Utility of check dams in dilution of fluoride concentration in ground water and the resultant analysis of blood serum and urine of villagers,Anantapur District,Andhra Pradesh,India

High levels of fluoride (beyond 1.5 ppm) in ground water as source of drinking water are common in many parts of Andhra Pradesh, India, causing fluorosis. The study carried out in endemic Nalgonda District, Andhra Pradesh, has indicated that the fluoride-rich ground water present in the wells located down stream and close to the surface water bodies is getting diluted by the low-fluoride surface water. Encouraged by this result, check dams were constructed upstream of the identified marginally high fluoride bearing ground water zones in Anantapur District to reduce fluoride levels as an alternate solution for safe drinking water.In this paper, an attempt is made to study the utility and effect of these check dams in dilution of fluoride concentration in drinking water and its resultant impact on the health aspects of certain villagers of Anantapur District through the analysis of their blood serum and urine. Ground water samples from three fluoride-affected villages, blood and urine of males and females from the same villages were collected and analyzed for fluoride using ion selective electrode method. The results indicated that the fluoride levels in blood serum and urine of males in the age group of 5–11 years are found to be the highest. The concentration of fluoride in ground water is directly proportional to the concentration of fluoride in blood serum and urine. The concentration of fluoride in ground water with depth of the aquifer is a function of lithology, amount and duration of rainfall, rate of infiltration, level of ground water exploitation in the area etc. The construction of check dams upstream of the identified marginally high fluoride waters will not only cause additional recharge of ground water but also reduces the fluoride concentration eventually improving the health of the villagers.     

Occurrence and problems of high fluoride waters in Turkey: an overview

Endemic dental fluorosis was first observed in Turkey in Isparta Province, located in the SW of Anatolia, with mottled enamel related to the high levels of fluoride (1.5–4.0 ppm) in drinking waters, about 55 years ago. The origin of fluoride was attributed to the contents of minerals in volcanic rocks, consisting of pyroxene, hornblende, biotite, fluorapatite and glassy groundmass minerals. It was also reported about 35 years ago that severe dental and skeletal fluorosis has been observed in human beings and livestock in Dogubeyaz?t and Caldiran areas, located around Tendurek Volcano in eastern Turkey, where natural waters contained fluoride levels between 2.5 and 12.5 ppm. It was hypothesised that fluoride, which might be transported by fumaroles or escaped from devitrified lavas, could be held on the surface of some minerals and then exchanged with OH^- in ground waters with high pH at the foothills of the young Tendurek Volcano. Endemic dental and skeletal fluorosis was also observed in the inhabitants in Kizilcaoren Village of Beylikova Town in Eski?ehir Province situated in the midwest of Turkey, where the fluoride content of the drinking waters ranged from 3.9 to 4.8 ppm. The origin of high fluoride in the natural waters was related to the fluorspar deposits, occurring in the catchment area near the village. During the survey in the Güllü Village of Esme-Usak, located in south-midwest of Turkey, it was observed that most of the inhabitants born and raised in the village and aged between 10 and 30 years, showed mild to moderate levels of mottled enamel. The fluoride contents of the deep well waters used for drinking in the village, varied from 0.7 to 2.0 ppm. Amorphous microscopic fluorite existing in the Pliocene lake limestones was considered as a possible origin of fluoride in the waters.     

Distribution and Risk Assessment of Fluoride in Drinking Water in the West Plain Region of Jilin Province, China

The west plain region of Jilin province of northeast China is one of the typical endemic fluorosis areas caused by drinking water for many years. Investigations of hydrogeological and ecoenvironmental conditions as well as endemic fluorosis were conducted in 1998. Results show that the ground water, especially, the water in the unconfined aquifer is the main source of drinking water for local residents. The fluoride concentration in groundwater in the unconfined aquifers is higher than that in the confined aquifer in the west plain of Jilin province. The fluoride concentration in the unconfined aquifer can be used to classify the plain into fluoride deficient area, optimum area and excess area, which trend from west to east. High fluoride (>1.0 mg L(-1)) in drinking water resulted in dental and skeletal fluorosis in local residents (children and pregnant women). There exists a positive correlation between fluoride concentration in the drinking water and the morbidities of endemic fluorosis disease (r1 = 0.781, r2 = 0.872). Health risks associated with fluoride concentration in drinking water are assessed. It has been determined that fluoride concentration in excess of 1.0 mg L(-1) exposes residents to high health risks based on risk identification. The study area is classified into five health risk classes as shown in Figure 4. The risk indexes of this area more than 1.0 are accounted for 68% of the total west plain region.     

