78
Water In Ecosystems: A Non Renewable Resource
1 INTRODUCTION
Historically, civilisation began and centered around regions of abundant water
supply. People knew very little about the quality of water and its impact on human
health. With the passage of time, however, it has been felt that 'potable/safe'
drinking water is as essential as any other nutritional component for societal
health. Increasing population pressure, evolving industrial-chemical society, and
advances in science and technology have contributed inter alia to contamination of
drinking water with bacteria and virus, containing excess iron, fluorides, sulphates,
carbonates and bicarbonates. The presence of these constituents in excess make
sources unsafe for drinking purposes and in fact, are harmful, when consumed
consistently.
One such constituent is the presence of excess fluorides in ground water. This is
almost a global phenomenon, prevalent in USA, Japan, Soviet Union, Afghanistan,
some African countries, some countries in Europe and also in many parts of
developing countries, Algeria, Argentina, China, India, Kenya, Morocco, Senegal,
Turkey and Thailand. In particular the fluoride problem is assuming alarming
proportions in many states in India (Fig. 1) - Andhra Pradesh, Bihar, Delhi,
Gujarat, Haryana, Himachal Pradesh, Karnataka, Madhya Pradesh, Maharashtra,
Tamil Nadu, Uttar Pradesh and small pockets in other states (Susheela, 1987).
2
FLUORIDE IN THE ENVIRONMENT
2.1 Fluoride in biological tissues
Fluoride is a component of human and animal tissue deposited mostly on bones
and teeth. While fluoride in limited quantities is desirable for the healthy growth of
bones and teeth in human beings, it has toxic effects if present in excess quantities
in waters and foods taken by them. This toxicity is reflected as a disease called
'Fluorosis'. Thus dental disorders are caused by ingestion of fluorides from
drinking water. It has been found that while about 1.0 mg/l of fluoride is good for
health, 1.5 mg/l would cause yellowing of teeth and their gradual decay. A
quantity of 3.0 mg/l would lead to skeletal fluorosis resulting in the weakening of
bones, especially at the joints.
In a bid to treat fluorosis in its early stages and prevent the irreparable deformities,
doctors are trying to diagnose the early symptoms of the disease. One of the
systems in the body which is affected very early is the gastro-intestinal system.
Severe damage is caused to the mucous lining, absorptive surfaces and mucous
production in the gastro-intestinal tract resulting in nausea, loss of appetite,
vomiting, gas formation, constipation and intermittent diarrhoea.
Other manifestations due to ingestion of fluoride ions are extreme weakness due to
damage to RBC'S leading to low haemoglobin levels as well as muscle destruction.
Fluoride poisoning can cause infertility in some cases, heart problems in others
due to calcification of blood vessels. Children under twelve are more prone to
fluorosis.
Water In Ecosystems: A Non Renewable Resource
1 INTRODUCTION
Historically, civilisation began and centered around regions of abundant water
supply. People knew very little about the quality of water and its impact on human
health. With the passage of time, however, it has been felt that 'potable/safe'
drinking water is as essential as any other nutritional component for societal
health. Increasing population pressure, evolving industrial-chemical society, and
advances in science and technology have contributed inter alia to contamination of
drinking water with bacteria and virus, containing excess iron, fluorides, sulphates,
carbonates and bicarbonates. The presence of these constituents in excess make
sources unsafe for drinking purposes and in fact, are harmful, when consumed
consistently.
One such constituent is the presence of excess fluorides in ground water. This is
almost a global phenomenon, prevalent in USA, Japan, Soviet Union, Afghanistan,
some African countries, some countries in Europe and also in many parts of
developing countries, Algeria, Argentina, China, India, Kenya, Morocco, Senegal,
Turkey and Thailand. In particular the fluoride problem is assuming alarming
proportions in many states in India (Fig. 1) - Andhra Pradesh, Bihar, Delhi,
Gujarat, Haryana, Himachal Pradesh, Karnataka, Madhya Pradesh, Maharashtra,
Tamil Nadu, Uttar Pradesh and small pockets in other states (Susheela, 1987).
2
FLUORIDE IN THE ENVIRONMENT
2.1 Fluoride in biological tissues
Fluoride is a component of human and animal tissue deposited mostly on bones
and teeth. While fluoride in limited quantities is desirable for the healthy growth of
bones and teeth in human beings, it has toxic effects if present in excess quantities
in waters and foods taken by them. This toxicity is reflected as a disease called
'Fluorosis'. Thus dental disorders are caused by ingestion of fluorides from
drinking water. It has been found that while about 1.0 mg/l of fluoride is good for
health, 1.5 mg/l would cause yellowing of teeth and their gradual decay. A
quantity of 3.0 mg/l would lead to skeletal fluorosis resulting in the weakening of
bones, especially at the joints.
In a bid to treat fluorosis in its early stages and prevent the irreparable deformities,
doctors are trying to diagnose the early symptoms of the disease. One of the
systems in the body which is affected very early is the gastro-intestinal system.
Severe damage is caused to the mucous lining, absorptive surfaces and mucous
production in the gastro-intestinal tract resulting in nausea, loss of appetite,
vomiting, gas formation, constipation and intermittent diarrhoea.
Other manifestations due to ingestion of fluoride ions are extreme weakness due to
damage to RBC'S leading to low haemoglobin levels as well as muscle destruction.
Fluoride poisoning can cause infertility in some cases, heart problems in others
due to calcification of blood vessels. Children under twelve are more prone to
fluorosis.