Distribution of enteric bacteria in Antarctic seawater surrounding the Port-aux-Français permanent station (Kerguelen Island)

Untreated sewage has been released from Port-aux Fran?ais station, Kerguelen Island, into the Southern Ocean for more than 50 years. We investigated the spatial distribution of faecal bacteria indicators during a one-year survey conducted in seawater off Morbihan Bay near the French permanent station of the Kerguelen Island (49 degrees 21(')S, 70 degrees 30(')E). Seawater samples were taken bimonthly from nine stations evenly distributed around the sewage outfalls of the station. Escherichia coli and enterococci were estimated using specific microplates (Miniaturized method for the enumeration of E. coli or enterococci in surface and waste waters, "MU/EC or MU/SF methods", BIO-RAD( Copyright)). In order to evaluate the role of seasonal changes of environmental parameters on the survival of enteric bacteria, total and saprophytic bacterial abundances were also estimated in all seawater samples. High densities of faecal bacteria (maximum 10(4) cells 100 ml(-1)) were found in seawater surrounding the sewage outfall. However, enteric bacterial counts decreased rapidly with increasing distance from the outfall. In all samples collected further than 2 km from the outfall, the bacterial indicators were absent or present in small numbers (<10 cells 100 ml(-1)). Faecal coliforms were not detected in samples collected at pristine sites located 10 km from Port-aux-Fran?ais. Despite these low contamination levels, faecal bacteria were always detected in the vicinity of the sewage outfall during the seasonal survey. The concentration of faecal bacteria may be related to the number of people inhabiting the station.     

Prevalence and diversity of norovirus genogroups I and II in Hong Kong marine waters and detection by real-time PCR

Marine waters from six sites around Hong Kong with varying levels of sewage pollution were examined for noroviruses (NoVs) by PCR cloning and sequencing of a highly-variable N-terminal region of the VP1 capsid gene, at the ORF1-ORF2 junction of NoV. Phylogenetic analysis of genogroups GI- and GII-specific PCR clones obtained from different marine sites indicated that human NoV GI.1 and GII.4 strains are the most prevalent genotypes circulating in Hong Kong waters. GI- and GII-specific TaqMan-based real-time PCR assays targeting the ORF1-ORF2 junction of NoVs were used to quantify NoV particles in marine water samples in parallel with total Escherichia coli counts which were enumerated on TBX medium. No correlation of any significance between NoV and E. coli counts was observed which highlighted the inadequacy in using E. coli as a fecal indicator to predict the level of NoVs in marine waters to protect public health.     

Microbiological and physicochemical analysis of the coastal waters of southern Brazil

The aim of this study was to assess the impact of sewage discharge on coastal waters by evaluating the influence of physicochemical parameters on the presence of enteric microorganisms in seawater samples collected from 11 beaches in Florianopolis, Santa Catarina, Brazil, over a one-year period (August 2009 to July 2010). Samples were assessed for the presence of human adenoviruses (HAdV), polyomavirus (JCPyV), hepatitis A virus (HAV), and noroviruses (HuNoV GI and GII). Escherichia coli and physicochemical parameters (salinity, temperature, pH and dissolved oxygen) were also evaluated. From the 132 samples analyzed, 55% were positive for HAdV, 51.5% for HAV, 7.5% for HuNoV GI, 4.5% for HuNoV GII, and 3% for JCPyV. E. coli levels ranged from 8 to 1325 CFU/100mL at all sites. The overall results highlight the problem of sewage discharge into coastal waters and confirm that there is no correlation between viral presence and bacterial contamination.     

Caesium-137 soil sampling and inventory variability in reference locations: A literature survey

