Air Pollution: Chapter 12 Module 35

• EQ: The student will be able to identify and describe the six criteria pollutants.
• Unit 6 Tests are graded, grades were updated in PowerSchool.
• Fish are here and will be placed in Ecocolumns.
• Unit 7 Calendar.
• Scrapesbook is due by April 11th at 11:59 p.m.
• Unit 7 Atmospheric Pollution includes Chapter 12 Module 35, Chapter 14 Module 44, Chapter 15 Module 46, 47, 48, 49 and 50.

7.1 Introduction to Air Pollution

• Air pollution: The introduction of chemicals, particulate matter, or microorganisms into the atmosphere at concentrations high enough to harm plants, animals, and materials such as buildings, or to alter ecosystems.
• Natural emissions of pollution include volcanoes, lightning, forest fires, and plants, both living and dead.
• Anthropogenic sources include on-road vehicles, power plants, and industrial processes.
• Residence time: The time a pollutant stays in the atmosphere.
• Pollutants with brief residence times exert localized impacts over short time periods, such as particulate matter and automobile exhaust.
• Pollutants with long residence times exert regional or global impacts, such as pollutants causing climate change or ozone depletion.
• The EPA sets nationwide standards for emissions and concentrations of toxic pollutants.
• States monitor air quality.
• The EPA takes over enforcement if plans are inadequate.
• Criteria pollutants: Pollutants that pose especially great threats to human health, which include carbon monoxide, sulfur dioxide, nitrogen dioxide, tropospheric ozone, particulate matter, and lead.
• Carbon Monoxide (CO): A common emission in vehicle exhaust and a significant component of air pollution in urban areas.
• It is a problem in developing countries where people may cook with manure, charcoal, or kerosene indoors and results from incomplete combustion.
• Sulfur dioxide (SO₂): A corrosive gas from combustion of fuels, such as coal, oil, and gasoline.
• It is a respiratory irritant that can adversely affect plant tissue and is released during volcanic eruptions and forest fires.
• Nitrogen Oxides (NOx): Motor vehicles and stationary fossil fuel combustion are the primary anthropogenic sources.
• Respiratory irritant, increases susceptibility to respiratory infection.
• An ozone precursor, leads to formation of photochemical smog.
• Converts to nitric acid in atmosphere, which is harmful to aquatic life and some vegetation.
• Contributes to over-fertilizing terrestrial and aquatic systems.
• Ozone (O3): A secondary pollutant formed when heat and sunlight cause chemical reactions between oxides of nitrogen (NOx) and Volatile Organic Compounds (VOCs), also known as Hydrocarbons.
• Reaction can occur both near the ground and high in the atmosphere.
• Tropospheric ozone is bad ozone, while stratospheric ozone is good ozone.
• Ozone has a sweet smell.

7.1 Introduction to Air Pollution and 7.4

• Particulate matter (PM): Solid or liquid particles suspended in air.
• PM2.5: Diameter less than 2.5 micrometers (fine particles).
• PM10: Diameter less than 10 micrometers.
• Sources of particulate matter include burning coal, oil, diesel, biofuels, agriculture, and road construction.
• Lead (Pb): A gasoline additive, also found in oil, coal, and old paint.
• It impairs the central nervous system and can have measurable effects on learning and ability to concentrate.
• Other emissions include carbon dioxide (CO2) released by burning fossil fuels, which has led to it becoming a major concern.
• CO2 recently exceeded a concentration of 400 parts per million in the atmosphere and appears to be steadily increasing each year.
• Appears naturally from respiration, decomposition and volcanic eruptions.
• Not a criteria pollutant.
• Is a greenhouse gas and does lead to Earth's warming.
• Volatile organic compound (VOC): An organic compound that evaporates or sublimates at room temperatures.
• Formed by evaporation of fuels, solvents, paints, and improper combustion of fuels such as gasoline.
• A precursor to ozone formation.
• Examples include formaldehyde and gasoline.
• Trees are a natural source of VOCs.