chapter 19 air pollution your responsibility… pages 438 - 441, 447 - 452 452 - 457, 483 - 484...
TRANSCRIPT
Chapter 19Chapter 19AIR POLLUTIONAIR POLLUTION
YOUR RESPONSIBILITY…YOUR RESPONSIBILITY…Pages Pages 438 - 441,438 - 441,
447 - 452447 - 452452 - 457,452 - 457,483 - 484483 - 484READING QUIZ!!!
Atmosphere as a Resource
• Composition:– Nitrogen (78.08%)– Oxygen (20.95%)– Argon (0.93%)– Carbon Dioxide (0.04%)
• 2 most important to living organisms:– CO2 and O2 (photosynthesis & respiration)
• N2 also important (N2 cycle)
• Ecosystem Services– UV filter, moderating climate, redistributing water
Types and Sources of Air Pollution
Air Pollution = gases, liquids, or solids present in the atmosphere in high enough levels to harm humans, other organisms, or materials.
• Natural pollution (lightning causes forest fires, volcanic eruptions)
• Human-induced pollution (ANTHROPOGENIC)– Harmful for 2 reasons:
• They precipitate & settle on Earth• They alter the chemistry of the atmosphere
– Much of the air pollution released by humans is concentrated in densely populated urban areas
Primary Air Pollutants• Harmful chemicals that
enter directly into the atmosphere
• EX: carbon oxides, nitrogen oxides, sulfur dioxide, particulate matter, and hydrocarbons
Secondary Air Pollutants• harmful chemicals that form
from other substances that have been released into the atmosphere.
• EX: ozone & sulfur trioxide
Air Pollution & Human HealthAir Pollution & Human Health
• Exposure to Low Levels causes…– Eye irritation– Inflammation of the respiratory tract– Immune system suppression– Development of emphysema & chronic bronchitis
Health Effects of Health Effects of Specific Air PollutantsSpecific Air Pollutants
QUESTION: Why are people who live & work in QUESTION: Why are people who live & work in the country’s most polluted cities 15-17% more the country’s most polluted cities 15-17% more likely to die prematurely than those living in US likely to die prematurely than those living in US
cities with the cleanest air?cities with the cleanest air?
ANSWER: ANSWER:
Exposure to Sulfur Dioxides (SOExposure to Sulfur Dioxides (SOxx), ),
Nitrogen Oxides (NONitrogen Oxides (NOxx, N, N22O), O),
Carbon Dioxide (COCarbon Dioxide (CO22), Ozone (O), Ozone (O33), ),
Particulate & VOC’sParticulate & VOC’s
SO2 & Particulate Matter•Produced as part of the coal combustion process & industry
•Travels long distances from source.
•SO2 reacts with H2O vapor and forms sulfuric acid ACID RAIN!ACID RAIN!
•Sulfate particles + nitrogen oxide create small particles or
particulates which have detrimental health effects including:
1. Respiratory tract irritation
2. Decrease in lung’s ability to exchange gases
3. Airway constriction
4. Increased sensitivity to pollen and dust mites
5. Leach nutrients from soil
Vulnerable Ecosystems: Lakes, Streams, Forests, High Elevations
Nitrogen Oxides (NOx)• Nitrogen oxides are formed from
atmospheric nitrogen when coal and otherfuels are burned.
• Ways to reduce the amount of NOx produced include catalytic
converters on cars and low-NOx burners on power plants.
• Interact with sunlight and other molecules to produce ground level ozone.
• Health effects include:1. Asthma among children2. Airway constriction3. Increased sensitivity to
pollen and dust mites4. Acid rain & atmospheric haze (photochemical smog)
Vulnerable Ecosystems: Lakes, Steams, Forests, High Elevations
CARBON DIOXIDE
• Formed when fuels are burned- Coal has highest content.
• Big greenhouse gas responsible for global warming.
• CO binds irreversibly with iron in the blood’s hemoglobin, eliminating its ability to transport O2 (asphyxiation)
• Health Effects include: 1. Linked to the spread of infectious disease, higher ozone levels,
increased heat & cold related illnesses
2.Medium Concentrations: causes headaches & fatigueHigher Concentrations: slower reflexes & drowsinessVery High Concentrations: death
3.Greatest risk: pregnant women, infants, those with heart or respiratory diseases.
