Review
Age Specific Fertility Rate
• Age Specific Fertility Rate (ASFR) = (Number of births to women in age
group i / Number of women in age group i) x 1000
• Total Fertility Rate (TFR) = (The sum of the Age Specific Fertility Rates
x The number of years in each age group) / 1000
Calculating Population Change
Growth
rate
Death
rate
Emigration
rate
r = (b – d) + (i – e)
Birth
rate
Immigration
rate
Birth (b), Death (d), Immigration (i) and Emigration (e) are
calculated per 1000 people
Demographic Stages
Rule of 70
• The rule of 70 states that in order to estimate the number of years for
a variable to double, take the number 70 and divide it by the growth
rate of the variable.
• if the growth rate of the China is 10%, the rule of 70 predicts it would
take 7 years (70/10) for China's real GDP to double.
Population Growth Rate vs. Percent Change
• Growth rate represents the average amount of change per year or per
month across a time period.
• Percent change represents the relative change in size between
populations across a time period.
• Take the difference of population in year two and the population in
year one and divide by the population in year two.
• new-old / old
# of year
• Percent change
• (New-old)/old
Leaching vs. Percilation
• In general, leaching is the extraction of certain materials from a
carrier into a liquid (usually, but not always a solvent).
• Percolation (from Lat. percōlāre, to filter or trickle through) refers to
the movement and filtering of fluids through porous materials.
Land Fragmentation/ Wildlife Corridors
Human Diet
Water Review
Water Pollution
WATER POLLUTION: SOURCES, TYPES,
AND EFFECTS
• Water pollution is any chemical, biological, or
physical change in water quality that has a
harmful effect on living organisms or makes water
unsuitable for desired uses.
• Point source: specific location (drain pipes,
ditches, sewer lines).
• Nonpoint source: cannot be traced to a single
site of discharge (atmospheric deposition,
agricultural / industrial / residential runoff)
Major Water Pollutants
and Their Effects
Major Water Pollutants
and Their Effects
• Water quality and dissolved oxygen (DO) content in parts
per million (ppm) at 20°C.
• Only a few fish species can survive in water less than 4ppm at
20°C.
POLLUTION OF FRESHWATER
STREAMS
• Most developed countries have sharply reduced pointsource pollution but toxic chemicals and pollution from
nonpoint sources are still a problem.
• Stream pollution from discharges of untreated sewage
and industrial wastes is a major problem in developing
countries.
Polluted air
Pesticides
and fertilizers
Coal strip
mine runoff
Hazardous
waste
injection
well
Deicing
road salt
Buried gasoline
and solvent tanks
Gasoline station
Pumping
well
Waste lagoon
Water
pumping well
Landfill
Cesspool,
septic tank
Sewer
Leakage
from
faulty
casing
Accidental
spills
Discharge
Confined
aquifer
Groundwater
flow
POLLUTION OF GROUNDWATER
• It can take hundreds to thousand of years for contaminated
groundwater to cleanse itself of degradable wastes.
• Nondegradable wastes (toxic lead, arsenic, flouride) are
there permanently.
• Slowly degradable wastes (such as DDT) are there for
decades.
Cultural Eutrophication
• Eutrophication: the natural nutrient enrichment of a shallow lake,
estuary or slow moving stream, mostly from runoff of plant nutrients
from the surrounding land.
• Cultural eutrophication: human activities accelerate the input of
plant nutrients (mostly nitrate- and phosphate-containing effluents)
to a lake.
• 85% of large lakes near major population centers in the U.S. have some
degree of cultural eutrophication.
OCEAN POLLUTION
• Harmful algal blooms (HAB) are caused by explosive
growth of harmful algae from sewage and agricultural
runoff.
Reducing Water Pollution through
Sewage Treatment
• Raw sewage reaching a municipal sewage treatment
plant typically undergoes:
• Primary sewage treatment: a physical process that uses
screens and a grit tank to remove large floating objects and
allows settling.
• Secondary sewage treatment: a biological process in which
aerobic bacteria remove as much as 90% of dissolved and
biodegradable, oxygen demanding organic wastes.
Reducing Water Pollution through
Sewage Treatment
• Primary and Secondary sewage treatment.
Aquaculture
• Aquaculture -- also known as fish or shellfish farming -- refers to the
breeding, rearing, and harvesting of plants and animals in all types of
water environments including ponds, rivers, lakes, and the ocean.
Aquacultures Cont.
• Arguments in Favor
• 1. Can create jobs in community 2.
