Drinking water-type fluorosis is the most harmful endemic disease in China with the largest number of sufferers. Although the implementation of the policy to alter water sources to lower fluoride level has effectively...Drinking water-type fluorosis is the most harmful endemic disease in China with the largest number of sufferers. Although the implementation of the policy to alter water sources to lower fluoride level has effectively controlled the spread of this kind of endemic disease,its prevalence could not thoroughly be stopped because the high-fluoride environmental background in these endemically diseased areas could still do harm to human health through food chain. Therefore,it is necessary to conduct a more deep-going study on the drinking water-type fluoro-sis. To investigate the effect of high fluorine environmental background on crops and human health in the hot spring-type fluorosis-diseased areas,local water,paddy soil,rice,whole vegetables and soils around their roots were sampled for analysis. The results were compared with those of the control groups in fluorosis-free areas which are similar to the fluorosis-diseased areas both in natural background and in social background. It is indicated that rice and vegetables can accumulate water-soluble fluorine either in soils or in irrigating water,and different crops have different abilities of fixing fluorine. The contents of fluorine in different parts of vegetables in the fluorosis-diseased and fluorosis-free areas were statistically categorized. The results showed that the fluorine contents of roots,tubers,leaves and flowers of vegetables in the fluorosis-diseased areas are 3.56,1.17,3.07 and 3.23 mg/kg,respectively. However,comparisons showed that in the fluorosis-free areas,the fluorine contents are 2.17,0.70,1.91 and 2.52 mg/kg,respectively. Moreover,different parts of a crop also show significantly different fluorine fixation abilities. It is demonstrated that the fluorine contents of the strongly metabolic parts are relatively high. For example,the fluo-rine contents of roots,leaves and flowers of vegetables are much higher than those of stems. The fluorine fixation ability of seeds is very weak. In order to reduce the risk of human body’s exposure to fluoride,the impact of hot spring water on the capability of crops to fix fluorine should be reduced as much as possible. It is of great importance to prevent crops from being irrigated with hot spring water and it is advisable to grow crops with relatively low ca-pabilities to enrich fluorine,such as those with seeds or tubers as the main edible parts in the areas which are se-verely affected by hot spring water.展开更多
This study was carried out to investigate the impact of drainage basin’s lithostratigraphy on the quality and type of stored water in the Mujib dam reservoir. The water samples were collected on a monthly basis from ...This study was carried out to investigate the impact of drainage basin’s lithostratigraphy on the quality and type of stored water in the Mujib dam reservoir. The water samples were collected on a monthly basis from surface water from January 2012 to December 2015. The classifications of collecting water samples for domestic and irrigation purposes were based on different physico- chemical parameters such as pH, EC, TDS, TSS, Na+, K+, Ca2+, Mg2+, Cl-, SO42-, HCO3- , NH4+, NO3- , NO2- , SAR, RSC, SSP, RSBC, PI, MAR, KR, and TH. All analyzed water samples were satisfied the Jordanian permissible limit and graded as “fresh water”. The hydrochemical indices (Mg/Ca and Cl/HCO3) and Cation Exchange values (CEV), indicating that the surface water chemistry is due to the rock weathering minerals with respect to their inland origin. The water samples have complied within the respective limits in respect of pH, EC, SAR, RSC, RSBC, MAR, KR, SSP and PI, and hard in respect of TH which may be due to the dissolution of the weathered rocks. Abundance of cations and anions is in the following order: Ca > Na > Mg > K and HCO3 > SO4 > Cl > NO3 during the period 2013-2015 and SO4 > HCO3 > Cl > NO3 through 2012. Thus, calcium and bicarbonate–sulfate are the dominant ions present in the surface water of this study. Piper diagram suggested that carbonate and gypsum weathering is the dominant process controlling reservoir water chemistry in the basin area. The quality and type of surface water can be modified by the lithology of the catchment area. The hydrogeochemical study of Mujib reservoir water indicated that the water quality is safe for drinking and agricultural purposes.展开更多
Objectives: 1) To identify the hydrogeological characteristics and fluoride (F-) concentration in drinking water in the southeast of the state of Morelos, Mexico, and 2) to estimate the association between the prevale...Objectives: 1) To identify the hydrogeological characteristics and fluoride (F-) concentration in drinking water in the southeast of the state of Morelos, Mexico, and 2) to estimate the association between the prevalence and severity of fluorosis, dental caries, and water F-?concentration. Methods: A hydrogeological model was developed to determine the vertical distribution of lithostratigraphic units, rocks’ hydraulic conductivities, and groundwater flow characteristics. A total of 649 schoolchildren from two communities received oral examinations. One community was located in an area with 0.75 mg F-/L in the water supply and the other in an area with 1.6 mg F-/L. Fluorosis was assessed using the Thylstrup & Fejerskov Index (TFI) and the dental caries were assessed with the decayed, missing, and filled teeth (DMFT) index. The region groundwater was extracted from an inter-granular aquifer consisting of volcano clasts of intermediate volcanic chemical composition. Results: Oral examinations showed that 32.35% of the children had severe forms of fluorosis (TFI ≥ 4) in the community with 1.60 mg F-/L and 7.8% in the 0.75 mg F-/L community (p < 0.0001). DMFT = 0.53 (±1.28) and 0.42 (±0.95) in the community with 1.60 mg F-/L and 0.75 mg F-/L, respectively (p = 0.2259). Conclusions: The increasing extraction of underground water was associated with deeper water flows and higher F-?concentration. In the community with high F-concentration, a third of the children showed objectionable levels of fluorosis. Adequate groundwater management actions are required to reduce fluorosis risk.展开更多
