air pollution prepared by : kholoud thiab dr : raed al kowni
TRANSCRIPT
Air PollutionPrepared by : Kholoud Thiab
Dr : Raed Al Kowni
Content-Atmosphere.
-Atmosphere layers.
-Air pollution.
-Major categories of air pollution sources.
-Effects of air pollution.
-Air Pollution & Health.
-The major air pollutants.
-Acid rain.
-Air toxics.
-Indoor air pollution.
-Control of air pollution.
-The atmosphere is a complex natural gaseous system (78% nitrogen and 21% oxygen with traces of water vapor, carbon dioxide, argon, and various other components) surrounding the planet Earth essential to support life on planet by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation).
Atmosphere layers: -Exosphere
-Thermosphere
-Mesosphere
-Stratosphere : ozone layer
-Troposphere.
-Stratospheric ozone depletion due to air pollution has been recognized as a threat to human health as well as to the Earth's ecosystems.
-Air pollution is the introduction of particulates, biological molecules, or other harmful materials into
the Earth's atmosphere, possibly causing disease, death to humans, damage to other living organisms
such as food crops, or the natural or built environment.
Major categories of air pollution sources1 -stationary sources include:
-point sources :emit pollution from controllable site.
-fugitive sources :generate air pollution from open area exposed to wind.
-area sources :area which had several sources of pollutants.
2 -mobile sources include:
Automobile, trucks, buses, ships, air craft and any thing pollute air and moves from place to place.
Effects of air pollution
Air pollution affect of many aspect of our
environment include visual qualities, vegetation,
animals, soils, water quality, natural and
artificial structures and human health .
Air Pollution & Health
-Lung Function , Lung Growth, Lung disease
-Inflammatory Markers
- Blood Viscosity & Irregularities in Heartbeats
- Pulmonary Deaths
- Cardiovascular Deaths
-Mortality
-Cardiovascular disease
-Cystic fibrosis
-Cancer
The major air pollutants
*Primary pollutant :emitted directly into the air .they
include particulates, carbon monoxide, sulfur dioxide,
nitrogen oxides and hydrocarbons.
*Secondary pollutant :produced from reaction between
primary pollutant and normal atmosphere compound .such
as ozone forms over urban area through reaction of primary
pollutants, sunlight and natural atmosphere gases .
Primary Pollutant
-Sulfur oxides (SOx) : colorless, odorless gas, produced by
volcanoes and in various industrial processes. Coal and
petroleum often contain sulfur compounds, and their combustion
generates sulfur dioxide. SO4 combines with water to form acid
rain ,toxic to plants and animals.
- Nitrogen oxides (NOx) ,nitrogen dioxide, and nitric oxide: yellow
brown to reddish gas . Nox converted to nitrates in atmosphere causing
acid rain . expelled from high temperature combustion, and are also
produced during thunderstorms by electric discharge.
-Carbon monoxide (CO) : colorless, odorless, toxic.9o%
natural 10%from incomplete combustion of fuel and
cigarettes . Vehicular exhaust is a major source of carbon
monoxide.
Combines with hemoglobin in blood →reduce ability to
carry oxygen.
.
-methane (CH4): is an extremely efficient greenhouse
gas which contributes to enhanced global warming .
-non-methane (NMVOCs) : benzene, toluene and
xylene are suspected carcinogens and may lead to
leukemia with prolonged exposure. 1,3-butadiene is
another dangerous compound often associated with
industrial use.
particulate matter (PM) : tiny particles of solid or liquid
suspended in a gas. Some particulates occur naturally,
originating from volcanoes, dust storms, forest and grassland
fires, living vegetation, and sea spray. Human activities, such
as the burning of fossil fuels in vehicles, power plants and
various industrial processes also generate significant amounts
of aerosols. Increased levels of fine particles in the air are
linked to health hazards such as heart disease, altered lung
function and lung cancer.
Ammonia (NH3) - emitted from agricultural processes. It is
normally encountered as a gas with a characteristic pungent
odor. Ammonia contributes significantly to the nutritional
needs of terrestrial organisms by serving as a precursor to
foodstuffs and fertilizers.it is also a building block for the
synthesis of many pharmaceuticals. Although in wide use,
ammonia is both caustic and hazardous. In the atmosphere,
ammonia reacts with oxides of nitrogen and sulfur to form
secondary particles.
