Wednesday, July 30, 2008

Fluorosis In AndhraPradesh



1. What is the history of fluorides and fluorosis in Andhra Pradesh?
1771 AD: C.W. Scheele identified the fluorine element
1886 AD: Henri Moissan isolated the element fluorine
1925 AD: Cristiani and Gautier coined the term fluorosis
1930 AD: Feil mentioned fluorosis in humans as occupational disease
1932 AD:
Moller and Gudjonsson reported cases of skeletal fluorosis from Denmark in Cryolite Miners
1937 AD:
Shortt and his colleagues described the cases of endemic fluorosis from Podili, Darsi and Kanigiri areas of Andhra Pradesh
1945 AD: Daver reported cases of fluorosis from Nalgonda
1955 AD:
Siddiqui described cases of fluorosis from Nalgonda subsequently cases of fluorosis described by others from 18 districts of Andhra Pradesh

2. What are fluorides?

Fluorine as an element was first detected by Scheele in 1771 and was first isolated by Moissan in 1886. Fluorine is a highly reactive element and hence does not occur in free form in nature but it forms compounds with other elements, which are ubiquitous in nature. Fluorides are the 13th commonest element in the earth’s crust and hence present in every thing we eat, drink and breath.

3. What is fluorosis?

Fluorosis is a disease caused by excessive ingestion of fluoride through water and or food. The upper limit of optimum fluoride level in drinking water for a tropical country like India is 0.5 PPM or 0.5 Mg/l. China fixed 0.7 PPM as upper safe limit in drinking water. It is the total daily intake through water and food that determines the development of fluorosis. Nearly all foods contain fluoride and the upper limit of safe total intake of fluoride from water and food per day for an adult is 8 mg.

4.What are the stages of fluorosis?

Fluorosis takes 4 forms dental, genu valgum, skeletal and neurological.

5. What is dental fluorosis and who develops it?

All children living in endemic areas of fluorosis consuming water containing more than 1.5 PPM of fluoride would develop dental fluorosis. Those exposed to excess ingestion of fluoride beyond the age of 10 years would not develop dental fluorosis. Dental fluorosis mainly involves enamel and mottling is one of the earliest recognizable features. Permanent teeth are affected which become rough, opaque and chalky white. Pitting and chipping of the teeth are also same. Brown, black or yellow pigmentation is deposited on the teeth.

6. How does fluoride reduce dental caries?

Firstly fluoride inhibits enzymes that breed acid producing oral bacteria whose acid eats away the tooth enamel. Secondary fluoride ions bind with calcium ions strengthening tooth enamel as it forms in children.

7. What is genu valgum?

These are the deformities of limb bones, which are notably seen in weight bearing lower limbs in children in endemic areas of fluorosis. These occur only in poorly nourished children whose diet is low in calcium intake. These changes are not seen in endemic regions in Punjab and adjacent Rajasthan where intake of dairy products containing calcium is higher. The average amount of calcium in the daily diet of Nalgonda Villager is 300 mg while it is 900 mg in residents of Punjab.

8. How does calcium help?

Calcium is very essential for humans. 99% of calcium in the body is in the bones and it constitutes 2% of body weight. At birth the body content of calcium is 30 grams and in adults it is 1200 grams. 180 milligrams a day should be retained during growth. Calcium binds with fluoride in the GI tract and such a compound is eliminated through the feces. A diet poor in calcium increases body’s retention of fluoride. Fluoride increases bone metabolism and the diets deficient in calcium intake provokes parathyroid hyperactivity. This in turn mobilizes calcium from bone to keep the serum levels, which causes weakening of bones by causing osteoporosis. Weight bearing lower limb bones suffers leading to grotesque deformities. These deformities in lower limb bones are called as ‘genu valgum’ and these are not seen in individuals living in high endemic regions of fluorosis in Punjab since their diet contains adequate calcium. Daily calcium requirements of preschool children are 500-800 milligrams and for adolescents it is 1200-1500 milligrams a day.

9. What is the role of magnesium?

Magnesium has peculiar relationship with fluoride. Magnesium forms 0.05% of body weight and is essential for humans. Magnesium helps in elimination of fluoride from the body by competing with calcium. Daily requirement of magnesium is 350-500 milligrams. Fluorosis incidence is less in villages whole water content of magnesium is high compared to those with lower levels with similar fluoride in drinking waters. Adequate magnesium lessens the fluoride toxicity and vice versa. Hence fluoride supplementation should help in endemic regions.

10. What is the role of vitamin C?

Epidemiological studies of Pandit and his colleagues proved that fluorosis incidence was high in individuals whose diet was poor in vitamin C intake. Daily requirement of Vitamin C is 40 milligrams and vitamin supplementation should be beneficial for individuals living in endemic regions.

