🌱Intro to Environmental Systems Unit 6 – Air and Water Pollution

Key Concepts and Definitions

• Air pollution occurs when harmful substances (particulate matter, gases, biological molecules) are introduced into Earth's atmosphere causing diseases, allergies, or death to humans and damage to other living organisms (plants, animals, microorganisms)
• Water pollution happens when chemicals, microorganisms, or physical changes degrade water quality and make it toxic to humans or the environment
  • Point source pollution originates from a single identifiable source (oil spill, wastewater discharge pipe)
  • Non-point source pollution comes from many diffuse sources (agricultural runoff, debris blown into waterways from land)
• Eutrophication is the process by which a body of water becomes enriched in dissolved nutrients (phosphates, nitrates) that stimulate the growth of aquatic plant life usually resulting in the depletion of dissolved oxygen
• Bioaccumulation refers to the gradual accumulation of substances (chemicals, pesticides) in an organism from the surrounding environment (water, air, food)
• Biomagnification is the increasing concentration of a substance (mercury, DDT) in the tissues of organisms at successively higher levels in a food chain
• Acid rain results when sulfur dioxide (SO2) and nitrogen oxides (NOX) are emitted into the atmosphere, undergo chemical transformations and are absorbed by water droplets in clouds, and fall to earth as acidic rain, snow, or fog
• Greenhouse gases (carbon dioxide, methane, nitrous oxide) trap heat in the atmosphere causing Earth's average temperature to rise over time

Types of Air Pollutants

• Particulate matter (PM10, PM2.5) consists of tiny particles of solid or liquid suspended in the air including dust, smoke, soot, and aerosols
• Sulfur oxides (SOx), particularly sulfur dioxide, are emitted from the burning of fossil fuels (coal, oil) and can cause acid rain
• Nitrogen oxides (NOx), especially nitrogen dioxide, form from emissions from cars, trucks, buses, power plants, and off-road equipment and contribute to the formation of smog and acid rain
• Carbon monoxide (CO) is an odorless, colorless gas formed by the incomplete combustion of fuels and is toxic to humans and animals
• Volatile organic compounds (VOCs) are emitted as gases from certain solids or liquids (paints, cleaning supplies, pesticides, building materials, furnishings) and may have short- and long-term adverse health effects
• Ground-level ozone (O3) is created by chemical reactions between NOx and VOCs in the presence of sunlight and can trigger a variety of health problems, particularly for children, the elderly, and people with lung diseases
• Lead can be emitted into the air from industrial sources, leaded aviation gasoline, waste incinerators, utilities, and lead-acid battery manufacturers and cause damage to the nervous system, kidneys, and immune system

Sources of Air Pollution

• Transportation (cars, trucks, buses, planes, trains) is a major source of air pollution, emitting significant amounts of nitrogen oxides, carbon monoxide, and other pollutants
• Industrial processes (factories, power plants, oil refineries, chemical plants) release large amounts of carbon monoxide, hydrocarbons, chemicals, and organic compounds into the air
• Agricultural activities (pesticides, herbicides, fungicides, fertilizers) can release harmful substances into the air, water, and soil
• Waste treatment and disposal (landfills, incinerators) can produce methane gas, carbon dioxide, and other toxic pollutants
• Household and commercial products (paints, cleaners, solvents) often contain volatile organic compounds (VOCs) that can escape into the air and react with other substances
• Natural sources like volcanic eruptions, wildfires, and dust storms can also contribute to air pollution by releasing particulate matter, gases, and ash into the atmosphere

Types of Water Pollutants

• Nutrients (phosphorus, nitrogen) from agricultural runoff, sewage, and industrial waste can cause eutrophication leading to algal blooms and dead zones
• Pathogens (bacteria, viruses, parasites) from human and animal waste can contaminate water and cause waterborne diseases (cholera, typhoid, dysentery)
• Organic material (plant debris, food waste, sewage) can deplete oxygen levels in water as it decomposes, harming aquatic life
• Inorganic pollutants (acids, salts, metals) from industrial effluents, mining activities, and urban runoff can make water unfit for drinking and harm aquatic ecosystems
  • Heavy metals (lead, mercury, cadmium) are toxic and can bioaccumulate in the food chain
• Oil and grease from oil spills, leaks, and improper disposal can contaminate water, harm wildlife, and create fire hazards
• Sediment (sand, silt, clay) from construction sites, agricultural fields, and eroded stream banks can cloud water, reducing photosynthesis and smothering aquatic habitats
• Thermal pollution from power plants and industrial facilities can raise water temperatures, harming temperature-sensitive species and decreasing oxygen levels