Can increase revenue on city, state
and national level 3. Can reduce
seafood trade deficit 4. Can help feed
a growing U.S. and world population
5. Can encourage local investment 6.
Can increase scientific knowledge and
technology 7. Can place more
emphasis on protecting coastal waters
from pollution, especially in the case
of mollusk and seaweed culture. 8.
May reduce fishing pressure on
certain wild stocks if that species can
be produced through aquaculture
rather than fished.
• Arguments against
• 1. Can conflict with other users of
water bodies such as lobstermen,
fishermen or migrating fish 2. Can put
excess pressure on wild stocks that
are used to create high protein feed
pellets 3. Can amplify and transfer
disease and parasites to wild fish
populations 4. Can pollute water
systems with excess nutrients (fish
feed & wastes), chemicals and
antibiotics 5. Can compromise native
gene pools if farmed fish and native
species interbreed 6. Can threaten
livelihood of fishermen 7. Can be an
unpredictable enterprise for small
local communities due to its
susceptibility to severe weather,
predators, disease, and global
competition 8. Can compromise the
aesthetic beauty of coastline
Thermocline
• Change in a lake’s temperature
El Nino, La Nina
Succession
Primary: No soil
Secondary: Soil present
Restoration Ecology
• Scientific study supporting the practice of ecological restoration,
which is the practice of renewing and restoring degraded, damaged,
or destroyed ecosystems and habitats in the environment by active
human intervention and action.
• Building back land when filling in a landfill or coal mine and wetlands.
• The Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA), commonly known as Superfund, was enacted
by Congress on December 11, 1980. This law created a tax on the
chemical and petroleum industries and provided broad Federal
authority to respond directly to releases or threatened releases of
hazardous substances that may endanger public health or the
environment.
Toxicology
• Effective Dose
• Lethal Dose
• ED50/LD50
Acute and Chronic Toxicology
• Acute toxicity describes the
adverse effects of a substance
that result either from a single
exposure or from multiple
exposures in a short space of
time (usually less than
24 hours). To be described
as acute toxicity, the adverse
effects should occur within
14 days of the administration of
the substance
• Chronic toxicity is a property of
a substance that has toxic effects
on a living organism, when that
organism is repeatedly exposed,
often at lower levels, to a
substance over a longer time
period (months or years).
Edge Effect
• edge effects refer to the changes in population or community
structures that occur at the boundary of two habitats
• Environmental conditions enable certain species of plants and
animals to colonize on habitat borders. Plants that colonize tend to be
shade-intolerant and tolerant of dry conditions, such
as shrubs and vines. Animals that colonize tend to be those that
require two or more habitats, such as white-tailed deer and mule, elk,
cottontail rabbits, blue jays, and robins. Some animals travel between
habitats, while edge species are restricted to edges. Larger patches
include more individuals and therefore have increased biodiversity.
+ and - Feedback
• NEGATIVE FEEDBACK
MECHANISMS- push a
system back to its
original equilibrium
position
• POSITIVE FEEDBACK
MECHANISMS– push a
system to a new state
of equilibrium, away
from the old
Coriolis Effect
Atmospheric Circulation
• Deflection of moving objects
when the motion is described
relative to a rotating reference
frame.
• The air deflects toward the
right in the Northern
Hemisphere and toward the
left in the Southern
Hemisphere
Thermohaline
I=PAT
• population (P): refers to the size of the human population
• affluence (A): refers to the level of consumption by that population
• technology (T): refers to the processes used to obtain resources and
transform them into useful goods and wastes
• environmental impact (I): may be expressed in terms of resource
depletion or waste accumulation
Example: 100 people each using average 3000 gallons of gas a year which takes 20 lbs of CO2 per gallon of
gas to make. What is the environmental impact?
100 people*3000 gallons*20bCO2/gallon= 6,000,000 lbs of CO2 made by population
PCBs and Dioxins
• Dioxins, a collective term for a group of environmental contaminants
that includes certain dioxin, furan, and dioxin-like PCB
(polychlorinated biphenyl) congeners, are found throughout the
world. Dioxins and furans are released into the air from combustion
processes.
• More than 90% of human exposure is through food, mainly meat and
dairy products, fish and shellfish. Many national authorities have
programs in place to monitor the food supply.
• Dioxins are highly toxic and can cause reproductive and
developmental problems, damage the immune system, interfere with
hormones and also cause cancer.
PCB
• Polychlorinated biphenyls are a group of 209 different chemicals
which share a common structure but vary in the number of attached
chlorine atoms.
• The major sources of polychlorinated biphenyls in drinking water are
runoff from landfills; and discharge of waste chemicals.
• PCBs are a probable human carcinogen.
• Studies of PCBs in humans have found increased rates of melanomas,
liver cancer, gall bladder cancer, biliary tract cancer, gastrointestinal
tract cancer, and brain cancer, and may be linked to breast cancer.
