POLLUTION &
EUTROPHICATION
Biology 420 Global Change
Announcements
Presentations/Science Brief
  Midterm
  Assignments

  Due
today by 5pm: Acid Precipitation Homework
  Due next Thursday: Sea Level Rise Homework
Smog
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Urban settings – cities
  As
humans settle, cities grow, waste
builds up
  Industrial revolution – burning of coal
  Urban air pollution – smog

Airborne toxic event – London
1952
  December
5-9, 1952 – British Isles
capped by a large-scale
temperature inversion and dense fog
  Pollutants accumulated in air
  Smog – smoke and fog
Los Angeles Smog
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Term “smog” used to describe air pollution derived from
emissions of automobiles
Los Angeles – overrun by cars
Emission react with sunlight to form “photochemical smog”
Primary and Secondary Pollutants
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Primary gaseous pollutants are those that are directly emitted into the
atmosphere
Secondary gaseous pollutants are those that are generated in the
atmosphere from primary pollutants
Also, difference between gaseous pollutants and aerosols/particulates
Basic Ingredients
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Coal-burning
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Smoke and organic fumes
High levels of sulfur dioxide
Acid precipitation
Automobile exhaust
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Nitrogen oxides – NOx
Carbon monoxide
Reactive hydrocarbons
Primary Pollutants

Sulfur oxides (SOx)
  Volcanoes
  industrial
processes –
found in coal and
petroleum – SO2
reacts to form sulfuric
acid

Nitrogen oxides (NOx)
  Result
from high
temperature
combustion
  Brown haze
Primary Pollutants cont’d

Carbon monoxide (CO)
  Colorless,
odorless, non-irritating but poisonous gas.
  By-product by incomplete combustion
  Vehicular exhaust

Carbon dioxide (CO2)
  colorless,
odorless, non-toxic greenhouse gas
  ocean acidification
  Sources include combustion, cement production, and
respiration
Primary Pollutants cont’d

Volatile organic compounds – VOCs
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Two categories: methane (CH4) and non-methane (NMVOCs).
Methane -greenhouse gas
Other hydrocarbon VOCs are also significant greenhouse gases via their
role in creating ozone and in prolonging the life of methane in the
atmosphere
NMVOCs - the aromatic compounds benzene, toluene and xylene are
suspected carcinogens
Particulate matter (PM)- PM10, PM2.5
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Tiny particles of solid or liquid suspended in a gas.
In contrast, aerosol refers to particles and the gas together.
Sources : volcanoes, dust storms, forest and grassland fires, living
vegetation, and sea spray and anthropogenic sources (~10% of total)
such as burning of fossil fuels in vehicles, power plants and various
industrial processes
Primary Pollutants cont’d
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Free radicals – disease
Toxic metals - lead, cadmium and copper.
Chlorofluorocarbons (CFCs) – ozone hole
Ammonia (NH3)
  Emitted
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from agricultural processes.
Odors (various organic compounds) — such as from
garbage, sewage, and industrial processes
Radioactive pollutants
  Produced
by nuclear explosions
  War explosives
  Natural radioactive decay of radon
Secondary Pollutants


Particulate matter formed from gaseous primary
pollutants and compounds in photochemical smog.
Ground level ozone (O3) formed from NOx and VOC.
  In
stratosphere - Ozone layer
  In troposphere - abnormally high concentrations brought
about by human activities (largely the combustion of fossil
fuel), ozone is a pollutant, and a constituent of smog.

