1. Water Pollution

2. Water is capable of dissolving or suspending a variety of materials, so it’s pretty tough to get "pure" water. All water, outside of a research laboratory, will have some other substance in it.
The Universal Solvent

3. Water Pollution Others, not so good
Some of the stuff that it dissolves / suspends is good for us
Others, not so good
Some substances that water absorbs are good for our health, while others may not be so beneficial. There are infinite numbers of possible contaminants in drinking water. Here we will talk about contaminants that are not good for us.
Water Pollution

4. Can you name 5 things that dissolve in water?
Know of any 2 that can be called ‘pollutants’ – those dangerous to life ?
Students can be encouraged to name things that they see in their homes that can dissolve in water.

5. Cholera Typhoid Jaundice Cancer Organ failure
If we drink polluted water, we can get sick
Cholera
Typhoid
Some pollutants (typically organic pollutants) introduce and favour the growth of germs in water, which can cause diseases like typhoid, cholera, and jaundice.
Others pollutants (typically inorganic pollutants) can collect in our bodies and affect our bones or cause diseases like cancer over time. These pollutants are excreted from our bodies very slowly and if the rate of intake is greater than the rate of excretion, they collect in our bodies. This process is called bio-accumulation. A high concentration of these pollutants in our bodies results in chronic diseases like cancer, organ failure, nervous system disease, etc.
Jaundice
Cancer
Organ failure

6. Figure out some pollutantsK C T
_ _ _ _ _ _ _ + + G H
_ _ _ _ _ _ _ +
Clue: toothpaste +
Sounds like
_ _ _ _ _ _ _ _
Led Zeppelin
Deep Purple
_ _ _ _ _ _ _ _ _ _
Black Sabbath
Iron Maiden

7. Figure out some pollutantsK C T
ARSENIC + + G H
NITRATE +
Clue: toothpaste
Arsenic is introduced into groundwater through dissolution of naturally occurring minerals and ores. It enters the human body through water consumption. It can cause cancer, affect the nervous system, cause birth defects and other serious health problems.
Fluorides leach into the groundwater from weathering of bedrock rich in fluoride bearing minerals with climatic conditions playing a significant role. It is also introduced into water through human activities – primarily industrial processes. It causes mottled teeth (dental fluorosis) or can affect the bones (skeletal fluorosis).
Inorganic fertilizers contain nitrate compounds. Excess nitrate that cannot be used by the crops leaches into the groundwater. Fertilizer runoff into lakes and streams can cause nitrate contamination of surface water bodies. Poorly treated or untreated sewage discharge also causes nitrate contamination. It enters the human body through water consumption and consumption of food irrigated by contaminated water. It can affect babies and cause the blue baby syndrome. It can also cause cancer, alzheimer’s disease and other serious health problems.
Pesticides contain many heavy metals and organo-chlorides which accumulate in our bodies over time and cause life-threatening diseases. +
Sounds like
FLUORIDE
Led Zeppelin
Deep Purple
Black Sabbath
Iron Maiden
HEAVY METAL

8. How do we know that water is polluted?
Sometimes polluted water changes colour…..but not always
Sometimes it tastes different ……..but not always
Some contaminants may introduce a change in colour, taste, or smell of water, but in many cases, especially inorganic contamination, such changes are not observed. Water contamination can be confirmed only by testing the water in a certified laboratory.
Sometimes it stinks……but not always

9. How do we know that water is polluted?
Water pollution can be confirmed only by testing it in a lab

10. Sources of water pollution are generally grouped into two categories
Non-point source of pollution:
Contamination gathered by water over a large area.
Examples of point source of pollution include discharges from a wastewater treatment plant, untreated effluent from a factory, leaking underground tanks, etc. They enter a water stream through a specific point.
Examples of non-point source of pollution include storm water runoff from agricultural fields and urban areas, or vehicular (air) pollutants that dissolve in water. One cannot identify a specific location from where the pollutants are introduced into the water stream.
For the past several decades, the focus was on reducing point sources of pollution. In recent years, greater attention has come to be placed on non-point source contributions, especially in urban areas.
Point-source of pollution:
Contaminants enter a waterway at a discrete point

11. Water can get polluted naturally
When water seeps into the ground, it absorbs different substances depending on the type of soil and rock that it flows through.
The geology of a place can introduce inorganic contaminants into groundwater. As water seeps into the ground, if the rocks and soil are rich in compounds of fluoride, arsenic, iron etc., these compounds dissolve in the groundwater. When groundwater is extracted and used for drinking, these compounds enter our bodies.

