WATER IN RELATION TO HUMAN
HEALTH
Prof. Dr. Faqir Muhammad Anjum (TI)
Director General
National Institute of Food Science & Technology
University of Agriculture, Faisalabad
Water in life
• 2/3 of body cells contain water
• Water plays pivotal role in:
• Body functions and
• Biochemical reactions
• Used as building material in every cell
• Involved in mechanisms for controlling and maintaining
normal body temperature
• Acts as a medium for carrying:
• nutrients to cells
• wastes out of cells
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Water In Life
20%
Water
99%
Water
• Organisms usually
contain 60% to 90%
water
– Lowest- Plant Seed
(20%)
– Highest- Jellyfish
(99%)
• Water helps all
organisms in metabolism
and plants in
photosynthesis and
support
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Human body water composition
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Water in Human Body
• Babies and kids have more water (%) than adults
• 70-80% water during birth, drops to 65% after 1
year
• Obese people have less water (%) than skinny
• Muscle is 75% water
• Fat is 20% water
• For this reason, older people (who generally have
a higher fat % have less water than younger
• Women have less water (%) than men due to
naturally higher fat content
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Human Body Water Composition By
Organ/Tissue
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Human Water Balance
Water input, mL/day
Drinks
1500
Food
700
Metabolic
300
water
Water output, mL/day
Urine
1500
Sweat
500
Respiration
Feces
400
100
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Water : Recommended Daily Amount
(litres/day)
• Children – 1.3-1.7
• Men – 3.7
• Women – 2.7
• Pregnant women – 3.0
• Lactating women – 3.8
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Functions of Water in Human Body
• Transports nutrients and oxygen into cells
• Regulates body temperature
• Detoxifies
• Moisturizes the air in lungs
• Helps with metabolism
• Protects vital organ
• Helps organs to absorb nutrients
• Protects and moisturizes our joints
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Fitness and Fat Loss
Water important for fitness and fat loss due to:
• Fills up stomach/ satiety without adding any
calories
• Dehydration degrades a person’s ability to exercise
and burn calories
• Dehydration reduces protein synthesis required for
building and/or repair muscles
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Water As A Solvent
• Water contains 1 oxygen atom and 2 hydrogen
atoms which are covalently bonded
• Water molecule is polar, because electrons are
not equally shared
• Because water molecule is polar, it can ionize
substances easily, making it a good solvent
• Water known as ‘The Universal Solvent’
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Water As A Way of Transport
Tree Sap
• Water is a carrier, distributing
essential nutrients to cells,
such as minerals, vitamins and
glucose
• Many different substances,
such as blood and sap, are
transported by water
Human Blood• Sap and blood contain high
Cells
amounts of water making
them good solvents
• Being good solvents allows
them
to
dissolve
the
substances
they
are
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transporting
Water As A Reactant
• Water, being a good solvent, allows many
reactions to occur
• Used in photosynthesis to make NADPH2, and
ultimately sugar
• These reactions release oxygen, which is vital to
human life
• Without water in photosynthesis, organisms
unable to obtain energy, and life would be
impossible
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Water As A Lubricant
• Water is an effective lubricant around joints
• It also acts as a shock absorber for eyes,
brain, spinal cord and even for the foetus
through amniotic fluid
• When bones meet at a joint, a fluid between
the bones is required to prevent scraping
against each other
• That fluid is called a synovial fluid, which is
made mainly of water
• Many internal organs have fluid around them
to keep them protected, e.g.,
Brain: Cerebro-spinal fluid
Lungs: Pleural Fluid
Eyes: Mix of fluids
Synovial
Fluid
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Hydrolysis/ Energy Release
