APES Unit 7 Flashcards
Pollution
The four major sources of emissions that contribute to air pollution
Natural, area, stationary, mobile
Clean Air Act 1970
- Required EPA to develop and enforce regulations to protect citizens
- Regulated especially the use of lead
- Prevents an estimated 160,000 deaths p/y
6 pollutants that the Clean Air Act identified as threatening to humans
Nitrogen oxides, ground level ozone, sulfur dioxide, carbon monoxide, lead, particulate matter (PM)
Nitrogen Oxides sources, effects, removal
Car and fuel combustion, forest fires, and lightning. Respiratory irritant, acid rain, smog. Removal through catalytic converters
Ground-level ozone (formation, effects, removal)
secondary pollutant formed by sunlight and water reacting with VOCS NOX and O2. Respiratory irritant, damages plants. Must reduce primary pollutants to remove
Nitrogen Oxides symbol
NO or NO2
Ground level ozone symbol
O3
Good Ozone (location and contents)
In the stratosphere, natural process, there is a depletion in this layer by CFCs which causes an increase in NO2 released
Bad Ozone (location and contents)
In troposphere, NOX and VOCS react with sunlight here, humans influence the process. There is an increase in sun cancer from harmful UV rays, destruction of marine life.
3 consequences of bad ozone
Respiratory problems, plant damage and greenhouse gas
Sulfur Dioxide (sources, effects and removal)
From the combustion of coal and oil, forest fires and volcanoes. Respiratory irritant, affects plant tissues. Forms acid rain and acid deposition which harms aquatic life. Reducing coal exhaust and using scrubbers help
Carbon Monoxide (how it forms, dangers, removal)
Formed during incomplete combustion of most matter through vehicle exhaust or other combustion. Especially dangerous indoors with poor ventilation, manure, charcoal, kerosene, can make it hard for people to breathe. Catalytic converters or cooking in ventilated areas
Sulfur Dioxide symbol
SO2
Carbon Monoxide symbol
CO
Lead (sources and side effects)
From old gasoline (1996 phased out) paint in older buildings, pipes. Toxic to the Central nervous system of living things
Particulate matter (PM) sources, effects, removal
Combustion of fossil fuels and biomass, road dust, volcanoes, dust storms, fires. Sunlight can be blocked preventing photosynthesis. Anything less than 10 is considered a respiratory irritant and can make lung conditions/asthma worse and lead to premature deaths. To remove: scrubbers, baghouse filters, gravitational settling
Which is worse for PM, gas or diesel?
diesel
PM 2.5
greatest health concern, usually more toxic
PM 10
too small to be filtered, health concern
PM 10+
Caught in nose and filtered out.
What does VOC stand for?
Volatile organic compounds
What are VOCs and removal
Organic chemicals with a high vapor pressure at room temp (plants) or hydrocarbons from building supplies in household products; things like benzene, toluene, formaldehyde. Range from very toxic to harmless. Using vapor recovery nozzles, lowering emissions, better ventilation and not using certain products all help
Sources of mercury, effects and removal
Coal, gold mining, oil, volcanoes, forest fires. Toxic to the CNS. Technologies to reduce PM also help reduce mercury
Mercury concentrations have increased in fish, what is this called?
Bioaccumulation
Primary pollutant (5) + sources
Comes from a source like a smokestack or an exhaust pipe. CO, NO, VOCs, PM, NH3
Secondary pollutant (6) + sources
Undergone transformation that occurs in the daytime in wet conditions. Ozone, SO3, H2SO4, H2O2, HNO3, PANS
There are two main categories of smog what are they?
Industrial and photochemical smog
Industrial smog examples
sulfurous smog, gray smog, london fog, winter fog pea soup smog
How does industrial smog form?
Caused by SO2 and particulates reacting with water vapor, the biggest cause is coal.
Photochemical smog examples
brown smog, yellow smog, LA smog, summer smog
How does photochemical smog form?
Caused by VOCs and NOx reacting wtih water. Biggest contributor is cars, Dry, wamr conditions.
All scents are from…
VOCs
Formation of photochemical smog
NOXs and VOCs react with heat and sunlight after being emitted into the air. This forms ozone and other chemical oxidants like PANS.
Photochemical oxidants like PANS can enhance…
the formation of particulates which scatter light, smoke and fog
Photochemical oxidants definition, negative effects, removal
reactive compounds that remove electrons from other substances. PANS, ozone, aldehydes. Can be harmful to plant tissues, are bad for the respiratory system, can cause eye problems and damage to construction materials. Must reduce primary pollutants to “remove”
PANS =
peroxyacetyl nitrates
How does the time of day affect the formation of photochemical smog? (NOX and Ozone)
NOXs are highest early in the day, ozone mid day.
Harmful physiological effects of toxic smog
stroke, depression, asthma, cancer, burning, eye irritation etc.
Ways to reduce photochemical smog
- Reduce production of anthropogenic VOCs and NOX
- Take care of cars
- Improve gas mileage
- Fuel up during cooler hours of the day
- Avoid using gas, use electric instead
What does temperature do in the troposphere?
Temperature decreases because pressure decreases
Thermal inversion is when…
there is a layer of warm air above a layer of cold air, trapping it. Pollutants then also get trapped.
Where does thermal inversion most commonly occur?
in valleys
What situations lead to thermal inversion?
