The document discusses World Water Day and highlights the importance of water for life and various human activities, while addressing the critical global water issues such as pollution, scarcity, and the environmental impact of water use. It emphasizes that approximately 700 million people suffer from water scarcity and outlines the significant health risks associated with water pollution. Additionally, it presents the need for effective measures to ensure water quality and availability, along with the implications of increased population and industrial demand on water resources.

1. 22 March is World Water Day
Presented by
Dr. B. Victor., Ph. D
Email : bonfiliusvictor@gmail.com
Blog: bonvictor.blogspot.com

2.  Introduction  Chemical structure
 Life – supporting  Global water cycle
functions of water.  Kinds and sources of
 Water is vital to human water pollution
life  Health impacts of water
 Global water issues pollution
 Global distribution of  Water footprint
water  Water pollution episodes
 Properties of water  Remedial measures

3.  The earth is the only planet with
water.
 The planet earth is also called the
‘blue planet’ due to the presence
abundant water on its surface.
 The earth is the only planet that
supports life.
Evidences:
1.water occurs on its surface as liquid, ice
and gas.
2.ocean covers 71% of the globe.
3.Freshwater cover les than 1%.
4.Ice sheets cover polar region.
5.Glacier’s are found in higher mountains.

4.  Water covers approx.71 %
of the planet earth and
constitutes 60-70 % of the
living world.
 The existence of life on
earth is not possible
without water.
 The environmental system
within which we live is
dependent on water.

5.  Human consumption-
(drinking and cooking)
 Food production
(irrigation)
 Personal hygiene
 Sanitation
 Industrial production
 Energy generation
 Economic development
 Environmental protection.

6.  An average adult human body contains
42 liters of water.
 Water is required for digestion and
absorption of food.
 Water transfers oxygen and nutrients to
the cells.
 Water carries metabolic wastes.
 Water act as a natural cooling system.

7.  Water shortage - levels of available water
do not meet minimum requirements.
 Water scarcity – the relationship between
demand for water and its availability.
 Water stress – decline in water quality.
 Water security – access to adequate
quantity and safe quality.

8.  Water is facing a crisis today.
 Water scarcity affects all
social and economic sectors.
 There are concerns that water
will increasingly be the cause
of violence and even war.
 Water is recognized as one of
the key limiting resources of
this millennium.

9.  Approx. 700 million people in 43 countries
suffer as a result of water scarcity.
 Nearly 1 billion people lack safe drinking
water.
 Half of the world’s 500 major rivers are
polluted.
 75% of India’s lakes and rivers are too
polluted for safe use.

13.  The total amount of water on
the earth is about 326 million
cubic miles of water.
 The needs for water rise along
with population growth,
urbanization and increases in
the number of households and
industrial uses.

14. 97.200% sea water
02.014% ice caps and glaciers
00.600% ground water
00.009% surface water
00.005% soil moisture
00.001% air moisture

15.  Solids: when water becomes very cold
and freezes it will change from a liquid
to a solid. It has a definite form and
shape.
 Liquids: in liquid form, water takes the
shape of its container.
 Gases: in vapor form water has no
definite size.

16.  Ocean Water: salt water is found in the
oceans and seas.
 Fresh Surface Water: fresh water is found
in rivers, streams, lakes and ponds.
 Ground water: Ground water is stored in
underground aquifers. Water in aquifer
remains there for an average of 1,400
years!

17.  A water molecule has one oxygen
atom and two hydrogen atoms.
 The two hydrogen atoms bound to
one oxygen atom to form a ‘V’
shape at an angle of 105 degree.
 The length of the bond between
the oxygen and the hydrogen is
95.84 pm (picometre).
 The chemical formula for water is
H2O, meaning two hydrogen
atoms covalently bonded to one
oxygen atom.

18.  Water is colorless, tasteless and odorless.
 Water is a great solvent.
 Water exists as a liquid, in rivers and seas,
a solid, as snow and ice, and as a gas, as
clouds or steam.
 Water can absorb a large amount
heat(high specific heat capacity).
 Water can stick together into beads and
drops( surface tension).
 Water flows and erodes the surface of the
earth.

