What are the major problems regarding
Natural Resources of Bangladesh resources with Dhaka City right now?
Population Waste Generation and Management
Land Mismanagement of traffic systems
Water (ground & surface)
Mismanagement-or-Shortage of
-Sea, River, Pond and Ground water etc
Energy/Electricity: Due to lack of energy and
Air
inefficiency in use and production of energy
Sun
Forest Shortage of potable water supply
Energy Pollution: Due to mismanagement of solid and
Animals & Birds industrial waste, misuse of water, polluting air
Mines (mainly through vehicle, brick field, developmental works)
-Oil, Coal, Natural Gas Land Degradation: Due to over use of land,
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dense population in per capita area
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As a student/citizen how can you save
Ways to use resource efficiently your scarce resources for future?
You have to change your behavior in some of your daily activity
Efficiently use existed Use Renewable energy like
Do not use too much electricity in day time, do not turn on lights
energy unnecessary, turn off your lights when you will go outside your room.
-Solar Energy
Do not misuse electricity -Wind Energy Turn of you stoves when you have done your cooking.
Do not waste water -Energy from Natural Gas Try to do gardening in your home, plant trees.
Recycle solid waste -Energy from Solid waste Manage your household solid waste, try to recycle your waste, avoid
Do not misuse natural gas using polythenes and plastics.
Dump your waste in proper places.
Do not use vehicle un-necessarily where there is a walking distance.
Try to use cycles, bus as vehicle to reduce emissions.
Know the causes and remedies of environmental pollution.
Let other people know about your environmental concern through
sharing information with family and peers.
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Atmospheric Basics Structure of the Atmosphere- Layers of
the atmosphere
There are 4
layers in the
atmosphere,
Each layer differs
in composition
and temperature.
They are the
troposphere,
stratosphere,
mesosphere and
thermosphere.
5 6
Troposphere Mesosphere
Where weather happens This layer is above
Location - surface to about 10 km. the stratosphere
Composition - unpolluted air: Nitrogen (78%) Oxygen (21%).
Remaining 1% is CO2 (0.0365%), H, He, Ar. from 50 to 100 km
Water vapor is an additional variable amount, .01% to
5%.
Thermosphere
This is the highest layer
Stratosphere of the atmosphere
Where jets fly (at the bottom of it)
Location - Above troposphere, about 10-50 km. Very thin 100 to 400 km
air - virtually no weather, and no turbulence.
Composition- Similar to troposphere, except
water vapor is 1000 x less
ozone is 1000 x greater. 7 8
Air Pollution Air Quality of Dhaka City
Dhaka is the eighth largest megacity of the world and home to
Atmospheric conditions both urban and rural areas are Around 25 million people living in an area of 306.38 square
deteriorating due to air pollution. kilometres.
Uncontrolled emission from motor vehicles, dust, industrial Air pollution is emerging as a major problem in Dhaka and other
cities of Bangladesh.
waste product, construction dust, garbage, brick kilns,
The main sources of air pollution in Dhaka are vehicles,
cooking stoves, burning of wood, coal and bio-mass are industries particularly brick kilns, re-suspended dust and
mainly responsible. biomass burning, Developmental Works etc.
Common pollutants: Dust, Carbon monoxide, Nitrogen Contributing factors for vehicular emission in Dhaka are: poor fuel
quality, poorly maintained vehicles, inadequate transport
oxides & Sulpher dioxide, Respirable Suspended Particulates infrastructure, lack of proper transport planning and management.
(RSP), Smoke etc.
90% days of the year.
Effects on human health such as chronic bronchitis, acute
A World Bank study says nearly 2x105 tons air pollutants are
respiratory infection in children, lung cancer, Stroke & Heart emitted from motor vehicles alone.
diseases, abnormality during birth. Another World Bank study says as many as 15,000 deaths, a
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million cases of major illness and 8.5 million cases of minor 10
illness are caused by air pollution in Dhaka and three other cities
of Bangladesh.
Brick kilns emissions:
Coal is the main fuel for the brick
Kilns, power plant, rice mils.
Traffic Emissions About 1000 brick kilns in and around
Dhaka mega city; and about 12000
brick kilns are in all over
Bangladesh operating only winter time.
Coal has also high sulfur and Hg.
Initiatives so far taken:
Ban of biomass burning in the brick kilns
20 years old vehicle banned Severe traffic jams in the street of Dhaka Stack height not less than 120 ft
Ban of leaded gasoline Phase out of traditional kilns to relatively
Trying to use low sulfur content fuel modern kilns.
