Air PollutionChloe, Melissa, Jauza, Joe

To Wake You Up...

Pollution“We rarely consider normal conditions a problem, or imagine alternatives, until a

crisis makes us start to question the costs of customary ways of doing

business”

Natural Air Pollutants● Volcanoes● Sea Spray and Decaying Vegetation● Trees and bushes● Storms in arid regions● Bacterial metabolism of decaying

vegetation in swamps

Criteria Pollutants ● What are criteria pollutants?

● Primary Pollutants vs Secondary PollutantsPrimary Pollutants: released directly from the source into the air in a harmful formSecondary Pollutants: converted to a hazardous form after they enter the air or are formed by chemical reactions as components of air mix and interact

● Fugitive Emissionthose pollutants that do not go through a smoke stack.

Sulfur dioxide Natural sources● Evaporation of sea

spray ● erosion of sulfate

containing dust from arid soils

● fumes from volcanoes and hot springs

● biogenic emission of hydrogen sulfide and organic sulfur containing compounds

Anthropogenic sources● Combustion of sulfur

containing fuel● Purification of sour

natural gas or oil● industrial processes -

smelting of sulfide ores

Effects of Sulfur dioxide?

● Further oxidised to sulfur-trioxide reacts with water vapour or dissolves in water droplets forming sulfuric acid Acid Rain

● Reduce visibility● Smelly ● Corrosive● Illness and death

Oxides of Nitrogen NOx

Natural sources● Lightening● Bacteria oxidize

nitrogen containing compounds in soil and water

● Denitrifying bacteria convert ammonia to nitrous oxide

Anthropogenic Sources● Fuel combustion in

transportation and electric power generation

● Fertilizers

Effects of Nitrogen oxides

● Reddish brown gas that gives photochemical smog the colour

● Greenhouse gas - absorbs UV light● Nitrogen oxides combine with water

Acid Rain● Eutrophication● Fertilise invasive plants andweeds affecting terrestrial plants

Carbon monoxide (CO)

● Produced by incomplete combustion of fuel

● Natural source: Decomposition of organic matter

● Anthropogenic Source: * Burning fuel in furnaces,

incinerators and engines* Land-clearing and cooking fires

Effects of CO?

● Blocks oxygen uptake in blood● About 90% of CO in air converted to

CO2 in photochemical smog this reaction produces Ozone

What can be done to reduce CO emission?Catalytic convertors ensure complete combustion.

Ozone and Photochemical Oxidants

● Ground level ozone is produced as a result of photochemical reactions between other pollutants.

● Photochemical oxidants● Volatile Organic Compounds (VOC)

*Plants* Natural wetlands and rice paddies*Bacteria in guts of termites and ruminant

animals

● Synthetic Organic ChemicalsEmitted mainly by unburned/ partially burned hydrocarbons from transportation, power plants, chemical plants, petroleum refineries.

● Ozone damages vegetation, building materials,sensitive tissues.

LeadSources:● Smelting of metal ores● Burning of coal and municipal waste● Mining● burning gasoline with leadEffects:Toxic to our nervous system

Particulate Matter* Particulate Matter: solid particles or liquid droplets suspended in a gaseous medium* Aerosols: very fine solid or liquid particles suspended in the atmosphere

Includes: dust, ash, soot, lint, smoke, pollen, spores, algal cells

Produced by:● Fires, ● Power plant or vehicle exhaust● ConstructionEffects:● Reduce visibility● Damage respiratory tissues

Mercury and Other Metals● Released into atmosphere by burning coal and

oil, mining, smelting of metal ores, or manufacturing

● Lead, mercury, cadmium, nickel, and arsenic are emitted as metal fumes or suspended particulates

● Lead and Mercury most abundant● Small doses cause nerve damage and other

impairments● Young children and fetuses are most vulnerable● Airborne mercury occurs naturally from

volcanoes and rock weathering● 70 percent atmospheric mercury is from coal

burning power plants, metal processing, and industrial processes

Mercury cont.● 75 percent of human exposure comes from fish● Aquatic bacteria convert airborne mercury to

methyl mercury● Methylmercury accumulates in animal tissue

and is passed on up trophic levels● Predatory fish contain highest levels of mercury● Tuna causes 40 percent of U.S. exposure● Mercury also accumulates in freshwater fish

