Environmental exposure to active pharmaceutical ingredients (APIs) can have negative effects on the health of ecosystems and humans. While numerous studies have monitored APIs in rivers, these employ different analytical methods, measure different APIs, and have ignored many of the countries of the world. This makes it difficult to quantify the scale of the problem from a global perspective. Furthermore, comparison of the existing data, generated for different studies/regions/continents, is challenging due to the vast differences between the analytical methodologies employed. Here, we present a global-scale study of API pollution in 258 of the world’s rivers, representing the environmental influence of 471.4 million people across 137 geographic regions. Samples were obtained from 1,052 locations in 104 countries (representing all continents and 36 countries not previously studied for API contamination) and analyzed for 61 APIs. Highest cumulative API concentrations were observed in sub-Saharan Africa, south Asia, and South America. The most contaminated sites were in low- to middle-income countries and were associated with areas with poor wastewater and waste management infrastructure and pharmaceutical manufacturing. The most frequently detected APIs were carbamazepine, metformin, and caffeine (a compound also arising from lifestyle use), which were detected at over half of the sites monitored. Concentrations of at least one API at 25.7% of the sampling sites were greater than concentrations considered safe for aquatic organisms, or which are of concern in terms of selection for antimicrobial resistance. Therefore, pharmaceutical pollution poses a global threat to environmental and human health, as well as to delivery of the United Nations Sustainable Development Goals.

Due to the erratic nature of microbial contaminants in drinking water, private and municipality water supply systems failed to deliver safe drinking water to households. In Ethiopia, there is lack of data and knowledge on the effectiveness of filter devices used to treat drinking water at household. This study aims to evaluate efficiency of household point of use filter devices (membrane filter, membrane with activated carbon, ceramic candle type filter and hybrid (multistage)) in reducing bacterial contaminants from drinking water. Percent reduction efficiency model was employed in evaluating bacterial removal efficiency. Membrane filter and membrane with activated carbon filter devices had good total coliform removal efficiency on the 1st and 2nd days than hybrid filter device which showed low removal efficiency. Similarly, all filter devices showed better fecal coliform removal efficiency on the 1st day compared to 2nd day but had low heterotrophic bacteria removal efficiency during the three days filtration. Fecal Streptococcus removal efficiency on the 2nd and 3rd days by all filter devices was low except the first day. The result in general showed that using of point of use filter devices for prolonged time could not guarantee in providing risk free drinking water at household level.

Understanding ecology of microbiomes in drinking water distribution systems is the most important notion in delivering safe drinking water. Despite cultivation-based methods routinely employed in monitoring drinking water quality, cultivation of specific indicator organisms alone is not always guarantee for assuring safe drinking water delivery. The presence of complex microbiomes in drinking water distribution systems affects treatment effectiveness leading to poor quality water which as a result affects health of human and animals. Drinking water treatment and distribution systems harbor various microbiota despite efforts made in improving water infrastructures and several waterborne diseases become serious problems in the water industry, specially, in developing Countries. Intermittent water supply, long-time of water storage, low water pressure in distribution systems, storage tankers and pipes as well as contaminated source water are among many of the factors responsible for low drinking water quality which in turn affecting health of people. The aim of this study was to explore microbial diversity and structure in water samples collected from source water, treated water, reservoirs, and several household points of use locations (taps). High throughput Illumina sequencing technology was employed by targeting V4 region of 16S rRNA following Illumina protocol to analyze the community structure of bacteria. The core dominating taxa were Proteobacteria followed by Firmicutes, Bacteroidetes and Actinobacteria. Gamma proteobacteria were dominant among other Proteobacterial classes across all sampling points. Opportunistic bacterial genera such as Pseudomonas, Legionella, Klebsiella, Escherichia, Actinobacteria, as well as eukaryotic microbes like Cryptosporidium, Hartmanella, Acanthamoeba, Aspergillus, and Candida were also the abundant taxa found along the distribution systems. The shift in microbial community structure from source to point of use locations were influenced by factors such as residual free chlorine, intermittent water supply and long-time storage at the household. The shift in microbial community structure from source to point of use locations were influenced by factors such as residual free chlorine, intermittent water supply and long-time storage at the household. The complex microbiota which was present in different sample sites receiving treated water from the two treatment plants (Legedadi and Gefersa) starting from source water to household point of consumption across the distribution systems in Addis Ababa brings drinking water quality problem which further causes significant health problems to both human and animal health. Treatment ineffectiveness, disinfection inefficiency, poor maintenance actions, leakage of sewage and other domestic wastes are few among many other factors responsible for degraded drinking water quality in this study putting health at high risk which, this, leads to morbidity and mortality. Findings of this research provide important and bassline information to understand the microbial profiles of drinking water along source water and distribution systems.

BackgroundUnderstanding ecology of microbiomes in drinking water distribution systems is the most important notion in delivering safe drinking water. Despite cultivation-based methods routinelyemployed in monitoring drinking water quality, cultivation of specific indicator organisms alone is not always guarantee for assuring safe drinking water delivery. The presence of complex microbiomes in drinking water distribution systems affects treatment effectiveness leading to poor quality water which as a result affects health of human and animals. Drinking water treatment and distribution systems harbor various microbiota despite efforts made in improving water infrastructures and several waterborne diseases become serious problems in the water industry, specially, in developing Countries. Intermittent water supply, long-time of water storage, low water pressure in distribution systems, storage tankers and pipes as well as contaminated source water are among many of the factors responsible for low drinking water quality which in turn affecting health of people. The aim of this study was to explore microbial diversity and structure in water samples collected from source water, treated water, reservoirs, and several household points of use locations (taps). High throughput Illumina sequencing technology was employed by targeting V4 region of 16S rRNA following Illumina protocol to analyze the community structure of bacteria. ResultsThe core dominating taxa were Proteobacteria followed by Firmicutes, Bacteroidetes and Actinobacteria. Gamma proteobacteria were dominant among other Proteobacterial classes across all sampling points. Opportunistic bacterial genera such as Pseudomonas, Legionella, Klebsiella, Escherichia, Actinobacteria, as well as eukaryotic microbes like Cryptosporidium, Hartmanella, Acanthamoeba, Aspergillus, and Candida were also the abundant taxa found alongthe distribution systems. The shift in microbial community structure from source to point of uselocations were influenced by factors such as residual free chlorine, intermittent water supply andlong-time storage at the household. The shift in microbial community structure from source to point of use locations were influenced by factors such as residual free chlorine, intermittent water supply and long-time storage at the household.ConclusionsThe complex microbiota which was present in different sample sites receiving treated water from the two treatment plants (Legedadi and Gefersa) starting from source water to household point of consumption across the distribution systems in Addis Ababa brings drinking water quality problem which further causes significant health problems to both human and animal health. Treatment ineffectiveness, disinfection inefficiency, poor maintenance actions, leakage of sewage and other domestic wastes are few among many other factors responsible for degraded drinking water quality in this study putting health at high risk which, this, leads to morbidity and mortality. Findings of this research provide important and bassline information to understand the microbial profiles of drinking water along source water and distribution systems.