12. Water can get polluted naturally
Some of these substances (arsenic, iron, fluoride, etc.) can be harmful to our health.
Compounds of arsenic, fluoride, etc., accumulate in our bodies over time due to bio-accumulation.
Natural pollution is a non-point source of pollution.
Natural pollution is a non-point source of pollution

13. Arsenic
In groundwater
Fluoride
Excess fluoride in groundwater is a problem in most parts of India. Fluoride in small levels is required for healthy teeth and bones. That is why many toothpastes contain a small amount of fluoride. But when levels of fluoride are beyond an acceptable limit, they accumulate in our bodies and cause fluorosis. Fluorosis can be of two types – dental and skeletal. In the initial stages, teeth start getting discoloured and with increasing concentrations, people get severely crippled. Though defluoridation kits are available, people living in fluoride affected areas are advised on counteracting the affects of fluoride contamination with diet– eating foods rich in vitamin C, calcium, and iron and avoiding foods with black salt, etc.
West Bengal and Bangladesh are affected by high arsenic concentration in groundwater. This causes arsenicosis in humans, which is a life threatening disease.
Such contamination is aggravated when there is excessive groundwater extraction. Concentrations of polluting compounds increase in the existing groundwater. People living in areas which have high levels of natural inorganic pollution in groundwater are advised to recharge their groundwater reservoirs with rainwater, so that the concentration of the salts in the groundwater reduces.
In groundwater
Natural pollution can introduce chemicals that collect in our bodies. Over time this can cause chronic problems and even life – threatening diseases.

14. Does Man Pollute Water?
This is what a young person like you has to say:
“ If you had a bottle of life-preserving fluid on which your life depended, would you pour into it all your sewage and rubbish, along with any other poisonous chemicals you could find? And yet, that is exactly what we are doing to our water supply – all over the world.”

15. The various ways in which man pollutes water 
Untreated or inadequately treated municipal sewage
An example of Point source of pollution
Yamuna, when it leaves Delhi, resembles a sewer full of the city’s wastes. A few hundred kms downstream is Agra, where this ‘sewer’ is the main municipal drinking water source.
Most of the water used in a home comes out as waste water – black water (sewage) and grey water from sinks, bathrooms, washing machines, etc. Our waste water treatment systems are inadequate. Excess untreated waste water is either led into surface water bodies (lakes, ponds, rivers, seas), or into the soil. This contaminates surface and ground water.
Sewage contains pathogens which can cause diseases like cholera, typhoid, jaundice, etc.
Grey water from washing contains phosphates and other chemicals which assist organic growth. This leads to eutrophication of water bodies like lakes and ponds.
 YUCK!!
eutrophication

16. An example of Point source of pollution
Reaches ground water bodies
The various ways in which man pollutes water 
Untreated or inadequately treated municipal sewage
An example of Point source of pollution
Untreated sewage seeps in and contaminates groundwater aquifers
Such aquifers show a higher than acceptable level of nitrate content
Increase in sewage content in the soil can result in contamination of groundwater sources with nitrates. Nitrate contamination can result in dangerous diseases like blue-baby syndrome. (Under certain conditions, consumed nitrate gets reduced to nitrite, which reacts with haemoglobin and reduces the capacity of blood to carry oxygen. When pregnant women drink nitrate contaminated water, it affects the baby and the baby can die if adequate oxygen does not reach the brain.)

17. The various ways in which man pollutes water 
Dumping garbage in surface water bodies
There is also increased solid waste generation (industrial and domestic). This waste is either thrown into surface water bodies or is left in waste dumps. Chemicals seep down from these waste dumps into the soil and into our groundwater resources, contaminating them.
When garbage is dumped in a landfill, toxic chemicals leach into the soil and groundwater.

18. The various ways in which man pollutes water 
Over 10 million people
bathe in the Ganga daily!
People bathing and washing clothes also contaminates surface water bodies. Soaps and detergents have phosphates, which are nutrient rich and can cause eutrophication of surface water bodies.
Washing and bathing introduces phosphates and other chemicals into water

19. The various ways in which man pollutes water
Agriculture
An example of Non- Point source of pollution
dissolve in irrigation water or rainwater.
They contaminate surface water and groundwater with pollutants like nitrates, phosphates, and non degradable synthetic organic pollutants.
Agriculture uses large quantities of pesticides and fertilizers. Water used for irrigating farms, or rainwater that falls on these lands dissolves the fertilizers and pesticides and seeps into the ground contaminating the soil and groundwater with pollutants like nitrates, phosphates, and non degradable synthetic organic pollutants.
Nitrogen based fertilizers are commonly used in India. Nitrogen is converted to nitrate. Excess nitrate that cannot be used by the crop leaches into soil and groundwater. Nitrate contamination of water can cause the blue baby syndrome.
We invented insecticides, herbicides, and fungicides to save our crops from pests and to save ourselves from diseases. Crop yields increased and pests like mosquitoes were destroyed. The pesticide industry grew to become a multi-billion dollar industry. We then started finding different kinds of cancers, birth defects, and other medical problems. Studies across the globe showed pesticides to be the culprit. Pesticides contain complex organo-chlorides and other heavy metals that bioaccumulate and biomagnify the food chain. Over time, their concentration in our bodies increase beyond safe levels and cause serious health problems most of which are fatal.
Agriculture is one of the most important sectors in India and the use of pesticides is rampant. World over, the usage of pesticide is reducing but in India it is on the rise. We continue to use pesticides that are banned in other parts of the world. Untrained farmers overuse pesticides and are ignorant of the ill-effects of pesticides. Today, pesticides are considered the foremost chemical threat to our groundwater.
We also use some pesticides in our homes – can you name one? (Insect sprays)
Agriculture is a major source of groundwater contamination.

