L-8Effects of air pollution on plants and materials and air pollution

episodes

Air pollution and control

(Elective –I)

Contents Today’s Lecture

• Effects of air pollutants on plants

• Effect of air pollutant on materials

• Air pollution episodes

Some important definitionsSome important definitions

1. Necrosis :- Necrosis is the killing orcollapse of tissues

2. Chlorosis :- is the loss or reduction of the green plant pigment, chlorophyll. The loss of chlorophyll usually results in a pale green or yellow pattern.

3. Abscission :-Leaf abscission is dropping of tree leaves

4. Epinasty :- is a downward curvature of the leaf due to higher rate of growth on the upper surface.

5. Defoliation

• Defoliation is a term which is used to describe the removal or loss of leaves. People usually use it to mean “total defoliation” meaning that all of the leaves on a plant are lost.

Effects of Air Pollutants on VegetablesPollutants Effects on Vegetables

Aldehydes The upper portions of Alfalfa (is a

flowering plant in the pea family) etc. will

be affected to Narcosis if 250 ppm of

Aldehydes is present for 2 hrs duration.

Ozone (O3) All ages of tobacco leaves, beans,

grapes, pine, pumpkins and potato are

affected. Fleck, stiple (several dots),

bleaching, bleached spotting,

pigmentation, growth suppression, and

early abscission are the effects.

Peroxy Acetyl

Nitrate (PAN)

Young spongy cells of plants are affected if

0.01 ppm of PAN is present in the ambient

air for more than 6 hrs.

Nitrogen dioxide

(NO2)

Irregular, white or brown collapsed region

on intercostals tissue and near leaf margin.

Suppressed growth is observed in many

plants.

Ammonia &

Sulfur dioxide

Bleached spots, bleached areas between

veins, bleached margins, Chlorosis, growth

suppression, early abscission, and

reduction in yield and tissue collapse

occur.

Chlorine (Cl2) If 0.10 ppm is present for at least 2

hrs, the epidermis(skin of plants)

and mesophyll of plants will be

affected.

Hydrogen

fluoride,

Silicon tetra

fluoride

Epidermis and mesophyll of grapes,

large seed fruits, pines are affected

and fluorosis in animals occur if

0.001 ppm of HF is present for 5

weeks.

Pesticides &

Herbicides

Defoliation, dwarfing(size reduction),

curling, twisting, growth reduction

and killing of plants may occur.

Particulates Affects quality of plants, reduces

vigor (plant growth) & hardness

and interferences with

photosynthesis due to plugging

leaf stomata and blocking of

light.

Mercury

(Hg)

Greenhouse crops, and floral

parts of all vegetations are

affected; abscission and growth

reduction occur in most of the

plants.

Trees damaged by acid rainTrees damaged by acid rain

EFFECT OF AIR POLLUTION EFFECT OF AIR POLLUTION ON MATERIALON MATERIAL

Effects on material

Mechanism of deterioration in polluted atmosphere

1. Abrasion :- solid particles of

sufficient size and travelling at high velocities can cause abrasive action.

Also large sharp edged particles imbedded in fabric can accelerate wear

2. Deposition and removal :- solid and liquid particles deposited on the surface may not damage the material itself but may spoil its surface appearance.

However removal of these particles may cause deterioration. Although single washing or cleaning may not cause deterioration but frequent can cause.

3. Direct chemical attack:- Some air pollutants can react with materials directly or indirectly to cause deterioration.

e.g. :- Bleaching of marble by SO2

Tarnishing of silver by H2S

Etching of metal surfaces by acid mist

4. Indirect chemical attack :- certain materials absorb some pollutants and get damaged when pollutant undergo chemical changes.

e.g.:- SO2 absorbed by leather converted to H2SO4, which deteriorates the leather

5. Corrosion :- Atmospheric deterioration of ferrous metals is by electrochemical action i.e. corrosion

. This is because of air pollutants and moisture present in the atmosphere.

Material Type of damage

Principal air pollutants

Other environmental factors influencingrate of attack

Metals Corrosion, soiling andtamishing

SOx and other acid gases

Moisture , temp., air, salt

Building materials

Surface erosion, discoloration, leaching and corrosion

SOx and other acid gasesAcid mist and sticky PM

Moisture , freezing temp.,

Paints Discoloration, softened finish,Surface erosion

SO2, H2S, O3, Sticky particulate

Moisture,sunlight, fungus and other micro-organisms

Textiles Soiling, spotting, reduces tensile strength

SOx, NOx, other acid gases, particulates

Moisture , sun light, physical ware

Leather Weakening,powdered surface

SOx, other acid gases,

Physical ware

Paper Embrittlement SOx, other acid gases

Moisture , sun light, physical ware

Dyes Fading , colour change

NOx, Ozone and oxidantrs

Moisture , sunlight

Ceramics Changes in surface appearance

HF, other acid gases

Moisture

Rubber Cracking, weakening

Ozone oxidants

Sunlight

WELFARE EFFECTS FOR CRITERIA POLLUTANTS.

Pollutant Welfare Effects

Carbon Monoxide (CO)

Sulphur Dioxide (SO2)

Contribute to the formation of smog.

Contribute to the formation of acid rain, visibility impairment, plant and water damage, aesthetic damage.

Nitrogen Dioxide (NO2)

Ozone (O3)

Contribute to the formation of smog, acid rain, water quality deterioration, global warming, and visibility impairment.

Plant and ecosystem damage.

Particulate Matter (PM)

Lead (Pb)

Visibility impairment, atmospheric deposition, aesthetic damage.

Affects animals and plants, affects aquatic ecosystems.

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 acidplant, freight yard, etc.

• Population—14,000

• Steep hills surrounding the valley

• Oct 26—temperature inversion (warmair 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

• 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

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 Azionariachemical plant

• Cloud of 2,3,7,8 tetrachlorodibenzo-para-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

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 _________________.

Objective Questions

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 QuestionsQ1. 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