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Environment Pollution
Enviroment Pollution
Environment pollution:-May be defined as the
contamination of air, water, food in such manner
as to cause real or potential harm to human health
or well-being or to damage the non-human
nature.
Basically pollution can be classified to:
1. Air pollution
2. Water pollution
3. Noise pollution
4. Solid waste
5. Radio active waste
Air pollution
Comes from
1. increase the population in the world
2. increase the amount of power
3. power plant (factories)
4. automobiles (trucks, Buses, Personal car, aircraft)
The major source of air pollutant comes from the non
stoichiometric combustion, dissociation of Nitrogen
oxides and impurities in the fuel of air.
The emission of concern are:
1. carbon monoxide CO
2. oxides of Nitrogen NO
3. hydro carbon HC
4. photo chemical smag
5. sulfur oxides SO
6. lead and phosphorous
7. solids particles
1- Carbon Monoxides CO:- is a product of
in complete combustion of hydrocarbon
fuel (CnHn). Most of CO comes from the
exhaust of vehicles, CO is colorless,
odorless.
O2 + HB  HBO2 + CO  HBCO
Stable
2- Hydro Carbon H-C
Comes from exhuse gases, and will be
different for each gasoline
depend on the original fuel. HC emission act
as irritants and odorant, all H-C except CH4
it may reach with atmosphere to form
photochemical smog some of H-C when get
into atmosphere act as carcinogenic
3-Oxides of Nitrogen (NO):Exhaust gases contion NO in most ofit's constituent
and trace amount of NO2 and other nitrogenoxygen combination NO2 is a very undesirable
emission, especially released of NO react with
atmosphere to form (ozone,O3)and is one of the
major causes of photochemical smog, high temp
produce (NO) which is then oxidized further to
form NO2
N2 + O2  2NO
NO + H2 O  NO2 + H2
4-Phatochemical smog
is one of the primary causes of photochemical
reaction of automobile exhaust and atmosphere
air in the presence of sunlight
NO2 + Energy of sunlight  NO + O + Smog
O + O2  O3 (ozone)
Ground level ozone is harmful to lung and biological
tissue, also it's harm tress and harm full to tress &
other vegetable plant.
5- Sulfur oxides
Many fuel used in engine contain sulfure in it's exhaust which
contribute in acid rain formation, at high temp, sulfur combines
with hydrogen to form H2S and with oxygen to form SO2
H2 + S  H2S
O2 + S  SO2
Then 2SO2 + O2  2SO3
SO3 combine with water vapour in the atmosphere to form
sulfuric acid (H2SO4)and sulfurous acid (H2SO4) and sulfurous
acid (H2SO3 ) which are ingredients in acid rain
SO3 + H2O  H2SO4
SO2 + H2O  H2SO3
6-Lead and phosphorans:
Lead was a major gasoline additive (tetraethyl lead)
was effectively used to increase the gasoline,
octane number which allowed higher compression
ratio and more efficient engine. However the
resulting lead engine exhaust was highly
poisonous pollutant, small amount of phosphorous
are emitted also, these comes from impurities in
the air and small amount found in some fuel
blends and lubrication oil.
7-Solid particles
(Particulates)
Small solid particles and liquid droplets collectively called
(Particulates) are present in air in great number, and at times
constitute a serious pollution problem, particulates are some
times classified as viable (capable of living), or non viable.
Some examples of viable particulates are bacteria, fungi, and spores. Non viable
particulates, include such substances as organic compounds, metals, dust, and
sea salt. Particulate air pollution warrant serious attention for several reasons:
1.
2.
3.
4.
Many particulates affect respiratory system, more effectively than air pollutant.
Particulates increase atmospheric turbidity and reduce visibility.
Particulates are formed within the atmosphere from some gaseous pollutant.
Some particulates behave as synergistic and enhance the toxic effects of other
pollutants.
Health Effects
The respiratory system
The major target of air pollutants is the respiratory system. Air
and entrained pollutants enter the body through the throat and
nasal cavities and pass to the lungs through the trachea and
bronchia.
Entrained pollutant particles can be prevented from entering the
lung by the action of ting hairs called (cilia) that sweep mucus
out through the throat and nose.
The bronchial cilia can be paralyzed by inhaled smoke enhancing
the synergistic effect between smoking and air pollution.
In the lungs, the air movies through bronchial tubes to the alveoli,
small air sacka in which oxygen from the lungs is transferred to
the blood.
Effect of Carbon Monoxide
The effect of CO inhalation on human health is directly
proportional to the quantity of CO bound to
hemoglobin.
Oxygen is transported in the blood as oxyhemoglubin
(HbO2 ), it is semi stable compound in which O2 is
weakly bound to Fe+2 in hemoglobin in red blood cells.
The O2 is removed for cell respiration and the
regenerated hemoglobin is available for more oxygen
transport.
CO reduces the oxygen-carring capacity of the blood
by combining with hemoglobin and forming
carboxyhemoglubin (HbCO) which is stable.
Hemoglobin that is tied up as (HbCO) can be
regenerated and is not available for oxygen
transport for the life of that particular red
blood cell.
In this way (CO) effectively poisens the
hemoglobin oxygen transport system.
Hemoglobin has a greater affinity for (CO)
than for molecular oxygen.
Effect of Sulfer Oxide
The cilia that protect the respiratory system by
sweeping out particles are effected by gaseous air
contamination.
The predominant effect on the cilia of smokers
is paralysis from the constituents of tobacco
smoke. Sulfur dioxide also affect ciliar behaviour.
Thus SO2 affects the protection mechanism of
the respiratory tract in addition to contracting the
bronchia.
Effect of NO
NO2 is a pulmonary irritant. High
concentration of NO2 can produce
pulmonary edema; an abnormally high
accumulation of fluid in the lung tissue
Effect of Ozone
Ozone and photo chemical oxidants are highly
irritating, oxidizing gases, concentration of few
parts million can produce pulmonary congestion,
edema, and pulmonary heamorrage.
A one hour exposure of human subject to
25g/m3 can decrease effective lung volume and
decrease maxium breathing capacity.
Symptoms of ozone and oxidixant exposure
are a dry throat followed by headache,
disorientation and altered breathing patterns.