Soil sampling design, the number of samples collected and the lateral variation of caesium-137 (¹³⁷Cs) in uneroded reference locations were extracted from previously published work. The focus was on published work which used ¹³⁷Cs reference inventory (Bq m⁻²) for qualitative or quantitative estimation of sediment redistribution (SRD) within the landscape. The objective of this study was to address one of the methodological concerns facing the ¹³⁷Cs technique—that is, the lack of a rigorous statistical treatment of reference locations. The limited attention paid to the reference location is not justified as ‘true’ estimates of SRD are based on the assumption of an unbiased, independent, random probability sample estimate, commonly the arithmetic mean. Results from the literature survey indicated that only 11% of the reference locations sampled for ¹³⁷Cs expressly stated that a probability sampling design was used (transect or systematic-aligned grid). The remaining locations were generally sampled using a non-probability based design, more commonly known as haphazard sampling. Of the 75 reference study areas identified only 40 provided enough information to determine the dispersion around the mean, and from this the coefficient of variation (CV) was calculated for all available data. The median CV was 19·3%, with 95% confidence limits of 13·0–23.4%, indicating that approximately 11 random, independent samples would generally be necessary to adequately quantify the reference ¹³⁷Cs area activity with an allowable error of 10% at 90% confidence. Further analysis indicated that only one-third of the studies sampled a sufficient number of ¹³⁷Cs reference locations. This value would actually be lower as sampling frameworks were based on non-probability sampling procedures. For ¹³⁷Cs reference locations it is recommended that a probability sampling design be utilized, preferably the systematic-aligned grid method, and as a minimum first-order estimate about 11 samples should be collected for inventory estimates.     

Comparison of Enterococcus density estimates in marine beach and bay samples by real-time polymerase chain reaction, membrane filtration and defined substrate testing

Currently, densities of Enterococcus in marine bathing beach samples are performed using conventional methods which require 24 h to obtain results. Real-time PCR methods are available which can measure results in as little as 3 h. The purpose of this study was to evaluate a more rapid test method for the determination of bacterial contamination in marine bathing beaches to better protect human health. The geometric mean of Enterococcus densities using Enterolert® defined substrate testing and membrane filtration ranged from 5.2 to 150 MPN or CFU/100 mL and corresponding qPCR results ranged from 6.6 to 1785 CCE/100 mL. The regression analysis of these results showed a positive correlation between qPCR and conventional tests with an overall correlation (r) of 0.71. qPCR was found to provide accurate and sensitive estimate of Enterococcus densities and has the potential to be used as a rapid test method for the quantification of Enterococcus in marine waters.     

An electrochemical RNA hybridization assay for detection of the fecal indicator bacterium Escherichia coli

Monitoring waters for indicator bacteria is required to protect the public from exposure to fecal pollution. Our proof-of-concept study describes a method for detecting fecal coliforms. The coliform Escherichia coli was used as a model fecal indicator. DNA probe-coated magnetic beads in combination with the electrochemical monitoring of the oxidation state of guanine nucleotides should allow for direct detection of bacterial RNA. To demonstrate this concept, we used voltammetry in connection with pencil electrodes to detect isolated E. coli 16S rRNA. Using this approach, 10(7) cells of E. coli were detected in a quantitative, reproducible fashion in 4h. Detection was achieved without a nucleic acid amplification step. The specificity of the assay for coliforms was demonstrated by testing against a panel of bacterial RNA. We also show that E. coli RNA can be detected directly from cell extracts. The method could be used for on-site detection and shows promise for adaptation into automated biosensors for water-quality monitoring.     

Estrogen equivalent concentration of individual isomer-specific 4-nonylphenol in Ariake sea water, Japan

Concentrations of 4-nonylphenol (NP) were determined by isomer-specific quantification of individual NP isomers based on relative response factor (RRF) quantification with GC–MS in combination with steam distillation extraction. Concentrations of NP in the Ariake Sea decreased with distance from the river mouth (St.A; 49 ng NP/l) to offshore areas (St.C; 11 ng NP/l). Even the least concentration in water from St.C in Ariake Sea was sufficient to have adverse effects on barnacles. The isomers, NP1–NP14 were separated by GC–PFC and identified structurally with NMR. The isomers varied in estrogenic activity with NP7 exhibiting the greatest estrogenic activity with a potency that was approximately 1.9 × 10⁻³ that of 17β-estradiol (E2) in recombinant yeast screen system. The coefficient of variation (CV) of NP isomer’s concentrations among three samples at St.A, B and C were 4–75%. This suggests that NP isomers might be independently degraded in aquatic environmental samples. The predicted estrogenic activity of measured concentrations of NP in Ariake Sea was 2.7–3.0-fold greater than the measured estrogen agonist activity.     