Peroxyacetyl nitrate (PAN)
  formed
from NOx and VOCs
Clean Air Act

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Passed in 1970,
amended in 1977
and again in 1990
The Clean Air Act U.S. Environmental
Protection Agency sets
national health-based
air quality standards
to protect against
common pollutants
including
(1) Not to be exceeded more than once per year.
(2)Final rule signed October 15, 2008. The 1978 lead standard (1.5 µg/m3 as a quarterly average) remains in effect until one year after an area is designated for the 2008 standard, except that in areas designated nonattainment for the 1978
standard, the 1978 standard remains in effect until implementation plans to attain or maintain the 2008 standard are approved.
(3) The official level of the annual NO2 standard is 0.053 ppm, equal to 53 ppb, which is shown here for the purpose of clearer comparison to the 1-hour standard
(4) To attain this standard, the 3-year average of the 98th percentile of the daily maximum 1-hour average at each monitor within an area must not exceed 100 ppb (effective January 22, 2010).
(5) Not to be exceeded more than once per year on average over 3 years.
(6) To attain this standard, the 3-year average of the weighted annual mean PM2.5 concentrations from single or multiple community-oriented monitors must not exceed 15.0 µg/m3.
(7) To attain this standard, the 3-year average of the 98th percentile of 24-hour concentrations at each population-oriented monitor within an area must not exceed 35 µg/m3 (effective December 17, 2006).
(8) To attain this standard, the 3-year average of the fourth-highest daily maximum 8-hour average ozone concentrations measured at each monitor within an area over each year must not exceed 0.075 ppm. (effective May 27, 2008)
(9) (a) To attain this standard, the 3-year average of the fourth-highest daily maximum 8-hour average ozone concentrations measured at each monitor within an area over each year must not exceed 0.08 ppm.
(b) The 1997 standard—and the implementation rules for that standard—will remain in place for implementation purposes as EPA undertakes rulemaking to address the transition from the 1997 ozone standard to the 2008 ozone standard.
(c) EPA is in the process of reconsidering these standards (set in March 2008).
(10) (a) EPA revoked the 1-hour ozone standard in all areas, although some areas have continuing obligations under that standard ("anti-backsliding").
(b) The standard is attained when the expected number of days per calendar year with maximum hourly average concentrations above 0.12 ppm is < 1.
(11) (a) Final rule signed June 2, 2010. To attain this standard, the 3-year average of the 99th percentile of the daily maximum 1-hour average at each monitor within an area must not exceed 75 ppb.
Water Pollution
Point and Non-Point Source
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Point source – industry, factory at a river or the ocean
Non-point – agriculture, feedlot, cropland, street runoff
etc…
Oxygen depletion
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Strong link between areas with high densities of industrial
activity and zones of seasonally oxygen-depleted waters
It has been estimated that about 80% of all marine
pollution originates from land-based activity (rivers and
atmospheric deposition)
Eutrophication has been linked to the formation of ‘dead
zones’ on the ocean floor.
One of the largest known ’dead zones’ is found along the
United States shoreline of the Gulf of Mexico, which receives
large volumes of fertilizer from the Mississippi River system
Eutrophication can also cause harmful algal blooms (HABs),
which can harm fish and shellfish, as well as the people who
consume them
Seasonal oxygen depleted waters
Hypoxia
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Dead zones (hypoxic i.e. oxygen deficient water) in the coastal
zones are increasing due to nutrient pollution, in the form of nitrogen
and phosphorous leading to algal blooms and eutrophication
Sewage/wastewater
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Sewage treatment is low or absent in many parts of the World
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Eutrophication
Algal blooms
Reduced ability of coral to recover from bleaching events
Biological Oxygen Demand
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The availability of oxygen is one of the most important indicators of the
condition of a water body, because dissolved oxygen, or DO, (the amount
of oxygen dissolved in water) is necessary for most aquatic organisms
Some improvement in Europe
Biological Oxygen Demand
A chemical procedure for determining the amount of
dissolved oxygen needed by aerobic biological
organisms in a body of water to break down
organic material present in a given water sample at
certain temperature over a specific time period.
  Used as an indication of the organic quality of
water.
  Expressed in mg O2/L consumed during 5 days of
incubation at 20 °C (BOD5)

De-Oxygenation

A closed system, where you start with a
concentration of O2 and your system has a BOD.
The O2 will be depleted exponentially.
Re-Aeration

If no BOD, the O2 from atmosphere will dissolve
into water to a saturation point that’s temperature
dependent.
Point Source Pollution – BOD Problem
Oxygen Sag Curve
Acid Mine Drainage
Pyrite Oxidation
2FeS2(s) + 7O2 + 2H2O = 2Fe2+ + 4SO42- + 4H+

Iron Oxidation
4Fe2+ + O2 + 4H+ = 4Fe3+ + 2H2O

Thiobacillus ferroxidans
More Oxidation
FeS2(s) + 14Fe3++ 8H2O = 15Fe2+ + 2SO42- + 16H+
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Link to Cryosphere

Recall the last lecture…
Pollution and Polar Bears
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Between 20,000 and 25,000 bears globally
Occur in19 relatively discrete sub-populations
Top the food chain in the Arctic and thus exposed to
high levels of pollutants - biomagnification.
Immune system may be weaker in polar bears with
higher levels of toxic contaminants (e.g., Polychlorinated
Biphenyls or PCBs)
PCBs- various applications:
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used as coolants
insulating fluids for transformers and capacitors
plasticizers in paints and cements
stabilizing additives
adhesives and more
Hormone system of polar bears is affected by
pollution, something that may interfere with
reproduction and growth.
Climate change - secondary release of toxic
contaminants in melting snow, ice and permafrost