environmental science chapter 13
thermal inversion
A departure from the normal temperature distribution in the atmosphere, in which a pocket of relatively cold air occurs near the ground, with warmer air above it. The cold air, denser than the air above it, traps pollutants near the ground and causes a buildup of smog.
tropospheric ozone
Ozone that occurs in the troposphere, where it is a secondary pollutant created by the interaction of sunlight, heat, nitrogen oxides, and volatile carbon-containing chemicals. A major component of smog, it can injure living tissues and cause respiratory problems. An EPA criteria pollutant.
criteria pollutants
Six air pollutants - carbon monoxide, sulfur dioxide, nitrogen dioxide, tropospheric ozone, particulate matter, and lead - for which the Environmental Protection Agency has established maximum allowable concentrations in ambient outdoor air because of the threats they pose to human health
atmosphere
a thin layer of gases that surrounds the Earth
toxic air pollutants
chemicals known to cause serious health or environmental problems
industrial smog
gray-air smog caused by the incomplete combustion of coal or oil when burned
particulate matter
solid or liquid particles small enough to be suspended in the atmosphere and able to damage respiratory tissues when inhaled
scrubbers
technology to chemically treat gases produced in combustion in order to reduce smokestack emissions; these devices typically remove hazardous components and neutralize acidic gases, such as sulfur dioxide and hydrochloric acid, turning them into water and salt
air pollution
the act of polluting the air, or the condition of being polluted by air pollutants
troposphere
the bottommost layer of the atmosphere; it extends to 11 km (7 mi) above sea level
stratosphere
the layer of the atmosphere above the troposphere and below the mesosphere; it extends from 11 km (7mi) to 50 km (31 mi) above sea level
- Point source pollution is specific places where large quantities of pollutants are emitted (ex: power plants) -Non-point source pollution is more diffuse, consisting of many small, widely spread sources (ex: automobiles) -Point source is easier to control because the source is from a given point, not widely spread.
Types of air pollution sources (1): Describe the difference between point and non-point source pollution - give an example of each and explain which type you think would be easier to control and why.
sulfur dioxide
a colorless gas that can result from the combustion and structure of an ecological community through time
carbon monoxide
a colorless, odorless gas produced primarily by the incomplete combustion of fuel
-Troposphere is the bottommost layer of the atmosphere; it extends to 11 km (7 mi) above sea level. Stratosphere is the layer of the atmosphere above the troposphere and below the mesosphere; it extends from 11 km (7mi) to 50 km (31 mi) above sea level. -The ozone layer is located in the stratosphere layer. -The stratospheric ozone is beneficial for people because it absorbs the sun's UV radiation. -
Layers where humans have the most impact: Contrast the Troposphere and the Stratosphere. In what layer of the atmosphere is the "ozone layer" located? Explain why stratospheric ozone is beneficial for people (what does the ozone layer do, and why is that helpful), and explain why tropospheric ozone is harmful. (also look at p. 284)
-The six criteria pollutants are carbon monoxide, sulfur dioxide, nitrogen dioxide, tropospheric ozone, particulate matter, and lead. -
The first focus - criteria air pollutants:(A table may be handy for this one). Identify the six criteria pollutants. For each of the six, list 1) whether it is a primary or secondary pollutant, 2) the most important source(s) of the pollutant (or of the ingredients for the pollutant if it is a secondary pollutant), 3) if it is a secondary pollutant--how it is made (leave out if primary pollutant), and 4) harmful effects of the pollutant.
photochemical smog
brown-air smog caused by light-driven reactions of primary pollutants with normal atmospheric compounds that produce a mix of over 100 different chemicals, ground-level ozone often being the most abundant among them
residence time
in a biogeochemical cycle, the amount of time a nutrient remains in a given pool or reservoir before moving to another; in the atmosphere, the amount of time a gas molecule or a pollution remains aloft
Montreal Protocol
international treaty ratified in 1987 in which 180 signatory nations agreed to restrict production of CFCs in order to halt stratospheric ozone depletion; this was a protocol of the Vienna Convention for the Protection of the Ozone Layer; it is widely considered the most successful effort to date in addressing a global environmental problem
nitrogen dioxide
one of a family of compounds that includes nitric oxide (NO) and nitrogen oxide (NO2)
volatile organic compounds (VOCs)
one of a large group of potentially harmful organic chemicals used in industrial processes
convective circulation
A circular current (of air, water, magma, etc.) driven by temperature differences. In the atmosphere, warm air rises into regions of lower atmospheric pressure, where it expands and cools and then descends and becomes denser, replacing warm air that is rising. The air picks up heat and moisture near ground level and prepares to rise again, continuing the process.
primary pollutants
A hazardous substance, such as soot or carbon monoxide, that is emitted into the troposphere in a form that is directly harmful.
ozone layer
A portion of the stratosphere, roughly 17-30 km (10-19 mi) above sea level, that contains most of the ozone in the atmosphere.
-the atmosphere is about 120 km -it is made of 78% nitrogen, 21% oxygen, 0.93% argon, <1% water, and <.05% gases responsible for climate change/air pollution/loss of stratospheric ozone -The atmosphere has changed over Earth's history: No atmosphere AT ALL to start!; Early atmosphere had lots of CO2 (like Venus); Life evolved and removed the CO2(now, most stored as rock); Photosynthetic bacteria added Oxygen (2.5 Bya) -Human activity is now increasing the amount of: carbon dioxide (CO2), methane (CH4), ground-level ozone (O3), halocarbons, and other pollutants
Atmosphere basics: About how thick is Earth's atmosphere, and what is it made of (including approximate %s)? How has its composition changed over time? How are humans changing its composition?
