Studied by 4 people
What is air pollution?
Presence of chemicals in the atmosphere that cause harm, and alter the climate. They can be in solid, liquid, or gaseous states.
Natural sources of pollutants
dust, forest fires, geologic processes
Human sources of pollutants
burning of fossil fuels, erosion of land, factory emissions
What are primary pollutants
Emitted directly into the troposphere
What are secondary pollutants
Pollutants formed when in atmosphere by combining with water vapor or atm. gases
Examples of primary pollutants:
pollen, volcanic ash, VOCs, CO, CO₂, SO₂, NO, NO₂, most hydrocarbons, most particulate matter
Examples of secondary pollutants:
SO₃, HNO₃ (nitric acid), H₃SO₄, H₂O₂, O₃ (ozone), PANS, NO₃, SO₄
Major outdoor air pollutants
Carbon oxides, nitrogen oxides, sulfur oxides, suspended particulate matter, photochemical oxidants (ozone), VOCs, hazardous air pollutants
Examples of solid particulate matter
dust, soot, lead, nitrate salts, sulfate salts
Examples of liquid particulate matter
sulfuric acid, PCBs, pesticides, dioxins
Examples of VOCs
gasoline, methane, octane, benzene, formaldehyde, trees, plant oils
Examples of hazardous air pollutants
benzene, formaldehyde, chloroform, lead, radioactives
Health effects of hazardous air pollutants
cause cancer, birth defects, nervous system damage
Who and when were the NAAQS (National Ambient Air Quality Standards)
EPA, in 1970
Six most harmful pollutants by NAAQS
Sulfur dioxide, particulate matter, lead, ozone, nitrogen dioxide, carbon monoxide
Trend in levels of lead in gasoline in blood
Downwards
Fossil fuels obtained from which location contain more fossil fuels, and which fossil fuels create significant amounts of sulfur emissions
Marine, coal and crude oil
Which type of combustion creates large amounts of sulfur dioxide
Diesel fuel combustion
When did the EPA start regulating diesel fuel sulfur levels
1993
Portion of acid gas pollution that comes from power plants (in US)
77%
Portion of arsenic pollution that comes from power plants (in US)
62%
Portion of sulfur dioxide pollution that comes from power plants (in US)
60%
Portion of nickel pollution that comes from power plants (in US)
28%
Portion of mercury pollution that comes from power plants (in US)
50%
Portion of NOx pollution that comes from power plants (in US)
13%
Portion of chromium pollution that comes from power plants (in US)
22%
Factors influencing smog formation
local climate, population density, amount of industry, fuels used in the area, urban buildings, hills and mountains, grasshopper effect
What is the grasshopper effect
moves atmospheric distribution of pollutants from tropic/temperate regions to poles
Elements in source fuels
Carbon, Hydrogen, Nitrogen, Oxygen, Sulfur
Examples of damage to human health done by pollutants
damage to lungs, eyes, nose and throat
Examples of damage to plants done by pollutants
tissue damage during photosynthesis and respiration
Transformations of nitrogen oxides (NOx)
Transform into tropospheric ozone (O3) when interacting with sunlight, transform into nitric acid (HNO3) when interacting with water vapor
Percentage effect of fertilizers on NOx emissions in California
51%
Equation for formation of photochemical smog
NOx + VOC + sunlight→ O3 + PANs
Timing of photochemical smog
Nitrogen oxide produced early in day during morning rush hour
Ozone peaks in afternoon due to peak sun intensity
Location and season affect on ozone
Ozone levels greater in sunny, warm climates
Ozone levels higher in summer
Human effects of photochemical smog
irritation of eyes, nose, throat, worsens heart and lung conditions, causes lung cancer
Plant effects of photochemical smog
enters plants through stomata and burns plant tissue, leading to leaf damage and reduced survival
Ways to reduce nitrogen oxides
catalytic converters - convert NO into O2 and N2
react CO and hydrocarbons to make CO2 and H2O
Emissions testing for vehicles
Ways to reduce VOCs
pump gas at night, be careful to not spill fuel, follow instructions for efficient vapor recovery, tighten gas cap securely
Ways to reduce smog and its effects
improve fuel efficiency, reduce use of internal combustion, and reduce health impacts (minimize outdoor activities in late summer afternoons, wear a mask on high ozone days)
Cause of industrial smog
burning large amounts of coal and heavy oil
Countries in which industrial smog is common
Urban areas in China, India, Ukraine, EE countries
How industrial smog is formed
Sulfur dioxide emissions react with water and form sulfuric acid (acid rain)
Color of industrial smog
grey
Color of photochemical smog
Reddish-brown
PM10 range and consequences
2.5 - 10 microns, upper respiratory concerns
PM2.5 range and consequences
1 - 2.5 microns, lower respiratory concern
PM1 - PM0.1 range and consequences
0.1-1, can enter bloodstream
Natural PM (particulate matter) sources
pollen, spores, bacteria, dust, airborne soil, sea salt
Geological PM
volcanic dust, sulfates
Ecosystem disturbance PM
wildfires
