A brief and critical review on hydrofluorosis in diverse species of domestic animals in India

India is one of the fluoride-endemic countries where the maximum numbers of ground or drinking water sources are naturally fluoridated. In India, a total of 23, out of 36 states and union territories have drinking water contaminated with fluoride in varying concentration. In the present scenario, especially in rural India, besides the surface waters (perennial ponds, dams, rivers, etc.), bore wells and hand pumps are the principal drinking water sources for domestic animals such as cattle (Bos taurus), water buffaloes (Bubalus bubalis), sheep (Ovis aries), goats (Capra hircus), horses (Equus caballus), donkeys (Equus asinus) and dromedary camels (Camelus dromedarius). Out of 23 states, 17 states, namely Andhra Pradesh, Assam, Bihar, Chhattisgarh, Gujarat, Haryana, Jharkhand, Karnataka, Kerala, Madhya Pradesh, Maharashtra, Odisha (Orissa), Punjab, Rajasthan, Telangana, Uttar Pradesh and West Bengal, have fluoride beyond the maximum permissible limit of 1.0 or 1.5 ppm in drinking water. This situation is a great concern for the animal health because fluoride is a slow toxicant and causes chronic diverse serious health hazards or toxic effects. Despite the fact that domestic animals are the basic income sources in rural areas and possess a significant contributory role not only in the agriculture sector but also in the strengthening of economy as well as in sustainable development of the country, research work on chronic fluoride intoxication (hydrofluorosis) due to drinking of fluoridated water in domestic animals rearing in various fluoride-endemic states is not enough as compared to work done in humans. However, some interesting and excellent research works conducted on different aspects of hydrofluorosis in domesticated animals rearing in different states are briefly and critically reviewed in the present communication. Author believes that this review paper not only will be more useful for researchers to do some more advance research work on fluoride-induced toxicosis in different species of animals but will also be helpful in the making of health policy for domestic animals at state and national level for the mitigation of hydrofluorosis in India.     

Physico-chemical characteristics of water samples of Bantwal Taluk, south-western Karnataka, India

Quality of water is an important criterion for evaluating the suitability of water for irrigation and drinking. In the present study the analysis of water samples from different sources like open wells, bore wells, farm ponds and streams/rivers of twenty villages of Bantwal taluk of Dakshina Kannada district, South-western Kamataka has been carried out. The physico-chemical characteristics of this water showed that it is suitable for irrigation and agricultural purposes.     

郑州市农村饮用水安全评价

通过对郑州市农村饮用水安全进行了较为详细的评价.此次评价工作首先对全市每个行政村、自然村、自然片的饮水水源、饮水困难情况等进行了调查和水质抽检,共布设水质取样点255个.评价结果为:郑州市总人口为4 174 866人,饮水不安全人数为1 540 359人,占农村总人口的38.03%.饮水不安全主要是由饮用水水质引起的,包括氟水、苦咸水和污染水.水量、用水方便程度、供水保证率对其有一定的影响,但作用比较小.表2,参5.     

Zooplankton diversity and physico-chemical conditions in three perennial ponds of Virudhunagar district, Tamilnadu

Plankton diversity and physico-chemical parameters are an important criterion for evaluating the suitability of water for irrigation and drinking purposes. In this study we tried to assess the zooplankton species richness, diversity and evenness and to predict the state of three perennial ponds according to physico-chemical parameters. A total of 47 taxa were recorded: 24 rotifers, 9 copepods, 8 cladocerans, 4 ostracods and 2 protozoans. More number of zooplankton species were recorded in Chinnapperkovil pond (47 species) followed by Nallanchettipatti (39 species) and Kadabamkulam pond (24 species). Among the rotifers, Branchionus sp. is abundant. Diaphanosoma sp. predominant among the cladocerans. Among copepods, numerical superiority was found in the case of Mesocyclopes sp. Cypris sp. repeated abundance among ostracoda. Present study revealed that zooplankton species richness (R1 and R2) was comparatively higher (R1: 4.39; R2: 2.13) in Chinnapperkovil pond. The species diversity was higher in the Chinnapperkovil pond (H': 2.53; N1: 15.05; N2: 15.75) as compared to other ponds. The water samples were analyzed for temperature, pH, electrical conductivity alkalinity salinity, phosphate, hardness, dissolved oxygen and biological oxygen demand. Higher value of physico-chemical parameters and zooplankton diversity were recorded in Chinnapperkovil pond as compared to other ponds. The zooplankton population shows positive significant correlation with physico-chemical parameters like, temperature, alkalinity phosphate, hardness and biological oxygen demand, whereas negatively correlated with rainfall and salinity. The study revealed that the presence of certain species like, Monostyla sp., Keratella sp., Lapadella sp., Leydigia sp., Moinodaphnia sp., Diaptomus sp., Diaphanosoma sp., Mesocyclopes sp., Cypris sp. and Brachionus sp. is considered to be biological indicator for eutrophication.     

