FLUORIDE THROUGH DRINKING WATER: AN ANALYSIS OF EFFECTS ON HUMAN BEING - BASED ON CASE STUDIES IN BIRBHUM DISTRICT, WEST BENGAL

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1 Man In India, 92 (3-4) : Serials Publications FLUORIDE THROUGH DRINKING WATER: AN ANALYSIS OF EFFECTS ON HUMAN BEING - BASED ON CASE STUDIES IN BIRBHUM DISTRICT, WEST BENGAL Bidisha Bagh, Amit Roy and Santanu Ray Fluoride is an electronegative element present naturally in the earth s crust as well as rocks and minerals. Exposure to fluoride contaminated drinking water beyond the recommended level for longer duration causes fluorosis, which may lead to serious health hazards. Present case study has been undertaken for the determination of fluoride in drinking water of 19 blocks of Birbhum district and the preparation of block wise fluoride map. This work focuses on adverse effects of fluorosis on human being and the related morphological symptoms. In these areas, villagers have been found to be suffering from dental, skeletal and non-skeletal fluorosis. Different kinds of fluorosis correlated with the fluoride concentration of drinking water in that area. The correlation between different kinds of fluorosis in different age groups of the population has also been highlighted. Introduction Fluoride-poisoning in drinking water is a serious public-health hazard in some parts of India and many other countries like China, Poland, New-Zealand etc. (Bhatia et al., 1980). The world s fluoride level in ground water is estimated to be 85 million tons, of which nearly 12 million tons is estimated in India (Ekstnard et al., 1984; Gupta et al., 1994). Fluoride is a most important constituent of bone tissues in vertebrate-skeleton. But excessive fluoride intake may lead to dental, skeletal and non-skeletal fluorosis a debilitating, irreversible disease. 1.5 mg/lit fluoride is the permissible limit set by WHO (WHO, Guideline for Drinking Water Quality, 1984). Birbhum is one of the important districts of Rarah region of W. Bengal having the geographical area of 4514 sq kms. This district lies between /30// and /0// North latitude and /40// and 87 05/25// East longitude. The large parts of this district lie on the Rajmahal trap consisting of volcanic eruption of basaltic composition. Seven lava cycles cover an extensive area of 4000 sq km. (Gupta, 1981). These lava plates are mother rock of fluoride. Fluoride ions occur mainly in these forms; fluorspar (CaF2), Rock phosphate [Ca5 F(PO4) 8] and sodium aluminum fluoride [Na3AIF6] (Chand, 1999). The fluoride, present in the rock and soils, when come in contact with water of high alkalinity, gets released into ground water. Day by day ground water level has been decreasing. Excessive Address for communication: Bidisha Bagh, Research Scholar, Centre for Biotechnology and Department of Zoology, Visva-Bharati University, Santiniketan

