By Ranjit Kumar, IVLP Fellow (Water Pricing and Water Economics), USA, Water Expert, KPMG
Background:
Water is essential for all physiological activities associated with humans, animals, and for plant. However, the nature and quality of surface and ground water are widely variable and are determined by the local geological history, including the rocks and hidden ore deposits surrounding the sites for the collection of the water, and other factors, such as the movement of elemental particles and pollutants by lentic and lotic waters and underground aquifers (Datta et al, 2014). All organic and inorganic minerals dissolved in water and its interaction with different minerals are different in nature. The interaction is not properly studied due to its complexity. In spite of the complex hydro and biogeochemical factors, the number of dissolved constituents in ground water is limited. In addition to the trace constituents in water, the major constituents are Na+ Ca2 + Mg2 + (SO4) 2 – (as acid and salts), Cl– HCO3 – etc., and the secondary constituents are Fe2+ Sr2+ K + CO3 2 – NO3 – and F – (fluoride) (Datta et al, 2014).
Fluorosis is a communal health problem which is caused by superfluous intake of fluoride through different sources like drinking water, food products, etc. In general, fluorosis is mainly caused by the drinking of ground water where the geological crust of the aquifer is heavily encumbered with fluoride and it subsequently leaches into the ground water and thereby contaminates them. Half of the world’s population uses groundwater as a source of potable drinking water (Ibrahim et al, 2011). It is widely believed that drinking water is typically the largest single contributor of daily fluoride intake (Scott,1937) Groundwater constitutes 97% of global freshwater; therefore, primarily people are dependent on groundwater sources for daily consumption.
Water is considered as a universal Solvent, it dissolves almost every organic and inorganic substance, however, any of these solvents is required in human diet within a permissible limit. The fluoride required in the body is in the range of 1 to 1.5mg/L (Handa, 1975). In India, this problem has troubled nearly 177 districts covering 19 states out of 28 (Kumar and Kumar, 2015). Efforts are being taken to address the problems of fluoride contamination in drinking water in rural areas in India by the inception of flagship programs like Rajiv Gandhi National Drinking Water Mission, along with extensive Support from an external agency like The United Nations Children’s Emergency Fund (UNICEF) (Fawell et al, 2004; WHO, 2006). Several types Central Ground Water Board (CGWB) in India to estimate and map the fluoride affected districts. These initiatives highlight the present condition of fluoride contamination in Bihar. As fluoride contamination is considered as endemic and there are increasing number of cases of fluorosis coming especially from rural areas of Bihar. Till now, there is no appropriate solution to handle the fluoride contamination issue. The dataset reveals that out of 37 districts in Bihar, 9 are severely affected. CGWB has clearly declared that many cases of dental, skeletal and non-skeletal fluorosis have been reported in Nawada, Jamui, Bhagalpur, Jahanabad, Gaya, Aurangabad, Munger, Nalanda, Banka districts of Bihar (NPPCF, 2014).
Occurrence of Fluoride
Ground water is the nation’s principle reserve of fresh and potable water and will serve as a future reserve for the upcoming generation. Ground water can be easily contaminated with the presence of different minerals and rock present in the crust. Such contamination termed as Geogenic contamination. Statistically, it’s seen that groundwater constitutes about 30.1% of total available freshwater on the earth (Mehta and Lyla, 2010). Fluoride is a naturally abundant element and found mostly in granite rocks. These rocks contain fluoride varying at a concentration from 20-360 O ppm and is one of the largest sources of fluoride to the underground water. These rocks generally form the layers of aquifers and are continuously submerged in the groundwater, but the whole process of dissolution of fluoride in water has not been well understood till now (Saxena and Ahmed, 2001). The decomposition, dissociation, and dissolution are considered as the main chemical processes for the enrichment of fluoride in the ground water.
Studies show that an alkaline environment (pH of water ranges between 7.6 to 8.5) with high bicarbonate concentration in the medium will provide a conducive environment for the dissolution of fluoride in ground water (Ayoob and Gupta, 2007). The space and time of rock-water interaction augment the concentration of fluoride in the water. The concentration of contaminants also increases with the increase in the residual timing of water in the aquifer (Saxena and Ahmed, 2001) and supplement the concentration of fluoride in the water. Another source of fluoride is soil which contains nearly 200 to 300 ppm of it (Saxena and Sewak, 2015). Most of the fluoride is found in complexes with either aluminium or iron in the soil. Intake of foods and beverages are other sources through which fluoride enters the human body.
