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- Bacteria:
When certain bacteria appear in places
where they do not normally reside, they can
cause illness. If these bacteria are ingested,
as in drinking water, they may cause illness,
usually diarrhea and abdominal cramps. Most
common water-borne bacterial diseases are cholera,
typhoid, bacterial dysentery, tularaemia, brucellosis,
shigellosis, infectious hepatitis, Weil's disease
and anthrax. These diseases are transmitted
by consuming water that has been infected with
fecal material, and can occur as the result
of faulty equipment, lack of maintenance, improperly
trained operators or unusual water conditions,
for instance, when heavy rains cause surface
runoff to contaminate drinking water supplies.
- Viruses: They
are the smallest of all pathogenic agents, some
being as small as a single molecule. In general,
they are both more dangerous and more resistant
to disinfection than bacteria. Those that occur
in polluted water include the adenoviruses,
Coxsakie and ECHO viruses reo viruses, polioviruses,
and those that cause infectious hepatitis. Viruses
are also harder to treat once an infection occurs,
because they are not affected by common antibiotics.
With viruses, prevention is truly the best medicine.
- Cryptosporidium:
is a protozoan which continues to show up in
an increasing number of water supplies across
the country. This chlorine-resistant pest can
overwhelm the body's immune system. AIDS and
cancer patients, the elderly, infants, and people
who are ill or have compromised immune systems
are most at risk. For them, drinking contaminated
water can result in death.
- Giardia:
is another cyst-forming protozoan responsible
for the disease known as giardiasis, the number-one
waterborne disease in the United States and
many other countries. Giardiasis produces acute
diarrhea, sometimes lasting for months, causing
so much distress to the system that children,
elderly people in weakened conditions can die.
Like Cryptosporidium, Giardia has the ability
to create a hard, protective coating known as
an oocyst. These cysts have the ability to protect
the organism against normal chlorination procedures.
Giardia therefore shows up periodically in municipal
water supplies around the country.
- Copper: may
exist in natural waters but the blue water from
the tap indicates the presence of high level
of copper from corrosion of pipe, which has
serious health implications. Dr Fergus Kerr,
a clinical toxicologist at Melbourne's Austen
Hospital, says side-effects of drinking copper
above the guidelines would initially start with
diarrhoeic illness, nausea, diarrhoea, vomiting
and abdominal cramping. Where there has been
long-term exposure, side effects could include
cirrhosis of the liver and renal failure and,
if left untreated, death has been reported.
- Lead:
is one of the most dangerous pollutants found
in drinking water. Lead is responsible for kidney,
brain and central nervous system disorders.
In adults, it can cause miscarriages, hypertension,
multiple sclerosis, impotency, numerous nervous
system disorders and even death. For infants,
consuming even very small amounts of lead can
lead to irreversible brain damage, intellectual,
emotional, and developmental problems, numerous
nervous system impairments, and stunted growth.
High levels of lead have been found in children
suffering from lethargy, personal aberrations,
and mental retardation. Since lead accumulates
in the human body, particular care must be taken
to ensure that lead does not enter your drinking
water supply.
- Arsenic:
is a well-known poison that occurs naturally
in many rocks, minerals and soils. Several industrial
processes require its use, but most man-made
pollution comes from the application of arsenic-containing
pesticides. Like lead, even very small amounts
build up in the body over time, causing a condition
known as chronic arsenosis. It may take many
years for the poisoning to become apparent.
Chronic poisoning is usually first noticeable
as weakness, tiredness, dry scaly skin, keratosis(changes
in skin pigmentation), ganglion cysts, and swelling
of the lining of the mouth. Degeneration of
the nerves then follows, which produces tingling,
then numbing in the hands and feet. Arsenic
is also known to cause cancer, and affects the
liver and the heart. Chronic arsenosis, in its
most extreme form, causes death.
- Asbestos:
a silica mineral, is a known lung carcinogen.
