air pollution
TRANSCRIPT
Air Pollution
Air Pollution
By: OmidAdamMoh’d SabzivaryAli HaiderSaif
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
Types of Sources:Types of Sources:
1. Point source - single, identifiable source e.g. smokestack, drainpipe etc
2. Non-point source - dispersed source, e.g. runoff from pesticides, fertilizers
Non-point sourcesNon-point sources
Point sourcePoint source
What are the key environmental problemsWhat are the key environmental problems
A. Population growth B. Resource use without preventing pollution and reducing waste C. Degrading habitats and reduction of biodiversity D. Poverty E. Failure of government to encourage earth sustaining economic development
The AtmosphereThe Atmosphere
Gases that envelop the Earth and are held here by 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 equator and many others hydrogen, neon, helium, krypton, ozone and methane
What are the major sources and types of air
pollution?
What are the major sources and types of air
pollution?
Air pollution-DefinitionAir pollution-Definition
the presence of one or more chemicals in the atmosphere in sufficient quantities and duration to cause harm to humans and other life forms.
Air PollutionAir PollutionAir pollution results from human
activities such as burning fossil fuels (oil, coal, and gasoline) to create electricity and 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.
Air pollutionAir pollution
The increased carbon dioxide in the atmosphere contributes to the warming of the global climate, the so-called "greenhouse effect."
The increased Chlorofluoro-carbons in the atmosphere has been depleting ozone.
Sources of Air pollutionSources of Air pollution
Natural: volcanoes, fumaroles and hot springs decay from marshes, bogs increase ozone due to thunderstorms,
fires.
Man made (most severe for human health):Man made (most severe for human health):
Stationary sources - those that are fixed in location.
point sources e.g. smoke stacks, 14% air pollution from plants generating electricity;
fugitive sources e.g. construction sites, exposed areas;
area sources e.g. dense urban community or agricultural area
Mobile sources - those that move while polluting, e.g. trucks, cars, busses etc. 60% of air pollution from motor vehicles. 80-88% in major cities!
What are the main categories of air
pollutants?
What are the main categories of air
pollutants?
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 pollutant with a natural component of the environment.; e.g. some ozone, sulfuric and nitric acids.
Primary pollutantsPrimary pollutants
Carbon oxides (CO2 and CO)Nitrogen oxidesSulphur oxidesVolatile organic compounds –
hydro carbonsSuspended particulate matter
Primary air pollutantsPrimary air pollutants
Sulfur dioxide, SO2, colorless, odorless gas. particulates of SO4 which combines with water to form 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 nitrogen dioxide NO2. NO2 yellow brown to reddish gas. (NOx) Converted to nitrates in atmosphere causing acid rain.
Photochemical smog, brown air smog. Smog is smoke + fog.
Photochemical Smog Photochemical Smog Smog is a kind of air pollution,
originally named for the mixture of smoke and fog in the air.
HC and NO react in presence of sunlight to produce ozone and PAN (peroxy acetyl nitrate)
Nitrogen oxides + hydrocarbons + Ultraviolet radiation -----> Peroxyacetyl nitrate PAN + O3 ozone.
Photochemical smog- EffectsPhotochemical smog- Effects
breathing ozone results in respiratory distress, headaches.
PAN damages plantsPAH's polynuclear aromatic hydrocarbons, carcinogenic.
Photochemical SmogPhotochemical Smog
What are the effects of air pollution?
What are the effects of air pollution?
The effects of air pollutionThe effects of air pollution
reduces visual range and atmospheric clarity, less contrast, less visibility
damage to vegetation, including leaves, needles, fruit, growth rate, reproduction, hardiness.
Decline in net primary productivity NPP.
Crop losses 1.9-5.4 b/yr.
The effects of air pollutionThe effects of air pollution
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.
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 lining of the upper respiratory tract causing diseases like lung cancer, asthma, chronic bronchitis etc.,
Nitrogen oxides and suspended particles both can irritate lungs, aggravate asthma or chronic bronchitis and increase respiratory infections.
