Transcript Acid Deposition http://www.natgeoeducationvideo.com/film/1233/acid-rain Acid Deposition  Air pollution is one of several interacting stresses that can damage, weaken, or kill trees and pollute.

Acid Deposition
http://www.natgeoeducationvideo.com/film/1233/acid-rain
Acid Deposition
 Air pollution is one of several interacting stresses that can damage, weaken,
or kill trees and pollute surface and groundwater.
 Acid deposition consists of rain, snow, dust, or gas with a pH lower than 5.6.
 As of 2010, the most acidic rain falling in the US has a pH of about 4.3
Emissions
SO2
Acid H O
2 2
deposition
PANs
NOx
O3
Others
Reduced
photosynthesis
and growth
Direct damage to
leaves & bark
Tree death
Soil acidification
Leaching
of soil
nutrients
Acids
Lake
Groundwater
Release of
toxic metal
ions
Susceptibility
to drought,
extreme cold,
insects,
mosses, &
disease
organisms
Root
damage
Reduced nutrient
& water uptake
Acid Deposition
 Sulfur dioxides,
nitrogen oxides, and
particulates can react in
the atmosphere to
produce acidic
chemicals that can
travel long distances
before returning to the
earth’s surface.
 Tall smokestacks
reduce local air
pollution but can
increase regional air
pollution.
Acid Deposition

Two main contributors
to acid deposition


Sulfur Dioxide (SO2)
Nitrogen Oxides
(NOx)
* 66% of all sulfur
dioxides and 25% of all
nitrogen oxides comes
from electric power
generation that produces
energy by burning fossil
fuels.
Acid Deposition
• Acidic water flows over and
through the ground which
affects a variety of plants and
animals
• Dry deposition refers to acidic
gases and particles.
• About half of the acidity in the
atmosphere falls back to earth
through dry deposition.
• The wind blows these acidic
particles and gases onto/into
buildings, cars, homes, and trees
Acid Deposition
• Acidic water dissolves the
•
•
nutrients and helpful
minerals in the soil
It washes nutrients away
before plants can use them to
grow
Acid rain also causes the release
of substances, such as
aluminum, that are toxic to
plants
Acid Deposition
 Acid rain does not
usually kill trees
directly
 Weakens trees
 Damages leaves
 Limits nutrients
available
 Toxic substances are
slowly released from
the soil.
Germany
South Carolina
Mongolia
Acid Deposition
• Acid Deposition can release
•
•
•
•
•
aluminum from lake sediments
which, in turn, adversely affects the
gills of fish.
Generally, the young of most species
are more sensitive to environmental
conditions than adults.
At pH 5, most fish eggs cannot
hatch.
At lower pH levels, some adult fish
die.
Chronic stress leads to lower body
weight and smaller size
Some acid lakes have no fish.
Acid Deposition
 During the 1970’s and 1980’s, many lakes in Canada
and the Northeastern U.S. lost all of their fish due to
lowered pH levels
Acid Deposition
Acid Deposition
 pH measurements in relation to major coal-burning and
industrial plants.
Acid Deposition
Acid Deposition
 Antiquities can be
destroyed by acid
deposition
Acid Deposition
 Lime (calcium carbonate) can be deposited into a lake
to increase the pH
Hubbard Brook Experimental Forest
ACID DEPOSITION
 Acid deposition contributes to chronic respiratory
disease and can leach toxic metals (such as lead and
mercury) from soils and rocks into acidic lakes used as
sources for drinking water.
Solutions
Acid Deposition
Prevention
Reduce air pollution
by improving
energy efficiency
Cleanup
Add lime to
neutralize
acidified lakes
Reduce coal use
Increase natural
gas use
Increase use of
renewable energy
resources
Burn low-sulfur coal
Remove SO2
particulates & NOx
from smokestack
gases
Remove NOx from
motor vehicular
exhaust
Tax emissions of SO2
Add phosphate
fertilizer to
neutralize
acidified lakes