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There has been a rising interest in the levels, diversity and potential impacts of yeasts in aquatic environments. Some of the species isolated from such niches are known pathogens or have pathogenic and antifungal resistance features. This deems it necessary to understand the characteristics and potential health implications of such environmental yeasts species. Studies on these subjects are limited. Most studies on aquatic yeasts have linked them to water pollution. However, the current gold standards to determine microbial pollution of water use bacteria as the main indicator organisms. Including yeasts in water quality standards may provide a different dimension on the quality of water when determining its fit-for-use properties. Pathogenic yeasts cause superficial infections or life-threatening infections, especially in immunocompromised people. Some of the yeast species isolated in recent studies were resistant to commonly used antifungal agents of clinical and veterinary relevance. With the high prevalence rate of HIV in sub-Saharan Africa, particularly in South Africa, antifungal resistance is a public concern as it poses serious medical and economic challenges. Most available studies are concerned with clinical environments only. There is, thus, a need to review the literature that also focuses on aquatic environments. [ABSTRACT FROM AUTHOR]

weight factors (WFs) were developed for surface raw water pollution indicator variables in Vaal River's Upper and Middle Vaal sub-basins, in South Africa. The overall objective was to formulate a quantifiable ranking system to indicate importance of pollutant variables given their established effects on human and environmental health. Multi-criteria decision analysis (MCDA) was applied to qualitative data that were obtained from South Africa's target water quality ranges as well as from literature which represented expert opinion. The human and environmental health effect choice sets were ranked from ito 5 on nine pollutant variable criteria: NH3/NH4+, Cl-, conductivity (EC), dissolved oxygen (Do), pH, F, NO3-/NO2-, PO43- and SO42-. The weighted-sum method (WSM) then assigned highest and lowest normalised weights (NWs) to F- and Cl-, respectively, for human health effects (ϵhh) alternative. Highest and lowest NWs were assigned to NH3/NH4+ and EC, respectively, for environmental health effects (ϵhh) alternative. After aggregating the ϵhh and ϵeh WFs, resultant values ranked the variables from highest to lowest as follows: F-> NO3-/NO2->/NH3/NH4+>DO> pH>SO42->PO43-> EC>Cl-. The results represented the importance of variables given their established effects on human and environmental health. It was concluded that WFS provided a quantifiable barometer which could signal harmful exposure to elucidate negative effects of using polluted surface raw water in the study area. The values could be incorporated into water quality models like water quality indices. The approach could be used to develop WFs for other sites, taking into account issues like the site's pollution variables of concern as well as using a ranking key constructed from established literature. [ABSTRACT FROM AUTHOR]