Environmental Science Overview

Environment

• Environment is the surroundings and conditions where living organisms exist.
• Environmental segments include the atmosphere, hydrosphere, lithosphere, and biosphere.
• Atmosphere: extends from 500 to 1200 km above the Earth's surface.
• Hydrosphere: encompasses water on, above, and below the Earth's surface.
• Lithosphere: contains minerals and soil.
• Biosphere: covers all living organisms.

Structure of the Earth

• The Earth's layers are:
  • Crust (0-100 km thick)
  • Asthenosphere
  • Mantle (2900 km)
  • Outer Core (liquid)
  • Inner Core (solid)
• Layers' depths are given in the provided diagrams.
• Lithosphere includes crust part of upper mantle.

Major Elements in Different Sectors

• Atmosphere: Nitrogen (N), Oxygen (O)
• Ocean: Oxygen (O), Hydrogen (H), Chlorine (Cl), Sodium (Na), Magnesium (Mg), Sulfur (S)
• Sedimentary rocks: Oxygen (O), Silicon (Si), Aluminum (Al), Iron (Fe), Calcium (Ca), Potassium (K), Magnesium (Mg), Carbon (C), Sodium (Na)
• Granitic igneous rock: Oxygen (O), Silicon (Si), Aluminum (Al), Potassium (K), Sodium (Na), Calcium (Ca), Iron (Fe), Magnesium (Mg)
• Basaltic igneous rock: Oxygen (O), Silicon (Si), Aluminum (Al), Iron (Fe), Calcium (Ca), Magnesium (Mg)
• Mantle: Oxygen (O), Silicon (Si), Magnesium (Mg), Iron (Fe)

Pollutant

• Pollutant: a substance whose abundance is higher in nature than normal due to human activity and sometimes naturally.
• Pollutants impact the environment, living organisms, and mankind negatively.
• Examples are lead (Pb), sulfur dioxide (SO2), carbon dioxide (CO2).
• Pollutants originate from human activity (anthropogenic) or natural processes.

Environmental Pollution

• Environmental pollution: any undesirable change in physical, chemical, or biological characteristics of land, air, or water.
• Pollution harms humans, other life forms, industrial processes, living conditions, and cultural assets.
• Pollution wastes and deteriorates natural resources.

Contaminants

• Contaminants are substances not naturally present in the environment but introduced by human activity.
• An example is chlorine gas, which escaped from a derailed train in Florida, resulting in fatalities.

Receptor and Sink

• Receptor: medium affected by a pollutant (e.g., humans affected by photochemical smog).
• Sink: medium that retains and interacts with long-lived pollutants (e.g., marble wall interacting with sulfuric acid).

Types of Environmental Pollution

• Examples of environmental pollution include water pollution, air pollution, thermal pollution, light pollution, noise pollution, and land pollution.

Primary and Secondary Pollutants

• Primary pollutants enter the atmosphere directly due to human activities.
• Examples of primary pollutants include sulfur dioxide, released when burning fossil fuels.
• Secondary pollutants are formed when primary pollutants interact with other pollutants, water vapor, or other substances in the atmosphere.
• Example of secondary pollutants is acid rain, formed when sulfur dioxide mixes with water in the atmosphere.

Sources of Primary Pollutants

• Primary pollutants originate from:
• Human activities (combustion processes, chemical processes, nuclear or atomic processes).
• Natural sources (volcanoes, breaking seas, release of pollens, terpenes, fire, blowing dust, bacteria, and viruses).
• Some are accentuated by humans.

Water Pollution

• Water pollution occurs when any human activity impairs water resources.
• Water pollutants include organic, inorganic substances, sediments, radioactive materials, and thermal pollutants.
• Sources of water pollution include industrial wastes, sewage, infectious agents, plant nutrients, synthetic chemicals, inorganic minerals, suspended solids, radioactive substances (like I-131, Sr-90, Ra-226), thermal discharges, oils, and detergents.

Effects of Water Pollution

• Water pollution negatively affects human health, leading to diseases like cholera, typhoid, and dysentery.
• Industrial discharges can contaminate water with lead, arsenic, mercury, and cadmium, harming liver, kidneys, causing lung cancer and ulcers in gastrointestinal tract.
• Agricultural activities can introduce toxic fertilizers and pesticides.

Atmospheric Chemistry

• The atmosphere is a gaseous envelope surrounding the Earth.
• It includes gases and aerosols (suspended solid and liquid particles).
• Aerosols are the "visible" components of the atmosphere, examples include California fire plumes, dust off West Africa, and pollution off US East Coast.

Air Pollution

• Air pollution occurs when harmful substances (particulates, biological molecules, other substances) are introduced to the atmosphere.
• These substances lead to diseases, health problems, and damage to organisms, and the environment.

Types of Air Pollution

• Outdoor air pollution includes smog, particulates, acid rain, and greenhouse gases..
• Indoor air pollution is an additional category.

Causes of Air Pollution

• Natural sources produce smoke from wildfires, volcanoes, methane, and dust.
• Human activities include power plants, burning fossil fuels, automobiles, burning wood in stoves, fireplaces, and furnaces.

Six Major Air Pollutants

• The six major air pollutants are carbon monoxide (CO), ozone (O3), nitrogen dioxide (NO2), sulfur oxides (SOx), carbon dioxide (CO2), and lead (Pb).

Effects of Air Pollution

• Air pollution's effects include human diseases, acid rain, environmental effects, eutrophication, haze, wildlife damage, ozone depletion, crop and forest damage, and global climate change.
• Specific health effects like respiratory tract irritation or issues with lung function or blood issues (with carbon monoxide).

Ozone Depletion

• Ozone depletion in the stratosphere is due to human-produced gases reacting with ozone.
• Ozone depletion leads to more UV radiation reaching Earth, causing problems like eye cataracts, skin cancer, and weakened immunity.
• The depletion also damages ecosystems and crops.

Greenhouse Effect

• The greenhouse effect is the warming of a planet’s surface due to the atmosphere’s gases absorbing outgoing radiation.
• Greenhouse gases (like carbon dioxide) trap heat, leading to a gradual atmospheric warming, often called global warming.