Arsenic in freshwater ecosystems of the Bengal delta: status,sources and seasonal variability

The study aimed to examine the contamination status of arsenic (As) in excavated small water bodies, commonly known as ponds – the integral part of daily life in the arsenic-affected rural areas of West Bengal, India in comparison to the unaffected areas. The ponds of the contaminated area had higher levels of As: water 2–174 µg L^?1 (mean 31 ± 2 µg L^?1) and sediment 1.3–37.3 mg kg^?1 (mean 10.3 ± 0.4 mg kg^?1), than those from the unaffected area: water 1–8 µg L^?1 (mean 4 ± 0 µg L^?1) and sediment 1.4–5.3 mg kg^?1 (mean 3.0 ± 0.1 mg kg^?1). A moderate positive correlation was observed between the water and sediment arsenic content of the ponds of the arsenic-affected region (r = 0.688, n = 277, p < 0.0001). Contaminated ground water, either as direct input or through agricultural washings, was found to be the major contributor of arsenic pollution to these ecosystems. Seasonal variations were not prominent. This study emphasized the beneficial role of using the studied ecosystems over the highly contaminated ground water for various livelihood activities in the Gangetic delta region.     

水生植物塘运行规律及设计参数的研究

通过对水生植物塘处理生活污水进行全年观测和研究证明：水生植物塘对有机污染物等有明显净化效果，特别是对氮、磷具有极强的降解能力。对照静态实验，提出了以磷酸盐负荷为主要水生植物塘设计参数的设计思想，提出了温度修正公式，并对其流态及数学模式进行了研究。同时，还对水生植物塘的一般运行规律进行了研究和探讨。     

Variability in the chemistry of private drinking water supplies and the impact of domestic treatment systems on water quality

Tap water from 497 properties using private water supplies, in an area of metalliferous and arsenic mineralisation (Cornwall, UK), was measured to assess the extent of compliance with chemical drinking water quality standards, and how this is influenced by householder water treatment decisions. The proportion of analyses exceeding water quality standards were high, with 65 % of tap water samples exceeding one or more chemical standards. The highest exceedances for health-based standards were nitrate (11 %) and arsenic (5 %). Arsenic had a maximum observed concentration of 440 µg/L. Exceedances were also high for pH (47 %), manganese (12 %) and aluminium (7 %), for which standards are set primarily on aesthetic grounds. However, the highest observed concentrations of manganese and aluminium also exceeded relevant health-based guidelines. Significant reductions in concentrations of aluminium, cadmium, copper, lead and/or nickel were found in tap waters where households were successfully treating low-pH groundwaters, and similar adventitious results were found for arsenic and nickel where treatment was installed for iron and/or manganese removal, and successful treatment specifically to decrease tap water arsenic concentrations was observed at two properties where it was installed. However, 31 % of samples where pH treatment was reported had pH < 6.5 (the minimum value in the drinking water regulations), suggesting widespread problems with system maintenance. Other examples of ineffectual treatment are seen in failed responses post-treatment, including for nitrate. This demonstrates that even where the tap waters are considered to be treated, they may still fail one or more drinking water quality standards. We find that the degree of drinking water standard exceedances warrant further work to understand environmental controls and the location of high concentrations. We also found that residents were more willing to accept drinking water with high metal (iron and manganese) concentrations than international guidelines assume. These findings point to the need for regulators to reinforce the guidance on drinking water quality standards to private water supply users, and the benefits to long-term health of complying with these, even in areas where treated mains water is widely available.     

Presence of metals in drinking water distribution networks due to pipe material leaching: a review

Drinking water quality should remain constant from the drinking water treatment plant to the consumer's tap. However, water quality characteristics might be affected by interactions with pipe materials. This review describes the iron, copper, lead, zinc, aluminum, chromium, and cadmium in drinking water leached from the pipe material present in drinking water, as well as the factors and mechanisms that affect leaching processes. Data analysis suggests that monitoring the water quality in distribution systems is important for their proper management; however, the low measured concentrations highlight the need for sensitive sensors. In addition, further research is necessary to anticipate possible future effects before the installation of new materials/infrastructure or changes in water source/treatment.     

