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    Public Health AssignmentOn Water Pollution and Global Warming

    Submitted to: Dr. Maleeha Azeem (Mea)

    Submitted By: Mushfiqur Rahman

    Id: 1110685030

    Section: 7

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    INDEX:

    WATER POLLUTION:oWHAT IS WATER POLLUTION?oTHE SOURCES OF WATER POLLUTIONoTHE COMMON POLLUTANTSoHEALTH HAZARDS OF WATER POLLUTION

    GLOBAL WARMING:oWHAT IS GLOBAL WARMING?o CAUSES OF GLOBAL WARMINGo CONSEQUENCES OF GLOBAL WARMING

    REFERENCES

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    WATER POLLUTION

    What Is Water Pollution?

    Water pollution refers to degradation of water quality. It is a large set of adverse effects upon waterbodies such as lakes, rivers, oceans, and groundwater caused by human activities. Water pollution can

    be defined as "the presence of a substance in the environment that because of its chemical composition

    or quantity prevents the functioning of natural processes and produces undesirable environmental and

    health effects

    Water pollution can be defined in many ways. Usually, it means one or more substances havebuilt up in water to such an extent that they cause problems for animals or people. This could

    affect the health of all the plants, animals, and humans whose lives depend on the river.

    Dozens of times a day those of us who live in the industrialized nations of the world enjoy ablessing denied to 75 percent of the world population: abundant supplies of clean water. For

    centuries water has been used as a dumping ground for human sewage and industrial wastes.

    Added to them are the materials leached out and transported from land by water percolating

    through the soil and running off its surface to aquatic ecosystems. Thus the term water

    pollution refers to "Water contamination by a variety of chemical substances or

    eutrophication caused by several nutrients and fertilizers (Southwick, 1976)".

    Water is typically referred to as polluted when it is impaired by anthropogenic contaminantsand either does not support a human use or undergoes a marked shift in its ability to support its

    constituent biotic communities.

    U.S. Department of Health Education and Welfare defines water pollution as "The adding towater ofany substance, or the changing ofwater's physical and chemical characteristics

    in any way which interferes with its use oflegitimate purposes".

    Water is typically referred to as polluted when it is impaired by anthropogenic contaminantsand either does not support a human use, such as drinking water, and/or undergoes a marked

    shift in its ability to support its constituent biotic communities, such as fish. Natural

    phenomena such as volcanoes, algae blooms, storms, and earthquakes also cause major

    changes in water quality and the ecological status of water.

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    The sources of Water Pollution:

    There two major kinds of pollution sources:

    - Point sources

    - Non-point sources

    Point sources:

    Point source water pollution refers to contaminants that enter a waterway from a single, identifiable

    source, such as a pipe or ditch. Examples of sources in this category include discharges from a sewage

    treatment plant, a factory, or a city storm drain. The U.S. Clean Water Act (CWA) defines point

    source for regulatory enforcement purposes. The CWA definition of point source was amended in

    1987 to include municipal storm sewer systems, as well as industrial storm water, such as from

    construction sites.

    Nonpoint sources:

    Nonpoint source pollution refers to diffuse contamination that does not originate from a single

    discrete source. NPS pollution is often the cumulative effect of small amounts of contaminants

    gathered from a large area. A common example is the leaching out of nitrogen compounds from

    fertilized agricultural lands. Nutrient runoffin storm water from "sheet flow" over an agriculturalfield

    or a forest is also cited as examples of NPS pollution.

    Contaminated storm water washed off of parking lots, roads and highways, called urban runoff, is

    sometimes included under the category of NPS pollution. However, this runoff is typically channeled

    into storm drain systems and discharged through pipes to local surface waters, and is a point source.

    However where such water is not channeled and drains directly to ground it is a non-point source.

    The Common Pollutants:

    Infectious Agents

    These are disease causing agents or pathogens, e.g. bacteria, viruses, protozoa, parasites. These come

    from raw sewage and animal waste. These are measured by the amount of Coliform bacteria present.

