Uploaded by Priya Kumaran

air pollution episodes

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AIR POLLUTION EPISODES
Air Pollution Episodes
Meuse Valley-Belgium, 1930
• About 60 died (mostly elderly)
• Sore throats, shortness of breath, cough,
phlegm, nausea, vomiting
• SO2, sulfur dioxide
• H2O (water vapours)
• SO4 , sulfuric acid mist
• Cattle, birds and rats died
• Got little news coverage
Cont…….
Fumigation of a valley floor caused by an inversion layer that
restricts diffusion from a stack
Donora, Pennsylvania—Oct. 1948
• Monongahela River Valley
• Industrial town—steel mill, sulfuric acid
plant, freight yard, etc.
• Population—14,000
• Steep hills surrounding the valley
• Oct 26—temperature inversion (warm
air trapping cold air near the ground)
• Stable air, fog, lasted 4.5 days
• 20 died and 7000 ill
Environs of Donora, Pennsylvania. Horseshoe curve of Monongahela River is
surrounded by mountains. Railroad tracks are located on both sides of the river.
Low-lying stretch of Monongahela valley between railroad and river is natural trap
for pollutants.
Poza Rico, Mexico 1950
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Single source– high sulfur crude oil
Hydrogen sulfide (H2S)
Flare went out
Inversion in valley
22 sudden deaths, 320 hospitalized
All ages affected
Forerunner of Bhopal
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December 1952 Great London Smog
Cold front, Londoners burned soft coal
Factories, power plants
Temperature inversion
5 days of worst smog city had ever
seen
Public transportation stopped
Indoor concerts had to be cancelled
because no one could see the stage,
etc.
4000 died
London smog repeats
• Repeated in 1956 and 1962
respectively
• 1000 and 700 dead respectively
London smog pictures
Weekly death registered from diseases of the lungs and
heart in the London Administrative County around the time
of the severe fog in December, 1952.
Total death in Greater London and air pollutants levels
measured during the fog of December 1952
Seveso, Italy --Dioxin
• July 10, 1976, north of Milan
• A valve broke at the Industry
Chimichee Meda Societa Azionaria
chemical plant
• Cloud of 2,3,7,8 tetrachlorodibenzopara-dioxin (TCDD) traveled southwest
through Seveso toward Milan
• Contaminant of herbicide
• 200 people suffered skin diseases and
liver problems
Bhopal, India Dec. 3, 1984
• Union Carbide pesticide plant leak kills up to
2,000 with up to 350,000 injured and 100,000
with permanent disabilities
• Methyl isocyanate (MIC)—used as an
intermediary in manufacture of Sevin
(Carbaryl)
• CO + Cl = phosgene
• Phosgene + methylamine = MIC
• MIC—irritant to the lungs---edema, fluid (cause
of death, corneal opacity (blindness)
• MIC is heavier than air
• 25 km2 area covered
• MIC is water soluble gas
• Leak was stopped after 40 minutes by
hosing down the tank with cold water.
• Disaster management plan was not in
existence
Hundreds Troubled by 'World Trade Center Cough‘ NYC
fire fighters, school workers have 9/11 breathing
problems, new studies say
Objective Questions
Q1. ___________ is the killing or collapse of
tissues.
Q2. ____________is the loss or reduction of the
green plant pigment, chlorophyll.
Q3. _________________is dropping of tree
leaves.
Q4. ________________is a downward curvature
of the leaf due to higher rate of growth on the
upper surface.
Q5. Solid particles with sufficient size and high
velocity causes _________________.
Q6. _____________ is electrochemical
process.
Q7. Toxic gas ___________ was responsible
for Bhopal gas tragedy in 1984.
Q8. MIC is formed by combination of
____________ and ______________.
Q9._____________ causes cracking of rubber.
Q 10.__________________ is affected by
pollution because of refineries.
Theory Questions
Q1. Define
1. Epinasty
2. Abscission
3. Chlorosis
4. Necrosis
Q2. Write Effects of following pollutants on plants
1. Aldehydes
2. Ozone
3. Particulates
4. NO2
Q3. Write short notes on
1. Mechanisms of deterioration in polluted
atmosphere.
2. London smog
3. Bhopal gas tragedy
4. Air pollution episodes
Q4. Give tabular format w r t
• Pollutant
• characteristics
• Sources
• Health Effects
• Welfare Effects for SO2, CO and O3