Influence of fish on habitat choice of water birds: a whole system experiment

It is notoriously difficult to study population interactions among highly mobile animals that cannot be meaningfully confined to experimental plots of limited size. For example, migratory water birds are believed to suffer from competition with resident fish populations for shared food resources. While observational evidence in support of this hypothesis is accumulating, replicated experiments addressing this issue at the proper spatial scale are lacking. Here, we report from a replicated whole-system experiment in which we stocked large (0.07 km2), shallow (< or =2.5 m deep), highly eutrophic ponds in the bird protection area "Ismaninger Speichersee mit Fischteichen" with different densities of carp and assessed the responses of water birds and their food resources during summer over several years. In all years, the biomasses of benthic macroinvertebrates, macroalgae, and macrophytes as well as the densities of herbivorous, carnivorous, and omnivorous water birds were reduced in carp ponds compared to fishless ponds. The negative effects of carp on food resources and on the numbers of water birds feeding in carp ponds increased over the season (May-September) and were stronger at high than at low stocking densities of carp. Consequently, differences in resource densities between ponds with and without carp increased, and the ranking of ponds with respect to resource densities became more predictable over the season. These factors may have contributed to a seasonal improvement of the birds' abilities to track resource densities across ponds, as suggested by tight correlations of bird numbers on ponds with resource densities late, but not early, in the season.     

Health Risks Associated with Contamination of Groundwater by Abandoned Mines Near Twisp in Okanogan County, Washington, USA

Abandoned mines are known to contaminate private drinking water wells with toxic metals and arsenic (As). Little attention is given, however, to sites in rural areas with low population densities where natural, geogenic sources of contaminants might also occur. This study measured arsenic and trace element exposure among residents consuming water from wells adjacent to abandoned mines near Twisp, in Okanogan County, Washington, USA, estimated the risk of adverse health effects, and considered the degree of uncertainty associated with the assessed risk. Water samples were collected between October 1999 and June 2001. Average As concentrations ranged from <1 to 298 microg L(-1), lead (Pb) ranged from 0 to 94 microg L(-1), cadmium (Cd) 0-5 microg L(-1), and selenium (Se) 0-390 microg L(-1). Concentrations varied seasonally with maximum concentrations occurring in conjunction with snow-melt. The calculated risk of mortality from cancer following exposure to As at average concentrations as low as 8 microg L(-1) was greater than one in 10,000. Additional noncarcinogenic risks are associated with exposure to As, Cd, Pb and Se. A potentially affected population, estimated to be between 1000 and 1287 residents, live within a 6.5-km (4-mile) radius of the study site. This study emphasises the need to test drinking water wells in the vicinity of abandoned mines during times of maximum snow-melt to determine the extent of risk to human health. Residents drinking water from wells tested in this study who want to reduce the estimated carcinogenic risk and the noncarcinogenic hazard quotient should consider treating their water or find alternative sources.     

Life cycle assessment and environmental improvement of residential and drinking water supply systems in Hanoi,Vietnam

In many Asian cities the public water supply is characterised by low pressure, frequent interruptions and occasional contamination. Hence, private households have to store water and increase pressure individually to ensure an uninterrupted supply at sufficient pressure and water for drinking has to be boiled or supplied separately in bottles. In this study the present water supply system in Hanoi and a number of modification options were analysed from an environmental point of view through life cycle assessment (LCA) in order to identify the most sustainable solutions for future water supply. It was found that the boiling of water for drinking was the largest source of impacts in the present system. Impacts could be reduced significantly if the public supply network was improved and private pumping and storage could be avoided and if the water could be used directly for drinking. It was also found that impacts could be reduced if consumers used bottled water for drinking instead of boiling tap water. Finally, it was demonstrated that even if drinking water cannot be supplied directly through the public network, a reliable public water supply at high pressure is environmentally advantageous. Sensitivity analyses revealed that the conclusions of this study are likely to be applicable to other cities with similar water supply systems.     

