Apes iBook #12 Air Pollution

Explain the source and effects of 2 indoor air pollutants.

Carbon monoxide: result of malfunctioning exhaust systems on household heaters, most typically natural gas heaters. Radon: humans can receive significant exposure to radon if it seeps into a home through cracks in the foundation or soil; or from drinking the water from underlying rock, soil, or groundwater.

List 3 each of natural and human sources of pollution.

Natural: dust from windstorms, pollutants from wildfires, and volcanic eruptions. Human: burning fossil fuels. Mobile sources like cars and trucks. Stationary sources like factories.

What are the main gases that make up our atmosphere? What are their percentages?

Nitrogen, 78%. Oxygen, 21%. The other one percent consists of trace gases such as CO2, water vapor, and CH4.

What do we call sources of pollution that come from human activities?

Anthropogenic sources of pollution.

What is a temperature(thermal) inversion?

A relatively warm layer of air at mid-altitude covers a layer of cold, dense air below.

More notes from class.

Air pollution sucks.

Industrial smog.

Coal burns and releases sulfur to form sulfur dioxide.

Primary Pollutants and examples.

Emitted directly into the air from natural sources such as volcanoes, mobile sources, or stationary sources. Particulate matter, Nitric oxide, Sulfur dioxide, Carbon monoxide, Lead.

Factors that reduce air pollution.

Heavier particles settle out due to gravity. Rain and snow help cleanse air pollution. Salty sea spray can wash out pollutants. Winds sweep pollutants away, diluting them.

Related to the last question, explain how a temperature inversion can lead to increased photochemical smog (discuss specific pollutants).

If there is a temperature inversion, the warm air traps all the pollutants underneath. Vehicle exhaust and industrial emissions are easily trapped by the inversion layer.

Compare/contrast indoor air pollution in developing countries and developed countries.

In developing countries, biomass and coal are usually burned in open-pit fires that lack the proper mix of fuel and air to allow complete combustion. Usually, there is no exhaust system and little or no ventilation in the home, which makes indoor air pollution from carbon monoxide and particulates a particular hazard. In developed countries homes have become more tightly insulated, which allows existing air to remain in contact with inhabitants for greater amounts of time. This is in part a result of improved insulation and tightly sealed building envelopes, which have been implemented in order to reduce energy consumption. Finally, there are more materials in the home that are made from plastics and other petroleum-based materials that can give off chemical vapors.

What is sick building syndrome?

Indoor levels of VOCs, hydrocarbons, and other potentially toxic materials are quite high. Sick building syndrome has been observed particularly in office buildings, where large numbers of workers have reported a variety of maladies such as headaches, nausea, throat or eye irritations, and fatigue.

Two types of smog.

Industrial smog: sulfur based also called gray-air smog. Photochemical smog: catalyzed by UV radiation and tends to be nitrogen-based. Brown air smog.

What are 3 effects of acid deposition?

Lowering the pH of lake water, which can harm the habitats that live there. Decreased pH can also affect the food sources of aquatic organisms, creating indirect effects at several trophic levels. On land, at least one species of tree, the red spruce (Picea rubens), at high elevations of the northeastern United States was shown to have been harmed by acid deposition.

Most air pollutants are expressed in ppm.

Move decimal four places to the left to make it a percentage.

What are the two types of photochemical smog? How do they differ in source and color?

Photochemical, or Los Angeles smog has a brown color to it. Sulfurous, or London smog has a gray color to it.

What are criteria pollutants?

Pollutants that under the Clean Air Act, the EPA must specify allowable concentrations of each pollutant.

What is the difference between primary and secondary pollutants?

Primary pollutants are harmful substances emitted directly into the air. Secondary pollutants are formed when primary pollutants react with one another or with the basic components of air to form new harmful pollutants.

List 3 each of primary and secondary pollutants.

Primary: Sulfur dioxide, nitrogen oxide, lead. Secondary: ozone, NO2, and acid rain.

Secondary Pollutants and examples.

Result from reaction of primary pollutants in the atmosphere to create a new pollutant. Sulfur trioxide, Sulfuric acid, Ozone, Chemicals in photochemical smog.

List the 6 criteria pollutants - and - the major source of each.

Sulfur dioxides- combustion of fuels such as coal and oil, nitrogen oxides- all combustion in the atmoshpere, carbon monoxides- incomplete combustion of any kind, particulate matter- combustion of coal, oil, and diesel, lead- gasoline additive, ozone- secondary pollutant.

Explain how a temperature inversion can decrease air quality.

The warm layer traps emissions that then accumulate beneath it. The trapped emissions often cause a severe pollution event.

What invisible barrier separates the 1st and 2nd layers?

Tropopause.

What is the layer closest to earth where all the earth's weather occurs?

Troposhpere.

What is necessary for the formation of photochemical smog?

UV radiation from the sun.

Photochemical smog.

Volatile organic compouds, NOx, heat, and sunlight forms ground level ozone, photochemical oxidants, aldehydes, and other secondary pollutants. Large amount of NO and VOC's are emitted from morning commuters. NO is converted to reddish-brown NO2. In the presence of UV radiation, some NO2 reacts with VOC's to create a mixture of ozone, nitric acid, aldehydes, PANS, and other secondary pollutants.

What are the 3 pollutants that are important to the environment and human health even though they are not classified as criteria pollutants according to the CAA?

Volatile organic compounds, mercury and carbon dioxide.

What primary pollutants lead to the formation of acid deposition? What is the main source of those primary pollutants?

When sulfur dioxide (SO2) and nitrogen oxides (NOX) are released into the atmosphere, they react with the waer vapor to from sulfuric (H2SO4) and nitric acid (HNO3). Large numbers of cars.