2 400 MAN IN INDIA use of ground water for agriculture (double cropping and triple cropping) and excessive water demand from an ever-growing population which is leading to a depletion of the underground water table and concomitantly increasing the fluoride concentration in the water bodies ultimately raising it to alarming and harmful levels. Fluorosis is one of the most neglected diseases in India; and misdiagnosis is very common. According to 1999 UNICEF report, about 66 million people including six million children in 19 Indian states are either afflicted with fluorosis or at very high risk. It has attained an alarming dimension all over the world. Presently, 17 Indian states viz., Andhra Pradesh, Karnataka, Tamilnadu, Punjab, Haryana, Maharastra, Gujarat, Rajasthan, Kerala, Uttar Pradesh, Jammu & Kashmir, New Delhi, Assam, Bihar, Orissa, Himachal Pradesh and Chandigarh are endemic for fluorosis. North Eastern states are also affected by fluorosis. Susheela (1999) reported that fluoride level in underground water is elevated in West Bengal and Assam also. Ground water in large areas of Birbhum, Purulia, Bankura and West Dinajpur of West Bengal contains fluoride much beyond the safe limit (above the maximum permissible limit mg/lit set by WHO). In case of Birbhum district the maximum fluoride concentration has been detected in Nasipur, the worst affected village is as much as 46 mg/lit - more than forty times of permissible limit. A large number of villagers of Nasipur (Birbhum district, West Bengal), living under the deep shadow of illiteracy and exposed to poor socioeconomic conditions and malnutrition, have been taking fluoride contaminated drinking water for many years continuously and have become the victim of endemic fluorosis. This fluorosis has been positively correlated with the high concentration of fluoride in drinking water consumed from four deep tube wells by the local people. As there is acute water scarcity in this village, villagers are forced to use the drinking water from these tube wells containing excessive fluoride. It has now been found that most of the ground water wells have very high levels of naturally occurring fluoride which has slowly and silently been killing the people. Fluorosis can affect young and old; men and women alike. Dental fluorosis is most common feature among the people of fluoride affected endemic areas. It occurs when the level of fluoride in water exceeds 1.5 mg/lit. Due to high calcium content, teeth easily take up fluoride. Mottling of teeth is one of the earliest sign in most recognizable feature. Teeth become rough, opaque and chalky white. Formation of yellow to dark brown lines takes place which is followed by pitting and choiring of tooth enamel. Skeletal fluorosis is the effect of fluoride on bones. Prolonged intake of water having high fluoride level (more than 8 mg/lit) leads to skeletal fluorosis. Bow vertebral column and knock knees are the characteristic features of skeletal fluorosis, which are shown in Fig. 2 & 4(a), (b).

3 FLUORIDE THROUGH DRINKING WATER 401 Calcium hydroxyapatite Ca5 (PO4) 3(OH) is the important constituent of bone tissues in vertebrate skeleton. It also takes part in the structure of teeth. Replacement of OH by F gives fluoroapatite which is required to strengthen the teeth. In fact to strengthen the teeth against the attack by organic acids produced through fermentation of organic substances (especially food particle), formation of fluoroapatite to some extent from hydroxyapatite is essentially required. Fluoroapatite is more resistant to acid attack (Ceopalan C. 1999). When the teeth fall to resist this acid attack, it produces dental caries but at higher concentration of fluoride (>1.5 ppm), it produces mottling of teeth (i.e. dental fluorosis, which is shown in Fig. 3) and the bone become course. Apart from bones and teeth, an excess intake of fluoride can damage or impart ill effects on other soft tissues, organs and systems also (Mcivor M.E. 1987). This is known as nonskeletal fluorosis. It reveals that almost all the systems of body including muscle, liver, kidney, blood, cardiovascular system and reproductive system are affected (Susheela, 1999). Fluoride can damage a fetus, if the pregnant woman consumes water with high fluoride content during breast feeding can cause infant mortality due to calcification of blood vessels (Gupta, 1993). Fluorosis is an incurable disease whose only solution is said to be prevention of the use of fluoride-contaminated water. The single, most vital strategy to check fluorosis is to chemically analyze the drinking water sources for detection of excessive fluoride before permitting consumption. And if the exact magnitude of the fluorosis crisis from the fluoride construction and zone division is discerned then it will help to combat this problem. House to house health survey has been conducted in fluoride hit areas to count the number of people suffering from dental, skeletal and non-skeletal fluorosis disease. The investigation has indicated the fact that millions of people here are at risk. Metarials & Methods Collection of Water Samples For water, the proportional sampling method has been used. Under stratification, the different blocks have been used as stratum. Then the number of samples collected from hth stratum will be denoted by n h and is given by n h = n (N h /N) where N h = number of tube wells in hth stratum, N = total number of tube wells and n = Total number of tube wells to be sampled. Here we will consider n = 100 (approximately square root of total number tube wells in the area of study). Drinking water samples have been collected from 557 deep tube wells (n = 557) in clean polythene containers of good quality and brought to the laboratory without adding any preservative. Suspended matters in the collected water have been removed by filtering through Whatman No. 41 filter paper.

