Assessment of long term changes in levels of biogenic substances and their amount, with regard to water yield and intensity of anthropogenic activity, in the water of different hydrological areas of Lithuania. Comparative analysis of methods for calculation of biogenic substance flows. Establishment of possibility to reduce frequency of water sampling. ATV-DVWk water quality model was for the first time in Lithuania used for forecasting of the changes in the water quality in the longitudinal profile of a river. / Biogeninių medžiagų kaitos upių vandenyje tyrimai ir įvertinimas.

INTRODUCTION: More than 2.2 million people die each year from diarrheal disease. Most cases of diarrheal disease can be linked with a lack of access to clean water and sanitation. The proper usage of sanitation, hygiene and safe drinking water are all mechanisms by which to prevent or limit fecal contamination, and in turn, reduce the risk of diarrheal disease. As a result, it is imperative to examine and understand risk factors for fecal contamination of drinking water in the home. One way to assess fecal contamination is to use indicator bacteria such as E. coli. These bacteria can be easily measured and have been weakly associated with increased risk of gastrointestinal illness. PURPOSE: The purpose of this study was to determine if characteristics of household drinking water storage containers impacted the concentration of total coliforms and E. coli in the stored household drinking water in rural Dominican Republic communities. METHODS: The data were collected through a cross-sectional survey and from a four month prospective cohort study in rural communities in the Dominican Republic during 2005. Data analysis was conducted using STATA 10. Descriptive statistics were calculated and reported as percentages. Bivariate statistics were carried out to test independent associations between container characteristics and E. coli. In addition, t-tests were used to examine differences in concentrations of E. coli and total coliforms as well as other household and water characteristics that may play an important role in household drinking water management and practice and contamination. RESULTS: After testing independent potential risk factors for E. coli contamination, it was determined that household storage practices have a significant impact on drinking water quality. More specifically, households that stored drinking water in containers with narrow openings (typically < 2 inches in diameter) had lower concentrations of E. coli. The water was more likely to remain protected from additional contamination once stored in the home. DISCUSSION: The association with household storage practices with E. coli contamination reveals the importance of point of drinking water management in the home. Specifically, we documented simple storage practices (commonly practiced in homes in the Dominican Republic) that can protect or reduce drinking water from contamination once in the home. While previous literature has been unable to identify a single most important risk factor of E. coli contamination in drinking water, findings from this study and previous studies indicate that more research is needed to further elucidate the role of household drinking water storage techniques in protecting household members and reducing risk of disease.

Background: 884 million people do not have access to clean water, which is a potential contributor to diarrhea (JMP, 2010). The purpose of this study was to examine the potential associations between the occurrence of diarrhea and the levels of turbidity, total coliforms, and Escherichia coli (E. coli), in 185 households in Bonao, Dominican Republic in 2005-2006. Methods: A biweekly water quality dataset and a weekly diarrhea occurrence dataset were merged using three different methods. T-tests and odds ratios were calculated for all three different datasets. Multivariate logistic regression was also conducted. Results: There were 430 cases of diarrhea out of 14,245 observations. In the age-adjusted multivariate logistic regression, turbidity (OR = 1.36; p-value = .012) and total coliforms (OR = .842; p-value = .006) were found to be significant for an association with the occurrence of diarrhea. E. coli was not found to be significant for an association. Conclusions: This study strengthens the evidence supporting a positive association between turbidity and the occurrence of diarrhea. This study also showed a negative association between total coliforms and diarrhea. Future studies are needed to clarify these associations.

