[Systematic sanitation of dairy herds with mastitis caused by Staphylococcus aureus]

Several strategies are known for sanitizing dairy herd problems caused by Staphylococcus (S.) aureus. They mostly consist of general management measures but specific decision-making at an individual animal level has not been described. A sanitation program in the form of a process chart developed by the Bern Clinic for Ruminants was undertaken in 10 dairy herds with this problem. In an affected herd the cows were divided into 3 groups: healthy, suspect, infected. Three milk samples (MS), taken at two-week intervals were cultivated. The cows were grouped according to the culture results. To measure the success of the sanitation program, the key figures <> (target < 150,000 SCC/ml) and <> (limit: 150'00 SCC/ml, target < 20 %) were used. These were compared with the corresponding key figures from dairy herds, which were followed-up by the Bern Clinic for Ruminants (control herds). The problem herd sanitation program lasted between 2 and 21 months. A total of 1598 MS were analyzed, of which 241 (15 %) were S. aureus positive (15 %). At the end of the sanitation the key figures between problem herds and control herds were similar. The sanitation program has proved to be practical. The detection of S. aureus positive cows proved to be reliable and the udder health of the herd could be significantly improved.

Arsenic and selenium mobilisation from organic matter treated mine spoil with and without inorganic fertilisation

Organic matter amendments are applied to contaminated soil to provide a better habitat for re-vegetation and remediation, and olive mill waste compost (OMWC) has been described as a promising material for this aim. We report here the results of an incubation experiment carried out in flooded conditions to study its influence in As and metal solubility in a trace elements contaminated soil. NPK fertilisation and especially organic amendment application resulted in increased As, Se and Cu concentrations in pore water. Independent of the amendment, dimethylarsenic acid (DMA) was the most abundant As species in solution. The application of OMWC increased pore water dissolved organic-carbon (DOC) concentrations, which may explain the observed mobilisation of As, Cu and Se; phosphate added in NPK could also be in part responsible of the mobilisation caused in As. Therefore, the application of soil amendments in mine soils may be particularly problematic in flooded systems.

Sanitation in developing countries: A review through a gender lens

Sanitation has evolved from a purely technical discipline to one that includes social, environmental, economic and, increasingly, gender considerations. However, blurry notions of gender are frequently offered in the sanitation literature. Although it has been recognized that gender-responsive sanitation does not mean ‘toilets for women’, substantial alternatives are rarely debated. We structure our review of sanitation in developing countries along three lines: we start by fine-tuning the concept of gender both from the academic and the practitioner's perspective, analyse relevant developments in gender-specific policies and programming, and finally review the most appropriate toilet room and menstrual hygiene technologies. We argue that strategies to make technologies gender-responsive need to be based upon a thorough analysis of the social arrangements of the intimate, and how these are negotiated and institutionalized in a specific context. A lack of robust gender-segregated data on sanitation policies and technologies, along with reductionist framings of gender are to blame for limited progress in verifying the need for, and impact of, gender-responsive sanitation. Technology and policy development and implementation would benefit from gender-considerate interpretations of shame, dignity, safety and status. Further progress could be achieved by improving the translation process between different academic framings of the sanitation crisis. Keywords: appropriate technology; development; gender; menstrual hygiene management (MHM); sanitation

Assessing the Environmental Hazard of Using Seawater for Ore Processing at the Lasail Mine Site in the Sultanate of Oman

The Lasail mining area (Sultanate of Oman) was contaminated by acid mine drainage during the exploitation and processing of local and imported copper ore and the subsequent deposition of sulphide-bearing waste material into an unsealed tailings dump. In this arid environment, the use of seawater in the initial stages of ore processing caused saline contamination of the fresh groundwater downstream of the tailings dump. After detection of the contamination in the 1980s, different source-controlled remediation activities were conducted including a seepage water collection system and, in 2005, surface sealing of the tailings dump using an HDPE-liner to prevent further infiltration of meteoric water. We have been assessing the benefits of the remediation actions undertaken so far. We present chemical and isotopic (δ18O, δ 2H, 3H) groundwater data from a long-term survey (8–16 years) of the Wadi Suq aquifer along a 28 km profile from the tailings dump to the Gulf of Oman. Over this period, most metal concentrations in the Wadi Suq groundwater decreased below detection limits. In addition, in the first boreholes downstream of the tailings pond, the salinity contamination has decreased by 30 % since 2005. This decrease appears to be related to the surface coverage of the tailings pond, which reduces flushing of the tailings by the sporadic, but commonly heavy, precipitation events. Despite generally low metal concentrations and the decreased salinity, groundwater quality still does not meet the WHO drinking water guidelines in more than 90 % of the Wadi Suq aquifer area. The observations show that under arid conditions, use of seawater for ore processing or any other industrial activity has the potential to contaminate aquifers for decades.

Redox front geochemistry and weathering: theory with application to the Osamu Utsumi uranium mine, Poços de Caldas, Brazil

Numerical calculations describing weathering of the Poços de Caldas alkaline complex (Minas Gerais, Brazil) by infiltrating groundwater are carried out for time spans up to two million years in the absence of pyrite, and up to 500,000 years with pyrite present. Deposition of uranium resulting from infiltration of oxygenated, uranium bearing groundwater through the hydrothermally altered phonolitic host rock at the Osamu Utsumi uranium mine is also included in the latter calculation. The calculations are based on the quasi-stationary state approximation to mass conservation equations for pure advective transport. This approximation enables the prediction of solute concentrations, mineral abundances and porosity as functions of time and distance over geologic time spans. Mineral reactions are described by kinetic rate laws for both precipitation and dissolution. Homogeneous equilibrium is assumed to be maintained within the aqueous phase. No other constraints are imposed on the calculations other than the initial composition of the unaltered host rock and the composition of the inlet fluid, taken as rainwater modified by percolation through a soil zone. The results are in qualitative agreement with field observations at the Osamu Utsumi uranium mine. They predict a lateritic cover followed by a highly porous saprolitic zone, a zone of oxidized rock with pyrite replaced by iron-hydroxide, a sharp redox front at which uranium is deposited, and the reduced unweathered host rock. Uranium is deposited in a narrow zone located on the reduced side of the redox front in association with pyrite, in agreement with field observations. The calculations predict the formation of a broad dissolution front of primary kaolinite that penetrates deep into the host rock accompanied by the precipitation of secondary illite. Secondary kaolinite occurs in a saprolitic zone near the surface and in the vicinity of the redox front. Gibbsite forms a bi-modal distribution consisting of a maximum near the surface followed by a thin tongue extending downward into the weathered profile in agreement with field observations. The results are found to be insensitive to the kinetic rate constants used to describe mineral reactions.