1. Human Impact on the
Environment
Mary Rodriguez

2. Mexico

3. Problems
• scarcity of hazardous
waste disposal facilities
• natural freshwater
resources scarce and
polluted in
north, inaccessible and
poor quality in center
and extreme southeast
• raw sewage and
industrial effluents
polluting rivers in urban
areas
• Deforestation
• widespread erosion
• desertification
deteriorating
agricultural lands
• serious air and water
pollution in the national
capital and urban
centers along US-Mexico
border
• land subsidence in
Valley of Mexico caused
by groundwater
depletion

4. Deforestation
• http://www.aae.wisc.edu/news/11/
• http://worldwildlife.org/threats/deforestation
• http://environment.nationalgeographic.com/environment/global-
warming/deforestation-overview/
• Forms:
– fires
– clear-cutting for agriculture
– ranching and development
– unsustainable logging for
timber
– degradation due to climate
change
• Facts:
– The world’s rain forests could
completely vanish in a
hundred years at the current
rate of deforestation
– Seventy percent of Earth’s
land animals and plants live
in forests, and many cannot
survive the deforestation that
destroys their homes.
– Forest soils are moist, but
without protection from sun-
blocking tree cover they
quickly dry out. Trees also
help perpetuate the water
cycle by returning water
vapor back into the
atmosphere.

6. Extinction
• http://edition.cnn.com/2008/WORLD/americas/03/17/mexico.nature3/
• http://www.explorandomexico.com/about-mexico/8/358/
• CAUSES:
– Neglect
– Excessive hunting
– Threatening Conditions in Environment
• Animals Become
– Vulnerable
– Threatened
– Endangered
– Extinct
• It is necessary that the organic and
inorganic elements of the environment
be in balance. If some being or factor
undergoes some type of alteration
(absence, mutation, decrease or increase)
in the long run, the whole habitat will
suffer from it, and in turn, be at risk of
disappearing.
• Extinct:
– The Mexican wolf
– The Imperial Woodpecker
– The Passenger Pigeon
– The Trumpeter Swan
– The Elf Owl
– The Caribbean Monk Seal
• Threatened Species:
– The jaguar
– The black bear
– The Socorro Dove
– The Volcano Rabbit
– The crocodile
– The Harpy Eagle
– The Antelope

7. EXTINCT

8. Loss of Soil
• http://topsoil.nserl.purdue.edu/nserlweb-
old/isco99/pdf/ISCOdisc/SustainingTheGlobalFarm/P109-Ventura.pdf
• Soil Erosion is a result of
intensive maize
cultivation on areas with
steep slopes
• Soil Erosion is a result of
deforestation for
agriculture
• If the rate of erosion
exceeds the rate of soil
formation (from rock and
decomposing organic
matter), then the land
will become infertile.
• Deforestation or other
vegetation often leads to
serious soil
erosion, because plant
roots bind soil, and
without them the soil is
free to wash or blow
away,

9. Flooding
• http://www.bbc.co.uk/news/world-latin-america-11226611
• Deforestation has
allowed silt to fill in
rivers thereby
reducing their capacity
and making floods
more likely
• Causes of Flooding:
– The constant
extraction of
petroleum and gas
– the construction of
dams in the zone
– the erosion of land
and deforestation

11. Water Pollution (Sewage)
• http://latimesblogs.latimes.com/lanow/2012/08/san-diego-beaches-closed-sewage-spill.html
• http://room233.wikispaces.com/Water+and+water+pollution
• http://www.redorbit.com/news/science/1991897/pollution_threatening_mexicos_riviera_maya_r
egion/
• Sewage, manure, and
chemical fertilizers, contain
"nutrients" such as nitrates
and phosphates. Deposition of
atmospheric nitrogen (from
nitrogen oxides) also causes
nutrient-type water pollution.
• Direct sources include effluent
outfalls from
factories, refineries, waste
treatment plants etc.. that
emit fluids of varying quality
directly into urban water
supplies.
• Indirect sources include
contaminants that enter the
water supply from
soils/groundwater systems
and from the atmosphere via
rain water. Soils and
groundwaters contain the
residue of human agricultural
practices
(fertilizers, pesticides, etc..)
and improperly disposed of
industrial wastes.

13. CO2 Build Up
• http://www.peoplesworld.org/greenhouse-gases-building-up-in-the-atmosphere/
• http://rainforests.mongabay.com/0907.htm
• Autotrophs draw in
Carbon Dioxide for
Photosynthesis and
with deforestation a
great amount of it
• The clearing and
burning of tropical
forests and peat lands
releases more than a
billion metric tons of
carbon
• Greenhouse Effect:
– Greenhouse gases (CO2)
are transparent to
incoming solar
radiation. This radiation
reaches the earth's
surface and heats it.
Greenhouse gasses trap
heat in the atmosphere.
As greenhouse gases
build up, more heat is
trapped in the
atmosphere.

14. AIR POLLUTION
• http://corrosion-doctors.org/AtmCorros/mapMexico.htm
• Exhaust fumes from Mexico City's 3 million cars are
the main source of air pollutants
• Mexico is home to many assembly plants
"maquiladoras" that are responsible for the release
of dangerous substances into the environment.
• The most important air pollutants of Mexico City
are ozone (O3), sulfur dioxide (SO2), precursors like
nitrogen oxides (NOX), hydrocarbons (HC), and
carbon monoxide (CO), that originate from the
incomplete combustion of fossil fuels.

15. Mexico City Air Pollution