    http://en.wikipedia.org/wiki/Point_source_water_pollutionhttp://en.wikipedia.org/wiki/Water_pipehttp://en.wikipedia.org/wiki/Ditchhttp://en.wikipedia.org/wiki/Sewage_treatmenthttp://en.wikipedia.org/wiki/Sewage_treatmenthttp://en.wikipedia.org/wiki/Factoryhttp://en.wikipedia.org/wiki/Storm_drainhttp://en.wikipedia.org/wiki/Clean_Water_Acthttp://en.wikipedia.org/wiki/Regulationhttp://en.wikipedia.org/wiki/Municipalityhttp://en.wikipedia.org/wiki/Storm_sewerhttp://en.wikipedia.org/wiki/Constructionhttp://en.wikipedia.org/wiki/Nonpoint_source_pollutionhttp://en.wikipedia.org/wiki/Nonpoint_source_pollutionhttp://en.wikipedia.org/wiki/Nonpoint_source_pollutionhttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Surface_runoffhttp://en.wikipedia.org/wiki/Stormwaterhttp://en.wikipedia.org/wiki/Agricultural_fieldhttp://en.wikipedia.org/wiki/Agricultural_fieldhttp://en.wikipedia.org/wiki/Agricultural_fieldhttp://en.wikipedia.org/wiki/Foresthttp://en.wikipedia.org/wiki/Parking_lothttp://en.wikipedia.org/wiki/Roadhttp://en.wikipedia.org/wiki/Highwayhttp://en.wikipedia.org/wiki/Urban_runoffhttp://en.wikipedia.org/wiki/Urban_runoffhttp://en.wikipedia.org/wiki/Highwayhttp://en.wikipedia.org/wiki/Roadhttp://en.wikipedia.org/wiki/Parking_lothttp://en.wikipedia.org/wiki/Foresthttp://en.wikipedia.org/wiki/Agricultural_fieldhttp://en.wikipedia.org/wiki/Stormwaterhttp://en.wikipedia.org/wiki/Surface_runoffhttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Nonpoint_source_pollutionhttp://en.wikipedia.org/wiki/Constructionhttp://en.wikipedia.org/wiki/Storm_sewerhttp://en.wikipedia.org/wiki/Municipalityhttp://en.wikipedia.org/wiki/Regulationhttp://en.wikipedia.org/wiki/Clean_Water_Acthttp://en.wikipedia.org/wiki/Storm_drainhttp://en.wikipedia.org/wiki/Factoryhttp://en.wikipedia.org/wiki/Sewage_treatmenthttp://en.wikipedia.org/wiki/Sewage_treatmenthttp://en.wikipedia.org/wiki/Ditchhttp://en.wikipedia.org/wiki/Water_pipehttp://en.wikipedia.org/wiki/Point_source_water_pollution
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    Oxygen-demanding wastes

    Sewage, animal manure or biodegradable organic wastes, which can be decomposed by aerobic

    bacteria which cause a reduction in dissolved oxygen (DO) results in suffocating for oxygen-

    consuming organisms (fish). These are measured by biological oxygen demand (BOD).

    Water soluble Inorganic chemicals

    Water-soluble inorganic chemicals, includes acids, salts, and metals. Make water unfit to consume and

    use for irrigation. Also can harm organisms and cause material corrosion.

    Organic chemicals

    Detergents

    Disinfection by-products found in chemically disinfected drinking water, such as chloroform Food processing waste, which can include oxygen-demanding substances, fats and grease Insecticides and herbicides, a huge range oforgan halides and other chemical compounds Petroleum hydrocarbons, including fuels (gasoline, diesel fuel, jet fuels, and fuel oil) and

    lubricants (motor oil), and fuel combustion byproducts, from storm water runoff.

    Tree and bush debris from logging operations Volatile organic compounds (VOCs), such as industrial solvents, from improper storage. Chlorinated solvents, which are dense non-aqueous phase liquids (DNAPLs), may fall to the

    bottom of reservoirs, since they don't mix well with water and are denser.

    o Polychlorinated biphenyl (PCBs)o Trichloroethylene

    Perchlorate Various chemical compounds found in personal hygiene and cosmetic products

    Inorganic water pollutants include:

    Acidity caused by industrial discharges (especially sulfur dioxide from power plants) Ammonia from food processing waste Chemical waste as industrial by-products Fertilizers containing nutrients--nitrates and phosphates--which are found in storm water runoff