4 402 MAN IN INDIA Fluoride Estimation Fluoride concentrations in water samples have been estimated by an Orion 407 ionometer equipped with a Fluoride Ion Electrode (IRON). A 20 ml aliquot was taken in polythene beaker & 20 ml of TISAB (Total Ionic Strength Adjuster Buffer, Orion application solution) was added. Water samples were analyzed by using standard methods (Fluoride Electrode Instruction Manual, 2001). Health Survey The total area under study has been divided into different strata based on the number of tube-wells. This is because it has been observed that a particular household in a particular locality takes water from a particular tube well only. So, if we form the strata according to the tube-well then any two strata will not be overlapped. Therefore, the number of strata is the number of tube wells in the proposed region. Now suppose there are k different strata, the ith stratum contains N i different houses. For the purpose of the survey, n i different samples from the ith stratum will be chosen. The values n is will be determined based on Bowley s Proportional allocation. For drawing samples within stratum, the procedure adopted by World Health Organization for Expanded Program on Immunization has been followed (S. Bennett et al. 1994). In this study, different kinds of fluorosis were diagnosed among the local people of the district through medically acceptable morphological studies in consultation with specialist doctors. A total of people were surveyed of which 5468 individuals exhibited different kinds of fluorosis. Collection of samples and survey of fluorosis were done since Fluoride Zone Division Depending on fluoride levels in drinking water and risk factor of fluorosis, the study area has been sub-divided in to 5 zones. 1. Safe zone : (0.50>/ ) ppm fluoride concentration level. e.g. Nanoor, Bolpur, Illambazar and Labpur. 2. Low concentration zone : (1.6-2) ppm fluoride concentration level. e.g. Sainthia, Murarai-II, Nalhati-II, Rampurhat-I. 3. Moderate concentration zone : (2.1-4) ppm fluoride concentration level. e.g. Moureswar-I, Moureswar-II, Suri-I, Murarai-I. 4. Medium concentration zone : ( ) ppm fluoride concentration level. e.g. Md. Bazar and Rajnagar. 5. High concentration zone : (6-46/>46) ppm fluoride concentration level. e.g. Nalhati-I, Rampurhat-I, Suri-II, Dubrajpur, Khyarasole

5 FLUORIDE THROUGH DRINKING WATER 403 Results & Discussion Fluoride concentration in drinking water has been measured from different villages of 19 blocks of the district. For the present study all 19 blocks of Birbhum district have been surveyed monthly for over two years for collection of data of fluoride content in drinking water, health status of the people inhabited in these areas etc. Highest fluoride concentrated zones of 19 blocks are shown in Table 1. Out of 19 blocks studied, only in four blocks fluoride in the drinking water has been found to be within the permissible limit of 1.5 ppm set by WHO; i.e. Illambazar, Labpur, Bolpur and Nanoor blocks. Remaining 15 blocks indicate high fluoride concentrations in drinking water and are above the permissible limit. Of these, Nalhati-I, Rampurhat-I, Dubrajpur, Khayrasole and Suri-II indicate presence of very high levels of fluoride concentrations. When fluoride concentration in drinking water in an area is below 0.5 ppm to 1.5 ppm, the area may be considered as safe zone following the levels set by WHO (Please see in Materials and Methods section). Entire areas of Nanoor, Bolpur, Illambazar and Labpur blocks belong to this zone. Areas with 1.6 to 2 ppm fluoride level in drinking water has been classified as the low-fluoride zone. Exposure for long duration at this level of fluoride concentration may have bad effects on enamel destruction of teeth. Some of parts of Nalhati-I, Murarai-II, Rampurhat-II and Sainthia belong to this zone. TABLE 1: HIGHEST FLUORIDE CONCENTRATION IN DRINKING WATER ZONES IN 19 BLOCKS OF BIRBHUM DISTRICT Sl. No Block Name Village name Zonal Identification Concentration of No. fluoride (ppm) 1 Murarai- I Rajgram Murarai- II Paikar Nalhati- I Nasipur Nalhati- II Bhadrapur Rampurhat- I Narayanpur Rampurhat- II Bishnupur Mayreswar- I Majharipara Mayreswar- II Kotasur Suri- I Adda Suri- II Chatra Md.Bazar Rampur Rajnagar Kushipur Khyrasole Kendragoria Saithia Mathpalsa Dubrajpur Bakeswar Bolpur Surul Illambazar Batikar Labpur Falgram Nanoor Jalundi