CO2 and other greenhouse gases● Human activities have increased CO2 in the atmosphere to

levels that are changing our climate● Regulating CO2 requires drastic changes in our technology and

behaviors● Greenhouse gas emissions often tied to economic productivity,

which makes it hard for policy-makers to impose severe regulations

● The Supreme Court ruled in 2007 that it was the EPA’s responsibility to limit greenhouse gases

● The EPA regulates six greenhouse gases: CO2, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride

Greenhouse gases cont.● Three of the six greenhouse gases regulated by the EPA are

halogens, which are highly reactive and toxic in elemental form● These have been used as fumigants and disinfectants, and in

hundreds of industrial and commercial products● Chlorofluorocarbons (CFCs) had long been used as spray

propellants and in refrigerator compressors until being banned● These diffuse into elemental chlorine and fluorine in the

stratosphere and destroy ozone molecules● Halogens are also strong greenhouse gases that trap far more

heat than CO2● Strategies for containing greenhouse gases include subsidies for

alternative energy, less subsidies and tax breaks for fossil fuels, taxes on coal and oil, and cap and trade systems

Hazardous Air Pollutants (HAPs)● Particularly dangerous toxins monitored by the EPA● Include carcinogens, neurotoxins, mutagens, teratogens,

endocrine system disruptors, etc.● Persist in ecosystems for long periods of time and accumulate in

animal tissues● Common HAPs include gasoline vapors, solvents, and

components of plastics● EPA’s Toxic Release Inventory (TRI) provides information from

23,000 factories, refineries, mines, power plants, and manufacturers about 667 different toxic chemicals

● 100 million Americans live in areas where cancer rates from HAPs exceed 10 in 1 million (10 times accepted standards)

Atmospheric Processes ● Temperature inversions: a stable layer of warm

air overlying cooler air, trapping pollutants near ground level○ This greatly concentrates air pollutants because

these conditions prevent convection currents from dispersing pollutants

○ These conditions often occur when cold air settles in a valley that is surrounded by hills or mountains

○ Inversions might last from a few hours to a few days

Examples:● The London Smog of 1952

○ Where drivers were blinded by the smoke and fog○ Hundreds of cattle died because their lungs were blackened by soot and

suffered suffocation while standing in their pens○ People ran to their homes but soot penetrated inside buildings and homes○ At least 4,700 deaths were attributable to air pollution and recent

epidemiological studies have found that perhaps another 8,000 people had died in the months that followed making a total death toll of over 12,000

● Los Angeleso The city is surrounded by mountains on 3 sides and the climate is dry with

abundant sunshine for photochemical oxidation and ozone productiono Millions of automobiles and trucks create high pollution levels

Wind Currents and Pollutants ● Areas downwind from industrial complexes often suffer serious contamination, even if they

have no pollution sources of their own Examples of wind carrying pollutants are:

Pollution from the industrial belt between the Great Lakes and the Ohio River Valley which regularly contaminates the Canadian Maritime Provinces and sometimes can be traced as far as Ireland

Long range transportation of Asian mercury to North America A 3-km-thick toxic cloud of ash, acids, aerosols, dust and photochemical

reactants regularly covers the entire Indian subcontinent and can last for much of the year

o Places usually considered among the cleanest in the world have heavy metals, pesticides, and radioactive elements in their air

Places like: Samoa, Greenland, Antarctica, and the North Pole

o Grasshopper transport or atmospheric distillation: helps deliver contaminants to the poles

o Contaminants accumulating in cold places bioaccumulate in food chains Top carnivores in polar regions have been shown to have dangerously high levels

of pesticides, metals, and other HAPs in their bodies

Some Estimates:● Nobel laureate Paul Crutzen estimates that up to 2 million

people in India alone die each year from atmospheric pollution● The Asian smog layer cuts by up to 15% the amount of solar

energy reaching the earth's surface● Meteorologists suggest that the cloud -80% of which is human-

made- could disrupt the monsoon weather patterns and may be disturbing rainfall and reducing rice harvests over much of South Asia

● UN Environment Programme executive director Klaus Töpfer said, "There are global implications because a pollution parcel like this, which stretches 3 km high, can travel halfway round the globe in a week"

● In 1985 the British Antarctic Atmospheric Survey announced a startling and disturbing discovery: the Stratospheric ozone concentrations over the South Pole were dropping abruptly during September and October every year as the sun reappeared at the end of the long polar winter

● What was this discovery called?