• Water is needed to separate (by a process called
hydrolysis) a phosphate group from adenosine
triphosphate (ATP) or guanosine triphosphate (GTP)
to get energy
• Without water hydrolysis is not possible
• ATP +H2O = Energy + ADP + Inorganic Phosphate
• GTP +H2O = Energy + GDP + Inorganic Phosphate
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Regulation of Body Temperature
• Water has a large heat capacity which helps limit changes in
body temperature in a warm or a cold environment
• Water allows the body to release heat when ambient
temperature is higher than body temperature
• The body begins to sweat, and the evaporation of water from
the skin surface very efficiently cools the body
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Regulation of Body Temperature
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Metabolism
• Water is the engine of metabolism
• Participates in the biochemical break-down of
what we eat
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Waste Removal
• Water removes waste products including toxins
that the organs’ cells reject, and removes them
through urines and faeces
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Treatment of Polycystic kidney disease (PKD)
• Polycystic kidney disease - Genetic disease that
occurs in 1 among 500 individuals and leads to
kidney failure in about half of affected individuals
• PKD-affected kidney cells divide and multiply
inappropriately, and form fluid-filled sacs called
cysts
• Kidney cysts continue to grow throughout life,
destroying normal kidney tissue, leading to kidney
failure
• Drinking high amounts of water can slow the
abnormal cysts growth
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Water Quality
• All people, irrespective of their stage of
development and social and economic condition,
have the right to access to safe drinking water in
quantities and of a quality equal to their basic
needs
• WHO recognizes that access to adequate water
supplies is a fundamental human right
• Water-related diseases are a human tragedy, killing
millions of people each year (account for 80% of all
deaths in developing countries)
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Chemical contamination in Water and Human Health
• Common chemical contaminants include:
– Nitrates
– Arsenic
– Fluoride
• Prevalence of arsenic and fluoride in drinking water
is known to cause cancer of lungs, bladder, still
births, post neonatal mortality, Ischemic heart
diseases (heart attack), diabetes mellitus etc.
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Nitrates
• Bacteria in drinking water in the human body can transform
nitrates/ nitrites into nitrosamines, a compound formed by
the reaction between nitrite and secondary amines
• Blue-baby syndrome (methemoglobinemia) is caused by
exposure to elevated levels of nitrite in infants less than 6
months old
• Blood’s ability to carry oxygen is affected
– result in a bluish color in the infant’s skin
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Arsenic
• Various studies have been conducted in arsenic
affected countries - notably Argentina, Chile,
China, Japan, and Taiwan - to find the potential
of arsenic exposure to cause development of
cancer
• Continuous arsenic exposure can
lead people to develop arsenicosis,
which in turn elevates the risk
of cancer
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Arsenic
• Arsenic ingestion increases risk of lungs and
kidney cancer
• Skin lesions are the most common
manifestations in arsenicosis patients
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Fluoride
• Fluorosis - Ingestion of excess fluoride, most commonly
in drinking-water affects:
– Teeth
– Bones
• Moderate amounts lead to dental effects
• Moderate-level chronic exposure (above 1.5 mg/L of
water - the WHO guideline value for fluoride in water) is
more common
• Long-term ingestion of large amounts can lead to severe
skeletal problems
• Fluorides lower the intelligence capacity of humans
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• Children are more susceptible to fluoride toxicity
Safe levels of chemical contaminants in drinking
water
Parameter
