Avoiding fluoride in drinking water, Andhra Pradesh, India

1Avoiding fluoride in drinkingwater, Andhra Pradesh,IndiaJohn Butterworth, Y.V. Malla Reddy, B.Renuka and G.V. ReddyIncreased exploitation of groundwater for irrigation is onefactor leading to dangerously high levels of fluoride indrinking water in parts of India. Involving local people intesting and monitoring can help to find safe sources. It isthen important to protect sources by improving localrecharge and reducing nearby extraction.111111The Reddy family who live inBattuvani Palli, a rural villagein southern India, have sufferedfor more than five years from theeffects of drinking water that containshigh amounts of fluoride. Their daughterhas chronic skeletal fluorosis, meaningthat she will never be able to walkproperly and is destined to be a socialoutcast. Their son has severely discolouredteeth: a tell-tale sign thatwater contains dangerous levels offluoride. All the other family memberssuffer from aching joints, which makeany kind of manual work very difficult,and even sleeping is disturbed by pain.This is a typical story from one of theincreasing number of villages that areaffected by fluoride in drinking water.The NGO Acción Fraterna is helpingto solve such drinking-water problemsin this part of Andhra Pradesh. Themethodology they developed was toincorporate integrated, participatory andproblem-focused approaches to improvingwater management into the pilotimplementation of a watershed developmentprogramme. This paper explainshow watershed programmes can, andarguably must, address water-qualityissues that are linked, in may cases, toover-extraction of groundwater.Over-exploitation ofresourcesExtensive exploitation of groundwater,made possible by enormous public andprivate investment in borewells forfarmers, has had huge benefits for agriculturalproduction and rural livelihoodsin rural India, especially over thelast decade. But an important negativeside effect has been the reduced localavailability of water for village domesticsupplies, leading to insufficientwater to sustain communities throughdrought periods.Less well known are the impacts ofunsustainable levels of groundwaterdevelopment on the quality of drinkingwater available in villages. In areaswhere groundwater levels have fallenand rocks contain fluoride-bearingminerals, longer flow pathways ofunderground water can lead to higherfluoride levels. Similar effects seem tocause fluoride levels to rise duringdroughts. Furthermore, uncontrolledborewell development means that inareas with water-quality problems, suchas where there are naturally highfluoride levels, the few available underground‘pockets’ of good quality waterare frequently used for irrigating crops.Fluoride in drinking waterFluoride occurs naturally in somegroundwater sources (linked to thepresence of minerals like fluorspar,cryolite and fluorapatite) and in foodsthat have been grown or producedusing water with high fluoride content.Ingestion of large amounts of fluoridecan cause serious health problems forhumans and animals (see Table 1).These range from discoloured teeth (i.e.dental fluorosis) to aching joints, brittlebones, stunted growth and deformedlimbs (i.e. skeletal fluorosis).The current World Health Organisationpermissible limit for the fluorideconcentration of drinking water suppliesTable 1waterEffects of fluoride in drinkingFluoride concentration Effects(mg/l)Below 1.0Safe1.0–1.5 Marginal1.5–3.0 High risk ofdental fluorosis3.0–10.0 Leads to skeletalfluorosis withadverse changesin bonesMore than 10.0 Crippling skeletalfluorosisis 1.5 mg/l (or ppm) with the addedrecommendation that ‘climaticconditions, volume of water consumedand intake from other sources should beconsidered when setting national standards’.In 1993, the Bureau of IndianStandards set a maximum permissiblefluoride concentration of 1.0 mg/l,although concentrations of up to 1.5 mg/lare considered to be acceptable in theabsence of an alternative safer source.Because fluoride levels in groundwaterare hugely variable, even acrossshort distances, and because of theimpacts of development, there is a needfor ‘catchment’ scale solutions to mitigatefluoride problems in aquifers usedfor domestic supply. Such solutionsshould make sure that: the best qualitywater available is used for drinking andthat the causes of groundwater overexploitationare addressed. Unsustain -able groundwater use can only betackled by a combination of improvedrecharge in areas near to domesticsources (e.g. by judicious location24Vol. 24 No. 1 July 2005

