APES
POLLUTION NOTES
POLLUTION VOCABULARY
Risk – a measure of the likelihood that you will suffer harm from a hazard.
Hazard –Something that can cause injury, disease, economic loss, or
environmental damage.
Toxicology – Study of adverse effects of chemicals on health.
Toxicity – Measures how harmful a substance is in causing injury, illness, or
death to a living organism.
Dose - is the amount of a substance a person has ingested, inhaled, or absorbed
through the skin.
Response – the type and amount of health damage that result from exposure to a
chemical or other agent.
Poison or toxin – is a chemical that adversely affects the health of a living
organisms causing injury, illness, or death.
How Much Exposure to a Particular Toxic
Chemical Causes a Harmful Response?
50 %
Method:
Measure chemical’s median
lethal dose (LD50); the
amount received in one dose
that kills 50% of the
organisms (usually rats or
mice) in a test population
within a 14 day period.
Threshold Level
0.0001
0.001
Dose mg/kg (ppm)
0.1
1.0
Measurements for Expressing Levels of Contaminants in Food
and Water
For Acute Toxicity Tests
Dose
Metric Equivelent
Approximate
Amount of Water
Parts per million
(ppm)
Milligrams per
kilogram (mg/kg)
1 teaspoon per
1000 gallons
Parts per billion
(ppb)
Micrograms per
kilogram (g/kg)
1 teaspoon per
1,000,000 gallons
Major Types of AIR Pollutants
Air Pollution is the presence of one or more chemicals in the
atmosphere in quantities and duration that cause harm to humans,
other forms of life, and materials.
Primary Pollutants – chemicals released into the atmosphere that mix
both vertically and horizontally and are dispersed and diluted in the
troposphere.
Secondary Pollutants – primary pollutants that react with other basic
component of air to form new pollutants.
Primary & Secondary Pollutants
Photochemical Smog (Brown Smog)
• Photochemical smog is a mixture of primary and secondary pollutants
formed under the influence of sunlight.
• Primary Pollutants involved are mostly NOx and volatile hydrocarbons
+ sunlight to produce ozone (O3), aldehydes (CH2O), PANS (peroxyacyl
nitrates), and nitric acid (HNO3).
Chemical Reactions Form Chemical Oxidants
• N2 + O2
2NO
• 2NO + O2
2NO2 (yellowish brown gas with a choking odor)
• Some of the NO2 reacts with water vapor to produce nitric acid and nitric oxide
which ultimately forms ozone.
• 3NO2 + H2O 2HNO3 + NO
• NO2 + uv radiation
NO + O
• O2 + O
O3
• Hydrocarbons + O2 + NO2
PANS
Industrial Smog (gray smog)
• Industrial smog consists mostly
of sulfur dioxide, suspended
droplets of sulfuric acid, and a
variety of suspended solid
particles and droplets that
emanate from coal and heavy
oil burning power plants and
factories.
Industrial Smog Chemistry
• When coal and oil are burned:
C + O2 CO2 and/or 2C +O2 2CO
• The sulfur compounds in coal and oil react with oxygen to produce sulfur dioxide, a colorless, suffocating gas.
S + O2 SO2
In the troposphere, some of the sulfur dioxide reacts with oxygen to form sulfur trioxide which then reacts with water
vapor to produce tiny suspended droplets of sulfuric acid.
2SO2 + O2 2SO3
SO3 + H2O H2SO4
Some of the sulfuric acid droplets react with ammonia in the atmosphere to form solid particles of ammonium sulfate
(salt). These salts + soot give the characteristic gray color to this smog.
2NH3 + H2SO4
(NH4)2SO4
Factors That Influence The Formation of Smog
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Local climate
Topography
Amount of industry
Fuels used in industry, heating & transportation
Amount of precipitation (rain and snow cleanse atmosphere of pollutants)
Wind patterns (winds sweep pollutants away)
Hills and mountains reduce flow of air in valleys and allow pollutants to
accumulate at ground level.
• Diurnal temperature fluctuations allow pollutants to move upward and
downward in atmosphere (density differences) to prevent pollutants from
accumulating at ground level.
Thermal Inversions
• Warm air normally rises in the atmosphere. In
a valley, a layer of dense, cool air, can become
trapped below a layer of warm air capped by a
denser cool air layer. This prevents air from
ascending keeping air pollutants trapped in the
lowest cool air layer. These events typically
only occur for a few hours. When high
pressure air masses stall over valley areas,
thermal inversions can last for several days.
• Las Angeles California is surrounded by
mountains on three sides with over 15 million
people, over 24 million motor vehicles and is
subject to thermal inversions 50% of the year!
• LA = has the worst air pollution in the USA
Other Highly Polluted Cities in the World
• Denver, Colorado
• Mexico City, Mexico
• Rio de Janeiro and Sao Paulo,
Brazil
• Beijing and Shenyang, China
• Bangkok, Thailand
Mexico City
Beijing,China
Effects of Air Pollutants on Health
• Sulfur dioxide – causes constriction of the airways and causes severe constriction
for people with asthma. (WHO estimates 625 million people exposed from
burning fossil fuels).