19.  There are TWO overlapping water cycles
in nature.

21.  Water evaporates from water bodies like
seas, and oceans, lakes and rivers.
 Water vapor cools and condenses in the
clouds.
 Water precipitates in the form of rain and
snow which fall on the soil.
 Runoff and accumulation forms fresh
water lakes, streams, ponds and
groundwater.

22.  Evaporation – the process by
which water changes from liquid
to gaseous state.
 Condensation – the process by
which a gas changes to a liquid.
 Precipitation – clouds in the air
drop rain on land.
 Transpiration – the process by
which plants release water vapor
thro’ leaves.
 Accumulation – water gets
collected in oceans , seas and
lakes.

23.  This cycle refers to volume of water content in the
body of an organism.
 Aquatic plants and freshwater animals absorb
water from the surrounding medium by osmosis.
 Trees absorb water from the moist soil thro’ roots.
 Land animals receive water by feeding and
drinking.
 Plants loose water by transpiration thro’ leaves.
 Animals loose water by sweating and elimination.
 After death water returned to the environment by
bacterial decomposition.

24.  Pure water = 7.0 pH
 Rain from unpolluted
atmosphere = 6.0 pH
 Natural rain water = 5.6
pH
 Acidic rain water = 4.5
pH
 Rain near urban areas
= 4.0 pH
 Rain from fog clouds =
1.7 pH

29.  Surface water pollution - pollution of lakes, rivers and
oceans
 Groundwater pollution - pollution of aquifers below soil.
 Microbial pollution – pollution by bacteria, viruses, protozoa
and parasitic worms.
 Oxygen depletion pollution – pollution by biodegradable
organics.
 Nutrient pollution – pollution by plant nutrients (nitrates,
phosphates)
 Suspended matter pollution – pollution by soil, silt
 Chemical pollution - pollution by pesticides, fertilizers,
industrial solvents, oil
 Thermal pollution- pollution by warm water, waste heat

30.  Point Sources – A single definable source
of the pollution, e.g. a factory, a sewage
plant, etc.- pollution is easy to monitor
and control,
 Non-point sources – No one single
source, but a wide range of sources, e.g.
runoff from urban areas, or farmland.
-Pollution is more difficult to monitor and
control.

31.  Non-point sources  Point Sources

32.  Non-persistent pollutants can be broken
down by natural chemical reactions or
by natural bacteria into simple, non-
polluting substances such as carbon
dioxide and nitrogen. e.g. wood, paper,
biological wastes
 More load of degradable pollutants can
lead to low oxygen levels and
eutrophication.
 But this damage is reversible.

33.  Organic chemical substances are
persistent that degrade very slowly or
cannot be broken down at all.
 They may remain in the aquatic
environment for longer periods of time.
 The damage is irreversible and is the most
rapidly growing type of pollution.

34.  Pesticides - DDT, dieldrin
 Leachate components from landfill sites
(municipal, industrial)
 Petroleum and petroleum products
 PCBs, dioxins, polycyclic aromatic
hydrocarbons (PAHs)
 Radioactive materials- strontium-90,
cesium-137, radium-226, and uranium
 Metals - lead, mercury, cadmium

37.  Industries effluents contain heavy
metals , resin pellets, organic toxins, oils,
nutrients, and solids.

38. Impact of
Microbial water pollution
 No. of people lack access to safe drinking water = Over
1 billion.
 No. of people lack adequate sanitation = 2.6 billion . This
has led to widespread microbial contamination of
drinking water.
 Deaths due to water-associated infectious diseases =up
to 3.2 million people per year. (approx. 6% of all deaths
globally).
 Deaths due to diseases caused by inadequate water,
sanitation, and hygiene = 1.8 million people.

39.  excessive amounts of plant
nutrients=P,N,C.
 Excessive growth or ‘blooms of algae’
 Algal blooms leads to oxygen depletion.
 Hypoxia leads to mass fish kills.
 Degradation of water and habitat
quality.

40.  Drought causes more damage and
suffering than any other natural disaster.
 80 countries experience droughts lasting
more than 1 year.
 According to the UN, almost 500 million
people, in 31 countries (~40% of the world’s
population) experience chronic water
scarcity.
 Water scarcity is already a problem in many
countries.

