Introduction on pollution :                                                                      Pollution: is the introduction of contaminants into the natural environments  that cause an  adverse change. Pollution can take the form of chemical substances or energy, such as  heat , noise or light.Pollutants, the components of pollution, can be either
foreign substances/energies or naturally occurring contaminants. Pollution is
often classed as point source or non point source pollution. In 2015, pollution killed 9 million  of people in the world.                                       Type
of pollution:                                                          
1.Air pollution                                                 
                               2.water pollution                                                  
                   3.soil pollution                                                   
                        4.Radiological & Nuclear pollution

Air pollution                                                               
 occurs
when harmful substances including particulates
and biological molecules are introduced
into Earth’s atmosphere.
It may cause diseases, allergies or death of humans; it may also cause harm to
other living organisms such as animals and food crops, and may damage the natural
or built environment.
Human activity and natural processes can both generate air pollution.

Indoor air
pollution and poor urban air quality are listed as two of the world’s worst toxic
pollution problems in the 2008 Blacksmith
Institute World’s
Worst Polluted Places report.1 According to the 2014 World Health Organization report, air pollution in 2012 caused the deaths of around 7
million people worldwide,an estimate roughly echoed by one from the International
Energy Agency.                                                              
Causes
of Air Pollution  :                                                                    • carbon dioxide -Deforestation and
fossil fuel burning                                                                                         
• Sulfur dioxide -burning of sulfur containing compounds of fossil fuels.                                                                                                          •
Chlorofluorocarbons (CFCs) reduces the amount of ozone. CFCs come from – the
burning of plastic foam items – leaking refrigerator equipment – spray cans..

• Hydrocarbons- from petrol
engines                                                              
• NOx- from burning of fossil fuels                                                              
• Suspended particulate matter- by diesel engines, thermal power plants                                                                                                     
• Lead compounds- from petrol engines Natural Air Pollutants                                                                                        
• Natural air pollutants can include: – Smoke from wild fires – Methane
released from live stock – Volcanic eruptions. 
•Consequences of Air Pollution                                                
   • CO2 is a good transmitter of sunlight, but
it also partially restrict  infrared
radiation going back from the earth into space, which produces the socalled
greenhouse effect that prevents a drastic cooling of the Earth during the night
..                                                       
                  • Increasing the
amount of CO2 in the atmosphere reinforces this effect and is expected to
result in a warming of the Earth’s surface.                                                       
                                   • CO2 in atmosphere  cause GLOBAL WARMING . 
                                                          

    Water Pollution:                                                               –
occurs when the water
becomes over loaded with too much of one thing and the aquatic organisms cannot
keep up with their cleaning responsibilities. Some organisms may die and others
may grow too fast. There are many types and sources of  the water pollution. Using the picture, list
sources of pollution (such as sewage pollution) that can pollute surface water
or ground water.                                                                                                                    
Types
and Sources of Water Pollution:                          Types and Sources of Water Pollution
There are several major types of water pollution. One of the most destructive
types is Petroleum Pollution. Petroleum products, such as oil and gasoline,
enter the water from ships and marine terminals, offshore oil rigs, runoff from
parking lots, factories, oil dumping, and  the other sources. Many of  worst pollution disasters have been due to
accidents involving an  oil rigs,
pipelines, or oil tankers. Sewage Pollution comes from both  city and 
country areas. Although many cities and towns have sewage treatment
plants, at times, such as during a flood event some may be unable to handle the
amount of sewage produced. Treatment plant failures and overflows may result in
untreated sewage entering rivers and coastal waters. Some coastal cities may
still be using the open ocean as a sewage dumping site. Small pleasure boats,
as well as larger ships, can pollute waters by illegally dumping. Pollution
from Solid Wastes Solid Wastes is a major problem for many communities. Most
solid wastes are handled by taking them to landfills, but some illegal dumping
of garbage, old tires and other solid wastes occurs. A hazard to both humans
and wildlife, solid wastes are unsightly, slow to degrade and, in some cases,
non-degradable. Nuclear-powered ships, power plants and other users of Nuclear
Energy are possible sources of Radiation Pollution, not so much from accidents,
but from disposal of nuclear materials such as spent numclear fuel cells. Many
factories and nuclear power plants use water cooling during manufacturing
processes and reactor cooling. Water taken from rivers, bays or lakes is heated
and, if returned directly to the environment, can lead to what is called Heat
or  the Thermal Pollution. The Chemical
and industrial plants produce thousands of different types of Toxic Chemicals
Toxic Chemicals and Wastes. Chemicals such as PCB’s (polychlorinated biphenyls)
and TCE (trichloroethene) have been highly publicized due to being found in the
environment and their harmful effects on living things. The use of Fertilizers
Fertilizers and Pesticides Pesticides on cropland, gardens and yards helps
farms and homeowners but can also be damaging to aquatic and marine life when
not properly applied or managed in rural and urban areas. Poorly managed Animal
Wastes from farms can also add excess nutrients to rivers and lakes. In
addition, runoff from farm lands and urban areas carries large amounts of
sediment into waterways making the water cloudy or murky. Sediment is the
number one pollutant by volume of surface water in the United States.                                    