Monitoring,mapping and health risk assessment of fluoride in drinking water supplies in rural areas of Maku and Poldasht,Iran

The aim of this study was to investigate and determine fluoride concentrations in drinking water supplies in rural areas of Maku and Poldasht in West Azerbaijan Province, the northwest of Iran. Fluorosis risk assessment and characterization was also investigated. Fluoride concentrations mapping was accomplished by using the GIS system. Totally, 356 water samples, including one sample in each season, were collected from 89 water supplies providing water for 95 and 61 rural areas of Maku and Poldasht, respectively. According to the results, in Maku and Poldasht, 25 and 30 rural areas had contaminated water sources, respectively. Average annual fluoride concentrations ranged from 3.04 to 7.31 mg/l in the contaminated villages of Maku, which is about 2–4.8 times higher than the maximum standard level of the Iranian drinking water standard, and 4.52–8.21 mg/l in the contaminated areas of Poldasht, which is about 3–5.47 times higher than the maximum standard level. The maximum fluoride level was determined 11.12 mg/l and 10.98 mg/l in one of villages of Maku and Poldasht Counties in summer, respectively. Neither in Maku nor in Poldasht, water resources showed dental cavity risk, while dental fluorosis risk and skeletal fluorosis risk were very significant in some villages of both cities. Children were at most risk of fluorosis. New alternative water supplies for the contaminated villages if possible, consumption of bottled water and application of reverse osmosis are recommended as remedial actions in the contaminated areas.

     

Improved source,improved quality? Demand for drinking water quality in rural India

This paper tests the hypothesis that the expansion of improved drinking water supplies in rural India reduced household expenditure on water quality, offsetting some of the quality benefits from source protection. I estimate demand for in-home treatment using geological characteristics to predict a household's drinking water source. The probability of treatment and in particular boiling reduces by 18–27 percentage points in response to source protection, offsetting 4% of the water quality gains and saving households 0.5–1% in monthly expenditure. Behavioral choices partly counteract the water quality gains from source protection.     

Improved source,improved quality? Demand for drinking water quality in rural India

This paper tests the hypothesis that the expansion of improved drinking water supplies in rural India reduced household expenditure on water quality, offsetting some of the quality benefits from source protection. I estimate demand for in-home treatment using geological characteristics to predict a household's drinking water source. The probability of treatment and in particular boiling reduces by 18–27 percentage points in response to source protection, offsetting 4% of the water quality gains and saving households 0.5–1% in monthly expenditure. Behavioral choices partly counteract the water quality gains from source protection.     

Giving respondents time to think in contingent valuation studies: A developing country application

This paper evaluates whether the time given people to think about their responses to CVM valuation questions influences their answers. Our study was conducted in Nigeria as part of an evaluation of rural households' willingness to pay for public taps and private connections to improved drinking water systems. Respondents who were allowed time to evaluate the proposed water system bid significantly less than those who did not have that time. Moreover, this conclusion was upheld regardless of whether the water system was a public tap or a private connection.     

Response of stormwater retention basins to two chemical aquatic weed control methods

The City of Winnipeg, Canada has 70 stormwater retention basins (SRBs) whose primary function is to act as land-drainage, storage reservoirs within the city. The ponds often become choked with vegetation and this disenchants property owners who have been led to believe, by subdivision developers, that the ponds are pristine ‘lakes’. The City has implemented some control measures to help alleviate customer dissatisfaction by removing vegetation using the herbicides Karmex-DF and Reglone-A. For this study, in order to evaluate herbicide control methods, water quality was assessed on 10 occasions, biweekly over the 5 months of a Canadian summer (May to September), on 37 of the SRBs. Various water quality parameters were determined, including total suspended solids (TSS), chlorophyll-a, turbidity, transparency, ammonia, nitrate, orthophosphate, temperature, dissolved oxygen, and pH. By comparing the water quality data resulting from the two aquatic weed control measures, it was established that neither herbicide method seemed to be as effective as the natural ability of the ponds to limit vegetative growth. It is suggested that utilization of the herbicide as a long-term aquatic weed control measure should therefore proceed with caution and perhaps, other alternative methods of control could also be investigated.     

Partikelentfernung in der Trinkwasseraufbereitung: Problematiken und Lösungsansätze