catchment management1Symptoms of skeletal fluorosisof water-harvesting structures) andreduced groundwater extraction near tothese critical sources (e.g. by zoning).Case studyOne example of how local solutionscan sometimes work is the village ofBattuvani Palli in Andhra Pradesh.Here, Acción Fraterna undertook participatoryfluoride surveys (Box 1)as part of a watershed developmentprogramme. Watershed developmentprogrammes in the area typicallyhad previously focused on activitieslike promoting tree-crops to enablefarmers to diversify from groundnutmonoculture, and constructing checkdamsand other water-harvestingstructures to catch more water forirrigation. Generally such programmesignore domestic water-supply issues,even though domestic water-supplyproblems are often related to patternsof ‘watershed management’: especiallygroundwater development. However,Acción Fraterna were motivated toinvestigate more integrated options todevelopment, and had noticed theprevalence of health problems thatmight be linked to fluoride in drinkingwater.The results of fluoride surveys inBattuvani Palli using portable field kitswere of huge interest to villagers, manyof whom suffered from symptoms offluorosis. The day after the surveys werecompleted, people were busily exchangingresults and had memorized most ofthem. They wanted information tounderstand why they were sufferinghealth problems and, more importantly,to start discussing solutions. Thevillagers’ interest in and acceptanceof results contrasted starkly with thereaction from district-level authoritieswho stuck firmly to the official line thatthere was not a fluoride problem in thevillage. It was only after approximately12 months of interactions that these11Box 1. A methodology for participatory fluoride surveysMeasurement techniquesMethodologies available to monitor fluoride in water samplesinclude:● Laboratory analysis: reliable, but usually slow, whichleads to long delays in giving feedback on results tocommunitie.● Portable field kits: these can be reliable if the kits (basedupon colorimeters or ion-selective electrodes) are usedproperly, and make it possible to feedback results.quickly, as well as sampling a large number of sourcesacross areas quickly. In this study, a HACH portablecolorimeter was used (HACH pocket colorimeter Type I,Hach Company, Loveland, Colorado).● Indicator test strips: these can make analysis veryparticipatory and are useful for raising awareness onfluoride problems, but are not sufficiently reliable forpotential life-and-death decision-making.SamplingIn the vicinity of the study villages, water samples werecollected from each well within approximately 2 km of thevillage centre. This included the main domestic water-supplysources for the villages, but also other sources like irrigationwells in order to provide information on the (large) variationsin fluoride levels around the villages where better qualitywater might be available. Information on the type and usemade of each well was also collected, and using a GPSsystem, the exact location was also logged. Occasionalmeasurements were also made of surface water in tanksand check dams that are used to recharge groundwater.Given the high levels of temporal variation, importantsources were monitored regularly (monthly).Training and testingSamples were analysed using the manufacturer’s prescribed‘pipette’ method. This requires use of standard fluoride solutionsto calibrate the meter, and adding reagents to watersamples, so users must be experienced and careful.Training should be given to check that the procedure recommendedby the manufacturer is carried out, and to checkresults for consistency (by repeating tests) and reliability (bycomparison with results from laboratories). Our testingperiod showed that we would also need to dilute sampleswith distilled water by a ratio of 2:1 in order to remain withinthe measurement limits of the equipment.Analysis proceduresSamples were analysed using the colorimeter in a temporarylaboratory – a clean room with space to layout the samplesand equipment – usually on the same day as sample collection,either within the village or nearby. After solving problemsrevealed by the initial cross-checks (poor results dueto procedure, dilution etc) it was possible to complete10–15 tests in an hour.Calibrations of the portable meter were regularly checkedagainst standard fluoride solutions, and samples sent toother laboratories for cross-comparison. Regular checkingof different batches of samples over time, tests by differentoperators, and with different laboratories are important toreveal possible errors. It is useful to plot the field and laboratoryresults together in a scatter graph and to look fordifferences and patterns. In order to triangulate the findingsof the surveys, results were compared with results from arapid assessment where water users had been asked toassess the quality of water from domestic sources on thebasis of taste and whether they felt the water containedfluoride.Feedback of resultsParticipation of the community in collecting water sampleswas encouraged, so that people understood the objectivesof the survey and felt some level of ownership of thefindings. Equally important, results were then rapidlyreported back to the community and well owners. Wellswhere fluoride levels exceeded the safe limit of 1.5 mg/lwere marked with a red cross to indicate that the water wasconsidered unsafe for drinking.Vol. 24 No. 1 July 2005 25

catchment management1●that was drilled in the tank bed andclose to some low fluoride sourcesturned out to be unsafe.Recharge of the existing source andmanagement: It was thought thatenhanced recharge in the zone closeto the existing well and managementof water levels in the area (e.g. byrestricting pumping from adjacentirrigation sources) might influencefluoride levels.1111Undertaking fluoride measurements locallyauthorities started to accept the findingsof the preliminary surveys and to recognizethat people in these villages havebeen suffering because of the waterquality of their drinking-water supply.Health problems are not routinely linkedto the monitoring of the performance ofwater-supply systems.As part of a participatory planningprocess, ideas for solutions were developedthat included:●Treatment: Given the existing plentifulwater supply, despite very highfluoride levels, household- or community-leveltreatment of water was●an option. Filters and lower-costtreatment methods were both tried,but neither was considered to be anadequate solution due to high cost orlimited effectiveness.An alternative source for drinking:eight out of a total of 65 irrigationwells sampled in the vicinity ofBattuvani Palli recorded fluoridelevels below the safe limit of 1.5mg/l (in the range 1.04–1.46 mg/l).There was a cluster of wells about2 km south of the village (see Map)where a new source could be sited,however this area was disputed witha neighbouring village. A borewellEventually, an irrigation well withsafe fluoride levels (1.5 mg/l in early2004 compared to the 3.8 mg/l of theexisting source at this time) was usedto develop a new drinking-water supplyfor the village (see map). This providesa limited quantity of relatively lowfluoridewater to supplement the existingdomestic supply. The farmer whoprovided this well was compensated,and a new short pipeline was laid totake safe water to the village. Rapidhealth improvements were reported.However, the quality of this water willneed to be monitored regularly and thesource protected.By March 2005, after a prolongeddry period, fluoride levels had risen toan unsafe, although still improved,1.7 mg/l. While new borewells within300 metres have been prevented, 30 newborewells were drilled in the village inthe previous year and recharge has beenlow. The community are now consideringconstruction of a check dam toenhance recharge of the source, andthe village water committee has alreadyhad to reduce daily water collectionfrom the low-fluoride source to 50 litresper household and only 25 litres duringsummer.Conclusions andrecommendations11Figure 1The location of some key monitoring wells in Battuvani PalliParticipatory fluoride surveys linked toimproved watershed management couldbring relief to some of the hundreds ofthousands of people who are currentlysuffering from fluoride poisoningthroughout India. The need for muchbetter monitoring and mitigation measures,both areas where rural communitiesare clearly able to play a vital role,should build upon the routine use ofparticipatory surveys by governmentline departments and a broader26Vol. 24 No. 1 July 2005