History of fluoride and its distribution
There are 60-65 million people in India who are consuming fluoridated water and are being severely affected by it (Ibrahim et al, 2010). The case of fluorosis is more severely found among children; about 6 million children are captured in a vicious fluorosis circle (Ayoob and Gupta , 2007). Children are more vulnerable to dental fluorosis as their teeth are in the crucial stage of development and even a small and continuous dose of fluoride can easily damage the developing permanent teeth and enamel. Therefore, the number of dental fluorosis cases is mostly observed in children. In the case of India, fluoride-related cases are more endemic in rural conditions, but the contamination and related disorders to this pollution like cases of dental, skeletal and non- skeletal fluorosis are spreading to different parts of the Indian subcontinent at a very rapid pace (Saxena and Sewa) Fluorosis can be identified through physical examination i.e. morphological Changes in teeth, joint pain, stiffness in joints, skeletal deformities and other muscular and neuro-related issues Fluorosis mainly causes three issues (Limeback, 1992). 8 Dental fluorosis 8 Skeletal Fluorosis 8 Non-Skeletal Fluorosis
Case Study: A case study of Nawada district of Bihar has been discussed here for dipper understanding. The geology of Nawada area indicates the presence of considerable amount of granite, quartzite and quartz schist. According to the study of CGWB, the areas of Nawada show a variable thickness of aquifer and alluvial content in different blocks. The studies conducted by CGWB in Roh block of Nawada district reveals that the concentration of fluoride is well above the permissible levels set by the BIS and WHO and it is about 1.7 mg/L (CGWB, 2014). It is proved that the presence of bicarbonate and carbonates in the rocks determine the concentration of fluoter CASE STUDY 71 Central Ground Water Board (CGWB) in India to estimate and map the fluoride affected districts.
The geology of Nawada area indicates the presence of considerable amount of granite, quartzite and quartz schist. According to the study of CGWB, the areas of Nawada show a variable thickness of aquifer and alluvial content in different blocks. The studies conducted by CGWB in Roh block of Nawada district reveals that the concentration of fluoride is well above the permissible levels set by the BIS and WHO and it is about 1.7 mg/L (CGWB, 2014). It is proved that the presence of bicarbonate and carbonates in the rocks determine the concentration of fluoride mobilization within the aquifer and the geology of Nawada shows this property very evidently. The pH of groundwater is also very crucial in determining the mobility of fluoride and it is proved that alkaline medium highly facilitates the conductivity of the element, and knowing the fact that the pH of groundwater in Nawada district varies from 6.96 to 8.41, it further legitimates and concretizes the enhanced expression of fluoride activity in the district (CGWB, 2014). Experimental studies indicate that the presence of alkaline media, high amount of bicarbonate and moderate specific conductivity are favourable factors for fluoride dissolution (Saxena and Ahmed, 2001).
The contamination of fluoride in drinking water is mostly due to geogenic process. But, a number of anthropogenic activities can also upsurge fluoride concentration in water and soil (Fawell et al, 2004; WHO, 2006). Utilization of agricultural fertilizers in the field, agricultural runoff, and sewage treatment plant are some of the point and non-point sources of fluoride pollution. Both, artificial and geogenic activities enhance the probabilities of fluoride admission into the human body. We see that the tropical regions are highly infested with fluorosis and the cases of fluorosis is highly prevalent in developing countries. Apart from the consumption of fluoride from polluted groundwater, lack of proper and balanced nutritional diet also enhance the process of fluorosis (Moynihan Paula et al, 2004) Nawada district of Bihar is prone to fluoride contamination due to its geological features and the type of fluoride-rich granite rock that lines the aquifer of the groundwater source. A number of cases of fluorosis have been registered by the government officials in the Bihar government’s survey report and it also shows the number of fluoride impacted people are growing (Ayoob and Gupta, 2015).
The reasons for the high amount of fluoride contamination in water is due to prolonged retention of water in the mineral rich aquifer, elongated residual time and limited fresh water interactions. This type of attribute and characteristic is shown by a closed aquifer and the geology of Bihar advocates that this condition is usually prevalent in other 9 districts of Bihar including Nawada. A research has been conducted in different villages of Roh Block, Nawada district, Bihar in order to observe the concentration of fluoride. The research includes the study of social behavior and also scientific study of water sample from Eight village of Roh, Village. The study of social behaviour of the people regarding the fluoride contamination in drinking water reveals the understanding of people about fluoride, related disease and degree of acceptance among people.
