source contamination
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Water Policy ◽  
2021 ◽  
Author(s):  
Tula M. Ngasala ◽  
Susan J. Masten ◽  
Stephen P. Gasteyer

Abstract There is an urgent need to address the challenges of inadequate safe water and proper sanitation in peri-urban communities in low-income countries. Agencies have tended to focus on a single aspect of the challenge for service delivery, which ultimately fails to capture the full scope of the problem. In this study, 63 household surveys and 15 key informant interviews were conducted in a peri-urban area of Dar es Salaam, Tanzania, regarding water and sanitation issues. Results revealed that 87% of households experience water scarcity issues. More than 50% of the homes were surrounded by swampy areas with sewage and stagnant pools, with 40% reporting water source contamination due to seepage and overflowing of sewage collection systems. Key informants reported water scarcity and poor water quality due to poor sanitation practices and a compromised water supply network. We found that a highly integrated approach that invests in cultural, social, political, human, financial, and built community capitals is needed to address these challenges. To accomplish this, the community must feel empowered and believe that they have control over their situation in ways that will effectively protect their health.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sean W. D. Turner ◽  
Jennie S. Rice ◽  
Kristian D. Nelson ◽  
Chris R. Vernon ◽  
Ryan McManamay ◽  
...  

AbstractDrinking water supplies of cities are exposed to potential contamination arising from land use and other anthropogenic activities in local and distal source watersheds. Because water quality sampling surveys are often piecemeal, regionally inconsistent, and incomplete with respect to unregulated contaminants, the United States lacks a detailed comparison of potential source water contamination across all of its large cities. Here we combine national-scale geospatial datasets with hydrologic simulations to compute two metrics representing potential contamination of water supplies from point and nonpoint sources for over a hundred U.S. cities. We reveal enormous diversity in anthropogenic activities across watersheds with corresponding disparities in the potential contamination of drinking water supplies to cities. Approximately 5% of large cities rely on water that is composed primarily of runoff from non-pristine lands (e.g., agriculture, residential, industrial), while four-fifths of all large cities that withdraw surface water are exposed to treated wastewater in their supplies.


Author(s):  
Simon R Dicker ◽  
Elia S Battistelli ◽  
Tanay Bhandarkar ◽  
Mark J Devlin ◽  
Shannon M Duff ◽  
...  

Abstract Compact sources can cause scatter in the scaling relationships between the amplitude of the thermal Sunyaev-Zel’dovich Effect (tSZE) in galaxy clusters and cluster mass. Estimates of the importance of this scatter vary – largely due to limited data on sources in clusters at the frequencies at which tSZE cluster surveys operate. In this paper we present 90 GHz compact source measurements from a sample of 30 clusters observed using the MUSTANG2 instrument on the Green Bank Telescope. We present simulations of how a source’s flux density, spectral index, and angular separation from the cluster’s center affect the measured tSZE in clusters detected by the Atacama Cosmology Telescope (ACT). By comparing the MUSTANG2 measurements with these simulations we calibrate an empirical relationship between 1.4 GHz flux densities from radio surveys and source contamination in ACT tSZE measurements. We find 3 per cent of the ACT clusters have more than a 20 per cent decrease in Compton-y but another 3 per cent have a 10 per cent increase in the Compton-y due to the matched filters used to find clusters. As sources affect the measured tSZE signal and hence the likelihood that a cluster will be detected, testing the level of source contamination in the tSZE signal using a tSZE selected catalog is inherently biased. We confirm this by comparing the ACT tSZE catalog with optically and X-ray selected cluster catalogs. There is a strong case for a large, high resolution survey of clusters to better characterize their source population.


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1507
Author(s):  
Laura Delgado-Moreno ◽  
Pieter van Dillewijn ◽  
Rogelio Nogales ◽  
Esperanza Romero

The continued discharge of pharmaceuticals and personal care products (PPCPs) into the environment due to their widespread use and the lack of effective systems for their removal from water is a global problem. In this study, the dissipation of ibuprofen, diclofenac and triclosan added simultaneously in biopurification systems (BPSs) with different compositions and their effect on the microbial community structure was analysed. Three BPSs, constituted by mixtures of soil (S), peat (P), or raw wet olive mill cake (A) or its vermicompost (V) and straw (S) were prepared (SPS, SAS and SVS). Sorption and degradation experiments were carried out. After 84 days of incubation, more than 85% of each PPCP applied had dissipated. Methyl-triclosan was determined to be highest in the SVS biomixture. Biomixtures with lower C/N ratio and higher alpha diversity were the most effective in the removal of PPCPs. Initially, the BPS biomixtures showed a different microbial structure dominated by Proteobacteria, Actinobacteria and Bacteroidetes but after addition of PPCPs, a similar pattern was observed in the relative abundance of the phylum Chloroflexi, the class Sphingobacteriia and the genus Brevundimonas. These biopurification systems can be useful to prevent point source contamination due to the disposal of PPCP-contaminated waters.