 

                                                           

 

 How Does Water Pollution Affect You?                          Most population centers are located near major
waterways. These areas were first settled because of their access to water, but
there is a continuing nationwide trend for people to move to areas near the
coast or major rivers. This movement places more stress on aquatic environments
as more people use water resources for recreation, food, water sources, energy
and transportation. Pollution of water resources can interfere with swimming
and fishing activities, make boating unsafe, affect wildlife and food resources
and even contaminate water supplies. Lakes, rivers and coastal areas are much
more enjoyable and safe when they are pollution free. Not only do you benefit
from a pollution free environment, but organisms that live there do as well. It
is every person’s responsibility to clean up after themselves. Throw away their
trash and to pick up any othe litter they see.                                                            Cleaning Up Dirty Water Cleaning Up Dirty
Water Water Pollution Can Cause Disease :                                          1. Water has been one of man most precious commodities
throughout history. Water, although essential for life, is frequently
squandered. Misuse of water became a problem during the Industrial Revolution
when populated cities developed. Wastes from the homes and factories were
discharged directly into rivers and streams near cities. Contaminated rivers
became a major threat to public health because they transmitted disease. For
example, 50,000 people died from cholera cholera — in London in 1831. Dysentery
and typhoid fever  rampaged city  areas late in the 19th century.                                                                                           
2. Microorganisms are found in all natural waterways. They will multiply
if there is enough food available and proper environmental conditions are maintained
for organism growth. In a polluted stream, microorganisms multiply very fast to
consume all of the organic pollution that is available . Unfortunately,
microorganisms also need oxygen. Oxygen in the stream is rapidly depleted
because microorganisms use oxygen while consuming their food. Dissolved oxygen
is essential to microorganisms, fish and plants in a healthy stream. When there
is no oxygen in the stream, fish, aquatic plants and microorganisms die and
fall to the bottom of the stream and decay. This degradation process causes the
bottom of the stream to become black and mucky. It produces odorous gases and
makes the stream unacceptable for many uses. This decay also adds to the
depleted oxygen problem.                                                                  Biological Pretreatment of Wastewater:                                     
Biological Pretreatment of Waste water The wastewater treatment process
at most wastewater treatment plants depends on pollutants in the sewage being
biodegradable. A pollutant is biodegradable if there is a naturally occurring
organism that can use it for food. — Many chemicals manufactured by industries
are not biodegradable. Therefore, they are difficult to treat at a biological
wastewater treatment plant. — Industries that discharge non-biodegradable
wastewater to a public wastewater treatment plant must pretreat pretreat their
wastes. Pretreatment is usually a chemical process that changes the industrial
wastewater to a form that is amenable to biological treatment by the public
waste water treatment plant.                                                              Soil
pollution:                                                                                  
Soil pollution (also
known as land pollution) is caused when the man-made chemicals, such as
hydrocarbons, heavy metals, solvents, get into the soil.These chemicals come
from industrial activities and from waste in disposal in leaky landfills. Soil
pollution may cause health risks. The chemicals can produce harmful vapours, or
they can contaminate water supplies underneath the polluted soil.

Plastic pollution is the accumulation of
plastic products in the environment that adversely affects wildlife, wildlife
habitat, or humans. It takes thousands of years to decompose or mix in the
earth.

