2. 1. INTRODUCTION
2. METEOROLOGY
3. CONTROL OF PARTICULATE CONTAMINANTS
4. CONTROL OF GASEOUS CONTAMINANTS
5. INDOOR AIR QUALITY MANAGEMENT
3. Unit – 1 INTRODUCTION
Structure and composition of atmosphere - Definition, scope and scales
of air pollution - Sources and classification of air pollutants and their
effect on human health, vegetation, animals, property, aesthetic value
and visibility - Ambient air quality and emission standards - Ambient and
stack sampling and analysis of particulate and gaseous pollutants.
4. Earth’s atmosphere
Layer of gases surrounding a planet
Provides essential oxygen
Provides medium for sound
Shields solar radiation
5. Atmosphere
It is a mixture of gases that forms a layer of about 500 km
thick around the earth.
Composition of Air – 78% Nitrogen, 21% oxygen, 1%
carbon dioxide, water, other gases
6.
7. Structure of the atmosphere (Zones)
Troposphere
Stratosphere
Mesosphere
Thermosphere (Ionosphere)
Exosphere
8. Troposphere
It is the lowermost layer of the atmosphere.
Troposphere contains dust particles and water vapour.
Surface layer - 30,000 ft
Heated from below
Bottom 10 – 15 km (Troposphere) are most important part in
terms of weather and other aspects of Biogeochemical cycle
Convection - weather, clouds form from rising air which cools by
pressure drop, and clouds dissipate as air falls and heats.
9. Stratosphere
Heated by ozone absorbing UV light
UV breaks apart ozone into O2 + atomic oxygen - get energy
release and heating.
Higher altitudes efficiently absorbs UV at 200 and 350 nm.
Lower altitudes less efficiently absorbs UV at 44 and 80 nm
Temperature inversion - no convection, no weather.
7 – 30 miles
10. Mesosphere
Mass of atmosphere 0.1%
Density is too low for ozone chemistry to heat
Get normal trend we saw in troposphere– lower T with
increasese altitude.
30-50 miles
11. Ionosphere (Thermosphere)
Density - low Space Shuttle orbits here, with little
drag
T can be very high; 4,000F.
But no significant heat because density low.
Heated by ionization by UV from the sun, and the
solar wind.
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14.
15. Air Pollution
Air pollution is defined as the introduction of chemical, particulate
matter, or biological materials that cause harm or discomfort to
humans or other living organisms, or cause damage to natural
environment/built environment to atmosphere.
Tends to be injurious to human, odor, smoke, gas, mist, dust,
animal or plant life, or property, or which unreasonably interferes
with the comfortable enjoyment of life or property or conduct of
business.
A pollutant can be solid (large or sub-molecular), liquid or gas .
16.
17. Types of air pollution
Personal air exposure (dust, fumes and gases – smoking)
Occupational air exposure (aerosols, vapors, and gases –
in working environment)
Community air exposure ( meteorological factors, &
wide variety of adverse social economical and health
effects)
18. Scope and scales of air pollution
Air pollution problems may occur on three scales:
i. Micro scale (covering less than cm to size of a house or slightly
larger – few meters to 100s of meter)
ii. Meso – scale (few hectares up to the size of city or country –
local to regional)
iii. Macro scale (problems extend from countries to states, nations
and in the broadest sense, globe (regional to continental scale)
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20.
21. Sources of Air Pollution
Air Pollution may originate from a natural or anthropogenic source or from
both sources.
E.g. of natural source – an erupting volcano, accidental fire, etc.,
Types of Sources
Mobile sources – such as cars, buses, planes, trucks, and trains
Stationary sources – such as power plants, oil refineries, industrial facilities,
and factories
Area sources – such as agricultural areas, cities, and wood burning fireplaces
Natural sources – such as wind-blown dust, wildfires, and volcanoes
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23.
24. Effect of air pollution on human health
Air pollution : one of the greatest “ENVIRONMENTAL EVIL”.
The air we breathe has not only LIFE SUPPORTING properties
but also LIFE DAMAGING properties.
An average man breathes 22,000 times a day and takes in 16 kg of
air each day.
All the impurities in the inhaled air do not necessarily cause harm.
Some may be harmful when present in air – small concentration
and others only if they are present in high concentration.