    from agriculture, as well as commercial and residential use

    http://en.wikipedia.org/wiki/Detergentshttp://en.wikipedia.org/wiki/Disinfection_by-producthttp://en.wikipedia.org/wiki/Disinfectionhttp://en.wikipedia.org/wiki/Drinking_waterhttp://en.wikipedia.org/wiki/Chloroformhttp://en.wikipedia.org/wiki/Food_processinghttp://en.wikipedia.org/wiki/Insecticidehttp://en.wikipedia.org/wiki/Herbicidehttp://en.wikipedia.org/wiki/Organohalidehttp://en.wikipedia.org/wiki/Chemical_compoundshttp://en.wikipedia.org/wiki/Petroleumhttp://en.wikipedia.org/wiki/Gasolinehttp://en.wikipedia.org/wiki/Diesel_fuelhttp://en.wikipedia.org/wiki/Fuel_oilhttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Stormwaterhttp://en.wikipedia.org/wiki/Surface_runoffhttp://en.wikipedia.org/wiki/Treehttp://en.wikipedia.org/wiki/Logginghttp://en.wikipedia.org/wiki/Volatile_organic_compoundshttp://en.wikipedia.org/wiki/Solventhttp://en.wikipedia.org/wiki/Chlorinated_solventhttp://en.wikipedia.org/wiki/DNAPLhttp://en.wikipedia.org/wiki/Polychlorinated_biphenylhttp://en.wikipedia.org/wiki/Trichloroethylenehttp://en.wikipedia.org/wiki/Perchloratehttp://en.wikipedia.org/wiki/Hygienehttp://en.wikipedia.org/wiki/Cosmeticshttp://en.wikipedia.org/wiki/Acidityhttp://en.wikipedia.org/wiki/Sulfur_dioxidehttp://en.wikipedia.org/wiki/Power_plantshttp://en.wikipedia.org/wiki/Ammoniahttp://en.wikipedia.org/wiki/Chemical_wastehttp://en.wikipedia.org/wiki/Fertilizerhttp://en.wikipedia.org/wiki/Nitrateshttp://en.wikipedia.org/wiki/Phosphatehttp://en.wikipedia.org/wiki/Agriculturehttp://en.wikipedia.org/wiki/Agriculturehttp://en.wikipedia.org/wiki/Phosphatehttp://en.wikipedia.org/wiki/Nitrateshttp://en.wikipedia.org/wiki/Fertilizerhttp://en.wikipedia.org/wiki/Chemical_wastehttp://en.wikipedia.org/wiki/Ammoniahttp://en.wikipedia.org/wiki/Power_plantshttp://en.wikipedia.org/wiki/Sulfur_dioxidehttp://en.wikipedia.org/wiki/Acidityhttp://en.wikipedia.org/wiki/Cosmeticshttp://en.wikipedia.org/wiki/Hygienehttp://en.wikipedia.org/wiki/Perchloratehttp://en.wikipedia.org/wiki/Trichloroethylenehttp://en.wikipedia.org/wiki/Polychlorinated_biphenylhttp://en.wikipedia.org/wiki/DNAPLhttp://en.wikipedia.org/wiki/Chlorinated_solventhttp://en.wikipedia.org/wiki/Solventhttp://en.wikipedia.org/wiki/Volatile_organic_compoundshttp://en.wikipedia.org/wiki/Logginghttp://en.wikipedia.org/wiki/Treehttp://en.wikipedia.org/wiki/Surface_runoffhttp://en.wikipedia.org/wiki/Stormwaterhttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Fuel_oilhttp://en.wikipedia.org/wiki/Diesel_fuelhttp://en.wikipedia.org/wiki/Gasolinehttp://en.wikipedia.org/wiki/Petroleumhttp://en.wikipedia.org/wiki/Chemical_compoundshttp://en.wikipedia.org/wiki/Organohalidehttp://en.wikipedia.org/wiki/Herbicidehttp://en.wikipedia.org/wiki/Insecticidehttp://en.wikipedia.org/wiki/Food_processinghttp://en.wikipedia.org/wiki/Chloroformhttp://en.wikipedia.org/wiki/Drinking_waterhttp://en.wikipedia.org/wiki/Disinfectionhttp://en.wikipedia.org/wiki/Disinfection_by-producthttp://en.wikipedia.org/wiki/Detergents
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    Heavy metals from motor vehicles (via urban storm water runoff) and acid minedrainage Silt (sediment) in runoff from construction sites, logging, slash and burn practices or land

    clearing sites

    Macroscopic pollutionlarge visible items polluting the watermay be termed "floatables" in anurban storm water context, or marine debris when found on the open seas, and can include such items

    as:

    Trash or garbage (e.g. paper, plastic, or food waste) discarded by people on the ground, alongwith accidental or intentional dumping of rubbish, that are washed by rainfall into storm drains

    and eventually discharged into surface waters

    Nurdles, small ubiquitous waterborne plastic pellets Shipwrecks, large derelict ships

    Thermal pollution

    Thermal pollution is the rise or fall in the temperature of a natural body of water caused by human

    influence. Thermal pollution, unlike chemical pollution, results in a change in the physical properties

    of water. A common cause of thermal pollution is the use of water as a coolant by power plants and

    industrial manufacturers. Elevated water temperatures decreases oxygen levels (which can kill fish)

    and affects ecosystem composition, such as invasion by new thermophilic species. Urban runoff may

    also elevate temperature in surface waters.

    Thermal pollution can also be caused by the release of very cold water from the base of reservoirs into

    warmer rivers.