• Nitrogen Oxides – especially NO2 can irritate the lungs, aggravate asthma and
chronic bronchitis, cause emphysema-like conditions, and increase susceptibility
to respiratory infections. NO2 has recently been attributed to the cause of
malignant melanoma.
• VOC’s – (benzenes and formaldehyde) and toxic particulates such as lead,
cadmium, PCB’s and dioxins (agent orange) can cause mutations, reproductive
problems, and cancer.
• Ozone – causes coughing, chest pain, shortness of breath, and eye, nose, and
throat irritation. “Ozone alert days” - Has nothing to do with UV index!
Solutions: Preventing and Reducing Air Pollutants
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Clean Air Acts of 1970, 1977, and 1990 – These laws require the
EPA to establish national ambient air quality standards (NAAQS) for
seven outdoor pollutants:
Suspended particulate matter
Sulfur oxides (SOx)
Carbon monoxide (CO)
Nitrogen oxides (NOx)
Ozone (O3)
Volatile Organic Compounds (VOC’s)
Lead (Pb)
How Can US Air Pollution Laws Be Improved?
• 1. Pollution prevention is best! Leaded gasoline outlawed, lead in air
was reduced by 98%.
• 2. Increase fuel efficiency standards for cars and trucks, this will
reduce oil imports.
• 3. Require stricter emission standards.
• 4. Fund research and development of alternative energy resources.
• Subsidize businesses and homeowners, vehicle owners for using
energy conservation approaches such as hybrid vehicles, solar and
wind energy for space heating, green buildings, etc..
WATER POLLUTION
SEDIMENT POLLUTION
• “Sediment Kills Reefs”
• Sediment releases into surface waters due to poor land management decreases water clarity,
increases turbidity, buries organisms, decreases the availability of light for photosynthesizing
organisms, and brings insoluble toxic pollutants including PCB’s and DDT.
• 1.3 million pounds of PCB’s in Hudson River from GE Plant. Must dredge 2.6 million yards! Long
residence time in environment.
• DDT banned in the USA for application BUT we are the #1 producers of DDT for sales worldwide!
Long residence time in environment. DDT (50years), DDE (200 years).
INORGANIC CHEMICALS
(water-soluble nutrients)
• Heavy metals such as mercury (Hg) and lead (Pb) from industry, mines, irrigation
runoff, oil drilling, and urban runoff from storm sewers. (point source and nonpoint source pollution)
• Lead (Pb) – additives in gasoline (MTBE’s) contaminate the air. Lead gas banned
in the USA (still available in other parts of the world). It is also present in
incinerator ash. This is classified as “hazardous” waste and must be disposed of
in a special landfill. It leaches into groundwater. Residues can also be found on
food resources located downwind from incinerators. Lead paints – banned in
USA, but can still be found in buildings.
• Greatest risk for Pb poisoning are mid-aged men (high blood pressure), pregnant
woman (miscarriage, premature births and stillbirths), and young children
(mental/physical impairments – hearing loss, hyperactivity, ADD, low IQ, LD).
INORGANIC CHEMICALS
(water-soluble nutrients)
• Mercury (Hg) – mostly from industrial processes (wastewater), also from
batteries, paints and plastics burned in incinerators. Burning converts it to
methyl mercury which readily enters food webs.
• Bioaccumulation in muscle of tuna, shark, and swordfish.
• Biomagnification since they are top predators.
• Long residence time in environment – toxic to humans and causes mental
retardation in children and kidney failure.
BIOACCUMULATION AND BIOMAGNIFICATION
Biomagnification
• Nitrogen and phosphorous loading (cultural eutrophication
causes and increase in algae (bloom) which causes a decrease
in DO resulting in the death of aquatic organisms.
Decomposing aerobic bacteria continue using DO (increase in
BOD) in water until the conditions become Anoxic!
SEPTIC TANKS
Septic tanks are used in areas where there are no combined
sewers.
Septic tanks
(cesspools) must
be emptied each
year. Old tanks
can crack and leak
coliform bacteria
into surrounding
soil, groundwater,
and surface
waters.
SEWAGE TREATMENT
• Sewage treatment means
removing impurities so
that the remaining waste
water can be safely
returned to the surface
waters (river, bay, ocean)
and become part of the
natural water cycle again.
• sewage treatment
separates solids from
liquids by physical
processes and purifies the
liquid by biological and
chemical processes
PRIMARY TREATMENT
• solids are separated from the
liquid by passing the sewage
through large settlement
tanks, where most of the solid
material sinks to the bottom.
About 70% of solids settle out
at this stage and are referred
to as sludge. The sludge is
used on farms after further
treatment called sludge
treatment.
SECONDARY TREATMENT
• a biological process which relies on naturally
occurring microorganisms acting to break
down organic material and purify the liquid.
• The rate of this process can be increased by
pumping air into tanks of sewage where the
aerobic digesters float freely and feed on the
bacteria. These treatment units are called
aeration tanks.
• Following either form of secondary
treatment, the waste water is settled in tanks
to separate the biological sludge from the
purified waste water.