41.  50% of the world’s population lives on or
within 160 miles of shore.
 Fourteen billion pounds of garbage, mostly
plastic, is dumped into the ocean every
year.
 For every 1 million tons of oil that is shipped,
about 1 ton is spilled.
 More oil is seeped into the ocean each
year as a result of leaking cars and other
non-point sources

42.  Asian rivers are the most polluted in the
world.
 River Ganges in India is one of the most
polluted rivers in the world.
 Approximately 46% of the lakes in
America are too polluted for fishing,
aquatic life, or swimming.

43.  The amount of plastic waste has been
increasing about 10% each year for the
past 20 years.
 Over 1 million seabirds are killed by
plastic waste per year.
 Over 100,000 sea mammals and
countless fish are killed per year due to
pollution.

44. “Water contributes much to health”
- Hippocrates ( 460 – 377 B.C )

45.  Neurotoxins – destroying nervous tissue.
 Carcinogens – inducing cancers
 Mutagens – altering genetic characteristics
 Teratogens – causing non-hereditary birth
defects.

46.  Pesticides - damage nervous system and also
cause cancer.
 Lead – affects central nervous system .
 Fluorides – damage teeth and the skeleton.
 Nitrates – cause blue – baby syndrome in infants.
 Petrochemicals – cause cancer.
 Arsenic – damage liver and nervous system, skin
cancer.
 Heavy metals – damage nervous system and
kidneys.

47. Toxicity- acute / chronic –
damages aquatic / human life
Changes in Sub-lethal toxicity
Water chemistry Endocrine disruption /
Changes in biodiversity
Effects of water Acidity/alkalinity
Eutrophication pollution Changes pH regime
Altered water Spread of microbial
temperature diseases
Deoxygenation-
Lack of O2 in water

48. Diseases caused by the ingestion of
contaminated water.

49. Water – scarce Water- related vector
(water –washed) diseases
diseases Vectors : Mosquitoes,
tsetse flies
 Trachoma
 Malaria
 Leprosy
 Yellow fever
 Tuberculosis
 Dengue fever
 Whooping cough
 Sleeping sickness
 Tetanus
 filariasis
 diphtheria

50.  Water – based
diseases
-skin contact with aquatic
intermediate host in water.
 Guinea worm infections
 Schistosomiasis.

51.  Each year, there are about 250 million
cases of water- related diseases.
 It is estimated that at least 1.5 million
children under the age of 12 die
annually due to water pollution.
 1.4 million people die each year in India
from water pollution.

53.  Water footprint measures the
consumption and contamination
of freshwater resources.
 It was first introduced by Hoekstra
in 2002 to provide a consumption-
based indicator of water use.
 Water footprint differs around the
world and depends on climate,
soil types, irrigation methods and
crop genetics.

55.  Your water footprint extends
beyond the average 80-100
gallons of water you use
everyday.
 A product water footprint is
the total volume of
freshwater consumed,
directly and indirectly, to
produce a product.

57.  Each person daily needs 20 to 50
liters for drinking and hygiene.
 Since 1970, global demand for
water has risen nearly 2.4 % per
annum.
 20 developing countries are
classified as ‘water scarce’.

59.  Locate the point sources of
pollution.
 Work against acid rain.
 Educate your community.
 Ensure sustainable sewage
treatment.
 Watch out for toxins.
 Be careful what you throw
away.
 Use water efficiently.
 Spread the word.

60. “ Water has the power to move millions of
people – let it move us in the direction of
peace”.
-Mikhail Gorbachev, president,
Green Cross International.

61.  Dr.B.Victor is a highly experienced postgraduate
professor from the reputed educational institution- St.
Xavier’ s College(autonomous), Palayamkottai,
India-627001.
 He had been the dean of sciences and assistant
controller of examinations.
 He has more than 32 years of teaching and research
experience
 He has taught a diversity of courses ranging from
pre- university to post graduate classes.
 He retired from service on 2008.
 Send your comments to : bonfiliusvictor@gmail.com