6 404 MAN IN INDIA 2.1 to 4 ppm fluoride concentration in the drinking water has been designated as moderate-fluoride zone. Exposure to this concentration for long duration causes endemic dental fluorosis in the population. Murarai-I, Suri-I, Mayureswar-I and Mayureswar-II belong to moderate-fluoride zone. (Table 2). When the fluoride concentration in drinking water in an area is between 4.1 and 5.9 ppm, it is placed in the medium-fluoride zone. In accordance with this elevated level of fluoride in drinking water, about 10% of the population has been found to be affected with skeletal fluorosis, the next level of fluorosis disease (Table 2). Some parts of Rajnagar and Md. Bazar belong to this zone. Areas with 6 to 46 ppm and above levels of fluoride in the drinking water have been classified as high-fluoride zone. Dental, skeletal and non-skeletal fluorosis TABLE 2: SURVEY OF FLUORIDE CONCENTRATION IN DRINKING WATER AND CORRESPONDING FLUOROSIS AFFECTED PEOPLE IN DIFFERENT BLOCKS OF BIRBHUM DISTRICT. FULL FORM OF THE ABBREVIATIONS DF (DENTAL FLUOROSIS), SF (SKELETAL FLUOROSIS), NSF (NON SKELETAL FLUOROSIS) Sl. Block Name Types of Fluoride Observed Category of No. of No. Fluoride concent- Population Fluorosis in villagers Zone ration the observed died for (ppm) population Fluorosis (dental/skeletal/ non-skeletal) 1 Muraroi- I Moderate DF Muraroi- II Low zone DF-34 3 Nalhati- I Serious DF1478 SF-112, 16 NSF-22 4 Nalhati- II Low DF-84 5 Rampurhat- I Serious zone DF802,SF-108, 11 NSF-20 6 Rampurhat- II Low D.F-76 7 Mayreswar- I Moderate DF Mayreswar- II Moderate DF Md.Bazar Medium DF-45,SF-16,NSF-4 10 Sainthia Low DF Labpur Safe Suri- I Moderate DF Suri- II Serious DF-102,SF-54, 2 NSF-3 14 Rajnagar Medium DF520,SF-125, NSF-6 15 Khyrasole Serious DF-1006,SF-98, 2 NSF-4 16 Dubrajpur Serious DF-980,SF-202, 13 NSF-6 17 Illambazar Safe Bolpur Safe Nanoor Safe

7 FLUORIDE THROUGH DRINKING WATER 405 and 2% death is the most common feature among the people living in these areas. Some parts of Nalhati-I, Suri-II, Rampurhat-I, Khayrasole, Rajnagar belong to this zone (Table 2). From the above findings of blockwise fluoride concentration, a fluoride map of Birbhum district has been drawn which is shown in Fig. 1. Figure 1: Fluoride Map of Birbhum District

8 406 MAN IN INDIA Because of the very high levels of fluoride found in the drinking water in many blocks of Birbhum, a survey of the local people with respect to fluorosis has been carried out. After studying many external symptoms associated with fluorosis, it is found that the local population has been suffering from various forms of this deadly disease. Types of fluorosis in these population range from dental fluorosis to skeletal fluorosis and non-skeletal fluorosis. In order to find if there is a correlation between the fluoride concentration in drinking water, that has been observed in different blocks, and the types of fluorosis that are associated with that area, different types of fluorosis in a given area have been classified and correlated with the fluoride concentration of drinking water in that area. The data are shown in Fig. 5, Fig. 6 and Fig. 7 which clearly indicate that when the fluoride level in drinking water reaches above 6 ppm, incidents of all three forms of fluorosis, i.e. dental, skeletal and non-skeletal fluorosis also increase in the population drastically. On the other hand, at a concentration of fluoride below 6 ppm only dental fluorosis is more common. However, it needs to be mentioned here that apart from high fluoride concentration in drinking water, the observed fluorosis might also be due to the actions of many other factors such as nutritional level in their daily food, age factor etc. Figure 2: Skeletal Fluorosis in Nasipur (Vertebral Column are bent like bow)

