Environmental Health - Chapter 1 Notes

Terms and Definitions

• Environment: The complex of physical, chemical, and biotic factors that act upon an organism or an ecological community and ultimately determine its form and survival.
• Ecological System (Ecosystem): A dynamic complex of plant, animal, and microorganism communities and the nonliving environment interacting as a functional unit.
• Environmental Health: Addresses all the physical, chemical, and biological factors external to the person, and all related factors impacting behaviors (WHO). Aims to prevent disease.
• Ecological Model: Proposes that the determinants of health interact and are interlinked over the life course of individuals.

Why Environmental Health Matters

• Maintaining environmental quality is a pressing task for the 21st century.

History of Environmental Health

• Hippocrates (460-370 BCE):
  • Greek philosopher who first recognized and wrote about the influence of the environment on people’s health.
• Ancient Romans:
  • Developed the first infrastructure for maintaining public health, including:
    • Transport of water and sewage.
    • Heating water.
    • Communal baths.
  • Increased recognition of the contribution of occupationally related exposures to adverse health conditions.
  • Heightened awareness of the effect of the environment on health led to public health reforms and increased legislation and regulation.

Environmental Health Today

• Global warming/global climate change.
• Air pollution.
• Water quality.
• Food quality.
• Industrial pollutants.
• Nuclear power.
• Pesticides and herbicides.
• Environmental justice.
• War and terrorism.

The Three P’s (Principal Determinants of Health)

• Pollution:
  • Combustion of fossil fuels (petroleum, coal) leads to the dispersal of greenhouse gases into the atmosphere, causing global warming.
  • Changes in the distribution of insect vectors.
• Population:
  • Human population exceeding the carrying capacity of the planet causing urban crowding.
• Poverty:
  • Linked to population growth and is a well-recognized determinant of adverse health outcomes.

Healthy People 2020 Goals

• Goal number 8, Environmental Health: Promote health for all through a healthy environment.
• Environmental Health Objectives:
  • Outdoor air quality.
  • Water quality.
  • Toxics and wastes.
  • Healthy homes and healthy communities.
  • Infrastructure and surveillance.
  • Global environmental health.

Population Growth

• Current World Population: $8,064,786,988$
• Current US Population: $336,879,831$
• Top 10 Most Populous Countries (July 1, 2024):
  1. China: $1,416,043,270$
  2. India: $1,409,128,296$
  3. United States: $336,673,595$
  4. Indonesia: $281,562,465$
  5. Pakistan: $252,363,571$
  6. Nigeria: $236,747,130$
  7. Brazil: $220,051,512$
  8. Bangladesh: $168,697,184$
  9. Russia: $140,820,810$
  10. Mexico: $130,739,927$
• Components of Population Change in the U.S.:
  • One birth every 8 seconds.
  • One death every 11 seconds.
  • One international migrant (net) every 28 seconds.
  • Net gain of one person every 14 seconds.

Consequences of Population Increases

• Urbanization:
  • Worldwide increase in proportion of urban residents:
    • About 5% in 1800.
    • About 50% in 2000.
    • Expected to reach about 66% by 2030.
  • Reasons:
    • Industrialization.
    • Food availability.
    • Employment opportunities.
    • Lifestyle considerations.
    • Escape from political conflict.
    • Climate change.
  • Hazards:
    • Biological pathogens or pollutants.
    • Chemical pollutants and industrial wastes.
    • Overcrowding.
    • Noise pollution.
    • Infrastructure challenges.
    • Natural resource degradation.
• Overtaxing Carrying Capacity:
  • Population that can be supported without undergoing environmental deterioration.
  • Tends to limit population size through:
    • Limits to food availability.
    • Reproductive behavior.
    • Infectious diseases.
    • Population crashes.
• Food Insecurity
• Loss of Biodiversity