-The four different categories of air pollution sources are natural, area, stationary, and mobile. -Natural includes lightning, volcanoes, wildfires, and forests. -Area includes cities, livestock, fertilizer, and oil/gas. -Stationary includes industry, power plants, and sewage treatments. -Mobile includes airplanes, cars, trucks, buses, and motorcycles.
Categories of Air Pollution Sources: Describe the four different categories of air pollution sources (diagram in PPT - natural, stationary, etc.) and provide examples of each
-1955 -Air Pollution Control Act - Didn't control anything -but did provide $$ for federal air pollution research. -1963 -Clean Air Act - Authorized research into techniques for monitoring and controlling air pollution -1967 -Air Quality Act - Supported first extensive air quality monitoring; Funded studies of pollution, monitoring techniques, and control techniques -1970 -Clean Air Act Extension - Big shift in federal role; Authorized development of state and federal regulations limiting pollution from stationary and mobile sources; EPA created to enforce these regulations (Required to set standards and regulate "criteria pollutants") -1990 -Clean Air Act Amendments (update) - Must now consider a) acid rain, b) toxic air pollution, c) urban air pollution, also d) ozone depletion -1997 -EPA addresses ground level-ozone and soot -2011 -EPA starts regulating greenhouse gases for 1st time
Clean Air Regulations: How have laws and regulations helped clean up air in the US? In the world? Are these laws effective? What is the evidence?
-Montreal Protocol (1987): 196 nations agreed to cut CFC production in half by 1998; Industry shifted to safer alternative chemicals; We stopped the Antarctic ozone hole from getting worse; Challenges still face us (CFCs will remain in the stratosphere for decades) (In fall 2011 -NASA & others found extra large hole over Arctic, also!) -More strict federal policies, regulations; Newer, improved technology (Ex: Cleaner-burning engines and catalytic converters); Reduced SO2 emissions (Permit trading programs); Phaseout of leaded gasoline
Cleaning things up: Describe some specific techniques that have been effective at reducing air pollution.
The five tips I would put in the brochure include no smoking, check your house for radon, limit use of plastics and treated wood, limit exposure to toxic substances, and keep rooms and air ducts clean. Smoking can cause lung cancer and lung damage, and radon in households can cause cancer. Plastics and treated wood, such as in furniture, can cause respiratory irritation and cancer. Toxic substances, such as pesticides and paints, can cause organ damage and cancer. Dirty rooms and air ducts can cause asthma, allergies, and respiratory problems.
D.You have just taken a job at a medical clinic in your hometown. The nursing staff have asked you to develop a brochure for patients featuring tips on how to minimize health impacts from indoor and outdoor air pollution in their daily lives. List the top five tips you will feature, and (for each tip) explain why you will include it in your brochure.
-Pollutants that are common in the developing world include cooking on indoor stoves, which burn wood/charcoal/dung/crop wastes. It causes 3 million premature deaths/year women & children, deforestation, and is the 2nd biggest contributor to climate change after burning fossil fuels. -Pollutants that are common in the developed world include cigarette smoke and radon. Cigarette smoke irritates eye, nose, and throat, causes lung cancer, and kills 160,000/year in the U.S. Radon (a radioactive gas that can seep into buildings) is from natural decay of radioactive elements found in rock and soil, it kills 21,000/year in the U.S. via lung cancer, and new homes reduce infiltration, older homes can be retrofitted.
Indoor air pollution: What sorts of pollutants are common in the developing world? The developed world? Why is indoor air pollution such a concern in the developed world? Describe three types of indoor air pollution, and (for each) explain how to reduce exposure.
-In the troposphere, the higher altitude=cooler air; warm air rises, causing mixing. -As the sun warms the surface, heat radiates up from the surface, and vice versa. There is vertical mixing and pollution gets trapped in the air. -Thermal inversion is when cool air is trapped beneath warm air (Dense, cool air at the bottom of the layer resists mixing). Inversions trap pollutants worse in cities surrounded by mountains.
Temperature patterns: Describe the normal temperature profile in the troposphere(how does temperature change as you go up?), and explain how that profile allows mixing of air near the ground with air higher up. Now, explain what a thermal inversion is, and explain how one can cause severe smog episodes like the ones in London and in Donora, Pennsylvania.
ozone hole
Term popularly used to describe the thinning of the stratospheric ozone layer that occurs over Antarctica each year, as a result of chlorofluorocarbons and other ozone-destroying pollutants.
acid rain
acid deposition that takes place through rain
acid deposition
The settling of acidic or acid-forming pollutants from the atmosphere onto Earth's surface. This may take place by precipitation, fog, gases, or the deposition of dry particles.
Clean Air Act
U.S. federal legislation to control air pollution that funds research into pollution control, sets standards for air quality, imposes limits on emissions from new stationary and mobile sources, enables citizens to sue parties violating the standards, and introduces an emissions trading program for sulfur dioxide; first enacted in 1963 and amended multiple times, particularly in 1970 and 1990
indoor air pollution
air pollution that occurs indoors
ozone-depleting substances
airborne chemicals, such as halocarbons, that destroy ozone molecules and thin the ozone layer in the stratosphere
secondary pollutants
a hazardous substance produced through the reaction of primary pollutants
lead
a heavy metal that may be ingested through water or paint, or that may enter the atmosphere as a particulate pollutant through combustion of leaded gasoline or other processes; when deposited on land and water can enter the food chain, accumulate within body tissues, and cause poisoning in animals and people
chlorofluorocarbons (CFCs)
a type of halocarbon consisting of only chlorine, fluorine, carbon, and hydrogen; were used as refrigerants, fire extinguishers, propellants for aerosol spray cans, cleaners for electronics, and for making polystyrene foam; they were phased out under the Montreal Protocol because they are ozone depleting substances that destroy stratospheric exposure