2021 ◽  
Vol 9 (3) ◽  
pp. 301-308
Author(s):  
W.A. Adewole ◽  
A.R. Ayoade ◽  
O.A Olaniyi ◽  
O.E Oladapo

The study examined the water sanitation facilities utilization among the rural households of south west Nigeria. The study specifically described the socio-economic characteristics of the rural household heads; identified various sources of water supply and their providers; examined the rural household heads’ knowledge of water source contamination; examined respondents’ awareness of adequate water treatment methods and the awareness of waterborne disease. The population of the study comprised of all the rural households in Ondo and Oyo States in Southwestern of Nigeria. The sampling procedure employed was multistage sampling technique to select 355 household heads comprising a total of 167 rural household considered out of 278 rural households from the selected cells in Oyo state while a total of 188 rural household heads selected out of 314 rural household heads from the selected cells in Ondo State for the study. The data for the study were analyzed with descriptive statistics such as frequency count, percentage, mean and standard deviation while inferential statistical tool such as logistic regression analysis model The mean age of the respondents from Ondo State was 47 years while that of respondents from Oyo State was 45 years. Rain water collection was the major source of improved water supply from Ondo State (87.4%) and Oyo State (86.7%). In both Ondo and Oyo States, the knowledge of water source contamination is still on moderate level. Households in Ondo State (WMS = 2.98) and Oyo State (WMS = 2.91) were more aware of boiling of water as the major adequate water treatment methods. In both states, the awareness of adequate water treatment methods is still on moderate level. In both States, the awareness of water-borne diseases is still on moderate level, majority had favourable attitude towards utilization of water sanitation facilities while the level of utilization of water sanitation facilities is still on moderate level. The result of the Regression analysis model indicated that years of schooling (t=-3.758***; p=0.000) and households’ size (t=-2.089**; p=0.037) were significantly related to utilization of water sanitation facilities.       It was therefore concluded that the utilization of water sanitation facilities was influenced by income level, knowledge of water source contamination, awareness of adequate water treatment methods, awareness of water-borne diseases, household size. The local council being the agency saddled with water provision, should be more empowered in terms of resources and facilities in order to be able to do their work of water provision and water sanitation information dissemination effectively


Author(s):  
Juan Zhang ◽  
Gang Li ◽  
Mingyu Ge ◽  
Christian Kirsch ◽  
Maximilian Lorenz ◽  
...  
Keyword(s):  

2020 ◽  
Vol 44 (1) ◽  
Author(s):  
Kome Otokunefor ◽  
Blessing O. Famakin ◽  
Dorothy O. Douglas

Abstract Background Fomites have long been known to play a key role in the spread of disease causing agents. Hospital-associated fomites in particular have been linked with transmission of members of the Enterococci sp which are key human pathogens. Few studies have explored the role non-hospital door handles might play as potential sources of these isolates. This study therefore set out to explore this role. Results A total of hundred toilet and office door handles in a tertiary institution in Rivers State, Nigeria, were sampled using the swab and rinse method. The presence and drug susceptibility of Enterococcus was determined using the selective bile esculin agar (BEA) and standard microbiological methods. Growth on BEA was observed in 71% of cases, with more growth (38/50, 76%) observed from toilet door handles. Only 35% of samples produced the characteristic black pigmentation associated with Enterococcus sp. Six different bacterial groups were identified from this subset with Enterococcus sp. making up only 14% (5/35) of the isolates. All (100%) Enterococci were isolated from toilet door handles. Antibiotic susceptibility testing revealed very high levels of resistance (80–100%) against 75% of the test antibiotics. An analysis of the antibiotic resistance pattern of each isolate revealed 11 unique antibiogram patterns. Only 2 of these patterns were associated with the enterococci, with majority (4/5) exhibiting resistance to Augmentin (AUG), Ceftazidime (CAZ), Ceftriaxone (CTR), Cefuroxime (CRX), Cloxacillin (CXC), Erythromycin (ERY), Gentamicin (GEN), Ofloxacin (OFL) (antibiogram of AUG–CAZ–CRX–CTR–CXC–ERY). None of the enterococci, however, was resistant to vancomycin. Conclusion This study reports low level contamination of door handles by enterococci. Identical antibiogram patterns linked with majority of the enterococci could however point at the occurrence of a single clone perhaps indicating single source contamination. Reports of high levels of ampicillin resistance among these isolates are problematic as ampicillin–gentamicin combination is the treatment of choice for nosocomial enterococci pathogens.


2020 ◽  
Vol 51 (1) ◽  
pp. 03-04
Author(s):  
Leon Kirk

Eutrophication is an overall contamination issue, when the directresource contamination is proficiently unnatural; contamination load from non-point foundation has the expanding extent in the complete burden. The investigation on non-point foundation contamination is a significant perspective in the exploration on water condition contamination. The nonpoint source contamination, highlighted by broad inclusion, dynamic intricacy and troublesome evaluation of precise spatial area and release degree, is a solution and troublesome concern for the investigation of water condition contamination. In this magazine, an improved fare co-efficient strategy is projected to gauge non-point foundation contamination load in watersheds, same thinking about the impacts of precipitation and the decrease of toxin during the time spent vehicle. The measures of downpour and overflow are enormous in soaked years, so the non-point foundation contamination heaps created are huge too in different years, the non-point foundation contamination loads are fewer a direct result of less precipitation in typical water years. Non-point resource contamination factors are investigated, for example, precipitation, land use, landscape, geography and soil P speciation in farmland soil tests in forest soil tests, and in orchardland soil tests.


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