Ecosystem effects: Rising sea levels, increased disease, larger storms, extinction of sensitive
species.
Ozone & VOC’sProduced when nitrogen oxides
react with volatitle organic compounds (VOC) in the presence
of sunlight.
•Health problems include:
1. Irritants: burning eyes, coughing, chest discomfort
2. Asthma attacks, immune system suppression
3. Pregnant women exposed to high levels of O3 and CO are 3X more likely to give birth to infants with serious heart defects.
4. Plant damage at low concentrations
Vulnerable Populations: Children, elderly those with respiratory disease, those who exercise outside.
Pollutants from Motor Vehicles, businesses &
IndustryLong-term exposure is linked to
cancer (although the risk is rather low compared to others like
smoking)
Some Health Effects of Air Pollution Nationwide
Mortality: 23,600 Hospital Admissions: 21,850
Emergency Room Visits for Asthma: 26,000 Heart Attacks: 38,200
Chronic Bronchitis: 16,200 Asthma Attacks: 554,000
DON’T WRITE THESE….
Just some statistics for ya
PARTICULATE
MATTER
smoke detector
filters
sticky materials
N & S & C OXIDES
devices /
equipment
CO detector
chemical tests
AIR TOXICS
mold tests & filters
radon detectors
OZONE
Schoenbien
papers
chemical tests
indirect
evidence
(plant growth,
etc)
ozone action
days
HYDROCAR
BONS
devices /
equipment
ACID DEPOSITION
pH tests
indirect evidence
Children and Air PollutionChildren and Air Pollution
• Air pollution is a greater health threat to children than adults.
• Restricts lung development• Causes early stages of lung disease
• Children have higher metabolic rates than adults• they breathe ~2X as much air per pound of body weight
• Studies show that children who move to areas with…
• less particulate matter have increased lung development.• more particulate matter have decreased lung development
GOOD NEWS:
• Fewer people in highly developed nations smoke.• Cigarette production in the US is down• Smoking decline in Japan & most European countries
BAD NEWS:
• More smokers in China, Brazil,
Pakistan, and other developing nations.• Some nations: smoking habit = 20% of a worker’s annual income• Sales in developing countries has increased 80% since 1990.• US tobacco companies promote smoking abroad, and we export
much of our tobacco.• 3M people die each year of smoking-related causes worldwide.• US: some minority groups & those with the least education have
high numbers of tobacco addicts• More than 1M US children & teens take up smoking every year.
Smog…Air pollution that is localized in urban areas
where it reduces visibility
1. Industrial Smog: aka: smoke pollution
principal pollutants are sulfur oxides and particulate matter. Worse in the winter months because of heating needs.
More people means more fuel!
Fossil fuel combustion creates NOx and VOCs (reactants)
Sunlight is the energy catalyst for the reaction.
Precipitation cleans the air, and winds disperse the smog.
Topography and Air PollutionUnder normal conditions, air circulation patterns
prevent toxic pollutants from increasing to dangerous levels near the ground.
That is not the case in this
picture of LA….
What do you think is causing this to happen?
Temperature InversionsTemperature Inversions
AKA: Thermal Inversions
Air near the ground is cooler than the
air at higher levels and the
polluting gases/particulate
matter remain trapped in high concentrations
near the ground.
Los Angeles• Located between coast and mountains• Sunny climate produces a layer of warm dry air at higher elevations• Upwelling in the ocean produces cool ocean air• As cool air blows inland, the mountains block movement further and
layer of warm dry air overlies cool air at the surface… Temp inversion!!
Think back to the Global Winds... how does this
relate??HINT:
Where is LA
Longitudinally?
Urban Heat Island: air in urban areas is warmer than the air in the surrounding suburban and
rural areas.Affects local air currents and weather conditions.
Q: Why do they increase the number of thunderstorms???
Urban Heat Islands & Dust Domes
Dust Domes: buildup of pollutants, especially particulate matter over cities.
Convection of air lifts pollutants into the air where they remain because of somewhat stable air masses produced by urban heat
island
CONTROLLING AIR POLLUTANTSRead pages 446- 447 in Raven & Berg and write a paragraph about
how scrubbers and electrostatic precipitators remove pollutants from factory exhaust.