20. The various ways in which man pollutes water 
Industry
An example of Point source of pollution
Agro industries (sugar, food processing, pulp and paper, distilleries) – their wastes have high concentration of dissolved organic matter.
Chemical Industries – If their wastes are not treated properly,
the chemicals can destroy our soil and water resources.
Petroleum refining – water used in the process needs to be
separated from all the oil before releasing it into
nature……but is that done?
Industrial processes also use a lot of water and the resultant effluents are not treated to the required extent in many cases. Some industries let out untreated effluents into municipal sewage drains and the municipal waste water treatment systems are geared to handle only sewage, not chemical-laden wastes. The output of the municipal wastewater treatment system ends up in surface water bodies, which are contaminated by these untreated chemicals.
Some industries may let out untreated effluents directly into water bodies, polluting them and others may let it out into the soil, from where it seeps into our groundwater resources.
Wastes from agro industries contain many organic substances which are nutrient rich. These wastes boost the growth of weedy species of plants in surface water bodies and can result in eutrophication.
Minamata disease

21. The various ways in which man pollutes water 
Industry
An example of Point source of pollution
Thermal power plants – water is needed to cool the process.
The water gets hot and when it’s released into a larger
water body, it upsets the ecology by modifying the
delicate temperature balance.
This is called ‘Thermal pollution’
Water is required for the process of cooling in power plants and during this process, its temperature increases slightly. This water, when released into a water body, alters its temperature and affects the ecosystem, which is in a state of delicate balance. Even a change of 1-2 degrees centigrade of the water can alter the aquatic ecosystem considerably.

22. Effluent treatment plants
Liquid wastes from an industry are treated in effluent treatment plants.
Large industries have in-house effluent treatment plants.
It’s expensive for small industries to have such plants of their own.
In some industrial estates, a group of small industries have a common effluent treatment plant.
Industries are supposed to treat their wastewater before releasing it into a water body. This treatment is done in ‘effluent treatment plants’, which are custom designed to handle the type and quantity of wastes generated by a particular industry. Larger industries usually have effluent treatment plants, but medium and small scale industries find this a very expensive proposition. Due to the high cost, most medium and small scale units do not have effluent treatment plants and release untreated wastewater into municipal drains, surface water bodies, or soil. Some industrial estates have tried to make a common effluent treatment plant which can be used by a group of industries together, but there have been technological issues due to the waste constituents, its quantity and the frequency at which the wastes are released.

23. A RE-CAP Water can be polluted naturally Water can be polluted by man
Sewage in our water bodies
Garbage dumps
Washing and bathing
Pesticides and fertilizers
Industries

24. Hangman Divide the class into 5 teams
Draw as many dashes as in the name of a water pollutant or a pollution cause.
Team A starts. They guess a letter. The teacher puts in the letter at the correct place, if it is there in that name.
Else, the letter is written down on one side.
A maximum of 10 wrong guesses are allowed.
The team gets as many points as letters on the side (maximum of 10).
The team with the lowest number of points wins.

25. Eutrophication (pronounced as you-tro-fi-kay-shun)
When wastes with high organic content (such as sewage wastes) are dumped into a water body like a lake or pond, eutrophication can occur, killing all life in the water body.
Organic wastes are rich in nutrients (nitrates and phosphates)
They stimulate excessive plant growth – especially weedy species

26. Eutrophication
On dying, the plants further add to the organic waste in water.
Microorganisms that decompose the organic material in water use up a lot of dissolved oxygen.
This depletes the available oxygen in the water and upsets the ecological balance, since fish and other life forms perish without adequate oxygen.
Eventually all the oxygen is used up.

27. Eutrophication Anaerobic organisms then attack the organic wastes,
releasing gases such as methane and hydrogen sulphide.
The result is a foul smelling, waste filled body of water, quite like many of
the lakes in India.
These water bodies are also natural groundwater recharge systems
and their contamination also leads to groundwater pollution.

28. Minamata disease Industrial wastewater from the Chisso corporation
(manufacturing fertilizers and other chemicals) was
released into the Minamata Bay in Japan.
The waste water was rich in methyl mercury.
Mercury content in shellfish in that region increased.
People ate the shellfish and the cats ate the leftovers.

29. Strange things started to happen – cats had convulsions and died,
crows fell from the sky, dead fish floated.
Young children had convulsions and difficulty in
walking and speaking.
People died.
Investigation showed organic mercury poisoning affecting the
nervous system.
First discovered in 1956.
Lawsuits and claims continue till today.