Transportation percentage of outdoor air pollution
57%
Fuel combustion (not from vehicles) percentage of outdoor air pollution
21%
Industrial processes percentage of outdoor air pollution
12%
Misc. percentage of outdoor air pollution
10%
Natural ways that reduce air pollution
Rain and snow, salty ocean spray, winds
Health consequences of outdoor air pollution
irritation of respiratory system, worsening asthma and bronchitis, emphysema, shortened life span
Air quality index levels
good 0-50, moderate 51-100, unhealthy for some 101-150, unhealthy 151-200, very unhealthy 201-300, hazardous 301+
Normal temperature gradient in troposphere
Temperature decreases with height
Temperature inversion description
warmer layer on top of cooler surface air
Consequence of thermal inversion
Traps cooler denser air, prevents air rising and pollutants from dispersing (photochemical smog and PM)
Ways that geography affects thermal inversion
valleys, mountain ranges, coastal or prevailing winds
Where temperature inversion occurs
large cities, high industrialization, lots of vehicles
At what level can human hearing be damaged
85 dB
Transportation sources of noise pollution
car horns, revving engines
Construction sources of noise pollution
jackhammers, demolition
Domestic activity sources of noise pollution
loud music
Industrial activity sources of noise pollution
SONAR for oil exploration, mining activities
Health consequences of noise pollution
stress, depression, anxiety, high blood pressure, heart disease
Environmental impacts of noise pollution
Hinders ability to find mates and avoid predation, impaired echolocation hunting, physiological changes (increased heart rate in caterpillars), animals change migration routes to avoid noise
Human ear damage due to noise pollution
causes stereocilia (hair in inner ear)to break off
damage to bones in middle ear and eardrum
Tinnitus
ringing in ears/head, can be temporary and permanent
Personal ways to reduce hearing loss
wearing earplugs
being aware of loud noises
protecting children’s ears
tell others about noise hazards
test for hearing loss
Government intervention to reduce hearing loss
US Noise Control Act 1972 - EPA regulation on noise emission from transportation, machinery, and construction
OSHA - limits on noise in workplace
Quiet Communities Act - funds communities to help reduce noise from airports and highways
Acid rain pH
4.3
Clean rain pH
5.6
Sulfur acid rain origin and reaction
Comes from coal burning power plants
2SO2 + O2+ 2H2O 🡪 2H2SO4
Nitrogen acid rain origin and reaction
comes from vehicle fossil fuel emissions
3NO2 + H2O 🡪 2HNO3 + NO
Natural sources of acid rain
Volcanoes, geysers, hot springs
Effects of long distance travel of SOx and NOx
When released high into the atmosphere, there is more time to react with water, increasing chance of acid rain formation
Impacts communities downwind of plants
pollutants high in atm. get carried hundreds of miles away, damaging areas far from source
Most acid rain region in US
Northeast US
Consequences of acid rain on plants
Causes aluminum ions to leach from soils
Roots unable to take up calcium when aluminum present
Damaged needles and leaves, nutrient deficiency, less efficient photosynthesis
Which materials make soils less vulnerable to acid rain
magnesium, calcium, carbonate, limestone buffers/neutralizes acid
Which materials make soils more vulnerable to acid rain
thin, nutrient poor
Effect of acid on materials
metal and stone eroded by acid rain
statues made of marble, that contains calcite, dissolved by acid
Human impact of acid rain
Contributes to diseases like bronchitis and asthma
Leaches toxic metals from water pipes into drinking water
acid rain prevention
reduce energy use and coal burning
switch to cleaner burning fuel source (like ng)
burn low sulfur coal
remove sulfur dioxide, particulates, and NOx from smokestacks
Rideshare to reduce NOx emissions
Regulation to reduce automobile emissions
eliminate lead in gasoline
encouraging clean transportation technology
regulation to reduce acid rain
Determining allowable pollution levels
Promoting technologies to reduce sulfur dioxide and NOx
Ozone regulation
Regulations on tropospheric ground level ozone
Alternative fuels
natural gas, propane, ethanol, electricity, biofuels
Conservation acts to reduce emissions
Energy efficient appliances and buildings
Water based paints and cleaners (instead of solvent based)
Improved transportation planning
Higher fuel standards (mpg)
composting, recycling, carpooling
What are vapor recovery nozzles
vapors from car fueling and send them to storage tank
When did the EPA require the auto industry to have onboard vapor systems
2006
When did the EPA stop requiring gas pump nozzle systems
2013
Catalyst reduction reaction for NO pollution
2NO2 → N2 + 2O2
Catalyst oxidation reaction for carbon monoxide
CO + O → CO2
Catalyst oxidation reaction for hydrocarbons
CxHx → CO2 + H2O
Where pollutants are released when coal is burned
flue or smokestacks
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