air pollution 2011

8/6/2019 Air Pollution 2011

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Air Pollution Air Pollution


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Pollution - Definition:Pollution - Definition:

Any addition to air, water, soil etc

that threatens the health, survival of

humans or other living organisms

1. Natural - volcanic eruption

2. Anthropogenic - burning coal


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The AtmosphereThe Atmosphere

Gases that envelop the Earth and are held hereby gravity regulates temperature.

Major gases: 78.08% nitrogen

20.95% oxygen

0.93% argon

0.03% carbon dioxide trace amounts of water vapor (close to surface)

0.01% by volume near poles to 5% near equatorand many others hydrogen, neon, helium,krypton, ozone and methane


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Stratospheric ozone layer, O3Stratospheric ozone layer, O3

.

Formed by a natural process.

Produced by O2 interacting withlightning and UV radiation.

Absorbs most of the shorter wavelengths -UV radiation which is damaging to living

things causing cancer, sunburn, cataractsetc.

allows life to live on earth

ozone depletion - a reduction of the ozone

layer.


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What are the major sources and types of air

pollution?

What are the major sources and types of air

pollution?


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Air pollution :DefinitionAir pollution :Definition

the presence of one or more

chemicals in the atmosphere in

sufficient quantities and duration tocause harm to humans etc.


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Air PollutionAir Pollution

Air pollution results from human

activities such as burning fossil fuels (oil,

coal, and gasoline) to create electricityand power automobiles, and manufacture

industrial products such as chemicals and

plastic.

The air Pollutants are particulates, HC,

CO2, CO, NO, NO2, SO3 -- source may

be industrial, autos, etc.


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Air pollutionAir pollution

The increased carbon dioxide in the

atmosphere contributes to the warming of th

global climate, the so-called "greenhouseeffect."

The increased Chlorofluoro-carbons in the

atmosphere has been depleting stratosphericozone.


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Man made (most severe forhuman health):Man made (most severe forhuman health):

Stationary sources - those that are fixed inlocation.

point sources e.g. smoke stacks, 14% airpollution from plants generating electricity;

fugitive sources e.g. construction sites, exposedareas;

area sources e.g. dense urban community oragricultural area

Mobile sources - those that move whilepolluting, e.g. trucks, cars, busses etc. 60% of

air pollution from motor vehicles. 80-88% inmajor cities!


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What are the main categories of air

pollutants?

What are the main categories of air

pollutants?


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The main categories of air pollutantsThe main categories of air pollutants

Primary: those emitted directly into the

air; e.g. sulfur dioxide (SO2), carbon

monoxide (CO), nitric oxide (NO),nitrogen dioxide (NO2)

Secondary: those that form as a result of a

chemical reaction of the primary pollutantwith a natural component of the

environment.; e.g. some ozone, sulfuric

and nitric acids.


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Primary pollutantsPrimary pollutants

Carbon oxides (CO2 and CO)

Nitrogen oxides

Sulphur oxides

Volatile organic compounds hydro

carbonsSuspended particulate matter


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Primary air pollutants-AutoexhaustPrimary air pollutants-Autoexhaust

hydrocarbons, methane, butane,propane others.

hydrogen sulfide, H2S, gas. Toxic.particulates, visible - dust, smoke, soot,very fine


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Primary air pollutantsPrimary air pollutants

Sulfur dioxide, SO2, colorless, odorless gas.particulates ofSO4 which combines with water toform acid rain. Toxic to plants and animals; paint

damage. Carbon monoxide CO colorless, odorless gas, readily

combines with hemoglobin in blood. Toxic.

Nitrogen oxides, NO, nitric oxide and nitrogendioxide NO2. NO2 yellow brown to reddish gas.(NOx) Converted to nitrates in atmosphere causingacid rain.

Photochemical smog, brown air smog. Smog issmoke + fog.


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Photochemical SmogPhotochemical SmogSmog is a kind of air pollution, originally

named for the mixture of smoke and fog inthe air.

HC and NO react in presence of sunlight toproduce ozone and PAN (peroxy acetylnitrate)

Nitrogen oxides + hydrocarbons +Ultraviolet radiation -----> Peroxyacetylnitrate PAN + O3 ozone.


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Photochemical smog- EffectsPhotochemical smog- Effects

breathing ozone results in

respiratory distress, headaches.

PAN damages plants

PAH's polynuclear aromatic

hydrocarbons, carcinogenic.


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What are the effects of air pollution?What are the effects of air pollution?