Sources of Water Pollution

• Agricultural activities (crop farming, livestock operations, aquaculture) can contribute nutrients, pesticides, and sediment to nearby water bodies through runoff
• Industrial facilities (factories, power plants, mines) may discharge toxic chemicals, heavy metals, and heated water directly into rivers, lakes, and oceans
• Sewage and wastewater from households, businesses, and municipal treatment plants can introduce pathogens, nutrients, and chemicals into water if not properly treated
• Urban and suburban areas generate polluted runoff (oil, grease, toxic chemicals, heavy metals) from streets, parking lots, and lawns that flows into storm drains and water bodies
• Marine transportation (ships, boats) can release oil, garbage, and invasive species into the water through spills, leaks, and improper waste disposal
  • Ballast water from ships can introduce non-native species that disrupt ecosystems
• Atmospheric deposition of pollutants (mercury, PCBs, pesticides) from air pollution can contaminate water bodies far from the original source
• Natural sources (volcanoes, algal blooms, animal waste) can also degrade water quality, although human activities often exacerbate these issues

Environmental Impacts

• Acid rain can acidify soils and water bodies, harming plants, animals, and aquatic life and corroding infrastructure (buildings, bridges, monuments)
• Eutrophication leads to algal blooms that block sunlight, deplete oxygen, and produce toxins, creating dead zones and fish kills
• Smog (ground-level ozone) damages crops, trees, and other vegetation, reducing agricultural yields and forest health
• Climate change driven by greenhouse gas emissions causes rising sea levels, more frequent and intense extreme weather events (hurricanes, floods, droughts), and shifts in species distributions
  • Ocean acidification from absorbed carbon dioxide threatens coral reefs and shellfish populations
• Bioaccumulation and biomagnification of toxic substances (mercury, PCBs) in the food chain can harm top predators and disrupt ecosystems
• Plastic pollution in oceans and other water bodies entangles and chokes marine life, transports invasive species, and breaks down into microplastics that enter the food chain
• Deforestation for agriculture, logging, and urbanization reduces biodiversity, alters water cycles, and contributes to soil erosion and landslides

Human Health Effects

• Air pollution can cause or aggravate respiratory diseases (asthma, bronchitis, lung cancer), cardiovascular problems (heart attacks, strokes), and neurological disorders (Alzheimer's, Parkinson's)
  • Particulate matter is especially harmful, penetrating deep into the lungs and bloodstream
• Water pollution can lead to waterborne illnesses (cholera, dysentery, typhoid fever) from contaminated drinking water or recreational contact
  • Exposure to toxic chemicals (lead, mercury, pesticides) in water can cause cancer, birth defects, and developmental problems
• Food contamination from polluted water or bioaccumulation of toxins can cause acute poisoning or long-term health issues
• Noise pollution from traffic, industrial activities, and construction can cause hearing loss, stress, sleep disturbance, and cognitive impairment
• Light pollution from excessive artificial lighting can disrupt circadian rhythms, leading to sleep disorders and other health problems
• Soil pollution from heavy metals, pesticides, and other contaminants can harm human health through direct contact, inhalation of dust, or consumption of contaminated crops
• Indoor air pollution from household products, building materials, and poor ventilation can cause respiratory irritation, allergies, and other health issues

Measurement and Monitoring Techniques

• Air quality monitoring stations measure concentrations of key pollutants (PM2.5, PM10, ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide) to assess compliance with air quality standards
  • Sensors and samplers collect data on pollutant levels, which is analyzed in labs
• Water quality testing involves sampling water from various locations and measuring physical, chemical, and biological parameters (pH, dissolved oxygen, turbidity, nutrients, bacteria)
  • Field test kits, probes, and lab analysis are used to assess water quality
• Remote sensing techniques (satellite imagery, aerial photography, LiDAR) can detect and monitor pollution sources, land use changes, and environmental impacts over large areas
• Biomonitoring uses living organisms (lichens, mussels, fish) as indicators of environmental health by assessing their population, diversity, or contaminant levels
• Citizen science programs engage the public in collecting data on air and water quality, species observations, and other environmental variables to supplement official monitoring efforts
• Environmental impact assessments (EIAs) evaluate the potential effects of proposed projects, policies, or programs on the environment and human health to inform decision-making
• Life cycle assessment (LCA) examines the environmental impacts of a product or process throughout its entire life cycle, from raw material extraction to disposal, to identify opportunities for improvement