VELOCITY DISPERSION OF SEISMIC WAVES*

In well velocity surveys made to calibrate Sonic (CV) Logs the calibration survey uses frequencies around 50 Hz whereas the Sonic Logging tool uses frequencies around 20 kHz. There thus exists the possibility of making a direct measure of velocity dispersion. In any one survey the disturbing factors, both instrumental and operational, will often mask any dispersive effect that might exist. Consequently this paper reports on a statistical analysis of the velocity differences resulting from calibration surveys and Sonic logs. Only Borehole Compensated Sonic Logs were used. Four areas were investigated: the North Sea, Abu Dhabi, Libya and Alaska. After rejecting logs and calibration records which were obviously in error there remained 424000 feet (about 130 km) of usable log distributed throughout 66 wells. The four areas were analysed separately and in no case was the estimated dispersion significantly different from zero. However, the mean values did correlate with lithology from (? 0.17 ± 0.18)% for the essentially carbonate section in Abu Dhabi to (+ 0.45 ± 0.25)% for the sand-shale section in Alaska, a positive sign meaning that the higher frequencies travelled faster. Except for Alaska the calibration surveys were made with a wall-clamp geophone, and for these areas amplitude measurements were made. After suitable corrections estimates of the absorption parameter Q were obtained. These varied from 20 to 200 with mean values of 63 for Libya, 70 for Abu Dhabi and 88 for the North Sea (excluding the Tertiary). If, as is usually assumed, the absorption mechanism is linear and is described by a Q which is independent of frequency, then these values would necessarily imply dispersion of several percent. As instanced above no such dispersion was observed. It is possible that the expected dispersion was compensated for by invasion of the mud filtrate into the borehole walls, but it is more likely that the absorption mechanism was substantially non-linear.     

A statistical evaluation of the potential genotoxic activity in the surface waters of the Golden Horn Estuary

The potential genotoxic activity in the surface waters of the Golden Horn Estuary was statistically evaluated utilizing a combination of appropriate parametric and non-parametric tests. The genotoxic activities that were associated with the water samples were determined by the SOS chromotest microplate assay. This assay utilizes β-galactosidase activity, alkaline phosphatase activity, and four different solvent controls, to generate reliable results when corrected induction factors (CIF) are used as quantitative measurements of genotoxic activity. The CIF values were obtained from a total of 384 different genotoxic experiments that were grouped into subsets according to the respective seasons and the selected sampling locations. A total of 160 subsets were statistically compared to assess any possible differences between the pairs of groups, with 95% confidence limits. The findings of this study clearly indicate that some seasonal variations exist in the CIF values at several sampling sites. However, no potentially hazardous impact to the aquatic environment was found in the estuarine system.     

Hydrologic and geologic control of carbonate water chemistry in the subarctic nahanni karst,canada

There are six classes of water and five geologic environments in the subarctic Nahanni karst. During the summers of 1972 and 1973, 214 water samples were collected from 15 of the 30 hydrogeologic categories. Linear discriminant function analysis, using five measured and two derived chemical variables, indicates that there are statistically significant (0.005 level) differences in water chemistry between similar waters in different geologic environments, between waters in the same geologic environment, and between waters in different hydrogeological categories. Geological environment labels a natural water because it determines the availability of soil CO₂ and of soluble minerals. Measurements indicate that mean soil log PCO₂ is greatest in areas of shale mantled by till (?2.39), and least in areas of sandy fluvioglacial drift (?3.27). Low values on the sandy drift are due to the sparse shrub vegetation, and to the high degree of soil aeration; soils in areas of shale are clay-rich and support a dense boreal forest. Hydrology influences water chemistry because it determines how much CO₂ natural waters pick up from the environment and how much they subsequently lose to the atmosphere, and as a result, whether they dissolve or deposit soluble materials. The similarity between mean calculated log PCO₂ in natural waters (?2.92) and mean measured soil log PCO₂ (?2.80) suggests that natural waters in Nahanni are dose to equilibrium with mean soil CO₂ levels.     

Wirkung der Chlorung auf die Abläufe einer Großkläranlage und ihres Vorfluters

To protect a water for the purpose of local recreation – inclusive of bathing – the effluent of an upstream clarification plant was chlorinated. Due to poorly controlled dosing, residual chlorine quantities exceeding the permissible level entered the receiving stream, its biocenosis having been considerably endangered. Detrimental effects on the chemical composition are graphically represented by the measured results for some waters – partly criteria of quality. There is explained that the self-purification capacity of the water decreased by about 30 % and that the hydrobiological species composition of periphyton was reduced by about 80 %. Finally, advice is given concerning the prevention of such damages to waters.     

