Air pollution
(Processes of air pollution) Attrition
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(Processes of air pollution) Combustion
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(Processes of air pollution) Vaporization
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Particles smaller than 2.5 micrometers, PM2.5, tend to penetrate into gas-exchange regions of the lung.
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The smallest particle, < 100 nanometer (nanoparticles), may be even more damaging to the cardiovascular system. Particles emitted from modern diesel engines are typically in the size range of 100 nanometers (0.1 micrometer)
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read about preventing and reducing air pollution in the prezi
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worst events for brown air cities?
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worst events for grey air cities?
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what is the annual emissions of carbon monoxide?
1 billion metric tons
what are the annual emissions of sulfur compounds?
114 million metric tons
according to the EPA how many Americans each year get cancer from breathing diesel fumes?
125,000 Americans get cancer each year from breathing diesel fumes.
In the U.S., the EPA estimates that annual death related to indoor and outdoor pollution range from?
150,000 to 350,000 deaths
what are the annual emissions of nitrogen compounds>
230 million metric tons
how many people die prematurely each year because of air pollution? mostly from what type of air pollutions
3 million people, mostly from indoor air pollution in developing countries.
how many metric tons do anthropogenic particulate emissions amount to annually?
362 million metric tons annually.
how many premature deaths a year is EPA responsible for according to the EPA?
6,000 premature deaths.
what percent of U.S. agricultural production is lost due to ozone pollution?
6-7% of U.S. agricultural production is lost due to ozone pollution
anual emissions of carbon dioxide?
7-8 bilion metric tons
(major air pollutants) Sulfer dioxide (SO2) and sulfuric acid
About one-third of SO2 in the troposphere occurs naturally through the sulfur cycle. Two-thirds come from human sources, mostly combustion of sulfur containing coal and from oil refining and smelting of sulfide ores SO2 in the atmosphere can convert to sulfuric acid and sulfate salts that return to earth as a component of acid deposition.
(conventional pollutants) Particulate Matter:
Atmospheric aerosols (solid or liquid) Respirable particles smaller than 2.5 micrometers are among the most dangerous.
Conventional Pollutants Carbon Oxides: what is the predominant form of carbon in the air?
Carbon dioxide is the predominant form of carbon in the air. Increasing levels due to human activities.
Major air pollutants Carbon Oxides:
Carbon monoxide (CO) is a highly toxic gas that forms during the incomplete combustion of carbon-containing materials.
The Clean Air Acts in the United States have greatly reduced out door air pollution from six major air pollutants:
Carbon monoxide. Nitrogen oxides. sulfur dioxides. and suspended particulate matter (less than PM-10)
Ozone (O3) can?
Cause and aggravate respiratory illness. can aggravate heart disease. Damage plants, rubber in tires, fabrics, and paints.
Cultural processes of Air Pollution
Continuous rather than sporadic emissions. Local concentration in small areas. Combinations of cultural pollutants are potentially bad. Local discharges can overwhelm natural buffers.
what is the equation for photochemical smog?
Ground level ozone (O3) + other photochemical oxidants + aldehydes + other secondary pollutants= photochemical smog "sunlight plus cars equals photochemical smog"
Indoor air pollution
Indoor air pollution usually is a greater threat to human health than outdoor air pollution.
(major air pollutants) Ozone (O3):
Is a highly reactive gas that is a major component of photochemical smog.
(major air pollutants) Radon (Rn):
Is a naturally occurring radioactive gas found in some types of soil and rock. It can seep into homes and buildings sitting above such deposits. Radon is the second leading cause of lung cancer.
in addition, these soot particles also carry carcinogenic components like benzopyrense absorbed on their surface.
It is becoming increasingly clear that the legislative limits for engines, which are in terms of mass, are not a proper measure of the health hazards.
(human-caused air pollution) Secondary Pollutants?
Modified to a hazardous form ofter entering the air and mixing with other environmental components. While in the atmosphere some primary pollutants react with one another and with other natural components of the air to form new harmful chemicals, called secondary pollutants.
(Major air pollutants) Volatile Organic Compounds (VOCs):
Most are hydrocarbons emitted by the leaves of many plants and methane. Other VOCs include industrial solvents such as trichlorethylene (TCE), benzene, and vynyl chloride. Long-term exposure to benzene can cause cancer, blood disorders, and immune system damage.
(major air pollutants) Nitric acid
NO reacts with air to form NO2. NO2 reacts with water vapor in the air to form nitric acid (HNO3) and nitrate salts (NO3-) which are components of acid deposition.
Natural sources of air pullution
Natural fires- smoke Volcanoes- ash and acidic components Sea Spray- sulfer Vegetation- Volatile organic compounds Bacterial Metabolism- Methane Dust Pollen Viruses and Bacteria
(conventional Pollutants) Nitrogen compounds
Nitrogen oxides are reactive gases formed when nitrogen is heated above 650 degrees C in the presence of oxygen, or when nitrogen compounds are oxidized.
stratosphere
Ozone in the atmospheres second layer (stratosphere) filters out most of the sun's UV radiation that is harmful to us and most other species.
very small particles (< 100 nanometers) may pass through the lungs to affect other organs. A study published in the Journal of American Medical Association indicates that PM2.5 leads to?
PM2.5 leads to high plauque deposits, causing vascular inflammation and atherosclerosis-( a hardening of the arteries that reduces elasticity) Researchers suggest that even short-term exposure at high concentrations could significantly contribute to heart disease.
