17 research outputs found

    The magnetic after-effect in pure iron at elevated temperatures

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    Pit Latrines and Their Impacts on Groundwater Quality: A Systematic Review

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    Background: Pit latrines are one of the most common human excreta disposal systems in low-income countries, and their use is on the rise as countries aim to meet the sanitation-related target of the Millennium Development Goals. There is concern, however, that discharges of chemical and microbial contaminants from pit latrines to groundwater may negatively affect human health. Objectives: Our goals were to a) calculate global pit latrine coverage, b) systematically review empirical studies of the impacts of pit latrines on groundwater quality, c) evaluate latrine siting standards, and d) identify knowledge gaps regarding the potential for and consequences of groundwater contamination by latrines. Methods: We used existing survey and population data to calculate global pit latrine coverage. We reviewed the scientific literature on the occurrence of contaminants originating from pit latrines and considered the factors affecting transport of these contaminants. Data were extracted from peer-reviewed articles, books, and reports identified using Web of Science(SM), PubMed, Google, and document reference lists. Discussion: We estimated that approximately 1.77 billion people use pit latrines as their primary means of sanitation. Studies of pit latrines and groundwater are limited and have generally focused on only a few indicator contaminants. Although groundwater contamination is frequently observed downstream of latrines, contaminant transport distances, recommendations based on empirical studies, and siting guidelines are variable and not well aligned with one another. Conclusions: In order to improve environmental and human health, future research should examine a larger set of contextual variables, improve measurement approaches, and develop better criteria for siting pit latrines

    The State of South African Cities a Decade after Democracy

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    a vision of an inclusive non-racial city in which democracy is stable and development flourishes. But the 2004 report is different from preceding urban policy statements in a number of critical respects, not least that it is not a formal statement of government. In part, the relative autonomy of the Report’s sponsor, the South African Cities Network (a quango of state and non-state affiliates), explains its divergent analytical point of departure in the assessment of the state of the cities 10 years after democracy. The 2004 report is premised on the notion that changing the racial pattern of inequality hinges on systematic responses to the material forces, demographic, economic, environmental and institutional, that shaped the inherited apartheid city form. The 2004 report is also different from earlier government policy positions in that it argues that urban development is not just a site of national reconstruction and development, but that the urban question lies at the heart of achieving the national vision of a productive, democratic and non-racial society based on a vision of sustainable human settlements
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