11. What is the treatment of genu valgum?

Once these deformities develop, very little can be done to rectify them. These deformities are to be prevented by providing adequate diet containing optimum amounts of calcium in growing children. Milk is a good source of calcium but it is expensive. There are many vegetables which are rich of source of calcium like Thotakura and Chamakura etc.,. The details of the vegetables rich in calcium are given separately.

12. What is skeletal flurosis?

96-99% of fluoride which is retained in the body besides in the bones and hence they suffer. Bony changes occur due to excessive ingestion of fluoride over a long period of time. They manifest with pain and stiffness of the back. Stiffness increases steadily and leads to restriction of back movements. Soon stiffness spreads to various joints of the limb bones. This becomes crippling in people in endemic regions beyond the age of 30 years.

13. What is neurological stage of fluorosis?

This is a late stage of skeletal fluorosis where in spinal nerves and spinal cord are compressed causing paralysis. This is a crippling stage and some of them can only be help them by surgery.

14. What are the beneficial uses of fluoride?

Fluoride is an effective agent for preventing dental caries if taken in ‘optimal’ amounts. The relation ship between fluoride and dental caries was first noted in the early part of the 20th century when it was observed that residents of certain areas of USA developed brown stains on their teeth. These stain teeth though unsightly were highly resistant to dental decay and caries. In the 1930’s it was discovered that the prevalence and severity of this type of mottled enamel was directly related to the amount of fluoride in water. Subsequently it was recognized that fluoride consumption in optimal amounts in the water supply imparted protection against the development of dental caries with out staining the teeth. Hence water fluoridation has been initiated in the water supplies of cities and towns, which are low in fluoride content. Another benefit of fluoride is that the incidence of osteoporosis seems to occur less frequently in regions with high fluoride content in water then those in which the inhabitants consumed little fluoride.

15. What are the benefits and problems with water fluoridation?

Optimum Water Fluoride Concentration & The Fluoridation Controversy

The fluorides are ubiquitous in nature and are present in foods, water, plants, rocks, soil and even air. The main contribution of fluoride to human beings is from water and only in some endemic areas significant amounts also come from food. The relationship between fluoride and dental caries was first noted in the early part of the 20th century when it was observed that residents of certain areas of U.S.A. developed brown stains on their teeth. These stained teeth, though unsightly were highly resistant to dental decay and caries. In the 1930's it was discovered that the prevalence and severity of this type of mottled enamel was directly related to the amount of fluoride in the water. Subsequently it was recognized that fluoride consumption in optimal amounts in the water supply imparted protection against the development of dental caries without staining the teeth. Another benefit of fluorides is that the incidence of osteoporosis seems to occur less frequently in regions with high fluoride content in water than in those in which the inhabitants consumed little fluoride. Although, the importance of this element to normal mineralization of hard tissues and formation of caries resistant enamel has been recognized, there has been as yet been no conclusive evidence proving that it is an essential element for human health. Indeed, the fluoride deficiency syndrome is yet to be described. This may be due to the fact that human body requirement of this micronutrient must be small, which is met with naturally through food and water.
Fluoridation of water supplies was undertaken after careful clinical studies, backed by epidemiological surveys and supplemented by experimental work, which proved beyond doubt that fluoride ingestion through water in optimal levels is beneficial for oral hygiene by reducing the caries incidence and has no proven deleterious effects in human beings. It is also very cost effective. Optimum fluoride concentration is the one at which maximum caries reduction is achieved while limiting dental fluorosis to acceptable levels of prevalence and severity. This knowledge is important for countries intending to begin fluoridation or for those with excessive natural fluoride, which requires partial defluoridation. Water fluoride level of 1PPM was tried first but it was realized that this level might be high for countries with tropical climate. Subsequently, a formula was devised whereby water fluoride concentration could be regulated according to the mean temperature of the region. In recent years it became clear that these standards were not appropriate for all parts of the world. It is accepted that 0.5 PPM is the optimum level in the drinking water sources for India.

