Pollution and Degradation …of the Lithosphere, Hydrosphere and Atmosphere

Our farming practices have changed: This is what farming used to look like and this is what it looks like today. Can anyone think of factors that have changed that might be bad for the lithosphere in the context of agriculture?

Impact of Intensive agriculture on soils: Gigantic fields vulnerable to wind erosion in dry periods. Fertilizers and pesticides threaten Biodiversity and kill microorganisms that help maintain soil balance. Use of heavy machines: compacting of soil, less oxygen available for microorganisms Rain water does not sink it but runs off the surface carrying away soil and nutrients  water erosion Reduce soil fertility Heavy machines compact soil  less oxygen, bad for miroorganisms  less humus production

Soil depletion is the loss of soil fertility

Contamination is the abnormal presence of a harmful substance in the environment Hydrocarbons from oil spills and and leaky gas station tanks Heavy metals from leaky land fills and industrial pollution Acidic waste from mining

Contamination from the atmosphere Sulfur dioxide (SO2) and Nitrogen oxides (NOx) from combustion of fossil fuels and other industry carried by wind Gases dissolve in rain  Acid rain What happens when acid rain hits the ground?

Effect of acid rain on lithosphere Leaching of soil  minerals are dissolved and carried away with the water (washed out). Mobilization of aluminum minerals  aluminum toxic for living organisms (particularly for plants) Acidification of soil  upsetting of vegetation (some species prefer acidic soil and others can’t tolerate it  change in vegetation will occur)

Impact of acid rain depends on soil A soil’s BUFFERING CAPACITY is its ability to resist changes in pH when acidic or alkaline products are added. Soils with low buffering capacity more vulnerable to effects of acid rain Sandy soil has a low buffering capacity Silt and clay soils have a higher buffering capacity

Summary: Degradation / Pollution of the lithosphere Soil depletion because of intensive farming: large fields  more wind erosion Use of pesticides and fertilizer  reduce biodiversity Heavy machines  soil compacting, less oxygen, water erosion Contamination by hydrocarbons (gas stations, cars) Heavy metals (leaky land fills) Acid waste (from mining) Contaminants from atmosphere (acid rain) Work book page 104 # 3 and 4  soil depletion, contamination, buffering

Pollution and Contamination of water Point sources Pollution can be traced to well defined site. Non point sources Difficult to locate exact origin of pollution

Sources of Pollution and Contamination of water Rain / Acid rain: acidifies water  some species more sensitive Dissolves aluminum from aluminum minerals and transports it into rivers and lakes.  Aluminum toxic Farming: Run off water carries fertilizer and pesticides into water Talked about itensive farming and the effects it has on our soil we had mentioned Domestic and industrial sewage: Organic and chemical pollutants heat

Pollution and Contamination of water Heat: Solubility of Oxygen decreases with in-creasing temperature Bad for animals and microorganisms.

Sources of Pollution and Contamination of water Rain / Acid rain: acidifies water  some species more sensitive Dissolves aluminum from aluminum minerals and transports it into rivers and lakes.  Aluminum toxic Farming: Run off water carries fertilizer and pesticides into water Talked about itensive farming and the effects it has on our soil we had mentioned Domestic and industrial sewage: Organic and chemical pollutants heat

Eutrophication Process by which natural waters lose their oxygen because of an excessive accumulation of of organic matter and nutrients

Over time sediment accumulates in lake  Water becomes shallower. Time: Centuries Over time sediment accumulates in lake  Water becomes shallower.  More plant growth, more production of organic material.  Bacteria decompose plant material, consuming large amounts of oxygen.

 High production of organic material sediment sediment Time: Decades Fertilizers form agriculture (particularly Phosphorus) and warming of water promote rapid growth of algae:  High production of organic material  Bacteria decomposing organic matter consume a lot of oxygen warm water less oxygen than cold water

Effect of pollutants depends on: Their concentration Their nature (toxicity) How long they will remain in the environment  how quickly is water exchanged/ renewed Which one will be affected more easily? creek Intro to slide: Aquatic ecosystems have ability to degrade and tolerate some contaminants. When system gets out of balance we say it is polluted pond

Contamination of oceans with oil Through: Pumping of oil from under the ocean Some leaks Oil tankers clean out on open sea accidents

Pollution and contamination of water Point source vs. non point source Contamination through: Acid rain Pesticides, fertilizer and manure from farming Sewage, either domestic or industrial Heat Hydrocarbons, oil (in particular oceans) Heat and fertilizer cause Eutrophication of lakes Note taking sheet page109 questions Page 110

Notes on contamination of hydrosphere Bill Ny clip herbicides and frogs Clip herbicides and frogs

Contamination of the atmosphere Green house gases “acid rain” gases ( Clean rain pH 5.5 -5,7, acid rain pH 3-5.) Heavy metals (mercury (Hg), arsenic (As), lead (Pb))  from combustion of oil, coal, waste incineration Chlorofluorocarbons (CFCs) – destroy Ozone Smog – CO2, H2O, N2O, CH4 – SO2 and NO, NO

Waste incineration, oil / coal combustion Release Heavy metals into the atmosphere: (mercury (Hg), arsenic (As), lead (Pb)) toxic Lead replaces other metals in enzymes but not functionally, in humans in particular enzymes involved in hemeproduction -> anemia

Where: In Stratosphere Ozone layer Ozone = O3; Chemical filter, absorbs UV… … when created: … when destroyed: Where: In Stratosphere O2 Why do we have a hole in the ozone layer O3

CFCs destroy the Ozone layer Chlorofluorocarbons Look for: Used in: insulation foam refrigeration and air conditioning systems in aerosols

How do CFCs act: 1 2 3 1. Release chlorine atoms 2. chlorine atoms destroy ozone 2 3. ClO catches oxygen atom and reproduces chlorine atom. 3

In 1987 … Montréal Protocol to gradually phase out use of CFCs until 2010. Prediction: Ozone layer will recover by the middle of this century (2050).

Smog Thick mixture of fog (water vapor), smoke (particles) and atmospheric pollutants atmospheric pollutants: ozone (O3), nitrogen dioxide (NO2), sulphur dioxide (SO2)  can cause asthma. forms when high pressure system prevents gases from rising ozone very reactive molecule  harmful to our health when it enters our lungs Notes on page 124

Note taking page 124 Homework: P. 110 all P. 126 # 4 P. 104 # 3, 4 Work book page 102 # ,5 page 104 # 3 and 4  soil depletion, contamination, buffering Page 109 notes on hydrosphere contamination, page 110 questions, http://www.youtube.com/watch?v=kdDSRRCKMiI