Air Pollution and Sulphur Dioxide
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Transcript of Air Pollution and Sulphur Dioxide
- 1. Sulphur Dioxide and Air Pollution
VCE Environmental Science: Unit 4
Area of Study 1: Pollution
2. Air Pollution
Air pollution is the introduction of chemicals, particulate matter
or biological materials that cause harm or discomfort to humans or
other living organisms, or cause damage to the natural or built
environment, into the atmosphere.
There is great concern over deteriorating air quality as it can
contribute to many health problems in our community, especially for
the very young, the elderly and those who already have respiratory
problems.
3. Air Pollution
Cancers and premature death can also be attributed to poor air
quality.
Air pollution not only has a real health cost, it also has an
economic and environmental cost.
Economic effects include the increased use of the health system and
reduced activity of affected people, while environmental effects
include damage to plants, animals and man-made structures, such as
buildings and monuments.
4. 5. Air Pollution and the weather
Weather conditions can affect the amount of pollution in the
air:
Wind
Temperature
Air pressure
Cloud cover
Fog, dew and frost
Precipitation (rain, snow, hail)
6. Air pollution and the weather
Larger particles in the air are readily washed out in light rain.
Fine and ultra fine particles require moderate to heavy rain to be
washed to the ground.
It should be noted that pollutant gases are generally not affected
by light rain. However, nitrogen dioxide dissolves in water and is
washed to the ground. Rainfall measurements will also be helpful in
interpreting other air pollution measurements.
For example, if there was exposed soil, windy days would cause much
of this to be blown into the atmosphere and raise particulate (PM)
readings. However, if there had been rain in the previous 48 hours,
the soil may well stay put and hence, particulate readings would be
lower.
7. Temperature Inversion
8. Air Pollutants
Carbon monoxide and CO2
Nitrogen oxides (esp. NO2)
CFCs
Ammonia
Odours
Volatile Organic Compounds
Particulate matter
Pollen, dust-mites and other allergens
Radioactive compounds
Oxides of Sulphur (esp. SO2)
9. Pollution from fireworks
It has been estimated that there were more dioxins released into
the atmosphere from the fireworks in Sydney for the commencement of
the year 2000 than was released for the entire year from industrial
sources. If this is so, why is there such a focus on industry,
rather than other sources for controlling dioxins?
10. Carbon monoxide
CO is a colourless, odourless, non-irritating but very poisonous
gas.
It is a product by incomplete combustion of fuel such as natural
gas, coal or wood.
Vehicular exhaust is a major source of carbon monoxide.
11. Carbon dioxide
CO2 is a colourless, odourless, non-toxic greenhouse gas associated
with ocean acidification, emitted from sources such as combustion
of fossil fuels, cement production and respiration.
12. Nitrogen Oxides
NOx, especially nitrogen dioxide, are emitted from high temperature
combustion. They can be seen as the brown haze dome above or plume
downwind of cities.
Nitrogen dioxide is a reddish-brown toxic gas with a characteristic
sharp, biting odour. NO2 is one of the most prominent air
pollutants, causing respiratory illnesses and reducing ventilation
(air getting to the lungs), especially in young children, the
elderly and those with respiratory illnesses.
13. Nitrogen dioxide
NO2 is also a precursor to summer smog, which is fast becoming a
major problem in our cities. The NO2 in the atmosphere reacts with
oxygen (O2) in the air when it is sunny and the temperatures are
high to form ozone (O3) the major component of summer smog.
Summer smog causes eye, nose and throat irritation, damages the
respiratory tract and increases our sensitivity to allergens.
These oxides of nitrogen are removed from the air by rain, by
plants and by contact with surfaces.
14. Chlorofluorocarbons
Chloroflourocarbons (CFCs) are harmful to the ozone layer
They are emitted from old aerosol cans and refrigeration
units.
Banned from use since 1989.
15. Ammonia (NH3)
Ammonia is emitted from agricultural processes and is normally
encountered as a gas with a characteristic pungent odour.
Ammonia contributes significantly to the nutritional needs of
terrestrial organisms by serving as a precursor to foodstuffs and
fertilizers.