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The effects of air pollutionThe effects of air pollution

reduces visual range and atmosphericclarity, less contrast, less visibility

damage to vegetation, includingleaves, needles, fruit, growth rate,reproduction, hardiness.

Decline in net primary productivityNPP.

Crop losses 1.9-5.4 b/yr.


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degradation of human health, from mild

problems e.g. eye irritation, to severe e.g.

respiratory disease asthma, bronchitis,emphysema, cancer.

CO, carbon monoxide, 90% natural, 10%

from incomplete combustion, cigarettes,combines with hemoglobin and reduces

bloods ability to carry oxygen. 150,000-

350,000 deaths/yr.


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degradation of vertebrate health, aquaticlife, with impacts on respiration, bones,teeth, reproduction; increase lake acidity,

decline in NPPdegradation of soil and water, when air

pollutants settle, toxic metals in soil, soilsleached

deterioration of man-made structures,break down car paint, roofing; acid rainchemically dissolves marble statues andother building materials


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Effects of air pollutionEffects of air pollution

Air pollutants can overload or break

down the natural defenses such as hair

in our nose, sticky mucus in the liningof the upper respiratory tract causing

diseases like lung cancer, asthma,

chronic bronchitis etc.,


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Doubling of carbon dioxideDoubling of carbon dioxide

In 1850, atmospheric carbon dioxide was about 280

parts per million (ppm).

Today, it is about 350 ppm.

This increase is due largely to burning of fossil fuels

and clearing of forests. Oceans (and photosynthetic organisms) currently

absorb half of the carbon dioxide emitted.


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Greenhouse gases (GHGs)Greenhouse gases (GHGs)

Some greenhouse gases occur

naturally in the atmosphere, while

others result from human activities.

Naturally occuring greenhouse

gases include water vapor, carbon

dioxide, methane, nitrous oxide, andozone.


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Greenhouse gases (GHGs)Greenhouse gases (GHGs)

Carbon dioxide is a product of burning fossil fuel andwood.

Nitrous oxide (NO2), produced by fertilizer use andreleased from decomposition of animal wastes.

Methane (CH4) is produced by bacteria fromsediments, swamps, and in flooded rice paddies.

Chlorofluorocarbons (CFCs), Freon (a refrigerant)

deplete the ozone layer in the upper atmosphere. Halons, such as halocarbons), are released from fire

extinguishers.

Water vapor in clouds reradiate heat back to Earth.


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Green house effectGreen house effectCarbon dioxide and other gases allow light to

pass, but trap heat in the atmosphere much likeglass in a greenhouse traps heat.

This greenhouse effect is thought to beresponsible for global warming.

Carbon dioxide contributes to only 56% ofgreenhouse heating.

The average surface temperature of Earth is about

15C (59F).Global Warming is increase in the average

temperature of the atmosphere, oceans, and

landmasses of Earth.


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Impact of Global warmingImpact of Global warming1. Temperature extremes

2. Rise in sea level, and change in precipitation

3. Injuries from storms, coastal flooding

4. Interruption of power supply, contamination of

drinking water5. Drought

6. Food shortages due to shift in agricultural foodproduction

7. Air pollution ( made worse by warming)

8. Asthma, bronchitis, emphysema complications

9. Strain on public health systems

10. Increased need due to population migrations

11. Unable to contain spread of infectious diseases


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Conserve EnergyConserve Energy

Be energy-wise

Explore alternatives

Recycle as much as is possible.Take showers instead of baths.

Check your taps.

Check the lights

Check your stove.Use less cooking water.

Check the refrigerator.


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Ozone depletionOzone depletion


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Ground level OzoneGround level Ozone

Ozone (O3) is a key constituent of the troposphere.

Ozone (Greekozein, to smell ), pale blue,highly poisonous gas with a strong odor.

Ozone is considered a pollutant at ground level.

Breathing O3 affects both the respiratory andnervous systems, resulting in respiratorydistress, headache, and exhaustion.

Ozone is damaging to plants, resulting in leafmottling and reduced growth.


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The Ozone LayerThe Ozone Layer

Earth's atmosphere consists of a number of

different layers.The troposphere is the lower atmospheric layer.

The stratosphere is often referred to as the upper

atmosphere.The stratosphere contains the ozone shield, a

layer of ozone (O3) in the stratosphere, 50 km

above the ground.


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Hazards of UV radiationHazards of UV radiation

Hazards of UV radiation include increased

mutation rate, which can lead to skin cancerand cataracts, depression of the immune

system, impaired crop and tree growth, and

the death of plankton.


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Thank

you

Thank

you

air pollution 2011

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