Adherence to Point-of-Use Water Treatment over Short-Term Implementation: Parallel Crossover Trials of Flocculation-Disinfection Sachets in Pakistan and Zambia.

The health benefits of point-of-use (POU) water treatment can only be realized through high adherence: correct, consistent, and sustained use. We conducted parallel randomized, longitudinal crossover trials measuring short-term adherence to two single-use flocculant-disinfectant sachets in Pakistan and Zambia. In both trials, adherence declined sharply for both products over the eight week surveillance periods, with overall lower adherence to both products in Zambia. There was no significant difference in adherence between the two products. Estimated median daily production of treated water dropped over the crossover period from 2.5 to 1.4 L person-1 day-1 (46% decline) in Pakistan and from 1.4 to 1.1 L person-1 day-1 (21% decline) in Zambia. The percentage of surveillance points with detectable total chlorine in household drinking water declined from 70% to 49% in Pakistan and rose marginally from 28% to 30% in Zambia. The relatively low and decreasing adherence observed in this study suggests that these products would have provided little protection from waterborne disease risk in these settings. Our findings underscore the challenge of achieving high adherence to POU water treatment, even under conditions of short-term adoption with intensive follow-up

Burden of disease from inadequate water, sanitation and hygiene in low- and middle-income settings: a retrospective analysis of data from 145 countries

objective To estimate the burden of diarrhoeal diseases from exposure to inadequate water, sanitation and hand hygiene in low- and middle-income settings and provide an overview of the impact on other diseases. methods For estimating the impact of water, sanitation and hygiene on diarrhoea, we selected exposure levels with both sufficient global exposure data and a matching exposure-risk relationship. Global exposure data were estimated for the year 2012, and risk estimates were taken from the most recent systematic analyses. We estimated attributable deaths and disability-adjusted life years (DALYs) by country, age and sex for inadequate water, sanitation and hand hygiene separately, and as a cluster of risk factors. Uncertainty estimates were computed on the basis of uncertainty surrounding exposure estimates and relative risks. results In 2012, 502 000 diarrhoea deaths were estimated to be caused by inadequate drinking water and 280 000 deaths by inadequate sanitation. The most likely estimate of disease burden from inadequate hand hygiene amounts to 297 000 deaths. In total, 842 000 diarrhoea deaths are estimated to be caused by this cluster of risk factors, which amounts to 1.5% of the total disease burden and 58% of diarrhoeal diseases. In children under 5 years old, 361 000 deaths could be prevented, representing 5.5% of deaths in that age group. conclusions This estimate confirms the importance of improving water and sanitation in low- and middle-income settings for the prevention of diarrhoeal disease burden. It also underscores the need for better data on exposure and risk reductions that can be achieved with provision of reliable piped water, community sewage with treatment and hand hygiene

Assessing the impact of drinking water and sanitation on diarrhoeal disease in low- and middle-income settings: Systematic review and meta-regression

Objective: To assess the impact of inadequate water and sanitation on diarrhoeal disease in low- and middle-income settings. Methods: The search strategy used Cochrane Library, MEDLINE & PubMed, Global Health, Embase and BIOSIS supplemented by screening of reference lists from previously published systematic reviews, to identify studies reporting on interventions examining the effect of drinking water and sanitation improvements in low- and middle-income settings published between 1970 and May 2013. Studies including randomised controlled trials, quasi-randomised trials with control group, observational studies using matching techniques and observational studies with a control group where the intervention was well defined were eligible. Risk of bias was assessed using a modified Ottawa-Newcastle scale. Study results were combined using meta-analysis and meta-regression to derive overall and intervention-specific risk estimates. Results: Of 6819 records identified for drinking water, 61 studies met the inclusion criteria, and of 12 515 records identified for sanitation, 11 studies were included. Overall, improvements in drinking water and sanitation were associated with decreased risks of diarrhoea. Specific improvements, such as the use of water filters, provision of high-quality piped water and sewer connections, were associated with greater reductions in diarrhoea compared with other interventions. Conclusions: The results show that inadequate water and sanitation are associated with considerable risks of diarrhoeal disease and that there are notable differences in illness reduction according to the type of improved water and sanitation implemented

Sedimentology and Stratigraphy

Exam paper for first semeste

From joint thinking to joint action: a call to action on improving water, sanitation, and hygiene for maternal and newborn health.