The impact of Shokarski stormwater canal on the quality of the Bulgarian Black Sea bathing waters in the area of discharge

The impact of Shokarski stormwater canal on the bathing waters quality of Varna Bay located in the northern Bulgarian Black Sea was investigated during 2007–2014. A total of five monitoring stations were selected: three city beaches near the area of discharge of the stormwater canal and two nearby resorts beaches. The water quality was assessed following the requirements of the old EU Bathing Water Directive (BWD) 76/160/EEC and the new BWD 2006/7/EC. The resort beaches exhibited excellent water quality through the whole period. The situation at the city beaches was worst. The “Officers Beach” situated exactly at the area of discharge of Shokarski stormwater canal exhibited concentrations of ammonium and nitrates significantly above the guide value in most of the cases, the lowest compliance with the total coliforms and faecal coliforms guide values and the highest concentrations of Escherichia coli and intestinal enterococci.     

Occurrence and Nutritional Relations of the Limax-Amoebae Group in Bathing Pool Waters

In 392 samples from 14 balneological therapeutic pools and two swimming pools with untreated and chlorinated water of 15… 30 °C the following species were found in 72% of the samples (percentage of positive samples): Acanthamoeba polyphaga (10.5), A. castellani (3.7), Naegleria gruberi (5.9), N. lovaniensis (12.7), Vahlkampfia ustiniana (7.2), V. spec. (15.8), Hartmanella vermiformis and H. exudans (13.1), H. spec. (31.2). 47% of the positive findings grew also at 37 °C, 9% of them also at 44 °C. The average densities amounted to between 27 and 777 ind./l, the maxima were between 66 and more than 1000 ind./l. Neither heterotrophic bacteria nor amoebas could be detected in 25 samples, in the other samples a significant regression exists between the number of amoebas per litre A and the number of bacteria N/ml of the form lg A=0.47 × lg N + 1.22. Because of the danger of the occurrence of pathogenic amoebas, too, in the bathing pool waters, the analysis for amoebas is recommended to check the bathing water. As a temporary working level, the absence of amoebas in a sample of 100 ml is proposed.     

Analysis of Endocrine Disrupting Steroids: Investigation of Their Release into the Environment and Their Behavior During Bank Filtration

A reliable and sensitive analytical method for the determination of estrone (E1), 17β-estradiol (E2), and the synthetic hormone 17α-ethinylestradiol (EE2) has been established. Samples are concentrated using automated solid-phase extraction and analysis is performed by liquid chromatography with detection by tandem mass spectrometry. Recoveries of all analytes were between 93% and 107%, and limits of quantification (LOQs) between 0.1 and 0.4 ng/L for purified sewage, and surface, ground, and drinking water, and between 1 and 2 ng/L in case of raw sewage. For the investigation of estrogen release into the environment and its behavior during sewage and surface water treatment, and during ground water recharge, samples from municipal waste water treatment plants (WWTPs), a surface water treatment plant, a bank filtration site, and a ground water enrichment (GWE) pond were analyzed. El was found in the raw waste water with an average concentration of 157 ng/L, whereas E2 and EE2 were found with mean concentrations of only 18 and 9 ng/L, respectively. Sewage treatment by municipal WWTPs affected a removal of EE2 (76%), El (92%), and E2 (94%). In the investigated surface water of Berlin, only E1 could be detected at concentrations around or below 1 ng/L. E2 and EE2 were not present in the Berlin surface water above the LOQ of 0.2 ng/L, respectively. Surface water treatment also leads to a significant removal of E1 (> 80%). In the ground water samples from the GWE site near Lake Tegel, only a few samples contained detectable concentrations of E1. These samples were collected from a shallow monitoring well located very close to the bank of the pond. Even a short distance between the bank and observation wells led to concentrations of El below the LOQ showing the potential of ground water recharge systems for the retention of estrogenic steroids depending on the environmental setting.     

Measurement of Low-level Extracellular Enzyme Activity in Natural Waters Using Fluorigenic Model Substrates

Activities of the extracellular enzymes ß-D-glucosidase, phosphatase, and leucine aminopeptidase were investigated in unpolluted waters to test the suitability of fluorigenic model substrates for measuring enzyme activities in water samples expected to sustain low levels of activity. The waters tested were surface running waters, shallow groundwaters, and deep groundwaters from water extraction wells. Enzyme activity was detected in all the waters tested, although some of the hydrolytic rates were at the lower limit of current analytical capability. Rates varied between 1.1 and 291 nmol/(L·h) for ß-D-glucosidase, between 9.2 and 320 nmol/(L·h) for phosphatase, and between 5.8 and 1560 nmol/(L·h) for leucine aminopeptidase. The method thus proved to be suitable for measuring low levels of extracellular enzyme activity in natural waters, but in any case, it is necessary to adapt the technique to the type of water investigated.     