Improvement of traffic signals Rules for not cutting soil from
Ban of track and heavy duty vehicle during day agricultural land or from hills.
time Rules also for not setting the kilns near
Change of holidays for shopping malls residential location
Change of routes of different bus lines
Car free day for selected areas 11
What are the impacts of Air pollution? Principal pollutants and sources of air
o Human Health pollution in Dhaka City
o Climate Change/Global warming
o Visibility reduction Principal pollutants Sources
o Agriculture Particulate Matter (PM10, Vehicle, Brick Kiln, Cooking,
o Atmospheric Chemistry PM2.5) Combustion
o Ecosystem
Nitrogen Dioxide and Fuel burning
Carbon Monoxide
Sulphur Dioxide Coal burning
Ozone Photochemical Reaction
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Key issues identified in respect of Levels of PM10 before and after removal of Baby
Vehicle Emission Control Taxis (Phase-II)
- Poor fuel quality
600
- Many of the vehicles ply on the road are very old, worn out,
poorly maintained and often overloaded 500
- Poor inspection and maintenance 400
- Poor enforcement of existing laws in the Motor Vehicles 300 PM10
ordinance and unfairment and mismanagement of concern Average
200
Authorities
- Street congestion due to mixed traffic 100
- Inadequate facilities for manually driven tricycle rickshaws 0
- Poor traffic management
- Poor traffic signaling system
- Lack of pavement for street walkers
- more.. 15 1/24/2025 16
What is AQI? Purpose of AQI
The Air Quality Index (AQI) is a public information tool
To give complex information about the air pollution
to express the air pollution level for a particular area on
level and the quality of air in a simple way that people
a certain period
can easily understand;
A pollutant's index is its concentration
expressed as a percentage of the relevant air
standard To inform how clean or polluted air you are breathing
in relation to health based objectives; and
This is a simple way of describing the quality of air
from human health point of view
The AQI is linked to the National Ambient Air Quality To advise the people about the general health effects
Standards (NAAQS) which is set based on health associated with different pollution levels.
impacts 17 1/24/2025 18
Air Quality Index (AQI) Criteria Pollutants
U.S. EPA uses six Criteria Pollutants as indicators of air
quality, and has established for each of them a National
Ambient Air Quality Standards
Particulate matter
Ground-level ozone
Nitrogen dioxide
Carbon monoxide
Sulfur dioxide
Lead
When an area does not meet the air quality standard for one of the
criteria pollutants, it may be defined as non-attainment (especially
for ozone, carbon monoxide, and some particulate matter).
Non-attainment classifications may be used to specify what air pollution
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reach attainment.
Control strategy development There are Four Main Steps in
How to determine the best approach to provide the emission reductions Developing a Control Strategy
necessary to achieve the air quality goal. Three primary considerations in
designing an effective control strategy are (1) Determine priority pollutants - based on health effects and the
E E E (Environmental Engineering Ecomomic) severity of the air quality problem
Environmental: factors such as equipment locations, ambient air quality
conditions, adequate utilities (i.e., water for scrubbers), legal requirements, Identify control measures. For specific source categories, choose
noise levels, and the contribution of the control system as a pollutant
the appropriate controls
Engineering: factors such as contaminant characteristics (abrasiveness,
(3) Incorporate the control measures into a plan - written plan with
toxicity, etc.), gas stream characteristics, and performance characteristics of implementation dates to formalize the strategy. It is important to
the control system; and adopt a regulatory program and include it in the plan so that control
Economic: factors such as capital cost, operating costs, equipment measures will be enforceable
maintenance, and the lifetime of the equipment.
Involve the public. As with the other management activities related
to the AQM process, it is critical to contact the regulated community
Pollution prevention should also be considered (eliminating pollution emissions
and other affected parties, as the public should be consulted as
at the source, substituting toxic raw materials, alternative processes, ) part of the strategy development process
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The Clean Air Act
Methods of Air Pollution Control The Clean Air Act of 1963 is a United States federal law
designed to control air pollution on a national level. It is one of the
United States' first and most influential modern environmental
laws, and one of the most comprehensive air quality laws in
the world. Authorizes EPA to set limits on amount of specific air
pollutants permitted.
Focuses on 6 pollutants:
Mechanical Collectors
NOx Control lead, particulate matter, sulfur dioxide, carbon monoxide,
(dust cyclone)
Pollution nitrogen oxides, and ozone
Electrostatic Precipitators VOC abatement
Act has led to decreases!