Ammonia, either directly or indirectly, is also a building block
for the synthesis of many pharmaceuticals. Although in wide use,
ammonia is both caustic and hazardous
16. Odours
Odours are also classified as air pollutants and can originate
from:
Garbage and landfills
Sewage and treatment plants
Industrial processes (milk and cheese processing for example)
Dairies, sheep-yards, saleyards, zoos and abattoirs
17. Volatile Organic Compounds (VOCs)
VOCs include methane and otherhydrocarbons, such asbenzene, toluene
and xylene.
VOCs are significant greenhouse gases via their role in creating
ozone and in prolonging the life of methane in the
atmosphere.
VOCs are suspected carcinogens and may lead to leukemia through
prolonged exposure.
18. Particulate matter
Particulates, alternatively referred to as particulate matter (PM)
or fine particles, are tiny particles of solid or liquid suspended
in a gas.
In contrast, aerosol refers to particles and the gas together.
Sources of particulate matter
can be man made or natural.
Some particulates occur naturally, originating from volcanoes, dust
storms, forest and grassland fires, living vegetation, and sea
spray.
Dirty Little Secrets from ABC Catalyst is about the effects of PM
on human health.
http://www.abc.net.au/catalyst/stories/s1630007.htm
19. Particulate matter
Indoor particulate matter can include dust, smoke, pollen, animal
dander, tobacco smoke, particles generated from combustion
appliances such as cooking stoves, and particles associated with
tiny organisms such as dust mites, moulds, bacteria, and
viruses.
Outdoors, the anthropogenic sources of particulate matter can be
vehicle exhausts, industrial processes, wood heaters,
fuel-reduction burning and power generation.
20.
http://www.mde.state.md.us/programs/ResearchCenter/ReportsandPublications/Pages/ResearchCenter/publications/general/emde/vol1no12/particlepollution_photo.aspx
21. Particulate matter
Human activities, such as the burning of fossil fuels in vehicles,
power plants and various industrial processes also generate
significant amounts of aerosols.
Averaged over the globe, anthropogenic aerosolsthose made by human
activitiescurrently account for about 10 percent of the total
amount of aerosols in our atmosphere.
Increased levels of fine particles in the air are linked to health
hazards such as heart disease, altered lung function and lung
cancer.
22. Air Pollution and allergies
The increased rates of allergy and asthma in city environments and
in those living close to highways has drawn attention to the role
of outdoor pollution.
Common air pollutants, such as ozone, sulfur dioxide, and nitrogen
dioxide probably act more as irritants than as promoters of
sensitization.
These pollutants have been shown to be hazardous to adults and
children with asthma. Recent studies suggest that prematurely born
children are more sensitive to the respiratory effects of outdoor
pollution.
There may also be an association with diesel exhaust particles and
the worldwide increase in respiratory allergies. Diesel exhaust has
been shown to enhance the ability to make the allergy antibody,
IgE, in response to exposure to allergens.
23. Pollen, dust-mite and other allergens
Indoor air pollution is among the top fiveenvironmental health
risks.* Gaseous pollutants can be released from furnishings and
from adhesives, paints, varnishes, cleaning products and
pesticides,all of which contribute to poor indoor air quality.
Pollen, dust-mite faeces, skin flakes, pet dander, tobacco smoke
and other allergens can be reduced by regular cleaning and adequate
ventilation.
*http://www.epa.gov/iaq/pubs/airclean.html
24. Pollen is in the air seasonally, with the amount varying from
one area to another,depending on the types of wind pollinating
plants in the region and the weather conditions.
For some people the amount of pollen in the air has a direct effect
upon their health. Airborne pollen on its own, or in combination
with fine particles in the air, can influence the incidence and
severity of asthma and hayfever in the community.
25. Pollen in the air
During and after rain (often thunderstorms) some grains of pollen
burst, releasing theallergen containing starch granules. In
Melbourne after rain, air samples have been shown to contain up to
50 times more starch granules than air sampled on a sunny day
during the grass pollen season. The starch granules are small
enough to be breathed in and can enter the bronchi (tubes to the
lungs), where they may trigger allergic asthma.