    Plant nutrients

    Nitrates, phosphates, ammonium originated mostly from fertilizers. Cause excessive algal and plantgrowth (algal bloom) that lower oxygen levels when they decompose leading to eutrophication

    (lectures on Ecology and Agriculture).

    Sediment

    Mud, silt, sand which disrupts photosynthesis and transports large amounts of other, adsorbed

    pollutants. These are bad for Aquatic animals.

    http://en.wikipedia.org/wiki/Heavy_metalshttp://en.wikipedia.org/wiki/Motor_vehiclehttp://en.wikipedia.org/wiki/Urban_runoffhttp://en.wikipedia.org/wiki/Acid_mine_drainagehttp://en.wikipedia.org/wiki/Acid_mine_drainagehttp://en.wikipedia.org/wiki/Acid_mine_drainagehttp://en.wikipedia.org/wiki/Silthttp://en.wikipedia.org/wiki/Sedimenthttp://en.wikipedia.org/wiki/Constructionhttp://en.wikipedia.org/wiki/Logginghttp://en.wikipedia.org/wiki/Slash_and_burnhttp://en.wikipedia.org/wiki/Marine_debrishttp://en.wikipedia.org/wiki/Trash_%28material%29http://en.wikipedia.org/wiki/Rainfallhttp://en.wikipedia.org/wiki/Storm_drainhttp://en.wikipedia.org/wiki/Plastichttp://en.wikipedia.org/wiki/Shipwreckhttp://en.wikipedia.org/wiki/Coolanthttp://en.wikipedia.org/wiki/Power_plantshttp://en.wikipedia.org/wiki/Ecosystemhttp://en.wikipedia.org/wiki/Thermophilichttp://en.wikipedia.org/wiki/Reservoirhttp://en.wikipedia.org/wiki/Reservoirhttp://en.wikipedia.org/wiki/Thermophilichttp://en.wikipedia.org/wiki/Ecosystemhttp://en.wikipedia.org/wiki/Power_plantshttp://en.wikipedia.org/wiki/Coolanthttp://en.wikipedia.org/wiki/Shipwreckhttp://en.wikipedia.org/wiki/Plastichttp://en.wikipedia.org/wiki/Storm_drainhttp://en.wikipedia.org/wiki/Rainfallhttp://en.wikipedia.org/wiki/Trash_%28material%29http://en.wikipedia.org/wiki/Marine_debrishttp://en.wikipedia.org/wiki/Slash_and_burnhttp://en.wikipedia.org/wiki/Logginghttp://en.wikipedia.org/wiki/Constructionhttp://en.wikipedia.org/wiki/Sedimenthttp://en.wikipedia.org/wiki/Silthttp://en.wikipedia.org/wiki/Acid_mine_drainagehttp://en.wikipedia.org/wiki/Urban_runoffhttp://en.wikipedia.org/wiki/Motor_vehiclehttp://en.wikipedia.org/wiki/Heavy_metals
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    Radioactive materials

    Radium, uranium, etc. may come either from natural or anthropogenic sources.

    Heat

    From cooling water for power plants & other industrial plants which lowers solubility of oxygen in

    water. Also affect aquatic lives directly.

    The Health Hazards of Water Pollution:

    Water-borne diseases are infectious diseases spread primarily through contaminated water.Though these diseases are spread either directly or through flies or filth, water is the chief

    medium for spread of these diseases and hence they are termed as water-borne diseases.

    Most intestinal (enteric) diseases are infectious and are transmitted through fecal waste.Pathogens which include virus, bacteria, protozoa, and parasitic worms - are disease-

    producing agents found in the feces of infected persons. These diseases are more prevalent in

    areas with poor sanitary conditions. These pathogens travel through water sources and

    interfuses directly through persons handling food and water. Since these diseases are highly

    infectious, extreme care and hygiene should be maintained by people looking after an infected

    patient. Hepatitis, cholera, dysentery, and typhoid are the more common water-borne diseases

    that affect large populations in the tropical regions.