Yael Velleman and colleagues argue for stronger integration between the water, sanitation, and hygiene (WASH) and maternal and newborn health sectors. Please see later in the article for the Editors' Summary

The implications of three major new trials for the effect of water, sanitation and hygiene on childhood diarrhea and stunting: a consensus statement

BACKGROUND: Three large new trials of unprecedented scale and cost, which included novel factorial designs, have found no effect of basic water, sanitation and hygiene (WASH) interventions on childhood stunting, and only mixed effects on childhood diarrhea. Arriving at the inception of the United Nations' Sustainable Development Goals, and the bold new target of safely managed water, sanitation and hygiene for all by 2030, these results warrant the attention of researchers, policy-makers and practitioners. MAIN BODY: Here we report the conclusions of an expert meeting convened by the World Health Organization and the Bill and Melinda Gates Foundation to discuss these findings, and present five key consensus messages as a basis for wider discussion and debate in the WASH and nutrition sectors. We judge these trials to have high internal validity, constituting good evidence that these specific interventions had no effect on childhood linear growth, and mixed effects on childhood diarrhea. These results suggest that, in settings such as these, more comprehensive or ambitious WASH interventions may be needed to achieve a major impact on child health. CONCLUSION: These results are important because such basic interventions are often deployed in low-income rural settings with the expectation of improving child health, although this is rarely the sole justification. Our view is that these three new trials do not show that WASH in general cannot influence child linear growth, but they do demonstrate that these specific interventions had no influence in settings where stunting remains an important public health challenge. We support a call for transformative WASH, in so much as it encapsulates the guiding principle that - in any context - a comprehensive package of WASH interventions is needed that is tailored to address the local exposure landscape and enteric disease burden

A geochemical and micro-textural comparison of basalt-hosted chalcedony from the Jurassic Drakensberg and Neoarchean Ventersdorp Supergroup (Vaal River alluvial gravels), South Africa

South African basalt-hosted chalcedonies provided an ideal case study, to (a) achieve information about the origin of mineral-forming fluids, the process of chalcedony formation and weathering alteration and (b) to verify if the geochemical and micro-textural characterization of chalcedony allowed multiple provenances to be distinguished. For the first time, Drakensberg chalcedonies from the Karoo Jurassic basalts and Windsorton chalcedonies from the alluvial environment of the Vaal River (traversing the Allanridge basaltic-andesitic lavas) were investigated by optical microscopy, laser ablation inductively coupled plasma mass spectroscopy and isotope ratio mass spectrometry (O-16, O-18). The results showed that the compositional differences observed in Drakensberg and Windsorton chalcedonies could not be explained by changes in host rocks composition. The tholeiitic basaltic-andesitic lavas of the Allanridge Formation (Pniel Group, comparison term for Windsorton samples) and the tholeiitic basaltic-andesitic lavas of the Golden Gate Unit (Drakensberg Group, comparison term for Drakensberg specimens) proved to be very similar, also in terms of alteration degree. Conversely, both geochemical and oxygen isotope compositions clearly supported a relatively low temperature, hydrothermal origin for all the investigated chalcedonies, further indicating that differences mostly occurred during their formation (fluid circulation). Moreover, several characteristics suggested deposition in non-equilibrium conditions, although oxidizing conditions were most likely. Weathering processes were effective in the alluvial environment only, leading to a wider compositional heterogeneity of Windsorton chalcedonies with respect to Drakensberg samples. Lastly, a correlation between color and chromophores (Fe and Mn) amounts was lacking while a correlation between the geochemical composition and the texture was clearly observed in several specimens

The National Heritage Resource Act (1999): Can legislation protect South Africa's rare geoheritage resources?

In South Africa, rare geological specimens are protected by the National Heritage Resource Act (1999). These portable geoheritage objects are neither defined nor described in this Act making their geoheritage status questionable. Thirteen categories and criteria for establishing a geological specimen's rarity status are discussed and include (1) rarity as defined by abundance per se; (2) rarity of a particular habit (external shape or form) of a mineral; (3) rare pseudomorphs; (4) rarity of a particular variety of a mineral; (5) rarity of a particular colour of a common mineral; (6) rarity defined by size; (7) rarity defined by quality; (8) a common species, but rare for a particular locality; (9) rarity of associations of minerals; (10) rarity determined by source being depleted, exhausted or mined out; (11) rare inclusions in minerals; (12) previously rare, now common specimens and (13) miscellaneous criteria that produce rare specimens. Geological specimens (resources) are complex objects when defining their rarity status and multiple rarity factors can apply to single specimens. A lack of clear criteria for defining rare geological specimens appears to place the National Heritage Resource Act (1999) in direct conflict with the more recent Mineral and Petroleum Resources Development Act (2002) which legitimizes the legal exploitation of any mineral resource.Heritage resources Legislation Rare geological specimens