Many volatile organic compounds such as benzene and formaldehyde and toxic particulates such as lead and cadmium can cause mutations, breathlessness and irritation of the eye, nose and throat.
Effects of air pollutionEffects of air pollution
Sulphur dioxide irritates respiratory tissues and chronic exposure causes bronchitis.
Sulphur dioxide also reacts with water, oxygen and other materials to form sulphur containing acids – The acids can become attached to particles which when inhaled are very corrosive to the lung.
Effects of air pollutionEffects of air pollution
Effects of air pollutionEffects of air pollution
Chronic exposure of the leaves to air pollutants can break down the waxy coating that helps prevent excessive water loss and leads to damage from diseases, pests, drought and frost.
It also affects photosynthesis, respiration and other metabolisms.
Doubling carbon dioxide
Doubling carbon dioxide
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.
Increase in the emissions of carbon during the interval from 1860-1995
Increase in the emissions of carbon during the interval from 1860-1995
Cycle of carbon dioxideCycle of carbon dioxide
Impact of increasing CO2 levels in the atmosphereImpact of increasing CO2 levels in the atmosphere
Increased photosynthesis and productivity by the earth’s vegetation .
Increased plant production also means increased respiration .
Elevated atmospheric CO2 is global warming
Elevated CO2 means an increase in global temperature - the greenhouse effect.
Global temperatures may increase by 3°C-4°C by the end of the next century .
Green house effectGreen house effect
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, and ozone.
Greenhouse gasesGreenhouse gases
Green house effectGreen house effectCarbon dioxide and other gases allow light
to pass, but trap heat in the atmosphere much like glass in a greenhouse traps heat.
This greenhouse effect is thought to be responsible for global warming.
Carbon dioxide contributes to only 56% of greenhouse heating.
The average surface temperature of Earth is about 15°C (59°F).
Global Warming is increase in the average temperature of the atmosphere, oceans, and landmasses of Earth.
Impact of Global warmingImpact of Global warming
1. 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 water 5. Drought 6. Food shortages due to shift in agricultural
food production 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
How To Conserve Energy How To Conserve Energy
Be energy-wiseExplore alternativesRecycle as much as possible. Take showers instead of baths.Check your taps. Check the lights Check your stove. Use less cooking water. Check the refrigerator.
What is acid rain; what are its causes and effects?
What is acid rain; what are its causes and effects?
Environmental Impact of Acid depositionEnvironmental Impact of Acid deposition
Sterilization of lakes and forests. Reducing the populations of small
invertebrates and decomposers. Reducing agricultural yields. Causing extensive structural damage by
corroding marble, metal, and stonework. Degrading water supplies by leaching heavy
metals from the soil into drinking-water supplies.
Increases in lung cancer and colon cancer.
Acid rainAcid rain The term "acid rain" is commonly used to mean the
deposition of acidic components in rain, snow, fog, dew, or dry particles.
The more accurate term is "acid precipitation.“ "Clean" or unpolluted rain is slightly acidic, its pH
being about 5.6, because carbon dioxide and water in the air react together to form carbonic acid, a weak acid.
• H2O + CO2 → H2CO3 (aq) The extra acidity in rain comes from the reaction of
primary air pollutants, primarily sulfur oxides and nitrogen oxides, with water in the air to form strong acids (like sulfuric and nitric acid).
The main sources of these pollutants are vehicles and industrial and power-generating plants.
Effects of Acid RainEffects of Acid Rain
Acidify lakes and disrupt the normal cycling of nutrients,
leaches metals out of rocks and soil
kill fish, plants; stress and defoliate trees due to moss growth, insect attack, and loss of nutrients.
Acid rain - causesAcid rain - causes
The principal cause of acid rain is sulfur- and nitrogen compounds from human sources, such as electricity generation, factories and motor vehicles. Coal power plants are one of the most polluting.