    Freshwater resources all over the world are threatened not only by over exploitation and poormanagement but also by ecological degradation. The main source of freshwater pollution can

    be attributed to discharge of untreated waste, dumping of industrial effluent, and run-off from

    agricultural fields. Industrial growth, urbanization and the increasing use of synthetic organic

    substances have serious and adverse impacts on freshwater bodies. It is a generally accepted

    fact that the developed countries suffer from problems of chemical discharge into the water

    sources mainly groundwater, while developing countries face problems of agricultural run-off

    in water sources. Polluted water like chemicals in drinking water causes problem to health and

    leads to water-borne diseases which can be prevented by taking measures can be taken even at

    the household level.

    http://edugreen.teri.res.in/explore/water/health.htm#groundhttp://edugreen.teri.res.in/explore/water/health.htm#chemhttp://edugreen.teri.res.in/explore/water/health.htm#disehttp://edugreen.teri.res.in/explore/water/health.htm#meashttp://edugreen.teri.res.in/explore/water/health.htm#meashttp://edugreen.teri.res.in/explore/water/health.htm#disehttp://edugreen.teri.res.in/explore/water/health.htm#chemhttp://edugreen.teri.res.in/explore/water/health.htm#ground
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    A large number of chemicals that either exist naturally in the land or are added due to humanactivity dissolve in the water, thereby contaminating it and leading to various diseases.

    Pesticides. The organophosphates and the carbonates present in pesticides affect and damagethe nervous system and can cause cancer. Some of the pesticides contain carcinogens that

    exceed recommended levels. They contain chlorides that cause reproductive and endocrinal

    damage.

    Lead. Lead is hazardous to health as it accumulates in the body and affects the central nervoussystem. Children and pregnant women are most at risk.

    Fluoride. Excess fluorides can cause yellowing of the teeth and damage to the spinal cord andother crippling diseases.

    Nitrates. Drinking water that gets contaminated with nitrates can prove fatal especially toinfants that drink formula milk as it restricts the amount of oxygen that reaches the brain

    causing the blue baby syndrome. It is also linked to digestive tract cancers. It causes algae to

    bloom resulting in eutrophication in surface water.

    Petrochemicals. Benzene and other petrochemicals can cause cancer even at low exposurelevels.

    Chlorinated solvents. These are linked to reproduction disorders and to some cancers. Arsenic. Arsenic poisoning through water can cause liver and nervous system damage,

    vascular diseases and also skin cancer.

    Other heavy metals. Heavy metals cause damage to the nervous system and the kidney, andother metabolic disruptions.

    Salts. It makes the fresh water unusable for drinking and irrigation purposes. Exposure to polluted water can cause diarrhea, skin irritation, respiratory problems, and other

    diseases, depending on the pollutant that is in the water body. Stagnant water and other

    untreated water provide a habitat for the mosquito and a host of other parasites and insects that

    cause a large number of diseases especially in the tropical regions. Among these, malaria is

    undoubtedly the most widely distributed and causes most damage to human health.

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    Common Diseases Transmitted to Humans through Contaminated Drinking Water

    Type of Organism Disease Effects

    Bacteria Typhoid fever Diarrhea, severe vomiting, enlarged spleen,

    inflamed intestine; often fatal if untreated

    Cholera Diarrhea, severe vomiting, dehydration;

    often fatal if untreated

    Bacterial dysentery Diarrhea; rarely fatal except in infants

    without proper treatment

    Enteritis Severe stomach pain, nausea, vomiting;

    rarely fatal

    Viruses Infectious hepatitis Fever, severe headache, loss of appetite,

    abdominal pain, jaundice, enlarged liver;

    rarely fatal but may cause permanent liver

    damage

    Parasitic protozoa Amoebic dysentery Severe diarrhea, headache, abdominal

    pain, chills, fever; if not treated can cause

    liver abscess, bowel perforation, and

    death

    Giardiasis Diarrhea, abdominal cramps, flatulence,belching, fatigue

    Parasitic worms Schistosomiasis Abdominal pain, skin rash, anemia, chronic

    fatigue, and chronic general ill health

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    Infectious diseases caused by pathogens (usually microorganisms) from animal fecal origins,of which the most common occur in developing countries involving:

    o Typhoido Giardiasiso Amoebiasiso Ascariasiso Hookworm

    Diseases caused by polluted beach water including:o Gastroenteritiso Dhiarrheao Encephalitiso Stomach cramps and acheso Vomitingo Hepatitiso Respiratory infections

    Liver damage and even cancer (due to DNA damage) caused by a series of chemicals (e.g.,chlorinated solvents, MTBE)

    Kidney damage caused by a series of chemicals Neurological problems - damage of the nervous system usually due to the presence of

    chemicals such as pesticides (i.e., DDT)

    Reproductive and endocrine damage including interrupted sexual development, inability tobreed, degraded immune function, decreased fertility and increase in some types of cancers

    caused by a series of chemicals including endocrine disruptorswhich

    Thyroid system disorders (a common example is exposure through perchlorate which is achemical contaminating large water bodies such as Colorado River)

    Increased water pollution creates breeding grounds for malaria-carrying mosquitoes killing 1.2-2.7 million people a year

    A series of less serious health effects could be associated by bathing into contaminated water(i.e., polluted beach water) including:

    o Rasheso Ear acheso Pink eyes

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    GLOBAL WARMING

    What is Global Warming?