Math Problem
• If an average refrigerator uses 500 watts of energy per hour on a daily
basis, and your energy cost is $0.11 per kwh, approximately how
much does the energy used by the refrigerator cost per month?
• a. $1.30
• b. $13
• c. $40
• d. $55
• e. $132
Long Division/ Decimals
• Lets try again!
Long Division... Last time.
• 96/6
• 170/5
• 1320/30
Urban Sprawl
• Urban sprawl or suburban sprawl describes the expansion of human
populations away from central urban areas into previously remote
and rural areas, particularly resulting in low-density communities
reliant upon heavy automobile usage. Urban sprawl is a multifaceted
concept of community planning especially relevant to developed
nations, involving topics that range from the outward spreading of
a city and itssuburbs, to low-density and auto-dependent
development on rural, examination of impact of high segregation
between residential and commercial uses, and analysis of various
design features to determine which may encourage car dependency.
Suburban Sprawl
• Suburban Sprawl
• Patchwork of vacant and developed tracts around the edges
of cities
o
Problems
•
•
•
•
o
Loss of wetlands
Air pollution
Water pollution
Loss of biological
habitat
11 states now have
new growth management laws (Smart Growth)
Leaking
tank
Water
table
Groundwater
flow
Free gasoline
dissolves in
Gasoline
groundwater
leakage plume
(dissolved
(liquid phase)
phase)
Migrating
vapor phase
Contaminant plume moves
with the groundwater
Water well
Solutions
Groundwater Pollution
Prevention
Find substitutes for toxic
chemicals
Keep toxic
chemicals out of
the environment
Install monitoring wells
near landfills and
underground tanks
Cleanup
Pump to surface,
clean, and return
to aquifer (very
expensive)
Inject microorganisms
to clean up
contamination (less
expensive but still
costly)
Require leak detectors on
underground tanks
Ban hazardous waste
disposal
in landfills and
injection wells
Store harmful liquids in
aboveground tanks with leak
detection and collection systems
Pump
nanoparticles of
inorganic compounds
to remove pollutants
(may be the cheapest,
easiest, and most
effective method but is
still being developed)
Industry
Nitrogen oxides
from autos and
smokestacks,
toxic chemicals,
and heavy metals in
effluents flow into
bays and estuaries.
Cities
Toxic metals
and oil from
streets and
parking lots
pollute waters;
Urban sprawl
Bacteria and viruses
from
sewers and septic
tanks contaminate
shellfish beds
Construction sites
Sediments are washed into
waterways, choking fish and plants,
clouding waters, and blocking
sunlight.
Farms
Runoff of pesticides, manure, and
fertilizers adds toxins and excess
nitrogen and phosphorus.
Closed
shellfish beds
Closed
beach
Oxygen-depleted
zone
Red tides
Excess nitrogen causes
explosive growth of
toxicmicroscopic algae,
poisoning fish and
marine mammals.
Toxic sediments
Chemicals and toxic
metals contaminate
shellfish beds, kill
spawning fish, and
accumulate in the tissues
of bottom feeders.
Oxygen-depleted zone
Sedimentation and algae
overgrowth reduce sunlight,
kill beneficial sea grasses, use
up oxygen, and degrade habitat.
Healthy zone
Clear, oxygen-rich
waters promote growth
of plankton and sea grasses,
and support fish.Fig. 21-10, p. 505
Solutions
Coastal Water Pollution
Prevention
Reduce input of toxic pollutants
Cleanup
Improve oil-spill cleanup
capabilities
Separate sewage and storm lines
Ban dumping of wastes and sewage by
maritime and cruise ships in coastal
waters
Ban ocean dumping of sludge and
hazardous dredged material
Sprinkle nanoparticles over an oil or
sewage spill to dissolve the oil or
sewage without
creating harmful by-products
(still under development)
Protect sensitive areas from
development, oil drilling, and
oil shipping
Require at least secondary
treatment of coastal sewage
Regulate coastal development
Recycle used oil
Require double hulls for oil tankers
Use wetlands, solar-aquatic,
or other methods to treat sewage
Solutions
Water Pollution
• Prevent groundwater contamination
• Reduce nonpoint runoff
• Reuse treated wastewater for irrigation
• Find substitutes for toxic pollutants
• Work with nature to treat sewage
• Practice four R's of resource use (refuse,
reduce, recycle, reuse)
• Reduce air pollution
• Reduce poverty
• Reduce birth rates
Environmental Organizations and Industries
• http://webecoist.momtastic.com/2008/09/24/25-environmentalagencies-and-organizations/