Atmosphere and Air Pollution

Troposphere

(1st) where weather occurs, contains majority of atmosphere's mass, temperature decreases with altitude

Stratosphere

(2nd) where the ozone layer occurs, temperature increases with altitude

Mesosphere

(3rd) ranges from 40-70 km, meteorites burn up in this layer, temperature decreases with altitude

Thermosphere

(4th) where the aura borealis occurs, international space station, temperature increases with altitude

Convection

The movement of gasses/liquids due to a decrease in density when heated therefore rising above other gasses/fluids present. Colder, denser gasses/liquids sink to lower layers within the mixture.

Convection and its connection to air circulation

cold, dense air moving from the poles, heating up as they travel along the surface, rising up within the troposphere around 60 degrees N and S and then being pushed back toward the poles

thermal inversion

Where colder denser air stays near the surface, warm air on top and does not have mixing. The cold air mass near the surface is very stable and does not allow mixing of gasses.

thermal inversion health hazards

Traps pollutants near the surface which leads to increased respiratory distress of residents living within the area such as irritation of the nose and throat, respiratory infections especially prominent with children and the elderly, increase in asthmatic symptoms

3 Convection Cells

Hadley cell, Ferrel cell, Polar cell

Hadley Cell

0°-30° latitude, where warm air rises near the equator and sinks around 30° latitude, creating trade winds

Ferrel Cell

0°-60° latitude, acting as a transitional zone where air flows poleward and sinks at mid-latitudes

Polar Cell

0°-90° latitude, where cold, dense air sinks at the poles and flows toward lower latitudes

Primary pollutant

emitted from original source (CO (car emissions), SO2 (coal fired electrical power plants), NOx (car emissions & electrical power plants), Lead (gasoline products), Particulate matter (car emissions)

Secondary pollutant

formed within the troposphere from interaction with other molecules present. (tropospheric ozone, particulate matter, acid deposition (H2SO4 - sulfuric acid, HNO3 - nitric acid)

Particulate matter

microscopic solids or liquids

size of particulate matter is most harmful to humans

The smaller the particulate the more harmful to the respiratory system

particulate matter health hazards

Respiratory infections and/or inflammation, allergic reactions originating in the lungs, cardiovascular disease, stroke

Industrial smog

burning of coal, release of CO2 and soot, major issue in London, England in the 1950s thousands were killed due to respiratory issues

Photochemical smog

brown-haze/LA smog, NOx, tropospheric ozone, and PANs

Clean Air Act

identifies and sets mandates for six criteria pollutants (CO, SO2, NOx, Lead, Particulate matter, and tropospheric ozone.)

1990 Amendments

focused on decrease in acid deposition, help in restoring stratospheric ozone layer, decrease in urban smog, and toxic air pollutants (benzene and Mercury - Hg).

six criteria pollutants

CO - carbon monoxide, SO2 - sulfur dioxide, NOx - nitrogen oxides, Particulate matter (PM10 and PM2.5), Tropospheric ozone, Lead

CO

carbon monoxide

SO2

sulfur dioxide

NOx

nitrogen oxides (dinitrogen monoxide, nitrogen monoxide, and nitrogen dioxide)

PM10 and PM2.5

Particulate matter

CO sources

fuel burning appliances (gas stoves/ovens/fireplaces, furnaces), vehicles

sulfur dioxide source

coal burning plants (electricity plants/factories)

sulfur dioxide health effect

irritates nasal passageways, respiratory irritant leading to shortness of breath, wheezing, exaggeration of asthma symptoms and interacts with water in the air leading to acid deposition

nitrogen oxides sources

anthropogenic: car emissions, agriculture (fertilizers) (interesting note - also produced from lighting strikes - natural source)

nitrogen oxides health effect

contributes to formation of tropospheric ozone and photochemical smog, inflammation of respiratory tract, long term exposure can lead to decreased functioning of the lungs, and increase response to allergens.

Particulate matter sources

construction (dust), bioaerosols (pet dander, dust mites, pollen, mold spores, human skin cells), also as a secondary pollutant from chemical reactions of sulfur dioxide and other molecules in the atmosphere.

Particulate matter health effect

allergic reactions, respiratory inflammation, chronic bronchitis, lung cancer, cardiovascular disease

Tropospheric ozone Sources

secondary pollutant - interaction of sunlight with NOx, SO2 in the stratosphere, a factor in photochemical smog

Tropospheric ozone Health effect

Respiratory irritant, exaggerate asthma symptoms

Lead Sources

primary pollutant - leaded gasoline, smelting

Lead Health effect

neurotoxin, miscarriages with pregnancies, birth defects (a teratogen)

forms of acid deposition

wet - rain, snow, fog; dry - sulfate and nitrate salts

natural air pollutants

Volcanic eruptions - connected to release of sulfur dioxide and the production of aerosols within the troposphere and possibly stratosphere leading to a cooling effect. Forest fires (tropospheric ozone and PM) and dust storms (PM)

Point source

smokestacks from power plants/factories, industrial dry cleaning, chemical storage facilities

Nonpoint source

feedlots/agricultural, gas stations, automobiles

Way governments regulate the release of emissions/pollutants

Command and Control, Carbon tax, Cap and trade

Command and Control

Government sets emissions standards and regulates equipment or means of reaching that standard across the board. Each company will be paying a different amount for upgrades and seen as unfair in that respect, less decision being made by the company. Pros are that across the board a standard emission decrease is reached.

Carbon tax

Government sets a standard for emissions, however the companies are given the choice as to how they are going to reach that standard. They are taxed on emissions that exceed the set value. Pros are there are more options for companies. However, it is typical that the standard emission decreased is not reached across the board since it might financially be less expensive to pay the tax.

Cap and trade

Government sets standard emission values. Companies again get the benefit of determining what would be financially better for them to reach that value. Some companies could easily install equipment at a lower cost and even decrease their emissions below the cap. They can then sell this decreased emission value to other companies that are not below the standard. Pros are that companies have more flexibility and there is a consistent decrease across the board of emissions.

Catalytic converters

connected to the exhaust system. As products from the combustion of gasoline (CO, NO2, & hydrocarbons) move through the exhaust system to exit the tailpipe they first move through the catalytic converter.

SBS

Refers to a building in which a number of people report adverse health effects, believed to be related to the time spent in the building

SBS health hazards

Chronic respiratory problems, asthma, ear infections, nerve disorders, headaches, eye irritation, muscle twitching, etc

Volatile Organic Compounds (VOCs)

cause respiratory and mucous membrane irritant, found in new carpets, new electronic devices, foam bedding/furniture

sources within a building of pollutants

Bacteria/Viruses/Mold - door mats, ventilation system, desks, door knobs, water fountains, restrooms