    Global warming means a long-term rise in global average temperature. The temperature at or near

    the surface of the Earth is determined by four main factors:

    The amount of sunlight Earth receives. The amount of sunlight Earth reflects. Retention of heat by the atmosphere. Evaporation and condensation ofwater vapor.

    More particularly, the constant increase in temperature that started a century ago is assumed to be

    caused mostly by pollution from human activities, including the combustion of fossil fuels and

    deforestation. In fact, global warming represents an enhancement of the greenhouse effect. The

    anthropogenic greenhouse effect would be a more suitable term for global warming. The

    Greenhouse Effect is what keeps Earth warm enough for people to live on (If there was no such

    GH effect the Earths average temperature which would be 34-350C colder than it is now.

    The average global air temperature is about 150C), but a build-up in the gases that generate

    this warmth is overheating our planet and causing global warming. Increasing temperatures have

    already resulted in an increase in extreme weather events, loss of sea ice and glaciers, rising sea

    level, and harm to wildlife.

    Causes of Global Warming:

    Carbon Dioxide (CO2)Carbon dioxide is the most vital anthropogenic greenhouse gas.

    Carbon dioxide is released from the interior of the Earth (volcanoes),and produced by respiration of biota, soil processes, oceanic

    evaporation, as well as human activities, such as deforestation (which

    causes 20% of the annual increase in this gas) and burning of fossil

    fuels. Deforestation might be sending an annual 4 billion tons of Fig: CO2 Emission

    carbon dioxide into the atmosphere that would otherwise be absorbed by plants during their

    metabolic processes.

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    Automobile exhausts causes 30% of carbon dioxide emissions in developed countries. The

    generation of carbon dioxide as a result of combustion of fossil fuels suggests that if the

    present trends continue, then its concentration will double every 50 years.

    Chlorofluorocarbons (CFCs)Chlorofluorocarbons (CF2Cl2 and CFCl3), better known as Freon F-11 and F-12,

    correspondingly, are entirely anthropogenically produced, are very persistent compounds, used

    in spray cans as aerosol propellants and in refrigeration units. They were not present in the

    atmosphere until the 1930s. Due to their persistence and to their high efficiency in absorbing

    thermal IR, each CFC molecule has the ability to cause the similar amount of global warming,

    as much as tens of thousands of carbon dioxide molecules do. It has been anticipated that

    around 15% to 25% of the anthropogenic greenhouse effect may be connected to CFCs in the

    atmosphere. Because CFCs are highly stable compounds, their residence time in the

    atmosphere is lengthy. Even if production of these chemicals is reduced drastically or

    eliminated within the next few years, their concentrations in the atmosphere will remain

    significant for many years, perhaps for as long as a century.

    Water VaporIndeed, water vapor is the most significant greenhouse gas in the Earths atmosphere, in the

    sense that it produces more warming than does any other gas. Though on a per molecule basis,

    it is a less efficient absorber than is carbon dioxide. On a global scale water vapor is unaffected

    by anthropogenic sources and sinks. As a result, water is not normally listed explicitly among

    gases whose increasing concentrations are enhancing the greenhouse effect.

    Methane (CH4)Major natural contributors are termites as they process wood. Today, rice culture, domestic

    ruminant animals, landfills, and our own use of methane as a fuel source supply additional

    methane to the atmosphere.Methane is 21 times more effective than carbon dioxide inmaintaining heat in the atmosphere. This results in the deaths of numerous marine animals.About 70% of current emissions of methane are anthropogenic in origin. Methane contributes

    15% to 20% to the anthropogenic greenhouse effect. The short atmospheric lifetime of

    methane suggests that efforts to reduce methane emissions could be successful in delaying the

    raise in the rate of global warming. Yet, control of methane sources is doubtful, since the key

    sources involve agricultural practices that would be very difficult to change.

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    Nitrous Oxide (N2O)Nitrous oxide, which is comparatively inert, originates primarily from microbial activity in

    soils and the oceans, by industrial combustion, automobiles, aircraft, biomass burning, and as a

    result of the use of chemical fertilizers. It could be reduced by more watchful use of nitrogen-

    containing fertilizers. Nitrous oxide is a stronger greenhouse gas than carbon dioxide or

    methane, although it contributes only 5% to the anthropogenic greenhouse effect. Per

    molecule, nitrous oxide is 206 times as capable as carbon dioxide in causing an immediate

    increase in global warming. However, this gas also has a long residence time; even if emissions

    were stabilized or reduced, elevated concentrations of nitrous oxide would carry on for at least

    several decades.