Layers of the Atmosphere

Ozone Depletion● Ozone depletion has been occurring at least since the 1960s but wasn't recognized

because early researchers ignored the ozone changes since they thought that they were "erroneous"

● Chlorine- based aerosols, especially chlorofluorocarbons (CFCs) and other halon gases, are the principal agents of ozone depletiono CFCs were extremely useful as industrial gases and in refrigerators,

A/Cs ,Styrofoam inflation, and aerosol spray cans for many years● An ozone "hole" is really a vast area of reduced concentrations of ozone in the

stratosphere.o Although ozone is a pollutant in the ambient air, ozone in the stratosphere is

important because it absorbs much of the harmful ultraviolet (UV) radiation that enters the outer atmosphere.

A 1% loss of ozone could result in about a million extra human skin cancers/year worldwide

Excessive UV exposure could reduce agricultural production and disrupt ecosystems

Antarctica's exceptionally cold winter temperatures help break down ozone.

Summary Video

The video mentions the Montreal Protocol, does anyone know what it is?

The Montreal Protocol● In 1987 an international meeting in Montreal, Canada, produced the Montreal Protocol, the first of several major international

agreements on phasing out most use of CFCs by 2000 Upon evidence of how fast and widespread the losses of the stratospheric ozone were, the deadline moved to

1996 and a $500 million fund was established to assist poorer countries in switching to non- CFC technologies The first substitutes were hydro-chlorofluorocarbons (HCFCs), which release much less chlorine per

molecule Montreal Protocol is cited as the most effective international environmental agreement ever established Global CFC production has been cut by more than 95% since 1988 Based on the progress, it's expected for stratospheric ozone levels to be back to normal by 2049.

There are varying views in this trend, however. The 2006 ozone hole was the largest ever. Ironically, climate warming (heat retention) in the lower atmosphere has contributed to cooling of the stratosphere. This cooling increases ice crystal formation over the Antarctic and results in more ozone depletion.

o Reductions in emissions of these gases under the Montreal Protocol amount to 1 quarter of all greenhouse gas emissions worldwide

o Under the Montreal Protocol, China, India, Korea, and Argentina were allowed to continue to produce 72,000 tons (combined) of CFCs per year until 2010

Effects of Air PollutionDamages to lungs● 5-6 million people die yearly due to

illnesses related to air pollution. ● In industrialised nations, soot and

particulate matter is the biggest health threats

● Linked with heart attacks, asthma, bronchitis, lung cancer, immune suppression and abnormal fetal development

Make us sick● damage delicate tissue like the eyes

and lungs.● penetrate deep into the lungs and

carry metals and other HAPs on the surface.

● Inflammation impair lung function and trigger cardiovascular problems

Bronchitis

- severe bronchitis leads to emphysema- 300,000 people suffer from pollutionrelated bronchitis inUS.

Plant Damage● Fumes from refineries, smelters, furnaces, and

chemical plants can destroy nearby vegetation● Since 1886, a copper and nickel smelter in

Sudbury, Ontario released sulfur dioxide into nearby ecosystems, killing all vegetation and leaving the land barren after rain washed away the soil

● 400 m tall smokestacks and sulfur scrubbers were added and ecosystems began to recover

● Pollution damages plants in two ways:o Can be directly toxic, resulting in damage

of cell membranes, mottling (discoloration), and necrotic (dead) spots

o Synergistic effects are caused by exposure to multiple pollutants that individually would have no effect

Acid deposition● Release of wet acidic

solutions or dry particles from the air

● Carried long distances by wind currents

● Can occur naturally from sea spray, volcanoes, and decomposition

● Anthropogenic acids are far more abundant than those that occur naturally

● Causes damage to forests and other ecosystems, and buildings and monuments

Controlling Air Pollution● Sulfur Removal

o “Clean Coal”

● Nitrogen Oxideso Control of air and fuel

● Hydrocarbono Complete combustiono Closed systems

● Particulate Removalo electrostatic precipitator

o solid waste

Alternatives + ProgressClean Energy = Less Air Pollution

● Low-sulfur coal● Switching fuel ● Clean Air Act

o “new source review”o Generally successful

Personal Change - What Can You Do?

● Carpool● Plant a tree!● Be involved in clean air

legislation● Avoid aerosol products

(spray paints)

International Population and industrialization growth is

outpacing pollution safety measures, but there is progress

● China● India

Minnesota, Olaf● Van Go! ● Sustainable Energy move● Toxic Taters Movement

o Pesticide Drift

Northfield http://weather.weatherbug.com/MN/Northfield-weather/air-quality.html

CAFO’s● Waste Storage/Disposal● Housing of Animals

o Methane, Ammonia, Hydrogen Sulfide