Proponents of fluoridation overlook one aspect i.e. the people with renal disease especially those who are on dialysis. Patients with chronic kidney diseases and those on dialysis with fluoridated water run the risk of contacting skeletal fluorosis. These patients and those with transplanted kidneys do excrete fluoride, though in small quantities but they are vulnerable to fluorosis. Hence provision must be made so that dialysate does not contain excess fluoride by improving dialysis membrane and people with kidney disease should be warned about their total daily intake of fluoride and to keep off those foods and beverages, which are rich in fluoride. The opponents of fluoridation seem to be a vocal intellectual group who considers that fluoride is a poison. They attribute all kinds of ailments stating from congenital anomalies, allergic illnesses, repetitive bony injury and fractures, degenerative diseases like Alzheimer to even cancers and their list is endless. If allergy to fluoride present in drinking water is true, it should have been found in billions of people around the world drinking fluoride rich beverage, tea. If it were true of claims of cancers caused by fluorides, such a happening would not have gone unnoticed in millions of people living in endemic regions in India, China etc. Any major carcinogenic effect of heavy fluoride exposure would be unlikely in humans as well as in animals. In support of their claims, opponents of fluoridation produce experimental evidence in animals, which were given very massive doses of fluoride. Rabbits weighing 1 kilogram were fed 50 mg/kg of fluoride for weeks and months while adult humans in endemic regions do not consume more than 20 mg of fluoride a day. Hence the results of such experiments are not tenable.

It is true that there is a need to reduce water fluoride concentration to 0.2-0.4 PPM because of overall increase in intake of fluoride in recent years. This is related to increase of fluoride in food chain, the unintentional use of fluoride containing dental health products and consumption of beverages rich in fluorides. In India there is no need to fluoridate water supplies since such levels of fluoride are found in water supplies all over the country except the northeastern states. There is also no need to supplement fluoride intake by using fluoride rich toothpaste's or other dental products in our country.
5. What is the fluoride content of different sources of water supplies in the endemic regions of Nalgonda district of Andhra Pradesh?

There are three kinds of water sources available namely rainwater, surface water and ground water. Rainwater is clean and ideal for drinking and cooking. Since rainfall is uneven storage becomes a major problem. Large storage reservoirs are needed which are very expensive to build and maintain. Rainwater harvesting in bunds and tanks will help in keeping ground water levels higher. Surface water sources are tanks, dams, canals and rivers. The fluoride content of Nagarjunasagar reservoir and its canals is low and suitable for drinking and cooking since the fluoride content ranges between 0.4-0.5 PPM. Tank waters are usually contaminated with biological and chemical pollutants. Such water should not be used without treatment and disinfection. Fluoride content of tank water is higher than rainwater and is in the range of 1.4 PPM. Rivers are not perennial and their fluoride content varies from 1.0 PPM in Alair vagu to 7 PPM in stream near Sivannagudem. It is surprising that fluoride content river waters in Nalgonda like Peda Vagu, Chandur Vagu, Chinnakaparthi stream, Kodabakshupalli vagu etc are higher and are not suitable for drinking.

Ground water sources are wells and boreholes. Fluoride content of well water can vary greatly depending on the geological structure of the aquifer and the depth at which water is drawn. The fluoride content is unevenly distributed in ground water both vertically and horizontally and hence every sample has to be tested before use. The fluoride content of granite rocks in Nalgonda varies between 325 to 3200 PPM with a mean of 1440 PPM. The fluoride content of soils in this district varies between 28 to1780 PPM. The fluoride content of ground waters in Nalgonda ranges between 0.4 to 20 PPM. The reasons adduced for this high level of fluoride in ground waters of this district are the low calcium content of rocks and soils and the presence of high levels of bicarbonate in soils and waters. Borehole content of fluoride is even higher and they may have abnormal concentrations of trace elements and hence may not be suitable for drinking. If all the sources of waters in the region are not suitable for use one has to consider defluoridation of waters to reduce its fluoride content. The experience with the use of defluoridation plants was not satisfactory in the past. Part of the problem may be poor maintenance due to lack of skilled help and also the cost. The majority of these plants clogs up after sometime and become ineffective in lowering the fluoride content of the water in the long run. Adding alum as done in Nalgonda technique may not be ideal because aluminum is being incriminated in the causation of Alzeimers disease in the west.

Among the three sources of water best is rainwater followed by Nagarjunasagar water supply through canals. Majority of ground waters in this endemic regions are not suitable for human consumption.

17. How to prevent endomic Fluorosis?

Alleviation of endemic Fluorosis - an action plan (Dr.D.Raja Reddy & Dr.Srikanth Deme)

Introduction:

Fluorosis is a disease caused by excessive ingestion of fluoride through water and or food. The upper limit of optimum fluoride level in drinking water for a tropical country like India is 0.5 PPM or 0.5 milligram per liter. The upper limit of safe total intake of fluoride per day for an adult is 8 milligram. It is the total daily intake through water and food that determines the development of fluorosis.

First ever Shortt and his colleagues recorded cases of endemic skeletal fluorosis and its neurological manifestations in the world from Podili, Darsi and Kanigiri areas of Andhra Pradesh in 1937. Next cases of fluorosis have been reported from Nalgonda district of A.P. in 1945. Subsequently cases of fluorosis have been recorded from 18 districts of A.P. It is obvious that fluorosis is a major public health problem in our state.