Viena svarbiausių aplinkosauginių problemų Lietuvoje yra paviršinių vandenų kokybė. Šiame darbe įvertinta Plungės rajono Nausodžio seniūnijos Varkalių gyvenvietės nuotekų bei taškinių taršos šaltinių įtaka drenažo vandenų kokybei bei paviršinių vandenų būklės atitiktis didžiausioms leistinoms teršalų koncentracijoms. Tyrimų objektas pasirinktas remiantis gyventojų skundai (2 ir 3 priedai), pateiktais žemės ūkio skyriui, dėl užterštos melioracijos sistemos išvalymo. Šioje gyvenvietėje gyvena apie 1277 gyventojų, didžioji dalis jų ūkinės veiklos nevykdo, o apie 40 % - ūkininkauja. Vyrauja smulkūs ūkiai, kurių pagrindinė šaka - gyvulininkystė. Natūriniai tyrimai pradėti vykdyti 2008 m., balandžio mėn., baigti - 2009 m., sausio mėn. Kas 40 – 45 paras dviejuose sausinimo sistemos vietose buvo imami vandens ištekančio iš sausinimo sistemos mėginiai ir ištirti 6 parametrai: vandens rūgštingumo reakcija pH, Nbendr, NH4-N, NO2-N, NO3-N, PO4-P. Pirmoji mėginių ėmimo vieta pasirinkta arčiau gyvenvietės pačioje sistemos pradžioje ties ištakomis, kur, manoma, ir yra pagrindiniai taršos šaltiniai, o antroji - prie sausinimo sistemos žiočių Mažosios Sruojos upelyje, šiek tiek aukščiau Varkalių tvenkinio. Ši parinkta tam, kad būtų galima nustatyti kokios kokybės vanduo patenka į paviršinių vandens telkinius. Tiriamųjų parametrų nustatymui bandiniai tirti LŽŪU Aplinkotyros laboratorijoje tirti jonometriniu ir spektrofotometrinės analizės metodu, atitinkančiu ISO standartus. Tirtieji mėginių... [toliau žr. visą tekstą] / One of the most important environmental problems in Lithuania is the surface water quality. This thesis evaluated waste water and other pollution influence of drainage water quality and surface waters accordance with the maximum concentrations of pollutants in Plunge district, Varkaliai village The object of research was selected in accordance with complaints from the population, by the agricultural department of contaminated drainage system. In this village lives about 1277 person. About 40%, of population are farmers. Prevailing small farms, whose main industry – stock-raising The investigation was launched in April of 2008, and finished in January of 2009,. Every 40 - 45 days, in two place of drainage systems, were taken water samples effluent from the drainage system and investigated 6 parameters: the water acidity pH, Ntotal, NH4-N, NO2-N, NO3-N, PO4-P. The first testing place was selected closer to the village in the headwater of the system , where supposedly is, the main sources of pollution, and the second - to the outfall of drainage system in the river Mazoji Sruoja, slightly above Varkalių pond. This was chosen in order to determine what quality of water access in the surface water. The water sample was investigated in LŽŪU environmental laboratory by the ionimetric and the spectrophotometer method of analysis conforming to ISO standards. Investigated characteristics of samples were compared and interdependence of the individual substances is determined using a... [to full text]

The aim of the research – to investigate and evaluate the criteria for water use and reuse, and to develop a model for effective management of water resources in industry.

The objective is to develop river basin management model that ensures integrated analysis of existing water resource problems and promotes implementation of sustainable development principles in water resources management.

Aim of study: to evaluate microbiological quality of drinking water according Lithuanian drinking water standard HN 24:2003. Material and methods. The data of microbiological tests of drinking water were collected from laboratories responsible of drinking water control in Kaunas region. Part of the study was carried out at Helsinki University (dep. of Food and Environmental Hygiene). Different microbiological criteria of drinking water samples from small community supply were examined. Results. The results of our study showed that 94.4 % of drinking water from centralist drinking water supplies in Lithuania fulfill requirements of drinking water standard HN 24:2003 and is safe to drink. Drinking water from dug wells more often are contaminated and does not fit drinking water standard requirements. We found that there were too much coliforms in 12,8 % of drinking water samples, enterococci in 23.4% and E. coli in 16.7 % respectively. The study showed that there is a season variation of microbiological quality of drinking water. Less microbiological contamination of dinking water samples was during winter season from both water supply systems - centralist drinking water supplies and small community supplies. Microbiological quality of drinking water in Lithuania from small community supplies was worse compare to drinking water from small community supplies in Finland. The average of E.coli bacteria in Lithuanian drinking water from small community supplies was 5.57±2,09/10... [to full text]