BIS Guideline General & health effects
value
(maximum)
pH
6.5-8.5
Affects mucous membrane, corrosion
Nitrate
Fluoride
Arsenic
100mg/ L
1.5mg/L
0.05mg/L
Blue baby disease
Dental and skeletal fluorosis
Carcinogenic
Lead
Pesticide
0.05mg/L
0.001mg/L
Damage kidney
Affects central nervous system
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Pharmaceuticals and Water Quality
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Water and Sanitation-related Diseases
Group Diseases
Group Diseases
Water-borne diseases
(diseases transmitted by
water)
Cholera; Typhoid; Bacillary
dysentery Infectious hepatitis;
Giardiasis
Water-washed diseases
(caused by lack of water)
Scabies; Skin sepsis and ulcers;
Yaws; Leprosy; Lice and thypus;
Trachoma; Dysenteries; Ascariasis;
Parathphoid
Water based diseases
Schistomiasis; Dracunuliasis;
Bilharziosis; Filariasis; Threadworm
Water-related insect vector
diseases
Yellow fever, Dengue fever,
Bancroftian filariasis, Malaria
Onchocerciasis
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Water-borne Diseases
• As per USAID report, an estimated 250,000 child
deaths occur each year in Pakistan due to waterborne disease
• A study conducted by UNICEF found that 20-40% of
the hospital beds in Pakistan are occupied by
patients suffering from water-related diseases, such
as typhoid, cholera, dysentery and hepatitis, which
are responsible for one third of all deaths
(Pak-SCEA 2006)
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Microbial Quality Standards for Drinking Water
• Water containing maximum 100 bacteria and
no single coliform, considered safe for drinking
• Microbiological standards applied to determine
safety of water
• Drinking water must meet defined standards
otherwise poor quality water hazardous to
health
• Hence, improvement in drinking water quality
results in substantial reduction in disease
prevalence
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Water Deficiency / Dehydration
• Being 2% dehydrated can seriously degrade
physical and mental functions
• Being 15% dehydrated is likely to be lethal
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Water deficiency: symptoms
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Diseases caused by dehydration over a long
period of time
• Symptoms of mild health problems
– Digestive problems - constipation, bad breath, acnes
– Skin disorders - dryness, dull-looking, sensitive
– Others - fatigue and lower concentration level
• Symptoms of more severe health problems
– Prolonged dehydration could contribute to arthritis, migraine and
the malfunctioning of the digestive system
– Insufficient water intake results in inefficient toxin removal, which
may induce high uric acid; diabetes; liver, kidney and heart
diseases; high blood pressure and even intestinal cancer
– It may accelerate aging in the long run
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Signs of Dehydration
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Allergies
Asthma
Arthritis
High cholesterol/ heart problems
High blood pressure
Diabetes
Peptic Ulcers
Angina
Migraines
Obesity and weight control problems
Water retention
Chronic back pain
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Effects of Water Deficiency
• Low blood pressure
• Clotting of blood
• Kidney malfunction
• Severe constipation
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Hyperhydration- water intoxication
• When too much water enters the body's cells, the tissues swell
• Cells try to maintain concentration gradient
• Excess water outside the cells (the serum) draws out sodium
from within the cells into serum in an attempt to re-establish
the necessary concentration
• Kidneys can tolerate about 17 litres water in a day
• Excessive ingestion of water and other liquids resulted in extra
work for the body
• Signs of water intoxication:
– Hyponatriemya - decreased amount of natrium in blood)
– Rubdomiolysis - damage of muscularity (collapse of
skeleton) , acute incompetence of kidneys
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Hyponatremia
• Hyponatremia, a metabolic condition in which there is
not enough sodium in body fluids outside the cells
• It is most common electrolyte disorder in the U. S.