Primary
Bar screen
Grit
chamber
Secondary
Settling tank
Aeration tank
Settling tank
Chlorine
disinfection tank
To river, lake,
or ocean
Raw sewage
from sewers
(kills bacteria)
Sludge
Activated sludge
Air pump
Sludge digester
Sludge drying bed
Disposed of in landfill or
ocean or applied to cropland,
pasture, or rangeland
(Sludge cake or pellets)
WAYS TO REDUCE CULTURAL EUTROPHICATION
• Advanced waste treatment (sewage and industrial)
• Regulate detergents cleaning products for phosphates. They have been regulated
since the 1970’s on Long Island!
• Promote soil conservation and preservation of wetlands to capture and filter
pollutants before they enter surface waters.
• Regulate fertilizer, pesticide, agricultural and livestock runoff to control Nitrogen,
phosphate, and PAH’s.
• Create policies and economic incentives for doing these things!
EXXON VALDEZ OIL SPIILL
• On March 24, 1989, shortly after midnight, the oil tanker Exxon Valdez struck
Bligh Reef in Prince William Sound, Alaska, spilling more than 11 million gallons of
crude oil. The spill was the largest in U.S. history. Capt. Joe Hazelwood, who later
admitted to having had several alcoholic drinks that day.
• The spill posed threats to the delicate food chain that supports Prince William
Sound's commercial fishing industry. Also in danger were ten million migratory
shore birds and waterfowl, hundreds of sea otters, dozens of other species, such
as harbor porpoises and sea lions, and several varieties of whales.
• In the aftermath of the Exxon Valdez incident, Congress passed the Oil Pollution
Act of 1990, which required the Coast Guard to strengthen its regulations on oil
tank vessels and oil tank owners and operators. Today, tank hulls provide better
protection against spills resulting from a similar accident, and communications
between vessel captains and vessel traffic centers have improved to make for
safer sailing.
OIL SPILLS
• Spills occur at offshore oil drilling rigs during natural disasters (Katrina) and
due to human error. They are called “blowouts”
• Spills occur from tanker accidents.
• Damage to environment from oil spills is dependent on type of oil (crude
oil most toxic due to benzene and toluene), weather conditions, season,
and type of organisms in the area.
• Oils spill cleanup is difficult and EXPENSIVE. It is very difficult to save
animals who have ingested the hydrocarbons into their digestive tracts,
especially aquatic birds who preen to insulate themselves.
FORMALDEHYDE
• Formaldehyde – emitted from
common building materials.
Formaldehyde exposure has caused
cancer in laboratory rats. Can also
cause dizziness, nausea and
headaches.
CIGARETTE SMOKE
1.Cigarette Smoke – (first hand or second hand); CO
gas from smoking reacts with hemoglobin in RBC and
decreases oxygen in the blood stream. This results in
impaired perception and thinking, slower reflexes,
headaches, drowsiness, dizziness, and nausea.
People who have heart disease are at risk of having
heart attacks. People with respiratory sensitivity or
disease can experience bronchitis, emphysema, and
anemia.
RADON-222-GAS
(odorless, tasteless, colorless). It is a product from the
radioactive decay of uranium 238 which is present in granite
and shale bedrock.
• Harmful – when it seeps upward through the
soil into basements through foundation cracks or
into the groundwater. It can build to dangerous
levels, cling to particles and become lodged in lung
tissue.
• If inhales, lung tissue is exposed to ionizing
radiation from alpha particles and may produce
lung cancer.
• To test for radon-222: purchase a hometesting kit for 20-100 dollars.
• New Jersey – high area for Radon-222 due to
much bedrock of granite and shale.
ASBESTOS
• Asbestos – A silicate
mineral (amphibole)
used in building
materials for
fireproofing. ONLY
dangerous when it is
airborne. The asbestos
shard-like fibers cause
lung cancer and
mesothelioma (cancer in
the lining of the chest
cavity).
Problems with DDT
• DDT is soluble in fats; when organisms digest DDT, the
pesticide concentrates in fatty parts of the body.
• This allows DDT to be passed along in the food web
(bioaccumulate) and since organisms higher in higher
trophic levels require more food to obtain their
energy, DDT is biomagnified.
• Predatory birds at the top of the food chain lay eggs with
unusually thin shells so that when hens sit on the nest, the eggs
break and no offspring are born. DDE blocks the formation of
calcium in egg production in the female. The eggs are formed
from calcium carbonate in the female. Without the correct
production of calcium carbonate, the eggs are produced too
thinly. This caused the near extinction of the American bald
eagle, osprey, and peregrine falcon.
Rachel Carson
• In 1958 DDT was sprayed to control mosquitoes near the home and
private bird sanctuary of one of Rachel’s friends (Olga Huckins).
• Initially, she found there was no independent critical research on
environmental effects of pesticides.
• Carson surveyed the scientific literature and methodically built her case
against the widespread use of pesticides.
• 1962 she published “Silent Spring”; an allusion to the silencing of robins,
catbirds, doves, jays, and wrens and scores of other bird voices because
of their exposure to pesticides.
• She pointed out that “for the first time in the history of the world, every
human being is now subjected to dangerous chemicals, from the
moment of conception until death.”