Pollution status of the Yellow River tributaries in middle and lower reaches.

SARS-CoV-2, the etiologic agent of COVID-19, is shed in stool. SARS coronaviruses have been detected in wastewater during outbreaks in China, Europe, and the United States. In this perspective, we outline the risk fecal shedding poses at locations without safely managed sanitation, as in most of Nigeria where we work. We believe that feco-oral transmission could occur if community transmission becomes high and sustained in densely populated cities without proper sanitation in Nigeria and many other African and Asian settings. In the absence of basic sanitation, or where existing sanitation is not safely managed, groundwater, which is often drawn up from wells and boreholes for drinking and household use, can become contaminated with enteric bacteria and viruses from fecal matter. Endemic and epidemic transmission of multiple feco-oral pathogens via this route continues to be documented in areas without safely managed sanitation, and, therefore, the risk of SARS-CoV-2 transmission needs to be evaluated, tracked, and forestalled in such settings. We suggest that fecal matter from treatment facilities and recovered patients should be carefully and properly disposed. Furthermore, environmental surveillance of SARS-CoV-2 in wastewater and accumulated human waste, as well as efforts to mitigate the virus' entry into unprotected household water sources, should be a priority part of the COVID-19 response in settings without safely managed sanitation for the duration of the pandemic.

/pdf/could-water-and-sanitation-shortfalls-exacerbate-sars-cov-2-2y7wq6lkpq.pdf

Could Water and Sanitation Shortfalls Exacerbate SARS-CoV-2 Transmission Risks?

Ultraviolet LEDs are one of the most promising technologies for preventing future pandemics, improving health outcomes, and disinfecting water sources. Currently available UV LEDs emitting in the conventional germicidal wavelength range (254 nm – 285 nm) have efficiencies below 5% and cost about 100 times more (per watt) than mercury vapor lamps. On the other hand, germicidal UV LEDs provide many advantages over vapor lamps including instant-on and dimmable functionality, wavelength tunability, miniaturization, and durability, and are already in widespread use for certain applications. It is expected that III-nitride based UV LEDs will soon have similar cost and efficiency to white LEDs and will become the dominant germicidal light source within this decade. Unlike vapor discharge lamps, LEDs have theoretical efficiency limits approaching 100%; the challenges to improving UV LED efficiency are not fundamental, but technological. Improvements in material quality, chemical purity, electrical conductivity, optical transparency, and fabrication technologies are needed. In this review, we outline the major challenges in each of these areas and summarize the recent advances that have enabled rapid improvements in UV LED efficiency within the past five years. We discuss the physical principles underlying the mechanisms of improved efficiency, and comment on likely future trends in UV LED design and commercialization.

Germicidal ultraviolet LEDs: a review of applications and semiconductor technologies

THMs, HAAs and NAs production from culturable microorganisms in pipeline network by ozonation, chlorination, chloramination and joint disinfection strategies

In low resourced countries, water-associated diseases have still impact on public health. Poor quality of water can cause waterborne diseases through bacteria, viruses, protozoa, and parasites that has been responsible for millions of morbidity and mortality. Therefore, this study aimed to assess quality and safety of public municipal drinking water in Addis Ababa City. Descriptive epidemiological study design that used quantitative approach was carried out at Addis Ababa City Administration from June 2016 to October 2016. Pre-tested and standardized aseptic sample collection technique was utilized to collect a total of 2976 samples (2951 water samples for bacteriological analysis by Presence-Absence (P-A) culturing method and 25 samples for parasites identification through direct microscopy examination). Descriptive data were summarized and cleaned by the SPSS version 20 software and presented in table and graph. The study revealed that 10%, 7% and 3% were positive for bacteriological, total coliforms, and fecal coliforms respectively through Presence-Absence Broth test. The bacterial distribution trends from 1st to 13th weeks of wet season were slight increment of total coliforms and slight decrement for fecal coliforms. All tested for parasitological samples from selected reservoirs were free from parasitological species. This study reflects that there were positive for bacterial, total coliforms, and fecal coliforms during the study period. It needs continuous screening and treating water sources to utmost important for prevention and control waterborne disease.

/pdf/quality-and-safety-of-municipal-drinking-water-in-addis-2wh4oyu91v.pdf

Quality and safety of municipal drinking water in Addis Ababa City, Ethiopia

Bacterial contamination of drinking water is a major public health problem in rural areas of sub-Saharan Africa. Unimproved water sources are a major reservoir of Escherichia coli (E. coli) causing severe diarrhoea in humans. This study assessed E. coli counts in drinking water from different sources and their relationship with water source protection status and neighbourhood sanitation and hygiene practices in rural villages of Mohale Basin in Lesotho. Thirty drinking water sources were purposively sampled and their water analysed for E. coli counts. The types of water sources, their protection status and neighbourhood sanitation and hygiene practices in their proximity were also assessed. E. coli counts in water samples were compared to water source protection status, neighbourhood sanitation, hygiene practices, livestock faeces and latrine proximity to water sources. E. coli counts were found in all water samples and ranged from less than 30 colony-forming units (cfu)/100 ml to 4800 cfu/100 ml in protected sources to 43,500,000 cfu/100 ml in unprotected sources. A significant association between E. coli counts in drinking water samples and lack of water source protection, high prevalence of open defecation (59%, n = 100), unhygienic practices, livestock faeces and latrine detections in proximity to water sources was found in the study (P < 0.05). Water sources in studied villages were contaminated with faeces and posed a health risk to consumers of that water. Community-led sanitation and hygiene education and better water source protection are urgently needed.

/pdf/bacterial-contamination-of-drinking-water-sources-in-rural-2v0jz28fdy.pdf

Bacterial contamination of drinking water sources in rural villages of Mohale Basin, Lesotho: exposures through neighbourhood sanitation and hygiene practices

Motena Ramphalile

Papers

Bacterial contamination of drinking water sources in rural villages of Mohale Basin, Lesotho: exposures through neighbourhood sanitation and hygiene practices