    Hydrogenated halocarbons (HFCs and HCFCs):These are also entirely anthropogenic gases. They have increased sharply in the atmosphere

    over the last few decades, following their use as alternative for CFCs. They usually have

    lifetimes of a few years, but still have significant greenhouse effect.

    Ozone Gas (O3)Like methane and nitrous oxide, Ozone is a natural greenhouse gas, but one which has a

    short residence period. Ozone is formed in the troposphere as a result of pollution from power

    plants and motor vehicles, and from forest fires and grass fires, as well as from natural

    processes (i.e., by light-induced reaction of pollutants and the phenomenon is called

    photochemical smog). As a result of these anthropogenic activities, the levels of ozone in the

    troposphere most likely have increased since preindustrial times. Approximately 10% of the

    increased global warming potential of the atmosphere, results from the increases in troposphere

    ozone, though the value is uncertain.

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    Consequences of Global Warming:

    Negative impacts:

    On climate:

    Rising Seas: Greenhouse gases make sea level rise due to thermal expansion of sea water andmelting of polar and mountain ice. The increase in temperature results to sea level raise from

    melting glaciers and polar ice caps (adds 0.2 mm annually). It is estimated to be up to 1 meter by

    2100. The coastal zone (100 km from the sea) contains: 1.5 billion peoplethats 1 in 4 people

    and 17 out of 20 of the worlds largest cities which are now endangered because of global

    warming. Results are: flooding of low-lying islands and coastal cities, flooding of coastal

    estuaries, wetlands and coral reefs, beach erosion, disruption of coastal fisheries, contamination

    of coastal aquifers with salt water, increase in the

    vulnerability of coastal areas to flooding from storm

    surges and intense rainfall.

    Drier conditions: Growing temperatures will also causedrier condition in many important agricultural regions.

    The rise of temperature, even to a few degrees, could lead

    to the melting of ice shelves that hold back glaciers. This

    results in rising sea levels. The Larsen areas of North

    Antarctic, South of Chili and Argentina have lost more

    than 5,200 sq miles of area due to meltdown of ice caps

    and glaciers.

    Changes in rainfall patterns: Droughts and fires in some areas, flooding in other areas. Increased likelihood of extreme events: Such as flooding, hurricanes, etc. Melting of the ice caps: Loss of habitat near the poles. Polar bears are now considered to be

    seriously endangered by the shortening of their feeding season due to dwindling ice packs.

    Melting glaciers: Significant melting of old glaciers is already observed. Increased pollution: High temperature can increase pollution of water and air, which harms

    the human body

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    Biodiversity: Extinction of some plant and animal species, loss of habitats, disruption ofaquatic life.

    Water resources: Disruption in water cycle; increase in evaporation will cause some areas tobecome drier (increased drought), while the increased moisture in the air will result in greater

    rainfall in other areas; changes in water supply, decreased water quality, , increased water

    pollution from coastal flooding.

    Weather Extremes: Prolonged heat waves and droughts, violent storms with more frequencyand intensity.

    Forestry: Changes in forest composition and locations, disappearance of some forests,increased fire from drying, loss of wildlife habitat and species.

    On sea life:

    Coral Reef Bleaching:

    Change in temperature and elevated sea level cause loss of algae in the coral. Coral appears white, or bleached. Result is mass death of sea animals, which are dependent on the coral reef.

    E.g. the penguin population near Antarctica has been declining as the distance between

    them and their food has increased

    On other living beings:

    Global warming can disrupt the migration, hibernation and reproductive cycles ofcertain types of animals.

    Plants and animals will find it difficult to escape or adjust to the consequences of globalwarming because humans occupy so much land.

    Farmland or cities disrupt the movement of species between habitats. Changes in forest composition and locations, disappearance of some forests, increased

    fire from drying, loss of wildlife habitat and species.

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    On human:

    Loss of life: Extreme temperatures can directly cause the loss of life (ex: 35,000people died during heat wave in Europe, Aug03). Warmer weather provides an ideal

    breeding environment for mosquitoes. Diseases such as West Nile will be more common. Food Production: Shift in food growing areas,changes in crop yield, increased irrigation

    demands, increased pests, crop diseases, and weeds in warmer areas. It is the poorest

    countries, where many already are subject to hunger, that are the most likely to suffer

    significant decreases in agricultural productivity.

    Tropical diseases: Global Warming increases drought which lessens the supply of clean drinking

    water. E.g. Cholera.

