Lecture 17_ESYS10_WI25_Shipp_Water Pollution, Environmental Hazards, Human Health I

Introduction

• Course Title: ESYS 10 Introduction to Environmental Systems

• Lecture Date: 7 Feb 14, 2025

• Topics Covered: Water Pollution; Environmental Hazards & Human Health Part I

Today's Agenda

• Focus on:

  • Water Pollution (Chapter 11)

  • Environmental Hazards & Human Health Part I (Chapter 14)

  • How to approach primary literature

Water Pollution

Definition

• Water Pollution: Changes in water quality that harm living organisms or render water unfit for drinking, irrigation, or recreation.

Causes and Types

• Prevention Method: Humans can employ natural methods to manage sewage, reduce waste, and slow population growth to mitigate water pollution.

• Point Sources:

  • Clearly identifiable locations

  • Easier to control and regulate

• Nonpoint Sources:

  • Diffuse areas, hard to identify

  • Expensive to manage

• Main Causes: Agricultural activity, industrial facilities, mining.

Major Types and Effects of Water Pollutants

Stream and River Pollution

• Streams/rivers use dilution and bacterial biodegradation to eliminate waste.

• Challenges: Overloading pollutants or reduced flow (due to drought/dams).

• Laws (1970s): Increased wastewater treatment plants and prohibition of harmful industrial discharges.

Lake and Reservoir Pollution

• Lakes/reservoirs have lower self-cleansing capabilities due to stratified layers.

• Causes: Nutrient enrichment from agricultural runoff leading to cultural eutrophication.

• Prevention Strategies: Limit runoff and phosphates in detergents.

• Clean-up Methods: Mechanical removal of weeds, chemical algae control, oxygenation.

Groundwater Pollution

• Groundwater cleanses more slowly due to lower dissolved oxygen and slower bacterial activity.

• Threats: Hydraulic fracking and saltwater intrusion from excessive groundwater withdrawal.

Drinking Water Quality

• U.S. Safe Drinking Water Act (1975): Establishes national drinking water standards; EPA sets maximum contaminant levels.

• Controversies: Opposition to limits and safety concerns.

• Flint Water Crisis:

  • 2014 switch to a corrosive water source resulting in lead leaching into water.

  • Significant health impacts and ongoing safety issues in Flint, MI.

Ocean Pollution

• Marine Pollution Statistics: 80% of marine pollution comes from land. 80-90% of sewage in developing nations is untreated.

• Sources: Urban runoff, oil spills, and waste from industries.

• Impacts: Harm to coastal ecosystems, wildlife, and significant economic implications.

Sustainable Solutions to Reduce Water Pollution

• Strategies:

  • Find substitutes for toxic pollutants.

  • Remove hazardous waste before it reaches sewage facilities.

  • Implement natural sewage treatment methods.

  • Control nonpoint runoff.

  • Support population control and poverty reduction.

  • Eliminate air pollution.

  • Promote recycling and resource reuse.

Environmental Hazards Exposure Assessment

• Types of Risks:

  • Biological, chemical, physical, cultural, lifestyle.

• Risk Definition: Probability of harm from potential hazards (injury, disease, economic damage).

• Risk Assessment: Statistical estimation of hazard harm, considering factors like ozone, pesticides, and water contaminants.

Types of Hazards

• Biological Hazards: Pathogens causing diseases.

• Chemical Hazards: Present in various environments—industrial, water, food.

• Natural Hazards: Such as fires and earthquakes.

• Cultural Hazards: Poor working conditions, poverty.

• Lifestyle Choices: Impacted by socioeconomic status and community systems.

Biological Hazards Overview

• Diseases: Infectious diseases like COVID-19, malaria, tuberculosis.

• Key Concepts:

  • Germ Theory: Microorganisms can invade hosts and cause disease.

  • Transmissible vs. Nontransmissible diseases.

  • Epidemics and pandemics defined.

How to Approach Primary Scientific Literature

• Reading Strategy:

  • Start with the title and abstract.

  • Skim the entire document and focus on understanding figures deeply.

  • Explore the introduction, methods, results, and references.

  • Resources: Links to literature reading guides provided.

  • Practice: Familiarize yourself over time for proficiency in interpretation.