25. Factors affecting human health
Nature of pollutants
Concentration of the pollutants
Duration of exposure
State of health of the receptor
Age group of the receptor
27. Effects of air pollution in human health
Acute effects
Chronic effects
Acute effects: are usually immediate and often reversible when
exposure to the pollutant ends. Some acute health effects includes
eye irritation, headaches and nausea.
Chronic effects: are usually not immediate and tend not to be
reversible when exposure to the pollutant ends.
Some chronic effects include decreased lung capacity and lung
cancer resulting from long-term exposure to toxic air pollutants.
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29.
30.
31. Effects of Air Pollution
Reduced lung functioning
Irritation of eyes, nose, mouth and throat
Asthma attacks
Respiratory symptoms such as coughing and wheezing
Increased respiratory disease such as bronchitis
Reduced energy levels
Headaches and dizziness
Disruption of endocrine, reproductive and immune systems
Neuro behavioural disorders
Cardiovascular problems
Cancer
Premature death
32. Effect of Air Pollution on Vegetation
Air pollutants affect plants worldwide.
These effects may be severe or subtle.
Various sir pollutants have been identified as phytotoxic
agents.
Effects of ozone (O3) for more than 30 years.
Acidic precipitation for almost 20 years.
33. Effects on Vegetation
Injury vs Damage
Injury: An observable alteration in the plant when exposed to
air pollution
Damage: An economic or aesthetic loss due to interference
with the use of a plant
34.
35. Pollutant deposition to plants
Pollutants can to deposited to plants as
Gases
Wet precipitation
Particulate matter
Gaseous pollutants may be taken up by plants via
Stomata or
Cuticle
The effects of pollutants can be observed at various levels of biological organs like:
Subcellular
Cellular
Plant organ
Whole plant
Plant population
community
36. Effects of Air Pollutants On Plants
Under field conditions detection of physiological changes in
plants and identification of their causes is difficult.
Therefore visible symptoms of injury are most commonly
used for detecting air pollution damage.
However, changes in physiological of plants may occur
before visible, morphological damage takes place.
37. Injury
Injury - Generally, pollution injury first appears as
leaf injury. Spots between the veins, leaf margin
discoloration, and tip burns are common.
38. Two ways of pollutant entrance to plant
Direct way: Through stomates which open and close to
allow air through the interior parts.
Indirect way: Through the root system. Pollutants deposit
in soil and water and these pollutants were taken by the
roots of the plant.
39. Common symptoms of damage on plants due to
air pollution
Yellowing of leaf
Burning
Stunted growth
Premature leaf drop
Early drop of blossoms
Reduced yield or quality
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43. Effects on materials
Effects on metals
Rusting
Chemical attack on surface
Corrosion due to moisture, temperature and pollutants
Alteration of electrical properties
44. Effects on stone
Discoloration
Blackening
Gypsum formation
Cracking
45. Effect of air pollution
GLOBAL WARMING
Global warming is largely caused by increasing CO2 and other heat
trapping gases (e.g. methane) in the atmosphere.
Large amount of heat trapped on Earth; Earth becomes hotter.
It results in rise in sea levels, flooding of low-lying lands, melting
of polar ice caps and changes in global climate.
Measures to reduce global warming-use of fossil fuels (to reduce
CO2 emission)
Use tidal, wind and hydroelectric energy to generate electricity -use
of solar energy.
46. Sources and classification of air pollutants and their
effect on animals, property, aesthetic value and visibility
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48.
49. Ambient air quality and emission standards
Ambient air quality criteria, or standards, are concentrations of
pollutants in the air, and typically refer to outdoor air. The
criteria are specified for a variety of reasons including for the
protection of human health, buildings, crops, vegetation,
ecosystems, as well as for planning and other purposes.
Ambient air pollution is a broader term used to describe air pollution
in outdoor environments.
Poor ambient air quality occurs when pollutants reach high enough
concentrations to affect human health and/or the environment.
51. Ambient and stack sampling and analysis
of particulate and gaseous pollutants
Ambient air quality measurement: Where the pollutant levels in the
ambient atmosphere are measured.
Stack sampling: It deals with the pollutants emitted from a source
such as smoke stack and is known as stack sampling.
Process of collecting and verifying emissions from industrial sources.