    It increases temperature providing an ideal breeding environment formosquitoes. E.g. Dengue fever, Malaria, Yellow fever

    Public Health Impacts of Global Warming Heat waves and deaths from hyperthermia Fresh water shortages (due to combined effects of global warming, overpopulation and

    water pollution) with wars fought over fresh water

    Air pollution related to greenhouse gases (increased disease and death due to heartattack, stroke, asthma, emphysema, lung cancer, allergy)

    Ozone depletion leading to increased cataracts, melanoma Extreme weather events (floods and storms) Water-borne and food-borne diseases (toxic algal blooms like red tide, survival of viral

    pathogens leading to shellfish poisoning, cholera)

    Vector-borne and rodent-borne diseases (mosquitoes, ticks, rodents) Elevated seas levels (population exodus, aquifers threatened in San Francisco and New

    Orleans)

    Crop failures and famine Economic and political stress may damage public health infrastructure Vector Bone Disease: Disease in humans carried from another warm-blooded animal by

    an insect such as a mosquito, tick or sand fly. In 1877 scientists showed for the first

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    time that blood-sucking insects were able to carry disease from one warm-blooded

    animal to another. .

    Infectious diseases: The following diseases are potentially spread by global warming Leishmaniasis Kyasanur Forest disease La Crosse encephalitis Eastern equine encephalitis Japanese encephalitis Oropouche Western equine encephalitis Venezuelan equine encephalitis Onchocerciasi Dengue fever Malaria Yellow fever Chickungunya fever Epidemic polyarthritis West Nile fever St. Louis encephalitis Lyme disease Ehrlichiosis Plague Loaiasis

    Impact on air:

    The atmospheres ultimate fate is unclear.

    More evaporation increase in cloud cover

    Clouds close to the earth reflect sunlight cooling effect.

    Clouds high in the atmosphere trap heat warming effect.

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    Generally:

    Cloud cover increases Levels of the greenhouse gas methane may increase Hurricanes range farther north, south on warmer water

    On Bangladesh:

    This is a topographic map designed to emphasize portions of Bangladesh that are near sea level and

    hence could potentially be vulnerable to sea level rise.

    With a population of ~150 million, Bangladesh is the 7th most

    populous country on Earth and has the highest population density

    of any country larger than 1000 km2

    in area. As large portions of

    Bangladesh are near sea level, sea level rise here has the potential

    to displace tens of millions of people.

    1 meter rise in sea level will mean:

    15-17% of the country under water

    Displacement of 15-20 million peoplePositive impacts:

    Not all of the effects of global warming appear to be negative ones, however, despite the barrage

    of predicted woes.

    In colder areas:

    In many colder areas, for instance, warmer temperatures would extend the growing season.

    Northern countries like Canada and Russia, along with the more northern areas of the United

    States, should reap the rewards of longer growing seasons. Several studies have shown that, while

    some regions will suffer agriculturally, Americas nationwide food production will not decline

    substantially. In fact, recent assessments recommend that the beneficial effects of climate change

    would probably offset the adverse ones in Americas general agricultural production. A 1995 study

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    conducted by the USDA concluded that even a three to five degree Celsius warming of the

    atmosphere shouldnt effect Americas agricultural production notably.

    In agriculture:

    Even the very thing that is the main cause of global warming could be beneficial to agriculture.

    The higher carbon dioxide levels in the atmosphere should increase the efficiency with which

    plants use water, possibly offsetting some of the undesirable effects of dryer soils. Higher levels of

    carbon dioxide also have a fertilizing effect that would allow plants to grow more quickly. A

    carbon dioxide concentration of 550 ppm (parts per million) could raise crop yields in some areas

    by thirty to forty percent. Along with the promising positive effects of increased carbon dioxide

    concentration, warmer temperatures would make it lucrative to cultivate new land, which could

    result in a 0.2 to 1.2 percent increase in agricultural production.

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    References:

    For Water Pollution:

    www.csshome.com/WaterMarine.html

    en.wikipedia.org/wiki/Water pollutionwww.water-pollution.org.uk/

    www.water-pollution.org.uk/causes.html

    www.epa.gov/ebtpages/watewaterpollution.html

    For Global Warming:

    http://www.ipcc.ch

    http://www.weathervane.rff.org/

    http://www.igpp.lanl.gov

    www.dosomething.org/tipsandtools/11-facts-about-global-warming

    www.edf.org/climate/global-warming-facts

    http://www.ipcc.ch/http://www.weathervane.rff.org/http://www.igpp.lanl.gov/http://www.dosomething.org/tipsandtools/11-facts-about-global-warminghttp://www.dosomething.org/tipsandtools/11-facts-about-global-warminghttp://www.igpp.lanl.gov/http://www.weathervane.rff.org/http://www.ipcc.ch/