HOMEWORK/CLASSWORK…..HOMEWORK/CLASSWORK…..Read and understand page 447-452
Key points to KNOW:
- Clean Air Act 1970
- Changes to the Clean Air Act (1997)
- Ways to improve air quality
- CASE IN POINT: Los Angeles
- Meeting the challenge: clean cars, clean fuels
- Pollution in developing Countries
- CASE IN POINT: Mexico City
…homework will be checked in one way or another….
HINT…HINT...HINT…HINT…HINT…HINT...HINT…HINT
LINK TO
DIISCUSSION SLIDES
Developing Countries & Energy ~Richard Spencer, The Daily Telegraph, from Beijing:
“…Here comes the man with the coal bricks we residents all use to fire the boilers of our homes... Not cold enough for the central heating yet? You're
right, but there's a discount - the earlier you buy, the cheaper it is.”
Global Distillation Effect- volatile chemicals evaporate from land as far away as the
tropics and are transported by winds to higher latitudes where they condense and fall to the ground
Certain hazardous air pollutants are distributed globally by atmospheric
transport
PCB’s & DDT are both persistent chemicals that do not readily
break down and accumulate in the environment.
They are still used in developing countries and move through the
atmosphere to developed nations where they are deposited on land
and surface water.
Global Distillation Effect cont…• Dangerous level of persistent toxic
compounds have been measured in the Yukon
• Chemicals enter food webs and become concentrated in the body fat of animals
Inuit eat the animals
And the concentration
of chemicals increases
in their system causing
problems for their
Health.
Why does this happen to Canada?
What can we do to stop this problem?
What can the US do to stop Canadian smog
problem?
Should we help alleviate the smog problem?
Are we?
Why is science involved in foreign relations?
Il, IN, MI, OH, PA, TN & WV produce 50-75% of the acid
deposition that contaminates New England and Canada
Stockholm Convention of Persistent Organic Pollutants (2001)
Goal: phase out the use of 12 persistent toxic chemicals
Countries: Canada, US, Russia, Finland, Norway, Sweden, Denmark, Iceland
ACID DEPOSITION• Acid deposition (rain, sleet, snow and fog) is a
type of air pollution• Sulfuric acid & Nitric acids
Estimated cost to the US is $10 Billion/yr
• Wet Deposition: – Sulfuric and nitric acids in
precipitation
• Dry Deposition: – Sulfuric acid and nitric acid
containing particles that settle out of the air.
End of Ch 20
The pH scale measures the
amount of H+ ions present in the
solution.
A pH of 6 is 10x more acidic than a
pH of 7.
Normal rain has a pH of ~ 5-6 because CO2 in the air dissolve in
rainwater forming dilute acids. Acid rain
= 3-4
Acid deposition occurs when sulfur dioxide and nitrogen oxides are released into the
atmosphere. Sources: Cars, Coal burning power plants, smelters,
industrial boilers
Effects: SO2 and NO react with water to produce dilute solutions of H2SO4, HNO3, HNO2
• Effects of Acid Deposition– Corrodes metals and building materials
Affects Animal populations (Adirondacks)• 1,469 lakes examined,
325 found with pH <5
• Birds with thin fragile shells (lack of Ca due to acidic soils)
–Forest DeclineCharacterized by gradual
deterioration and eventual
death of trees.
- Black forest of Germany
50% of trees dead
-MOUNT MITCHELL, NC
Results from a combination of multiple stressors (acid deposition, tropospheric O3, UV radiation, insect attack, drought, etc.)
Soil ChemistryCa & K wash readily
out of acidic soil where others (N)
become available in large amounts
Heavy metals dissolve in acidic soil becoming available
for absorption in toxic amounts.
Links between GW, Ozone Depletion & Acid Deposition
• Global warming, ozone depletion and acid deposition interact
• Combined effects of acid deposition and climate warming make North American lakes more susceptible to damage from UV radiation caused by the thinning of the ozone layer.
READ PAGES 483-484…. The book says it best!!!
What does this cartoon tell you about the United
States air quality in 2002?
Is this a fair representation?
Is there bias? If so, WHAT???
What can we do to avoid this
type of situation?
Sources of smog in Los Angeles
What would happen to California’s smog if 20 of
every 100 cars was a hybrid?
Do you think that it is alright for the government to restrict
car companies from producing polluting cars?
Should tax incentives be given to those who purchase
fuel economic vehicles?
Would it be fair to impose a tax on vehicles that do not
burn fuel efficiently?
Discussion points of the HOMEWORK…