendemic:

  • Gradually increased disease occurrence beyond endemic levels (e.g. common cold in winter).

• Outbreak:

  • Sudden occurrence in a limited population area.

• Epidemic:

  • Significant disease occurrence affecting many people simultaneously (e.g., influenza).

• Pandemic:

  • Increased disease occurrence impacting extensive populations across countries (e.g., COVID-19).

• Reservoir Host:

  • Organism carrying a pathogen, remaining healthy while transmitting to susceptible hosts.

• Index Case:

  • First identified case in an epidemic.

• Attack Rate:

  • Proportion of cases developing in a population exposed to the infectious agent.

Public Health Surveillance

• Definition:

  • Continuous systemic collection and evaluation of health-related data.

• Sources:

  • Clinical reports, laboratory specimens, surveys, disease registries, sentinel surveys.

Information Loop of Public Health Surveillance

• Collection of reports/data.

• Involvement of health agencies/providers.

• Data analysis and production of summaries, recommendations.

• Public notifications for execution of recommendations.

Surveillance Data Utilization

• Informs officials about population morbidity and mortality, impacts on school and employee attendance, and animal/vector control policies.

Pandemic Measures in Public Health

• Involves testing, isolating infected individuals, contact tracing, and quarantining exposed individuals to manage pathogen spread effectively.

Lesson Outcomes Summary

• Understand industrial air pollution and its standards.

• Define conventional pollutants and their public health implications.

• Grasp epidemiology and the essential components of public health surveillance.

• Comprehend the data sources used for monitoring and the flow of surveillance for disease management.

Specific Conventional Pollutants

• Sulfur Dioxide (SO₂):

  • Health Issues: Causes respiratory problems, aggravates conditions like asthma, and can lead to heart disease.

• Nitrogen Oxides (NOx):

  • Health Issues: Contributes to respiratory issues, increased susceptibility to respiratory infections, and can worsen asthma symptoms.

• Carbon Monoxide (CO):

  • Health Issues: Impairs oxygen transport in the blood, leading to symptoms like dizziness, headaches, and in high concentrations, can be fatal.

• Ozone (O₃):

  • Health Issues: Causes respiratory problems, can exacerbate asthma and other lung diseases, and impacts overall lung function.

• Volatile Organic Compounds (VOCs):

  • Health Issues: Long-term exposure can lead to liver, kidney, and central nervous system damage; can also cause irritations of the eyes, nose, and throat.

• Lead:

  • Health Issues: Affects almost every organ and system in your body, particularly harmful to the nervous systems of both adults and children; can cause cognitive impairments and developmental issues in children.

• Particulate Matter (PM):

  • Health Issues: Associated with heart attacks, respiratory diseases, and can contribute to premature mortality in people with existing heart and lung conditions.