Environmental Science: Air and Water Pollutants

Environmental Science: Air and Water Pollutants

• Air Pollutants: Air pollution occurs when unwanted substances or materials, called pollutants, reach high enough concentrations in the air to pose a health hazard. Pollutants can be solids, liquids, or gases. They come from natural or human sources.

Sources of Air Pollution

• Natural Sources: Wind-blown dust, wildfires, and volcanoes.
• Point Sources: Stationary sources like factory smokestacks, power plants, or any single source of pollution.
• Line Sources: Mobile sources like vehicles (considered non-point/line sources).
• Area Sources: Sources of pollutants that are close together in an area.

Pollutant Emissions (Diagram)

• Natural: Lightning, volcanoes, wildfires, forests, fertilizer, oil & gas
• Mobile: Airplanes, cars, trucks, buses, motorcycles
• Stationary: Cities, Industry, power plants, sewage treatment

Classification of Air Pollutants

• Primary Pollutants: Substances directly released into the air by point and non-point sources. Examples include carbon monoxide (CO) from factories and vehicles, sulfur dioxide (SO2), nitrous oxide (N2O), nitrogen dioxide (NO2), hydrocarbons, particulate matter (smoke, dust), and metal oxides (lead, cadmium, copper, iron).
• Secondary Pollutants: Products of chemical reactions of primary pollutants, often more harmful. Example: sulfuric acid (H2SO4), formed from SO2, ozone (O3) formed from NO2.

Equations for Secondary Pollutants

• Photochemical smog: Nitrous oxide + VOCs
• Ozone: Nitrous oxide + unburned hydrocarbons
• Sulfuric acid: Sulfur dioxide + water
• Nitric acid: Nitrous oxide + water

Categories of Air Pollutants

• Outdoor Air Pollutants: A mixture of pollutants in the atmosphere producing an adverse effect.
• Indoor Air Pollutants: Chemical, biological, or physical contaminants in homes, buildings, or institutions. Indoor air pollution can be worse than outdoor if the source isn't removed.

Human Impacts on Bodies of Water

• Water Pollution: Any contamination of bodies of water (bays, rivers, streams, lakes, underground water, seas, oceans) harmful to living organisms.
• Causes of Water Pollution: Throwing garbage, using fertilizers, pesticides, and other chemicals, and undisciplined consumption of freshwater.

Different Examples of Outdoor Air Pollutants (Table)

• Pollutant: Total Suspended Particulates (TSP) or Particulate Matter, Carbon Monoxide (CO)
• Source/Description: Tiny solid particles suspended in air, exhaust from incomplete combustion of fossil fuels.
• Harmful Effects: Allergic reactions, respiratory problems, can destroy ozone formation, combines with blood, interferes with oxygen transport.

Different Examples of Outdoor Air Pollutants (Table) Continued

• Pollutant: Sulfur Dioxide (SO2), Ozone (O3)
• Source/Description: Colorless gas from power plants, industries, motor vehicles, generated from chemical reactions of oxygen and hydrocarbons in sunlight.
• Harmful Effects: Acid precipitation, eye, mouth, and throat problems in humans, harms vegetation health, ground-level ozone hazards in humans, accelerates environmental temperature.

Airborne Pathogens

• Are disease-causing agents (viruses/bacteria). Examples: common cold, influenza, chicken pox, measles, tuberculosis, SARS.

Different Examples of Indoor Air Pollutants (Table)

• Pollutant: Dust mite, Environmental Tobacco Smoke (ETS), Volatile Organic Compounds (VOCs)
• Source/Description: Tiny insects, smoke from burning tobacco, hydrocarbons, solvents, fuel, pesticides
• Harmful Effects: Allergic reactions, lung cancer, respiratory diseases, cause headaches, breathing problems, some can be carcinogenic, fire hazards, eye/respiratory irritation, prolonged exposure can cause leukemia and cancer.

Combustion Products

• Soot/Carbon Monoxide/Carbon Dioxide: Products of burning fossil fuels. Burning fossil fuels generates pollutants like soot, which can cause lung problems. Inhaling too much CO can lead to asphyxiation because it binds more easily to heme than oxygen.

Chlorinated Chemicals

• Chlorinated Chemicals: Household chemicals (sodium hypochlorite, Carbon tetrachloride, chloroform), often used for cleaning, which can cause nerve disorders/carcinogenity.

Asbestos

• Asbestos: Used as a fire retardant in building materials, even if no longer used, exposure to asbestos fibers can cause lung disease (asbestosis).

Controlling Air Pollutants

• Minimize Vehicle Use: Reduces fossil fuel burning. Mass transit systems are an aid in this area.
• Proper Vehicle Maintenance: Prevents emissions of black smoke.
• Report Factory Emissions: Reporting black smoke from factories and power plants helps authorities address environmental issues.
• Greening Projects: Planting trees and other vegetation absorbs pollutants, like Sulfur Dioxide and Nitrogen Dioxide e.g., ipil-ipil, yellow bell, chichirica, molave.

Water Pollutants: Types

• Point Sources: Pollution directly released into water bodies (Exxon Valdez oil spill).
• Nonpoint Sources: Pollution indirectly entering water bodies (fertilizers carried by runoff).

Different Examples of Water Pollutants (Table)

• Pollutant: Sediment, Nutrients (nitrates & phosphates), Oxygen demanding substances
• Source/Description: Dust and land erosion, fertilizers, decaying organic matter.
• Harmful Effects: Affects people's health, causing water-borne disease, damages aquatic ecosystems, leads to a condition called eutrophication; prevents oxygen entry; coats fish gills causing suffocation.

Different Examples of Water Pollutants (Table) continued

• Pollutant: pH (acidity), Toxic chemicals (persistent organic pollutants, pesticides, herbicides), Heavy metals
• Source/Description: Atmospheric gases, decaying matter, spillage, sewer overflows and septic tank leaks.
• Harmful Effects: Massive fish kills from high acidic substances, toxic to genes, induces cancer, toxic to nervous systems, massive fish kills, suffocates aquatic organisms

Removing Water Pollutants

• Stop Garbage Disposal: Advise people to stop throwing garbage directly into bodies of water.
• Household Chemical Disposal: Act responsibly when disposing of household chemicals.
• Wastewater Treatment Plants: Mandate industries, hospitals, and other establishments to have wastewater treatment plants.
• Save Water: Conserves water resources/reduces contamination by reducing use.
• Reduce Fertilizer Use: Reduce fertilizer use to lessen runoff and contaminating water bodies.