9 FLUORIDE THROUGH DRINKING WATER 407 Figure 3: Dental Fluorosis in an Adult Individual at Nasipur, Birbhum Figure 4: (a) & (b) Deformity of Knee Joints, Paralysis of Lower Parts of Body Including Legs are also Skeletal Fluorosis

10 408 MAN IN INDIA Figure 5: Safe zone ( ) ppm, Low zone (1.6-2) ppm, Moderate zone (2.1-4) ppm, Medium zone ( ) ppm, Serious zone (6-46) ppm. Figure 6: Safe zone ( ) ppm, Low zone (1.6-2) ppm, Moderate zone (2.1-4) ppm, Medium zone ( ) ppm, Serious zone (6-46) ppm. The correlation between different kinds of fluorosis in different age groups of the population (Nasipur village; 46 ppm of fluoride in drinking water at the time of study) is shown in Fig. 8. Observations show that the fluoride concentration beyond the recommended level for longer duration causes 80% dental fluorosis and 20% skeletal fluorosis among 1 to 16 years old children in the population. In case of 17 to 34 years age group people, the percentage of occurrence of skeletal fluorosis is 60%, dental fluorosis is 30% and gastrointestinal fluorosis is 9%. Ultimately 1%

11 FLUORIDE THROUGH DRINKING WATER 409 death is caused in the population from this type of fluorosis in this age group. Among people of age group 35 years and beyond the observed percentage of fluorosis are as follows: 5% dental, 70% skeletal and 20% gastrointestinal fluorosis which in about 5% cases leads to death (Fig. 8). Figure 7: Safe zone ( ) ppm, Low zone (1.6-2) ppm, Moderate zone (2.1-4) ppm, Medium zone ( ) ppm, serious zone (6-46) ppm Figure 8

12 410 MAN IN INDIA Conclusion The ground water reserve is very limited and has been reducing very fast due to man made activities such as excess use of ground water for agricultural purpose. Based on the results of the present study, it is found that the fluoride ion concentrations in some villages of Birbhum district are much above the permissible limit. The increase of fluoride ion in the drinking water is mainly due to some geochemical processes and unplanned use of ground water. This fluoride problem in drinking water can be checked by increasing the ground water level. The only way to increase ground water level is rain water harvesting. In West Bengal normally villages possess many ponds and sometimes large tanks also; which are the natural systems for rain water harvesting. During our survey work it is observed that in most of the fluoride affected villages the ponds and the water bodies are silted and their rain water harvesting capacities reduced to a large extent. On the other hand, for agricultural purpose ground water are used excessively without following any scientific regulation. Government should take urgent and necessary action with the help of local panchayet to increase the rain water harvesting capacity in the natural water reservoirs such as pond, ditches, small lakes etc. by removing the silt and constructing more water bodies. Stringent law and its proper implementation through panchayet are also necessary to check the excessive and unscientific use of ground water. Definite awareness programmes are to be chalked out an implemented to alert the common rural folk in the regard. Additionally, the local municipalities should routinely monitor the water bodies, dug-wells, tube-wells in and around the affected areas for fluoride situation. Equally importantly, the local authorities should conduct the awareness programmes as has been indicated. If such proactive and remedial measures are not taken now, the problems associated with fluoride will become a very dangerous public health hazard in near future. Lastly fluoride in drinking water is obviously the main cause of fluorosis in some parts of Birbhum district. We have found that poor nutritional level enhances the fluorosis problem. So our observation indicates that the fluorosis and prolonged poverty are walking parallel. Acknowledgements Authors are thankful to Centre for Biotechnology and Department of Zoology, Visva-Bharati University & Public health engineering Department (Bolpur) for providing research facilities. The financial support forwarded by the UGC is thankfully acknowledged. References Bagh B. (2002). Endemic Fluorosis through Fluoride Contaminated Drinking Water and Control of Fluoride through Bacterial Population (M.Sc. Dissertation, Centre for Biotechnology, Visva-Bharati University, India. Bhatia R. and Dave J. M., (1980). Study of Water Quality of an Urban Village in Delhi. J. Ind. Wat. Works. Asson. 12(4):

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