Work object – Vyžuona river, which has 26 km lenght, is left affluent of Šventoji river, belongs to subbasin of Šventoji river and runs from northeast to southwest of Lithuania. Work aim – identify water quality and bounded with it live organisms of Vyžuona river. Work tasks – analyse physical-chemical water parameters of Vyžuona river, identify varietal composition of organisms, define and evaluate contamination of river objects. Work results – After the reasearch was made there was defined that Vyžuona river in Utena town (1 km from Krašuona river and Vieša river junction) belongs to average contaminated rivers category measuring by parameters of water quality: common nitrogen quantity 1.9 times exceeds permissible quotas, 68.6 % of common nitrogen is composed of nitrate nitrogen, BDS7 quantity 2,7 times exceeds the LDK, concentration of phosphates 2.3 times exceeded permissible quotas. Krašuona river and Vieša river runs trough private houses section, which has no central sewer and that is the reason why mentioned rivers are bearing domestic contaminants into Vyžuona river. According to 2004-2006 data below the outlet from drain mechanism of UAB „Utenos vandenys“ refinement system there was found concentration of phosphorus which averagely 1,75 times, common nitrogen 1,1 times and BDS7 1,7 times less in comparison with river part in centre of Utena town above UAB „Utenos vandenys“. That may be explained by UAB „Utenos vandeys“ affect, which drains large amount of enough... [to full text]

Endocrine disruption and high occurrences of intersex have been observed in wild fish associated with wastewater treatment plant (WWTP) effluents in the urbanized reaches of the Grand River watershed located in southern Ontario, Canada. WWTP effluent is a complex matrix with diverse aquatic environmental contaminants and stressors. This study aimed to: (1) characterize the spatio-temporal distribution and fate of antiandrogenic personal care products (triclosan, chlorophene, and dichlorophene), along with selected pharmaceuticals (carbamazepine, ibuprofen, naproxen, and venlafaxine) and the herbicide, atrazine in the Grand River watershed and (2) model the behaviour of these contaminants in the aquatic environment. Water sampling of 29 sites which covered six municipal WWTPs and ~100 km of river length was completed during summer low flows (July 2012). Monthly samples were also collected immediately upstream and downstream of a major WWTP (Kitchener) from August to November 2012. Many of the target pharmaceuticals and triclosan were detected in WWTP effluents in the Grand River watershed, especially those that did not nitrify (minimal treatment with high ammonia). Chlorophene was either undetected or was only found at trace levels in the effluents. Under low flow conditions, triclosan and several other pharmaceuticals exhibited a spatial pattern where concentrations increased directly downstream of the WWTPs, then decreased with distance downstream (dilution and/or degradation). Chlorophene, in contrast, was not found downstream of most of the WWTP outfalls but was first detected at a site 5 km upstream of a WWTP and then continued with relatively constant concentrations for approximately 29 km downstream. It was also only found during the summer sampling period. Atrazine was consistently found in all sampling locations which reflected the agricultural non-point source nature of this compound. The WASP 7.5 model (US Environmental Protection Agency) was adapted and calibrated to a reach of the Grand River associated with the Kitchener WWTP. The simulation of the fate and transport of the target compounds revealed that flow-driven transport processes (advection and dispersion) greatly influence their behaviour in the aquatic environment. However, fate mechanisms such as biodegradation and photolysis also potentially play an important role in the attenuation of most compounds. The exception was carbamazepine where it was shown to act as a conservative tracer compound for wastewater specific contaminants in the water phase. The fate model developed can be applied in the future to predict the fate of a wide variety of contaminants of emerging concern across the watershed to help define the exposure of these biologically active chemicals to sensitive ecosystems.

Waterborne pathogen presence caused by fecal pollution is a leading cause of morbidity and mortality worldwide. In developed countries, this problem can result in waterborne outbreaks. Research suggests that there is a need for better fecal indicators because current methods (total coliforms and E. coli) are insufficient. This study investigated Bacteroidales 16S rRNA markers as a microbial source tracking tool in an agricultural watershed. Correlations between pathogens and markers were also investigated. Water quality monitoring was conducted following assay validation of ruminant-, bovine-, human-specific, and universal Bacteroidales markers. Results revealed a positive relationship between E. coli and the universal marker. Ruminant- and bovine-specific marker detection was associated with increased runoff due to precipitation; however, the human associated marker was not detected. Furthermore, no correlations between Campylobacter, Salmonella, or E. coli O157:H7 could be made. Consequently, these techniques have potential to become a powerful tool; however, further research is needed