Control
Baghouses Acid Gas/SO2 control Other Ways to Improve Air Quality
Devices
Reduce sulfur content in gasoline
Scrubbers Mercury Control
Sulfur clogs catalytic converters
Require emission standards for all passenger vehicles
These items are commonly used as pollution control devices by Including bus, trucks and minivans
industry or transportation devices. Require emission testing for all vehicles
They can either destroy contaminants or remove them from an 23 24
Including diesel
exhaust stream before it is emitted into the atmosphere.
Air Pollution Around the World Outdoor Air Pollution
Primary -
Air quality is deteriorating rapidly in developing smoke particles, Nitrogen, Carbon etc.
countries Secondary - Formed when primary pollutants react or
Shenyang, China combine with one another, or basic elements.
Residents only see sunlight a few weeks each year
Developing countries have older cars
Still use leaded gasoline
Worst cities in world
Beijing, China; Mexico City, Mexico; Shanghai, China;
Tehran, Iran; Delhi & Calcutta, India; Dhaka and Gazipur,
Bangladesh
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Primary Air Pollutants Primary Air Pollutants
Carbon Monoxide - Produced when organic materials are Particulates Minute pieces of solid materials dispersed
incompletely burned. into the atmosphere (<10 microns).
Single largest source is the automobile.
Smoke, Asbestos, Dust, Ash
Not a persistent pollutant.
Can accumulate in lungs and interfere with the ability of
Binds to hemoglobin in blood and makes the hemoglobin
less able to carry oxygen. lungs to exchange gases.
Most dangerous in enclosed spaces. Sulfur Dioxide (SO2) Sulfur and oxygen compound
produced when sulfur-containing fossil fuels are burned.
Cigarette smoking an important source.
Burning coal is primary artificial source
Volatile Organic Compounds (VOC)
Hydrocarbons - Group of organic compounds consisting of carbon
Volcanoes and hot springs are natural sources
and hydrogen. SO2 is also a precursor to acid rain (a secondary
Evaporated from automobile fuel or remnants of fuel pollutant)
incompletely burned.
Catalytic converters used to burn exhaust gases more
completely. 27 28
Primary Air Pollutants Photochemical Smog
Nitrogen Oxides (NO, NO2) Formed when combustion
takes place in the air.
Brown-air smog
Automobile exhaust is primary source.
Some primary
NOx is also a precursor to acid rain and pollutants react
photochemical smog (both secondary pollutants) and
is a greenhouse gas
under the influence
of sunlight
Ozone (O3) (photochemical
PANs (Peroxyacetyl nitrate) reaction), including
Aldehydes NOx, O3, PANs
all three formed by interaction between NOx and VOCs. (Peroxyacyl nitrates).
Corrosive, irritating.
Note: - Ozone is a pollutant in the troposphere, but
natural and beneficial in the stratosphere.
29 30
Regional Outdoor Air Pollution from
Industrial Smog
Acid Deposition
Gray-air smog
Wet deposition Dry deposition
From burning coal and oil (particulates, sulfur
dioxide, sulfuric acid).
London was the smog capitol. In 1952, smog
developed for days, no atmospheric mixing,
4,000 people died.
31 32
Acid Deposition and Humans Acid Deposition, Plants, and Soil
Respiratory diseases
Toxic metal leaching
Nutrient
Damage to structures, especially containing
leaching
calcium carbonate
Heavy metal
Decreased visibility
release
Decreased productivity and profitability of
Weakens trees
fisheries, forests, and farms
Acid Deposition and Aquatic Systems
Fish declines
Aluminum toxicity
Acid shock
33 34
Solutions Effects of Air Pollution on
to Acid People
Deposition
Respiratory diseases
Asthma
Lung cancer
Chronic bronchitis
Emphysema
Premature death
35 36
Control of Air Pollution What is in your car s exhaust?
CO
Industrial Activities
Scrubbers CO2
Precipitators NOx
Filters VOCs
Sulfur Removal PM
Switch to low-sulfur fuel. And can lead to formation of secondary
Remove sulfur from fuel before use. pollutants
Scrubbing gases emitted from smokestack.
37 38
Emission Reduction Reducing Motor Vehicle Air Pollution
39 40
Reducing
Indoor Air
Indoor
Pollution
Air Pollution
Pollutants can be
5-100X greater
than outdoors
Most common:
Radon, cigarette
smoke, carbon
monoxide,
nitrogen dioxide,
formaldehyde
pesticides, lead,
cleaning solvents,
ozone, and
asbestos
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