稀土元素的脑部蓄积性、毒性及其对人群健康的潜在危害

论述了稀土元素在动物脑部的蓄积性、对脑的毒性以及稀土区人群的脑部毒性效应,分析了稀土农业应用和稀土厂“三废”对生态环境和人群健康的潜在危害。     

稀土元素的脑部蓄积性、毒性及其对人群健康的潜在危害

论述了稀土元素在动物脑部的蓄积性、对脑的毒性以及稀土区人群的脑部毒性效应，分析了稀土农业应用和稀土厂“三废”对生态环境和人群健康的潜在危害。     

杭嘉湖蚕桑区主要大气氟污染源及治理现状

对杭嘉湖蚕桑区大气氟主要污染源——砖瓦厂氟的排放状况及各种含氟烟道废气治理装置的治理效果进行了较为深入的调查分析,认为砖瓦厂含氟废气不经烟道排放较为严重。目前砖瓦厂所采用的各种含氟废气治理装置中,旋流板塔装置除氟效率较佳,可使废气氟的排放浓度降至5mg/m~3以下,基本上能消除下风向300m以远的大气氟污染对蚕桑的严重危害。     

Daily dietary fluoride intake in rural villages of the Ethiopian Rift Valley

Dental and skeletal fluorosis is widespread in the Ethiopian Rift Valley region. Drinking water has been considered the main reason for the development of fluorosis, but dietary intake may also be a contributor in areas with high concentration of fluoride in water, soil, and biota. The purpose of this study is to assess the total daily dietary fluoride intake by adults in a rural part of the Ethiopian Rift Valley. The food, beverage, and water samples were collected from selected households of three neighboring villages with similar dietary pattern, but with different fluoride content in their water sources. Village A uses water with 1.0 mg L^?1 fluoride, village B uses water with 3.0 mg L^?1 fluoride, and village C uses water with 11.5 mg L^?1 fluoride both for food preparation and for drinking. The level of fluoride was determined in all food ingredients, in the prepared food, beverages, and in the water used for food preparation and drinking. Recipe and food frequency questionnaires were used to gather household food preparation and consumption patterns. An alkali fusion method was used for digestion of food samples and for subsequent determination of fluoride with ion-selective electrode. The daily fluoride intake varied depending on its concentration in the water used for cooking and drinking. In households using water with 1 mg L^?1, 3 mg L^?1, and 11.5 mg L^?1 fluoride, the total personal intake was found to be 10.5, 16.6, and 35.3 mg d^?1, respectively. Contribution of the water to the daily fluoride intake was 33%, 58%, and 86%, respectively. Even in households using water containing fluoride at a concentration of 1 mg L^?1, the daily intake was higher than the recommended safe intake of 1.5–4.0 mg d^?1 for adults, which indicates that the fluoride intake through food may cause health risks. Minimizing the fluoride concentration in water to the lowest possible level will greatly reduce the daily intake. The form of fluorine (organic or inorganic) in the food items and the associated health risk factors need further investigation.     

A review of global outlook on fluoride contamination in groundwater with prominence on the Pakistan current situation