Biological effect of fluoride intoxication are related to the total amount of fluoride ingested, whatever the source be it food, water or both. The factors, which govern the development of fluorosis, are:

a) The prevalence of high levels of fluoride intake
b) Continued exposure to fluoride
c) Strenuous manual labor
d) Poor nutrition especially deficient intake of calcium, magnesium and vit.C
e) Impaired renal function due to disease
f) Presence abnormal amounts of trace elements like Uranium, Strontium which may aggravate fluoride toxicity.

Fluorosis takes four forms: dental, genu valgum, skeletal and crippling due to compression of the nerves and spinal cord, the later occurring in advanced stages of fluorosis.

Alleviation of fluorosis:

Aim should be to prevent fluorosis wherever possible and to relieve or lessen the suffering of the people in established cases.
Step-1
.
Detection of fluorotic villages and towns
.
AP Villages (28,123) Towns (210)


Check the teeth of school children Brown / Yellow Pigmentation

All children living in endemic areas of fluorosis consuming water containing more than 1.5 PPM of fluoride would develop dental fluorosis. Those exposed to excess ingesion of fluoride beyond the age of 10 years would not develop dental fluorosis.

Step–2

One has to differentiate fluorotic villages and towns into those with low and high endemicity. Low endemicity is those villages, which have only cases of dental fluorosis. In addition if there are cases of Genu valgum, Skeletal and Crippling forms, they should be considered as the villages with high endemicity. Low endemicity cases only need calcium and vitamin supplementation to children and adolescents to prevent Genu valgum deformities occurring.

Step–3

Investigation of cases of High Endemicity.

A) Fluoride estimation of all water sources in every village:

Even in villages with high endemic areas there may be water sources, which are good for drinking according to WHO guidelines. For example – 10 water sources were examined in Yellareddyguda and the results are shown in the table below:

Step–4

B) Trace element estimation of all water sources:

It is very important to know the trace element concentration in water sources of high endemic villages. Out of the 60 trace elements tested in Podili, Darsi and Kanigiri areas about 15 trace elements were in abnormal concentration. Their role in aggravation of fluoride toxicity is not known at present. Some with very high contents should be avoided for drinking purposes.

Step-5
C) Estimate the contribution of water and food to the total daily intake of fluoride:
It is very important to estimate how much fluoride is coming from water and food to the daily intake of fluoride in these villages. For example – in three villages viz., Naibai, Yellareddyguda and Yedavalli of Nalgonda district majority of their fluoride intake came from food. Following tables show the average diet of these villages and the amount of fluoride coming from food and water.
Average daily diet of a villager in Endemic areas
Rice 450 Grams
Pulses 110 Grams
Jowar 200 Grams
Vegetables 200 Grams
Oil 20 Grams
Water 1200 ML

Amount of Fluoride in daily Diet as detailed above
Village

Fluoride in Milligrams
Naibai (2.0 – 6.2 PPM)
75.76
Yellareddyguda (2.6 – 10.0)
54.66
Yedavalli (4.4 – 7.5)
62.20
Note: In brackets are given fluoride levels in water samples of the villages
Average of water fluoride content in 1200 ml of water was calculated. For example – in Naibai fluoride from water 4.92 mg out of 75.76 total.

One has to decide whether water or the food is the predominant fluoride source in individuals residing in endemic areas. Both need safe water supplies but those with predominantly food related fluorosis they also need water for irrigation to lessen the amount of fluoride in the foodstuffs grown in these villages.

Step – 6

Planning the optimum diet content of calcium, magnesium and vitamin-C

As per the treatment of Genu Valgum deformities, which are mainly due to the deficiency of calcium and probably of magnesium and vitamin C, their supplementation becomes mandatory. It is easy to get enough calcium by drinking milk which is very expensive hence local food should be selected which have high content of these elements. Tablets containing optimum amounts of calcium for a growing child, magnesium and vit.C may be a practicable solution.

An outline of the overall management is given below:

Summary of Management

* Provide surface water from nearby dams if any.
* Harvest rainwater.
* Look for sources of water, which are good as per WHO guidelines for drinking and cooking.
* Provide nutritious food to children and adolescents preferably from local foodstuffs.
* Need to establish a laboratory to estimate Fluoride levels in every district. This laboratory should be within easy reach of villagers.
* Setup a major laboratory to estimate trace elements and Fluoride levels in Foodstuffs. There is also a need to have a ward for studying the fluorosis cases. This ward must be attached to a major hospital like NIMS.
http://www.fluorosisinandhra.org/faqs_page.htm

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