Pollution Control Strategies

• Source reduction and pollution prevention aim to minimize waste and emissions at the source through process modifications, material substitution, and improved efficiency
  • Cleaner production techniques and green chemistry principles can help prevent pollution
• End-of-pipe controls treat pollutants after they have been generated but before they are released into the environment (scrubbers, filters, wastewater treatment plants)
• Best management practices (BMPs) are techniques, measures, or structural controls that prevent or reduce pollution from nonpoint sources (construction sites, agricultural fields, urban runoff)
  • Examples include buffer strips, cover crops, and permeable pavement
• Recycling and waste minimization programs reduce the amount of waste that ends up in landfills or incinerators, conserving resources and reducing pollution
• Renewable energy sources (solar, wind, hydro) can replace fossil fuels, reducing air pollution and greenhouse gas emissions
• Green infrastructure (rain gardens, green roofs, wetlands) mimics natural processes to manage stormwater runoff, filter pollutants, and provide other ecosystem services
• Environmental remediation techniques (bioremediation, phytoremediation, chemical oxidation) clean up contaminated soil, groundwater, and other media

Regulations and Policies

• The Clean Air Act (CAA) regulates air emissions from stationary and mobile sources, sets air quality standards, and requires permits for major polluters in the United States
• The Clean Water Act (CWA) establishes the basic structure for regulating discharges of pollutants into U.S. waters and regulating quality standards for surface waters
  • The National Pollutant Discharge Elimination System (NPDES) permit program controls water pollution by regulating point sources that discharge pollutants into waters of the United States
• The Safe Drinking Water Act (SDWA) protects public drinking water supplies by setting standards for drinking water quality and requiring testing and treatment by water utilities
• The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund) provides for the cleanup of hazardous waste sites and emergency response to releases of hazardous substances
• The Resource Conservation and Recovery Act (RCRA) regulates the generation, transportation, treatment, storage, and disposal of hazardous waste and non-hazardous solid wastes
• International agreements like the Montreal Protocol (ozone depletion), the Stockholm Convention (persistent organic pollutants), and the Paris Agreement (climate change) address global environmental issues
• Market-based instruments (carbon taxes, cap-and-trade programs, subsidies for clean technologies) use economic incentives to reduce pollution and encourage sustainable practices

Case Studies and Examples

• The Love Canal disaster in Niagara Falls, New York, where a community was built on a former chemical waste dump, led to the creation of the Superfund program for cleaning up hazardous waste sites
• The Cuyahoga River in Cleveland, Ohio, caught fire multiple times due to industrial pollution, sparking the environmental movement and leading to the Clean Water Act
• The Flint water crisis in Michigan, where cost-cutting measures and inadequate treatment led to lead contamination of the city's drinking water supply, highlighting issues of environmental justice and aging infrastructure
• The Deepwater Horizon oil spill in the Gulf of Mexico, the largest marine oil spill in history, caused widespread damage to ecosystems, fisheries, and coastal communities
• The Volkswagen emissions scandal, where the company installed "defeat devices" in diesel vehicles to cheat on emissions tests, undermining air quality regulations and public trust
• The Aral Sea disaster in Central Asia, where diversion of rivers for irrigation caused the sea to shrink by 90%, creating dust storms, water pollution, and economic hardship
• The success of the Montreal Protocol in phasing out ozone-depleting substances, leading to the gradual recovery of the ozone layer and preventing millions of cases of skin cancer and cataracts

Future Challenges and Solutions

• Climate change will exacerbate many pollution problems, such as increased smog formation, more frequent and intense wildfires, and the spread of waterborne diseases
  • Mitigating greenhouse gas emissions and adapting to the impacts of climate change will be critical for protecting human health and the environment
• Population growth and urbanization will increase demand for resources and generate more waste, requiring sustainable city planning, green building practices, and improved waste management
• Emerging contaminants, such as pharmaceuticals, personal care products, and microplastics, pose new challenges for monitoring and regulation
  • Advanced wastewater treatment technologies and source reduction strategies will be needed to address these issues
• Environmental justice concerns, such as the disproportionate exposure of low-income and minority communities to pollution, must be addressed through inclusive decision-making, targeted investments, and community empowerment
• Transboundary pollution issues, such as long-range transport of air pollutants and marine debris, require international cooperation and governance frameworks
• Sustainable consumption and production patterns, including the circular economy approach, can help decouple economic growth from environmental degradation
  • This involves designing products for durability, reuse, and recycling, and shifting consumer behavior towards more sustainable choices
• Investing in research and development of clean technologies, such as renewable energy, green chemistry, and pollution control devices, can drive innovation and create economic opportunities while protecting the environment.