Valleys, warm fronts/high pressure, areas of oceanic upwelling, radiation.
Can thermal inversion happen on water?
No, typically they happen on land, oceans retain heat
Natural sources of CO2 + percentages
Ocean atmospheric exchange (40) plant and animal respiration (30) soil respiration and decomposition (30) volcanic eruptions (0.03)
Natural sources of particulate matter
pollen, sea salt, dust, secondary sulfates, volcanic ash, black carbon from wildfires
The 3 sources of indoor pollutants
Natural, anthropogenic, combustion
Examples of natural indoor pollutants
radon, mold, dust
Examples of anthropogenic indoor pollutants
insulation, lead paint, VOCs
Examples of combustion indoor pollutants
carbon monoxide, NOx, SO2, PM, tobacco smoke
Unidentified illnesses with unspecified causes often affecting office workers may be a result of…
sick building syndrome
What is radon? What are its side effects?
Radon-222 is naturally occuring radiactive gas that is produced by the decay of uranium found in rocks and soils. It is the #2 cause of lung cancer
How does radon infiltrate homes?
Moves up through the soil into homes through cracks in the basement, dissolves into groundwater that enters homes through the well.
Recommended EPA action level for radon
4.0
Air pollution in developing countries
indoor burning of woods, charcoal, dung, crop residues, coal. The poor suffer the greatest risk based on location and the inability to escape
Air pollution in developed countries
indoor air pollution is a bigger problem than in developing countries, common air pollutants are higher inside, 90% of the time indoors.
Carbon dioxide (CO2), effects, and how it is removed
Part of the carbon cycle so at normal levels is safe. A greenhouse gas so when concentration increases, acts as a blanket over Earth as it absorbs infrared rays. Removed by carbon capture and sequestration as well as reforestation
Photochemical oxidants examples (2)
ozone, PANS
Nitric acid (formation, effects, removal)
formed when NOx reacts with water vapor and oxygen. Leads to acid rain and deposition. Lowers the natural acidity of rain, lowers the pH of lakes and soil. Must reduce primary pollutants to “remove”
Nitric acid symbol
HNO3
What are hydrocarbons? Effects and removal
CH4 and gasoline, combustion releases CO2, harmful if swallowed. Using vapor recovery nozzles help prevent emissions.
Mold (formation, effects, removal)
Forms in humid, warm conditions. Can cause allergy symptoms to people who are sensitive, controlling humidity levels and fixing leaks all helps
Asbestos (formation, effects, removal)
Long, fibrous silicate material with insulate properties. Can cause lung cancer and respiratory diseases. No longer used in new houses, removal form old houses helps
Sulfuric acid (formation, effects, removal)
sulfur dioxide that causes acid deposition from coal burning plants. Formed when SO2 reacts with water vapor and oxygen. Leads to acid rain and like nitric acid can lower the acidity of rain and the pH of soil and lakes. Can be “removed” through the reduction of primary pollutants
Methods to reduce air pollutants (3)
Regulatory practices, conservation, alternative
Vapor recovery nozzle
prevents fumes from escaping into the atmosphere when fueling a motor vehicle
Catalytic converters
Made in 1975, used for internal combustion engines that convert pollutants in exhaust into less harmful molecules. Hydrocarbons CO, NO into H2O, N2 and CO2
Scrubbers
remove particulates and or gases from industrial exhaust streams
There are 2 types of scrubbers…
wet and dry
Wet scrubbers
Introduce water to dirty gas stream, particulates or gases are collected, most appropriate device to use to pick up particulates and gas
Dry scrubbers
dry reagents are sprayed into the exhaust stream, pollutants are neutralized or react and turn into a different substance. That substance falls out of the gas stream and is caught in a particulate screen
Coal burning power plants use scrubbers… (2)
Electrostatic precipitators and desulfurization
Electrostatic precipitators
dirt particles gain negative charge from one wire and a positive charge from another for collection and diposal
Desulfurization
reduce SO2 emissions, burn coal near CaCO2 (calcium carbonate to produce sheetrock.
Solutions for air pollution
- energy efficient power generation and building
- improve waste management
- greener more compact cities
- safe, affordable public transit
Examples of areas where local control measures for air pollution have been implemented
- dry cleaning fluids
- gas stations
- lighter fluid
- wood burning stores
- transportation
Wet deposition of acid
rain, snow, fog
Dry deposition of acid
aerosol particles and gases
Sources of acid deposition
both natural and anthropogenic, both nitrogen oxides and sulfur oxides
Nitrogen oxides natural + anthropogenic
Lightning & microbes. Motor vehicles, coal burning power plants
Sulfur oxides natural + anthropogenic
volcanoes. coal burning power plants
Nitrogen oxides (3)
NO, NO2, N2O
Sulfur oxides (2)
SO2, SO
Harmful impacts of acid deposition
communities downwind are at the most risk, soil and water acidification, corrosion of man-made structures
What can neutralize acid?
limestone through its “buffering” ability.
Sound at high enough levels can cause…
physiological stress and hearing loss
Sources of noise pollution
domestic/industrial activity, transportation, construction
Effects of noise pollution on children & adults
hearing loss, hormone imbalance, stress, anxiety, impaired hearing, etc.
Effects of noise pollution on other organisms
stress, masking of sounds used to communicate/hunt, damaged hearing, changes to migratory route. Marine animals are especially effected.