Larger particles are generally filtered in the nose and the throat and do not cause problems, but particulate matter smaller than how many micrometers, referred to as what? can settle in the bronchi and lungs and cause health problems
Particulate matter smaller than about 10 micrometers, referred to as PM10, can settle in the bronchi and lungs and cause health problems. The 10 micrometer size does not represent a strict boundary between respirable and non-respirable particles, but has been agreed upon for monitoring.
what is the predominant form of anthropogenic sulfur?
Predominant form of anthropogenic sulfur is sulfur-dioxide from fossil fuel combustion.
(human-caused air pollution) Primary Pollutants?
Released directly from the source. Primary pollutants are chemicals or substances emitted directly into the air from natural processes and human activities at concentrations high enough to do harm.
key note: some pollutants can be both primary and secondary at the same time.
Some primary air pollutants may react with one another or with other chemicals in the air to form secondary pollutants
Acid deposition
Sulfer dioxides, nitrogen oxides, and particulates can react in the atmosphere to produce acidic chemicals that can travel long distances before returning to the earth's surface.
indoor air pollutants in developed countries are:
Tabacco smoke. Formaldehyde. Radioactive radon-222 gas. Very small fine and ultra-fine particles.
(climate and topography) Inversions:
Temperature inversions occur when a stab;e layer of warm air overlays cooler air, reversing the normal temperature decline with increasing height, and preventing convection currents from dispersing pollutants. 2 types of inversions: Cold front slides under warm air mass. cool air subsides down slope. (rapid nighttime cooling in a basin)
what fraction of global methane emissions comes from human sources?
Two thirds
Outdoor air pollution can be increased by:
Urban buildings (slow wind dispersal of pollutants. Mountains (promote temp. inversions) and high temperatures (promote photochemical reactions).
Case study: South Asia's massive brown cloud.
a huge dark brown cloud of industrial smog, caused by coal-burning in countries such as China and India, stretches over much of southeastern Asia. In areas beneath the cloud, photosynthesis os reduced interfering with crop development. Fine particles and droplets in the cloud appear to be changing regional climates.
Photochemical smog
air pollution containing ozone and other reactive chemical compounds formed by the action of sunlight on nitrogen oxides and hydrocarbons, especially those in automobile exhaust.m
Fugitive Emissions
are emissions of gases or vapors from pressurized equipment due to leaks and other unintended or irregular releases of gases, mostly from industrial activities
Conventional Pollutants Carbon monoxide
carbon monoxide is a colorless, odorless, toxic gas produced by incomplete fuel combustion.
(Major air pollutants) Suspended particulate matter (SPM)
consists of a variety of solid particles and liquid droplets small and light enough to remain suspended in the air.
(conventional pollutants) Sulfur Compounds: Natural sources of sulfur in the atmosphere include?
evaporation from sea spray. volcanic fumes. and organic compounds.
7% of CO2 in the troposphere occurs as a result of?
human activities mostly burning fossil fuels. it is not regulated as a pollutant under the U.S. clean air act.
Tall smokestacks reduce local air pollution but can?
increase local air pollution
Core Case study: when is a lichen like a canary?
lichens can warn us of bad air because they absorb it as a source of nourishment. after Chernobyl, more than 70,000 reindeer had to be killed because they ate highly radioactive lichens. Because lichens are widespread, long lived, and anchored in place, they can help track pollution to its source.
Acid deposition consists of rain snow, dust or gas with a ph
lower than 5.6
(major air pollutants) Nitrogen oxide
nitrogen oxide (NO) forms when nitrogen and oxygen gas in the air react at high-cumbustion temperatures in automobile engines and coal-burning plants NO can also form from lightening and certain soil bacteria. No reacts with air to form NO2.
one particle of 10 micrometers in diameter as approximately the sam mass as?
one particle of 10 micrometers in diameter as approximately the sam mass as 1 million particles of 100 nanometers in diameter. but it is clearly much less hazardous, as it probably never enters the human body- and if it doers it is quickly removed.
case study: Radioactive Radon
radon-222 a radioactive gas found in some soils and rocks, can seep into some houses and increase the risk of lung cancer.
Outdoor air pollution can be reduced by:
settling out, precipitation, sea spray, winds, and chemical reactions.
Troposphere
the atmospheres inner most layer is made up mostly of nitrogen and oxygen, with smaller amounts of water vapor and CO2
93% of carbon dioxide (CO2) in the troposphere occurs as a result of?
the carbon cycle
what are the most harmful forms of SPM?
the most harmful forms of SPM are fine particles (PM10, with an average diameter < 10 micrometers) and ultra-fine particles (PM2.5)
Particulate Size
the size of a particulate is a main determinant of where in the respiratory tract the particle will come to rest when inhaled. Because of the size of the particle, then can penetrate the deepest part of the lungs.
Solutions: reducing air pollution
there are a few ways to prevent and control air pollution from coal-burning facilities. these ways include: Electrostatic precipitator: used to attract negatively charged particles in a smokestack into a collector. Wet scrubber: fine mists of vapor trap particulates and convert them to a sludge that is collected and disposed of usually in a landfill.
What are the layers of the atmosphere in order from closest to furthest away from the earths surface?
troposphere. stratosphere. mesosphere. thermosphere. exosphere.
health effects of air pollution
your respiratory system can help protect you from air pollution, but some pollutants can overcome these defenses.