26. 27. Radioactive Pollutants
Produced by nuclear explosions and damaged nuclear power plants,
war explosives and natural processes such as the radioactive decay
of radon.
28. Sulphur Oxides
Oxides of Sulphur, especially sulphur dioxide, a chemical compound
with the formula SO2are common pollutants of the air. SO2 is
produced by volcanoes and in various industrial processes.
Since coal and petroleum often contain sulphur compounds, their
combustion generates sulphfur dioxide. Further oxidation of SO2,
usually in the presence of a catalyst such as NO2, forms H2SO4, and
thus acid rain.
29. Sulphur Dioxide
Sulphur dioxide (SO2) is a colourless gas that is similar in smell
to a matchstick being struck.
As its name suggests it is a compound consisting of sulphur and
oxygen, and has both natural and anthropogenic or man-made
sources.
It has significant health and environmental effects, including the
formation of acid rain and smog and influences global
warming.
30. Characteristics of SO2
Sulphur dioxide consists of one atom of sulphur bonded to two atoms
of oxygen. It is a strong, acrid smelling, non-flammable gas.
It reacts in the atmosphere to form sulphur trioxide, and dissolves
readily in water vapour, forming sulphuric acid. It can also attach
to dust and soot particles in the atmosphere to form
particulates.
From these reactions, a wide range of effects are possible,
including the formation of pollutants that influence both human
health and environmental processes.
31. Sources of SO2
Sulphur dioxide is formed through a number of pathways, including
the burning of sulphur in the presence of oxygen and the oxidation
of hydrogen sulphide, commonly emitted from wetlands.
Natural sources include volcanoes, forest-fires, oceans and
decaying plant matter. These outweigh anthropogenic sources, with
volcanic activity producing about 20% of the global total.
In Australia, the two main anthropogenic sources are power stations
and metal manufacturing, while smaller sources include
home-heating, chemical production and transportation
emissions.
32. Sulphur dioxide sinks
Sulphur dioxide is a naturally occurring compound with a number of
'sinks' or areas that can absorb excess amounts thus reducing its
abundance in the environment,such as the oceans, wetlands and
lakes.
33. Acid Rain
This phenomenon results when sulphur dioxide dissolves in moisture
in the air, forming sulphur acids, which eventually fall to the
surface of the earth as acid rain.
Acid rain directly attacks the protective coating of plants,
acidifies lakes and soils which may result in the formation of
substances that are toxic to plants and animals.
34. Acid Rain
This has been a major problem in northern USA, Canada and
Scandinavia, where forests have been severely damaged, but
fortunately regulations are improving emission standards, and
reducing the incidence of acid rain.
Coal mined in Australia is typically low in sulphur; therefore
emissions are usually not a problem.
We also have large sinks (oceans) in the southern hemisphere which
assists to reduce the effects.
35. 36. Effect on the Built Environment
In addition to damaging living organisms, acid rain can have a
severe effect on buildings made of marble or limestone.Commonly
used in statues and older buildings, these materials slowly
dissolve under acidic conditions leading to structural failure.
This has been a significant problem in Europe with many old
buildings made of marble and limestone.
37. Effects of SO2 on Humans
The presence of high levels of sulphur dioxide has a negative
effect on human health and society.
Inhaled sulphur dioxide quickly dissolves with moisture on the
lining of the lungs and nose, burning the mucous membranes. This is
clear to anyone who accidentally inhales the smoke from a match
being struck.
Chronic - or long-term - exposure to high levels of SO2 leads to
breathing problems and respiratory illnesses such as asthma,
bronchitis as well as heart disease.
Children tend to more vulnerable due to less developed lungs.
38. 39. 40. 41. 42. 43. 44. 45. References
http://www.npi.gov.au/students/sulfur-dioxide.html
http://www.npi.gov.au/substances/sulfur-dioxide/index.html
http://en.wikipedia.org/wiki/Sulfur_dioxide
http://science.howstuffworks.com/nature/climate-weather/atmospheric/acid-rain.htm