Stomach cancers were also common among those
exposed to asbestos, possibly due to the swallowing
of lung mucus that contained asbestos that then
came in contact with the stomach lining. Asbestos
is widely distributed through the environment
and can reach drinking water sources through
weathering of local geological sites, through
pollution of water sources from mining and refining
of iron, or through erosion of asbestos-based
water pipes and conduits. In studies from San
Francisco, associations between asbestos in
water with stomach, esophagus, and lung cancer
were found.
This category includes several large classes
of carbon-containing chemicals. Among them are
synthetic fertilizers, pesticides, herbicides,
disinfectants, paints, fuels, plastics, dyes,
floorings, pharmaceuticals and preservatives,
to name a few. When synthetic chemicals are
found in a water supply, the actual polluting
source may be a leaking gasoline tank or factory
discharge many miles away, it may be agricultural
runoff, herbicide spraying of highways or any
of hundreds of legal or illegal sources.
One type of organic chemical is particularly
dangerous. VOCs(volatile organic chemicals),
are absorbed through your skin when you come
into contact with water, as in a shower or bath.
Further, hot water allows these chemicals to
evaporate rapidly, and they are harmful if inhaled.
VOCs can be in any tap water, regardless of
where you live or what your source of water
is.
In addition to the organic chemicals that have
gotten into water supplies, new and dangerous
ones are created in the water itself. Chlorine,
which is in essentially all Australian tap water,
combines with organic chemicals to form a category
of toxic pollutants called THMs(trihalomethanes).
These substances have been associated with impaired
fertility and cancer.
- Chlorine:
is a highly effective and inexpensive disinfecting
agent used extensively in Australia and many
other countries to treat municipal and individual
water supplies. But while chlorination has helped
to eradicate water-borne diseases, a growing
body of evidence indicates that the practice
maybe very hazardous to human health, especially
when high levels of free residual chlorine leave
the water treatment facility and arrive at your
tap. Joseph M. Price, M.D., makes it clear that
the presence of free chlorine in water creates
heart disease. Chlorine causes fats to form
the cholesterol deposits known as plaque. It
is this plaque that clogs arteries, resulting
in heart attacks and strokes. Disinfection by-products
(DBPs) are formed when chlorine is used to disinfect
water. One class of these chemical compounds
is called trihalomethanes (THMs), which are
formed when chlorine reacts with organic matter
in water. A recent study by doctors from Harvard
found that DBPs may be responsible for rectal
and bladder cancers. Another massive study of
pregnant women and their babies found that certain
birth defects are significantly associated with
DBPs. THMs, one class of DBPs, are known to
damage the kidney, liver and nervous system,
and to cause birth defects. Many THMs are proven
to be potent carcinogens.
- Fluoride:
is added in our drinking water to improve children's
dental health. While studies from proponents
of fluoridation show dramatic reductions of
tooth decay in children who drink fluoridated
water, opponents of fluoridation cite equally
valid studies that show no difference in the
dental health of children in fluoridated and
no fluoridated areas. Regardless of this dispute,
there are some important facts to remember about
water fluoridation. First, fluoride is a highly
toxic chemical, rated as more toxic than lead
in chemistry indexes, whose level of ingestion
must be carefully regulated. The difficulty
is that no one knows for sure how much fluoride
the average child is receiving. This is because,
in addition to water fluoridation, children
can ingest fluoride through toothpaste and through
the fluoridated water that may be used in canned
foods and beverages. Secondly, in addition to
hardening children's teeth, there are many side
effects like tooth mottling, and increased risks
of bone diseases and cancer.
- Flocculants:
In addition to chlorine, and sometimes
fluoride, water treatment plants often add several
other substances to water to improve the efficiency
of treatment. Flocculants are substances that
are added to the water to make the particles
in it clump together for more efficient sedimentation.
Some of the most commonly used flocculants are
called polyelectrolytes. These types have been
banned for use by several countries because
some of their constituents are known to be mutagenic
(causing genetic mutations) and carcinogenic.
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