Study On Health Technology Assessment And Optimized Measures For Drinking Water Defluoridation In Rural Area In Tianjin

Objective To perform the study on health technology assessment andthe optimized measures for drinking water defluoridation in rural areain Tianjin.Methods The investigation was carried in rural area inTianjin, including Jinghai County, Baodi District and Dongli District,where the defluoridation facilities were applied to remove thefluorides from drinking water with higher level of fluorides. Theinvestigation on the sanitary quality of the raw water and thefinished water; drinking water defluoridation efficiency, details onrunning and operation, were carried out among 15 water stationstotal, including 4 water stations using electrodialysis techniques, 6water stations using reverse osmosis techniques county, 3 waterstations using activated aluminum oxide adsorption techniques and 2water stations using nanofiltration techniques, which had been runningfor 6-7 years. Investigation on the awareness of health effects ofhigh fluoride drinking water, effectiveness of drinking waterdefluoridation station, application of defluoridated drinking waterwas carried out by questionnaire among residents in 15 villages, wherethe drinking water defluoridation station had been operating for morethan 6 years located. Investigation on the awareness of healtheffects of high fluoride drinking water, effectiveness of drinkingwater defluoridation station, application of defluoridated drinkingwater was carried out by questionnaire among workers in water stationsand residents in 15 villages mentioned above. The urine fluoride anddental fluorosis were monitored among local children aged 8-12 yearsold. The effectiveness, safety, benefit and cost, acceptability of four kinds of drinking water defluoridation facilities were syntheticallyassessed based on the data, then the optimized measures were performedscientifically.Results The finished water samples from electrodialysis defluoridationfacilities and reverse osmosis defluoridation facilities showedlower fluoride level of below 1.0 mg/L with fluoride removal rates of90.01% and 75.32%, and lower total dissolved solids and total hardnesslevels with removal rates of 75.83%-93.48%. The finished water samplesfrom nanofiltration defluoridation facilities also showed lowerfluoride level of below 1.0 mg/L with fluoride removal rates of75.16%, and lower total dissolved solids and totalhardness levels withremoval rates of 64.90% and 77.22% respectively. Among the finishedwater samples from e]ectrodialysis defluoridation facilities andreverse osmosis defluoridation facilities, most of them showed higherqualified rates of microbiological indexes, but coliform bacteria andfecal coliform were found in some of them. 60.7% of the individualsknew the adverse health effects of drinking water with higher levelof fluorides, and 39.3% didn't know it. The awareness ratio ofdental fluorosis caused by intaking over fluorides from drinking waterwith higher level of fluorides reached 52.4%. The recognition rate ofthe efficacy drinking water defluoridation station was 83.3%. Among300 investigated families, consumption of barreled defluoridateddrinking water variated from 3 barreles to 8 barrels in one month, 70%of them showed lower consumption of barreled defluoridated drinkingwater. In 70.24 % of the investigated families, the barreleddefluoridated drinking water was only used for drinking, and drinkingwater with higher level of fluorides was usually used for cooking. The prevalence rate of dental fluorosis was 35.3% for local children aged8-12 drinking defluoridated drinking water, which was significantlylower than those drinking water with higher level of fluorides(P＜0.05)and met the requirement of that in national standard forlight-fluorosis district. Local children aged 8-12 drinkingdefluoridated drinking water also showed higher level of fluoride inurine compared with the normal level,Conclusion The present defluoridation facilities applied incountryside of Tianjin, including electrodialysis defluoridationfacilities, reverse osmosis defluoridation facilities andnanofiltration defluoridation facilities, which make a feature ofautomatically controlled running and operation, online-displayedtinning parameters reflecting the sanitary quality of the finishedwater and stable defluoridation, show higher efficacy, and were suitablefor drinking water defluoridation in rural area in Tianjin. The longterm health effect of residents drinking the defluoridated drinkingwater finished by the reverse osmosis defluoridation facilities, whichcan effectively remove the fluorides from the raw water with the higherlevel of fluoride, as well as most of the trace element essential tohuman health, should be researched further. The defluoridationfacilities using activated aluminum oxide adsorption techniques is notsuitable for drinking water defluoridation dew to some shortage, suchas unsatisfied taste, increasing aluminum level in the finished wateradverse for human health, trouble in management and running. Thedefluoridated drinking water is barreled and supplied for residents,of which the bacterial index don' t meet the requirement of DrinkingWater Sanitary Standard due to the combination with water purifier sometime. Although the prevalence of dental fluorosis and the contentof fluorides of children aged 8-12 have been primarily controlled ina certain degree, they still meet related standards for lightfluorosis area. Health education should be strengthened further to makethe residents know the importance of using defluoridated drinking waterto human health and use defluoridated drinking water for cooking anddrinking on their own initiative. It is essential to realizing andensuring the running of water defluoridation facilities and the safetyand sanitation of drinking water for residents in rural area that theinvestment, construction and management of water delfuoridationstation should be associated with various economic structure, and ledto a new developing model that investment, construction and managementof water delfuoridation station were carried out by social institutionand government cooperatively instead of government alone, as well asthe convenient and express supplying of defluoridated drinking, freeand paid-for defluoridated water supply ways, ,based on the financialability in countryside.