922 resultados para Drinking-water surveillance
Resumo:
To investigate the neurotoxic effects of aluminium (Al) Al was administered: 1) in the diet of the rat (30 mg Al/kg body weight for 6 weeks); 2) as a suspension of aluminium acetate in drinking water of the rat for 3 months and 3) in a long-term study in the mouse in which aluminosilicates were incorporated into a pelleted diet (1035 mg/kg of food over 23 months). In the latter treatment, increased Al was combined with a reduction in calcium and magnesium; a treatment designed to increase absorption of Al into the body. Administration of Al in the drinking water significantly reduced total brain biopterins and BH4 synthesis. However, no significant affect of Al in the diet on total biopterins or BH4 synthesis was found either in the rat or in the long-term study in the mouse. In addition, in the mouse no significant effects of the Al diet on levels of noradrenaline, serotonin, dopamine, 5-HIAA or CAT could be demonstrated. Hence, the occurrence of brain alterations may depend on the Al species present and the method of administration. Al salts in drinking water may increase brain tissue levels compared with the administration of a more insoluble species. Since alterations in biopterin metabolism are also a feature of Alzheimer's disease (AD) these results support the hypothesis that Al in the water supply may be a factor in AD.
Resumo:
To investigate the neurotoxic effects of aluminium (Al) three studies were carried out in which Al was administered: 1) in the diet, 2) as a suspension of aluminium acetate in drinking water and 3) a long-term study in which aluminosilicates were incorporated into a pelleted diet. Admistration of Al in the drinking water significantly reduced total brain biopterin. However, no significant affect of Al in the diet on total bipterins or BH4 synthesis was found.
Resumo:
This paper analyzes the performance of Dutch drinking water utilities before and after the introduction of sunshine regulation, which involves publication of the performance of utilities but no formal price regulation. By decomposing profit change into its economic drivers, our results suggest that, in the Dutch political and institutional context, sunshine regulation was effective in improving the productivity of publicly organised services. Nevertheless, while sunshine regulation did bring about a moderate reduction in water prices, sustained and substantial economic profits suggest that it may not have the potential to fully align output prices with economic costs in the long run. In methodological terms, the DEA based profit decomposition is extended to robust and conditional non-parametric efficiency measures, so as to account better for both uncertainty and differences in operating environment between utilities.
Resumo:
Rwanda is a landlocked country located in Africa's Central-East Great Lakes region. It has a population of 7.5 million which occupies 26,338 km'. Its population density (285/km') is one of the highest in the world and has prompted fear of a rapid degradation of the ecosystem. There are no central sewer systems in Rwanda. The use of pit latrines and septic tanks is common in urban and rural areas. People still defecate in the fields (World Bank, 1989). Less than half of the urban population is served by a central water supply. The majority of people get their water untreated from rivers that have been polluted by chemicals and human excreta. In and around the capital city of Kigali, there is a concentration of people, farms, and industries which discharge wastewater into the Nyabarongo River and its tributaries. The Nyabarongo River, a tributary of the Nile, empties into the Akagera River which flows into Lake Victoria. Nyabarongo River water is used for drinking water, cooking, bathing, and agriculture in the Kigali area. There has been very little monitoring of the water quality of the Nyabarongo River and of industrial outfalls located on tributaries of the Nyabarongo River. As a first step in understanding the water quality of the Nyabarongo River, wastewater samples were collected in 1993 from industrial outfalls located on tributaries of the Nyabarongo River. Most of the facilities sampled had no wastewater treatment. The impact of these discharges on the water quality of the Nyabarongo River was evaluated.
Resumo:
This report contains information about Iowa's public drinking water program for the calendar year 2015. Included in the report are descriptions of Iowa's systems, monitoring and reporting requirements of the systems, and violations incurred during the year. This report meets the federal Safe Drinking Water Act's requirement of an annual report on violations of national primary drinking water regulations by public water supply systems in Iowa.