 

 

 

 

Causes of Soil
Pollution:                                                           
• Contamination of soil system by
considerable quantity of chemicals or other substances resulting in reduction
of its fertility.                                                     
                                                       • Four Main causes of Soil pollution : Construction
 ,Agriculture ,Domestic waste ,
Industrial Waste Chemicals causing soil pollution                                                  
                       • Metallic pollutants- textiles, dyes, soaps,
detergents, drugs, cement, rubber, paper, metal industries release Fe, Pb, Cu,
Zn, Hg, Cd, CN, acids, alkalies etc.                                                                                                              
• Agro chemicals- Fertilizers, pesticides, insecticides, weedicides,
rodenticides, fumigants release toxic chemicals like Pb, As, Cd, Hg, Co
etc.                                                    • Radioactive Chemicals Biological
Pollution                                          •
Disturbance of the ecological balance by the accidental or deliberate
introduction of a foreign organism, animal or plant species into an
environment.                                                                               •
an individual organism (internal biological pollution by parasites or
pathogens)                                                                     • A population (by genetic change) continued                         • a community                                                                     
      • a habitat (by modification of
physical-chemical conditions),                                                                        
                   • An ecosystem (by alteration of energy and
organic material flow).                                                                       
   • Biopollution may also cause decline in
naturalness of nature conservation areas. Biological Agents                      • Soil gets human, animal
& bird excreta                                    • Digested
sewage sludge                                                                 
• Heavy applications of manure to soil Scale of Biologic Contaminant
Problem: -Major cause of infant deaths in third world -Diarrhea kills 4-15
million children/year -Bacteria, viruses, parasites .                                             Radiological & Nuclear pollution                                                                                • Special form of physical pollution of air, water and
soil with radioactive materials.                                               
                     •
Radioactivity- Property of certain elements like Ra, Th, U etc to spontaneously
emit alpha, beta & gamma rays by disintegration of atomic nuclei.
Sources                                                                                            
• Nuclear explosions and detonations of nuclear weapons – U-235, Pu-239
for fission, H & Li for fusion. Fallouts contain Sr-90, Cs-137, I-131                                             •
Defense weapon production- C-14, I-125, P-32                       • Nuclear waste handling
and disposal- high level & low level Sources                                                                                •
Mining – radioactive gases like radon                                             •
Nuclear accidents                                                                   
• Medical X-Rays- from diagnostic X-rays & radiation therapy for
cancer.                                                    
                          •
Nuclear reactors- U-235, U-238, Th-232 Effects of nuclear pollution                                                                          •  effects vary from organism to organism and
from level of radioactivity of nuclear isotopes. The radiations destroy the
cells in human body and causes cancer.                                                                       
     • A longer exposure to
radioactive radiations can damage the DNA cells that results in cancer, genetic
defects for the generations to come and even death.                                   • Affects
animals, some species preferentially accumulate specific radioactive materials-
oysters deposit Zn-65, fish Fe-55, marine animals Sr-90. Chemical Warfare
agents                                                            
                    • A chemical used in warfare is called a
chemical warfare agent .                                                                                                • These agents may be in liquid, gas or solid
form. Liquid agents are generally designed to evaporate quickly; such liquids
are said to be volatile or have a high vapour pressure.                                                                 
                              • In July 1917, the Germans employed
mustard gas. Mustard gas easily penetrates leather and fabric to inflict
painful burns on the skin.                                                         •
Chemical warfare agents are divided – into lethal and incapacitating
categories. A substance is classified as incapacitating if less than 1/100 of
the lethal dose causes incapacitation, e.g., through nausea or visual
problems.                                                          
• Choking Agents (e.g., phosgene, chlorine)                              • Blister Agents
(e.g., nitrogen mustard, Lewisite)                     • Nerve Agents (e.g.,
tabun, sarin, VX)                                           •
The most commonly used chemicals are four lung destroying poisons: chlorine,
chloropicrin, phosgene, and trichloromethyl chloroformate, along with a
skin-blistering agent known as mustard gas, or bis (2- chloroethyl)
sulfide.                                                     
Pollution has cost:                                                                
Manufacturing activities that cause air pollution impose health and
clean-up costs on the whole society, whereas the neighbors of an individual who
chooses to fire-proof his home may benefit from a reduced risk of a fire
spreading to their own houses. If external costs exist, such as pollution, the
producer may choose to produce more of the product than would be produced if
the producer were required to pay all associated environmental costs. Because
responsibility or consequence for self-directed action lies partly outside the
self, an element of externalization is involved. If there are external benefits,
such as in public safety, less of the good may be produced than would be the
case if the producer were to receive payment for the external benefits to
others.