Several million people are exposed to fluoride (F^?) via drinking water in the world. Current review emphasized the elevated level of fluoride concentrations in the groundwater and associated potential health risk globally with a special focus on Pakistan. Millions of people are deeply dependent on groundwater from different countries of the world encompassing with an elevated level of fluoride. The latest estimates suggest that around 200 million people, from among 25 nations the world over, are under the dreadful fate of fluorosis. India and China, the two most populous countries of the world, are the worst affected. In Pakistan, fluoride data of 29 major cities are reviewed and 34% of the cities show fluoride levels with a mean value greater than 1.5 mg/L where Lahore, Quetta and Tehsil Mailsi are having the maximum values of 23.60, 24.48, > 5.5 mg/L, respectively. In recent years, however, other countries have minimized, even eliminated its use due to health issues. High concentration of fluoride for extended time period causes adverse effects of health such as skin lesions, discoloration, cardiovascular disorders, dental fluorosis and crippling skeletal fluorosis. This review deliberates comprehensive strategy of drinking water quality in the global scenario of fluoride contamination, especially in Pakistan with prominence on major pollutants, mitigation technologies, sources of pollution and ensuing health problems. Considering these verities, health authorities urgently need to establish alternative means of water decontamination in order to prevent associated health problems.     

Fluoride in Antarctic marine crustaceans

The concentration of fluoride in the body parts of a range of Antarctic crustaceans from a variety of habits was examined with the aim of determining whether fluoride concentration is related to lifestyle or phylogenetic grouping. Euphausiids had the highest overall fluoride concentrations of a range of Antarctic marine crustaceans examined; levels of up to 5477 μg g⁻¹ were found in the exoskeleton of Euphausia crystallorophias. Copepods had the lowest fluoride levels (0.87 μg g⁻¹ whole-body); some amphipods and mysids also exhibited relatively high fluoride levels. There was no apparent relationship between the lifestyle of the crustaceans and their fluoride level; benthic and pelagic species exhibited both high and low fluoride levels. Fluoride was concentrated in the exoskeleton, but not evenly distributed through it; the exoskeleton of the head, carapace and abdomen contained the highest concentrations of fluoride, followed by the feeding basket and pleopods, and the eyes. The mouthparts of E.␣superba contained almost 13 000 μg F g⁻¹ dry wt. Antarctic krill tail muscle had low levels of fluoride. After long-term (1 to 5 yr) storage in formalin, fluoride was almost completely lost from whole euphausiids. Received: 1 April 1998 / Accepted: 29 July 1998     

氟离子慢性暴露对中国林蛙蝌蚪生长发育的毒性效应研究

氟元素以不同的结合形式广泛存在于自然界中,适量氟的摄取有益于龋齿预防和骨骼发育,然而过量氟的摄取会对动物及人体健康造成危害。近年来,大量的人类活动导致水环境中氟含量持续升高。为探究水域氟污染对中国林蛙的毒性影响,本研究以中国林蛙(Rana chensinensis)胚胎为试验材料,对卵黄栓期(G12期)胚胎进行了0、0.7、4.2、19.4、42.8 mg·L~(-1)F-慢性水体暴露直至胚胎发育到变态高峰期(G42期)的研究。分别于暴露25 d和40 d后取样测定了蝌蚪全长、体长、体重和发育分期;此外,分析了F-慢性暴露对变态率、G42期蝌蚪的全长、体长、体重和后肢长以及G42期蝌蚪骨骼发育的影响。结果表明:暴露25 d时,4.2 mg·L~(-1)F-处理组促进了林蛙蝌蚪的生长发育,而42.8 mg·L~(-1)F-处理组显著抑制了蝌蚪的生长发育;暴露40 d时,19.4 mg·L~(-1)F-和42.8 mg·L~(-1)F-处理组蝌蚪的生长发育均受到显著抑制。持续进行慢性暴露78 d后,4.2 mg·L~(-1)F-处理组蝌蚪的变态率显著升高,而42.8 mg·L~(-1)F-处理组蝌蚪的变态率受到了显著抑制。此外,42.8 mg·L~(-1)F-处理组G42期蝌蚪形态指标(全长、体长和后肢长)以及骨骼发育均受到抑制。依据G42期中国林蛙蝌蚪的生长发育指标和变态率为观察指标,氟离子慢性暴露对中国林蛙蝌蚪的最低可观察效应浓度(LOEC)为0.7 mg·L~(-1)。研究表明,水环境中高浓度的氟污染会对中国林蛙蝌蚪的生长发育、变态和骨骼发育等造成潜在的不利影响,水体氟污染的生态毒性效应理应引起高度重视。