• In hyponatremia, the imbalance of water to salt is caused
by one of three conditions:
– Euvolemic hyponatremia- total body water increases,
but the body's sodium content stays the same
– Hypervolemic hyponatremia- both sodium and water
content in the body increase, but the water gain is
greater
– Hypovolemic hyponatremia- water and sodium are
both lost from the body, but the sodium loss is greater
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Rhabdomyolysis
• Breakdown of muscle fibers result in the release myoglobin
into the bloodstream
• Some of these are harmful to kidneys and frequently result
in kidney damage
• Rhabdomyolysis affects about one out of 10,000 people in
the United States, with slighter higher incidence in men
• Rhabdomyolysis accounts for an estimated eight to fifteen
percent of cases of acute renal failure
• About five percent of rhabdomyolysis cases result in death
• There are two crucial factors involved in the development
of myoglobinuric ARF (acute renal failure):
– Hypo-volemia/dehydration
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Situation of Drinking Water in Pakistan
• Water and sanitation are ignored sector sin Pakistan
• Majority of Pakistani people do not have access to safe
drinking water and lack satisfactory sanitation systems
• In 2005, approximately 38.5 million people did not have
access to safe drinking water and approximately 50.7 million
people lacked access to improved sanitation facilities in
Pakistan
• With the same trend, by 2015, 52.8 million people will be
deprived of safe drinking water and 43.2 million people will
be lacking adequate sanitation facilities in Pakistan
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Khan and Javed (2007)
Situation of Drinking Water in Pakistan
• Hence quality of drinking water in Pakistan far from being
satisfactory
• Rivers and sub-soil water contaminated due to disposal of
untreated domestic and industrial fluid wastes
• Contamination starts right in the mountains
• Tourists to the hill stations contribute to garbage
• Shandur Festival, at 12,520 ft. altitude gathers almost 20,000
people
• Produce around 5,000 kg garbage – pollutes glaciers, lakes and
rivers
• Causes toxicity in residents using it
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Situation of Drinking Water in Pakistan
• Tourist points like Murree become heavily polluted contributed by
tourists
• Naturally garbage produced finds its way into water channels that
supply drinking water to downstream areas
• Survey conducted by NIH, Islamabad - upward trend in nitrate
contents in drinking water of Islamabad and Rawalpindi
• Bacteriological examination shows 94% water samples unsuitable
for human consumption
• Situation alarming because samples taken from posh F-11, G-7, G-9,
G-11, and Airport areas in Islamabad
• If this quality of water in model and modern city, imagine situation
in other cities
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Situation of Drinking Water in Pakistan
SOME NEWSPAPER REPORTS
• Residents of some villages on banks of River Chenab near
Chiniot reported to suffer from stomach diseases due to
poor quality drinking water
• Reports appeared a few years back from Manga Mandi
near Lahore
– residents suffered from bone deformations
• Unsafe drinking water reports from Sheikhupura, Lahore,
Toba Tek Singh, Qsur, Hyderabad, Peshawar and other cities
• In Karachi, people sell dirty water after recycling
– Increased risk of kidney, stomach and skin diseases
• Seashores exposed to oil contamination because of ship
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breaking in Gadani and leakage from oil tankers
Situation of Drinking Water in Pakistan
• Oil drained into water damages marine life and
pollutes environment
• It finds its way into drinking water in Karachi
– residents develop diseases and allergies
• Practically no organized solid disposal system in
any city in Pakistan
• Solid waste dumped in some open places and then
burnt
• Gives rise to numerous chemicals including dioxin
- highly toxic man-made organic chemical
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Bacterial Contamination in Water
• Campylobacter: diarrhoea
• E. coli: Bloody diarrhoea, mild fever, anaemia
• Pseudomonas: dermatitis and infections in urinary tract,
respiratory system, soft tissues, bones, joints,
gastrointestinal tract
• Shigella: gastroenteritis, bacillary dysentery
• Salmonella: Nausea, vomiting, abdominal cramps,
diarrhoea, fever, headache
• Vibrio cholerae: abdominal pains, mild fever, chills, and
headache, watery diarrhoea followed by lethargy and
dehydration.
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Viruses Contamination in Water
• Noroviruses - Group of viruses that
cause
gastroenteritis, inflammation of lining of stomach and
intestines
• Hepatitis A – Results in inflammation of liver
• Sources of infection:
an infected person who didn’t wash his or her hands
after using washroom
drinking untreated water or
eating food washed in untreated water
• Rotavirus: Very common cause of severe diarrhoea
among infants and children
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Take Home Message
Drink ample quantity of GOOD QUALITY water:
• Helps in digestion and avoid constipation
• Relieves fatigue
• Less cramps and sprains
• Good mood
• Natural remedy for headache
• Look younger with healthier skin
• Lose weight
• Better productivity at work
• Less likely to get sick and feel healthy
• Reduce risks of kidney failure
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