Lead : exposure to lead occurs through inhalation air and ingestion of
lead in food, water, soil or dust.
It accumulates in blood, bone and soft tissue and can adversely affect
kidney, liver, nervous system and other organs.
*Excessive exposure to lead cause:
-Neurological impairment such as seizures, Mental retardation and
behavioral disorders.
*Recent studies indicated that lead may be factor in high blood pressure
and heart disease.
*Lead deposited on leaves of plants presented a hazard to grazing animal
and to human through ingestion.
Secondary pollutants
ozone (O3) : is a key constituent of the troposphere, highly
poisonous gas with strong odor.
*Breathing O3 Irritates Airways affect respiratory and nervous
systems.
*O3damage plants → leaf mottling and reduce growth.
-Photochemical oxidant : arising from atmospheric
interaction of nitrogen dioxide and sunlight .
Formation of ozone
Symptoms
-Cough
–Sore or scratchy throat
–Pain with deep breath, or chest pain
–Fatigue
Ozone Causes Inflammation
•Ozone reacts completely in surface layer
•Forms reactive oxygen molecules
•Influx of white blood cells – neutrophils, eosinophils
•Damages cells that line the airway
•Effect is greater 24 hours after exposure
Acid rain
is a rain or any other form of precipitation that is unusually acidic,
meaning that it possesses elevated levels of hydrogen ions (low pH ≤
5.6). It can have harmful effects on plants, aquatic animals and in forest.
Acid rain is caused by emissions of sulfur dioxide and nitrogen oxide,
which react with the water molecules in the atmosphere to produce
acids .
H2O (l) + CO2 (g) is in equilibrium with H2CO3 (aq)
H2O (l) + H2CO3 (aq) is in equilibrium with HCO3− (aq) + H3O+ (aq)
Combustion of fuels produces sulfur dioxide and nitric
oxides. They are converted into sulfuric acid and nitric
acid.
SO2 + OH· → HOSO2·
HOSO2· + O2 → HO2· + SO3
SO3 (g) + H2O (l) → H2SO4 (aq)
Acid rain
Adverse effects
Surface waters and aquatic animals : damage fish and other
aquatic animals. biodiversity is reduced.
Soils : Soil biology and chemistry can be seriously damaged by
acid rain. Some microbes are unable to tolerate changes to low
pH and are killed . The enzymes of these microbes are
denatured (changed in shape so they no longer function) by the
acid .
.
Human society : Acid rain can damage buildings, historic
monuments, and statues, especially those made of rocks, such as
limestone and marble, that contain large amounts of calcium
carbonate. Acids in the rain react with the calcium compounds
in the stones to create gypsum, which then flakes off.
Forest ecosystem : slowed tree growth, leaves turn brown and
fall off, death of trees.
Air toxics
Air toxics include gases, metals and organic chemicals that are
emitted in relatively small volume (example: benzene).
They cause respiratory, neurological, reproductive and immune
disease and may be carcinogenic
The effect on individual health depend on:
-duration and frequency of exposure.
-toxicity of chemicals.
-concentration of pollutant.
-mode of exposure.
Indoor air pollution
-The pollution com from our homes, schools and other
building that we are spend time in it.
-Formaldehyde is the major cause of indoor air
pollution.
Sources of indoor air pollution
-building materials.
-cigarette smoking.
-pesticides.
-Volatile organic from paints, furniture, rugs, insulation.
Symptoms of indoor air pollution
-irritation of mucous membrane.
-coughing.
-dizziness.
-nausea.
-death.
Solution to indoor air pollution
-use ventilation system.
-Source removal: no smoking.
-Source modification: more efficient stove design.
-Pollutant removal: filters.
-Education.
-Designing building to minimize indoor air pollution.
Control of air pollution
-planting more trees.
-reducing vehicle exhausts.
-using less polluting fuels.
-removal of particulate matter using electrostatic precipitator,
cyclone filter.
-industrial area should be cited far away from residential area.