基金financially supported jointly by the National Natural Science Foundation of China (Grant No.40601004)the Scientific and Technological Project of the Educa-tion Department of Jiangxi Province (No. GJJ08032)+1 种基金the K.C. Wong Education FoundationHong Kong and China’s Post-doctoral Science Funds
文摘Drinking water-type fluorosis is the most harmful endemic disease in China with the largest number of sufferers. Although the implementation of the policy to alter water sources to lower fluoride level has effectively controlled the spread of this kind of endemic disease,its prevalence could not thoroughly be stopped because the high-fluoride environmental background in these endemically diseased areas could still do harm to human health through food chain. Therefore,it is necessary to conduct a more deep-going study on the drinking water-type fluoro-sis. To investigate the effect of high fluorine environmental background on crops and human health in the hot spring-type fluorosis-diseased areas,local water,paddy soil,rice,whole vegetables and soils around their roots were sampled for analysis. The results were compared with those of the control groups in fluorosis-free areas which are similar to the fluorosis-diseased areas both in natural background and in social background. It is indicated that rice and vegetables can accumulate water-soluble fluorine either in soils or in irrigating water,and different crops have different abilities of fixing fluorine. The contents of fluorine in different parts of vegetables in the fluorosis-diseased and fluorosis-free areas were statistically categorized. The results showed that the fluorine contents of roots,tubers,leaves and flowers of vegetables in the fluorosis-diseased areas are 3.56,1.17,3.07 and 3.23 mg/kg,respectively. However,comparisons showed that in the fluorosis-free areas,the fluorine contents are 2.17,0.70,1.91 and 2.52 mg/kg,respectively. Moreover,different parts of a crop also show significantly different fluorine fixation abilities. It is demonstrated that the fluorine contents of the strongly metabolic parts are relatively high. For example,the fluo-rine contents of roots,leaves and flowers of vegetables are much higher than those of stems. The fluorine fixation ability of seeds is very weak. In order to reduce the risk of human body’s exposure to fluoride,the impact of hot spring water on the capability of crops to fix fluorine should be reduced as much as possible. It is of great importance to prevent crops from being irrigated with hot spring water and it is advisable to grow crops with relatively low ca-pabilities to enrich fluorine,such as those with seeds or tubers as the main edible parts in the areas which are se-verely affected by hot spring water.
文摘This study was carried out to investigate the impact of drainage basin’s lithostratigraphy on the quality and type of stored water in the Mujib dam reservoir. The water samples were collected on a monthly basis from surface water from January 2012 to December 2015. The classifications of collecting water samples for domestic and irrigation purposes were based on different physico- chemical parameters such as pH, EC, TDS, TSS, Na+, K+, Ca2+, Mg2+, Cl-, SO42-, HCO3- , NH4+, NO3- , NO2- , SAR, RSC, SSP, RSBC, PI, MAR, KR, and TH. All analyzed water samples were satisfied the Jordanian permissible limit and graded as “fresh water”. The hydrochemical indices (Mg/Ca and Cl/HCO3) and Cation Exchange values (CEV), indicating that the surface water chemistry is due to the rock weathering minerals with respect to their inland origin. The water samples have complied within the respective limits in respect of pH, EC, SAR, RSC, RSBC, MAR, KR, SSP and PI, and hard in respect of TH which may be due to the dissolution of the weathered rocks. Abundance of cations and anions is in the following order: Ca > Na > Mg > K and HCO3 > SO4 > Cl > NO3 during the period 2013-2015 and SO4 > HCO3 > Cl > NO3 through 2012. Thus, calcium and bicarbonate–sulfate are the dominant ions present in the surface water of this study. Piper diagram suggested that carbonate and gypsum weathering is the dominant process controlling reservoir water chemistry in the basin area. The quality and type of surface water can be modified by the lithology of the catchment area. The hydrogeochemical study of Mujib reservoir water indicated that the water quality is safe for drinking and agricultural purposes.
文摘Objectives: 1) To identify the hydrogeological characteristics and fluoride (F-) concentration in drinking water in the southeast of the state of Morelos, Mexico, and 2) to estimate the association between the prevalence and severity of fluorosis, dental caries, and water F-?concentration. Methods: A hydrogeological model was developed to determine the vertical distribution of lithostratigraphic units, rocks’ hydraulic conductivities, and groundwater flow characteristics. A total of 649 schoolchildren from two communities received oral examinations. One community was located in an area with 0.75 mg F-/L in the water supply and the other in an area with 1.6 mg F-/L. Fluorosis was assessed using the Thylstrup & Fejerskov Index (TFI) and the dental caries were assessed with the decayed, missing, and filled teeth (DMFT) index. The region groundwater was extracted from an inter-granular aquifer consisting of volcano clasts of intermediate volcanic chemical composition. Results: Oral examinations showed that 32.35% of the children had severe forms of fluorosis (TFI ≥ 4) in the community with 1.60 mg F-/L and 7.8% in the 0.75 mg F-/L community (p < 0.0001). DMFT = 0.53 (±1.28) and 0.42 (±0.95) in the community with 1.60 mg F-/L and 0.75 mg F-/L, respectively (p = 0.2259). Conclusions: The increasing extraction of underground water was associated with deeper water flows and higher F-?concentration. In the community with high F-concentration, a third of the children showed objectionable levels of fluorosis. Adequate groundwater management actions are required to reduce fluorosis risk.