The technique devised for analysis of social behavioural pattern is via Focused Group Discussions (FGDs) and comprehensive questionnaire survey of one village based on the laboratory testing of the collected water sample. This was second important components of the research. As per the objective of the research, analysis of public perception regarding fluoride and its impact on their health in the context of fluoride contamination was extremely vital to understand during the research. Hence, the combination
of scientific and social science approach is the best way to synthesize and explain the holistic details regarding contamination of fluoride and peoples’ view regarding the fluoride contamination in the ground water. The water samples were collected from deep and shallow borewells after flushing the water for 7-10 minutes to remove stagnant water and to collect the fresh water from the aquifer. The process of scientific study of water involved laboratory testing of water with the help of spectrophotometer SPADNS method. It is the most recognized and authentic way to conduct a laboratory test of fluoride.
In the SPADNS (parasulfophenylazo)–1,8–dihydroxy–3,6– naphthalene disulfonate) colorimetric method, fluoride reacts with the dye lake, dissociating a proportion into a colourless complex anion (ZrF6–) and the dye. As the amount of fluoride increases, the colour obtained became progressively lighter. After preliminary distillation, the distillate is reacted with the zirconium-dye lake and measured calorimetrically at 570 nm (nanometre) in a spectrophotometer. The working of spectrophotometer required a huge amount of accuracy and precision. The process involved preparation of standard curve between fluoride concentration vs absorbance; followed by a process of calculation of fluoride concentration with the linear equation obtained from the graph (figure 05) 8 Fawell and WHO followed the following steps in order to evaluate the standard curve: (Fawell et al, 2004; WHO, 2006). 8 Fluoride standards were prepared with the help of known concentration of fluoride. 5 mL SPADNS and Zirconyl-acid reagent were prepared. 8 Spectrophotometer was set to zero absorbance absorbance readings of standards was obtained. 8 A curve of the fluoride-absorbance relationship was plotted. And linear equation were obtained from the graph.
Estimation of fluoride was done in the laboratory with the help of Agilent Carry series UV-V spectrophotometer 1 cm Quartz crystal for the measurement of absorbance at a fixed wavelength of 570nm. This wavelength was selected as per the wavelength scan function of the dyed solution. A standard solution was prepared with the known Concentration of chemical reagent in order to examine the fluoride concentration of unknown substance. Four different standard solutions were prepared to generate the standard curve through spectrophotometer. The curve was prepared from standard solution so that it allows the same properties to be determined by unknown samples by interpolation on the graph. The standard curve between absorbance vs concentration was plotted (figure 05) SPANDS reagent was prepared by mixing 958 mg of SPANDS and dilute to 500 ml of double distilled water. Zirconyl reagent was prepared by mixing 133 mg of Zirconyl acid (ZroCl2.8H2O), and 350 mL of concentrated HCl and the double distilled water was added until the total volume of solution was 500 mL. SPANDS and Zirconyl reagents was mixed in 1:1 volume ratio to prepare SPANDS- Zirconyl reagent.The standard reactions is shown below (Kongpun et al., 2013)
According to these statistics, there seems to be little or no awareness about the relation between the water quality and the health conditions. The awareness about fluoride contamination was abnormalities. The most common speculation about the reason for teeth staining and decay is tobacco and “paan “consumption. Skeletal fluorosis is the worst case due to fluorosis. The bone becomes brittle and weak due to this disease. Though the number of cases of extreme skeletal fluorosis was not very significant but five people lying in the age group of sixty and eighty years were having skeletal fluorosis. Their legs were not straight and they needed support for walking. was examined, 87.6 % were effected by Fluorosis and none of them even remotely aware about fluoride or the symptoms due to its contamination. These two major observations stand out through the social survey as conditions of this degree of severity were not anticipated before the field work began
Conclusion: It has been found through pilot study and other studies also shows a comparative high level of fluoride contamination i.e. 2.2 mg/L which is much greater than the desired level, in the eight targeted villages present in Nawada district of Bihar. The health conditions of the people in these places is largely effected by fluoride related diseases. Yet, there is zero knowledge about fluoride contamination among the masses and very less awareness about water contamination and the symptoms of diseases caused by fluoride and water contamination. Research on fluoride contamination was done by a governmental research institute – Central Ground Water Board. But, currently the representative population chosen for the study are not accessing them and seem to be unaware of any governmental schemes and programs for water purification. Campaigns and awareness programs regarding contamination issues and ways to mitigate them can help to alleviate the issues to certain possible extent. In order to deal with this menace the entry point activities that are designed for fluoride contamination, need to be more effective by designing appropriate schemes that fit with the social contexts and preferences of the population and this can be achieved by well-designed and targeted social surveys