The drinking water treatment plant (WTP) in Irsch-Treves is one of the WTPs operated by the Public Utility Company of Treves (SWT) responsible for supplying the city of Treves with drinking water. This treatment plant has been responsible for the treatment of raw, soft water from the oligotrophic reservoir Riveris since 1958. The main functions of the WTP are the removal of particulate matter, manganese, iron, aluminium and organic material, especially humic substances. The removal of particulate matter such as bacteria, other microorganisms and plankton is very important to ensure a microbiologically and hygienically stable drinking water. Insufficient removal of particulate manganese may lead to manganese scaling in the supply system and, in extreme conditions, may lead to a brown-coloured drinking water. The so called Multi-Barrier-System is being used in the entire water treatment process. Under this system, great importance is given to the monitoring of the catchment area, the inflows, and the reservoirs. After a preliminary and subsequent sedimentation and biological treatment in the preliminary and in the main reservoirs respectively, the raw water is finally treated through flocculation filtration over the rapid multi-layer sand filters in the WTP Irsch. With this approach, only a rigid application of the above mentioned steps and the application of the latest recognized technology to maintain the supply system can best guarantee a constant supply of clean drinking water. Online particle count in raw water and in drinking water is one of the main quality control measures applied in the WTP Irsch. The conventional flocculation filtration is not always able to fulfil the increasing quality demands for drinking water, especially during adverse raw water quality conditions. This is the reason why more and more membrane filtration units are currently being installed in completely new plants, as substitutes in conventional plants, or for upgrade purposes. The SWT is currently planning an enlargement and upgrade of the WTP Irsch, integrating ultrafiltration, which was successfully tested in a pilot study. The upgrade of the elimination of particulate matter is one of the most important targets, after the enlargement and upgrade of the plant.     

Environmental issue of exotic catfish culture in Uttar Pradesh

A survey was conducted in Uttar Pradesh to enlist the available exotic fish species in culture. The culture and feeding details of unofficially introduced Clarias gariepinus was collected from 419 ponds existing in rural areas of 23 districts of Uttar Pradesh. The data indicated that 32% ponds were culturing exotic fishes of which 79% cases are of monoculture of exotic African catfish. Feeding analysis of these exotic African catfish revealed that 7% cases subsist on natural pond feed while 29% cases are fed on slaughter house waste. In 32% cases of the exotic magur monoculture, chicken waste was given whereas 11% cases were recorded with fish waste feeding. The possible threats and environmental risks of such unauthorised and indiscreminate culture of exotic magur has been discussed in this paper.     

Contamination status of arsenic,lead, and cadmium of different wetland waters

The present investigation was conducted to determine the contamination status of arsenic (As), cadmium (Cd), and lead (Pb) in the wetland waters of Bhaluka in Bangladesh. Water samples were collected from 15 selected wetlands of Bhaluka region and analyzed using an atomic absorption spectrophotometer. Estimated results of three metals detected were As (7–80?µg?L^?1), Pb (0–86?µg?L^?1) and Cd (0–70?µg?L^?1) in water samples in all wetlands. The level of As in all investigated wetlands (93%) was higher than that of WHO recommended permissible limit of drinking water except Alanga wetland. However, As levels were higher than that recommended for livestock water quality levels. Eighty-seven percent of the investigated wetlands showed lower content of Pb than WHO recommended permissible limit of drinking water, but two wetland waters (Dohuria-1 and Chowdhuri) were polluted with higher Pb levels. Sixty-seven percent of the investigated wetlands displayed higher levels of Cd than WHO recommended permissible limit in drinking water. Dissolved organic material showed no significant difference among the 15 investigated wetlands water, but total dissolved solids was significantly greater. The condition of the water of all wetlands was basic pH. All water samples were applied to linear regression equation and correlation coefficients where values showed no significant differences. Data demonstrate that the estimated high metal concentrations of these ponds may contribute to bioaccumulation within plants, food grains and shrimp.     

A red water occurrence in drinking water distribution systems caused by changes in water source in Beijing,China: mechanism analysis and control measures

A red water phenomenon occurred in several communities few days after the change of water source in Beijing, China in 2008. In this study, the origin of this problem, the mechanism of iron release and various control measures were investigated. The results indicated that a significant increase in sulphate concentration as a result of the new water source was the cause of the red water phenomenon. The mechanism of iron release was found that the high-concentration sulphate in the new water source disrupted the stable shell of scale on the inner pipe and led to the release of iron compounds. Experiments showed that the iron release rate in the new source water within pipe section was over 11-fold higher than that occurring within the local source water. The recovery of tap water quality lasted several months despite ameliora- tive measures being implemented, including adding phosphate, reducing the overall proportion of the new water source, elevating the pH and alkalinity, and utilizing free chlorine as a disinfectant instead of chloramine. Adding phosphate was more effective and more practical than the other measures. The iron release rate was decreased after the addition of 1.5 mg. L-1 orthophosphate- P, tripolyphosphate-P and hexametaphosphate-P by 68%, 83% and 87%, respectively. Elevating the pH and alkalinity also reduced the iron release rate by 50%. However, the iron release rate did not decreased after replacing chloramine by 0.5-0.8 mg. L-1 of free chlorine as disinfectant.