Seasonal variation of polycyclic aromatic hydrocarbons concentrations in urban streams at Niterói City,RJ, Brazil

Polycyclic aromatic hydrocarbons (PAHs) were determined in water samples collected in two streams and a lake located at Niteroi City, Rio de Janeiro State, Brazil between October 2008 and September 2009. Samples were extracted using liquid–liquid extraction and analyzed using high performance liquid chromatography with fluorescence detection. The limits of quantification were sufficiently low to accomplish PAH determination below the maximum concentration levels established by the Brazilian (50 ng/L) and USEPA legislations, with recoveries larger than 81.6%. Phenanthrene, fluoranthene, pyrene and benz[a]anthracene predominated among PAHs. Total concentrations of PAHs were well correlated with rainfall indicating a possible role of runoff to local pollution of water by PAHs and showed a seasonal variation in wet and dry seasons. Our results highlight the contribution of the widespread streams located around Guanabara Bay to the PAH burden found in its waters.     

Reduzierung von Bakterien- und Coliphagen-Konzentrationen auf der Fließstrecke eines Klärwerksableiters

Reduction of the Concentration of Bacteria and Coliphages along the Flowing Stretch of a Treated Sewage Channel The efficiency of surface waters to eliminate E. coli, fecal streptococci, Salmonella spp., and coliphages was evaluated in a small river which receives treated wastewater and which is rich in submerged macrophytes. The study took place between April and December, 1994. Total colony count, BOD₅, O₂ concentration and water temperature were determined in the river as well. As the river does not receive additional water downwards along its 17.2 km course, dilution effects could be ruled out as the cause for the elimination of the microorganisms. The reduction is assumed to happen rather due to sedimentation, grazing, and adsorption to the submerged waterplants. Immediately after discharge of the wastewater, the river water contained about 10⁵ cfu/100 mL E. coli and 10⁴ cfu/100 mL fecal streptococci, about 1000 pfu/100 mL coliphages, and, as a rule, was positive for salmonella in 10 mL. The reduction of E. coli, fecal streptococci, salmonella, clostridia, and coliphages at the end of the course was 1 to 2 orders of magnitude. This reduction took place mainly within the first 4.7 km, a part in which, due to low flowing velocities, suspended solids settle down efficiently. Besides, at the end of this part the submerged waterplants are especially abundant. The reduction of suspended solids correlated positively with that of BOD₅, bacteria, and coliphages. The reduction of microorganisms was not sufficient to fulfill the requirements of the European Community guidelines for bathing waters and for surface waters used as drinking water source. The regenerating capacity of surface waters is not sufficient to eliminate pathogens from convenionally treated wastewater. Therefore, tertiary treatment is necessary to keep receiving waters reasonably free from pathogens.     

Bathing water quality monitoring of Varna Black Sea coastal zone,Bulgaria

Physicochemical and microbiological characteristics of the bathing waters in Varna’s Black Sea coastal area were investigated during year 2007 at 23 monitoring stations. Most of the determined physicochemical parameters—pH, mineral oils, surface active substances, phenols, dissolved oxygen, nutrients and microbiological parameters—“Total coliforms”, “Faecal coliforms”, “Faecal streptococci” were in compliance with the guidline’ limits and exhibited good water quality. Ammonium and phosphate’s pollution above the limits was determined at the South beach, Officers beach and Central beach situated in Varna’s central bathing zone. For the period of 13.08 to 24.10.2007—70% of the South beach samples analyzed for NH₄⁺ exceeded the limits 60 times and the concentrations of PO₄³⁻ exceeded the limits 17.5 times. Some deviations from the guidline’ limits regarding the microbiology were exhibited at the same beaches. A conclusion is made that the area of study is not yet seriously threatened, in spite of the rapid recreation during the last years.     

Salmonella: The forgotten pathogen: Health hazards of compliance with European Bathing Water Legislation

The increasing demands on recreational waters have made microbial contamination a matter of public and scientific concern. This study aimed to search for Salmonella spp. in waters classified according EU Directive 2006/7/EC, in order to assess associations between its prevalence and the concentration of the non-pathogenic new faecal indicators: Escherichia coli and intestinal enterococci. Although a statistically significant association was observed Salmonella was detected on beaches classified as “Good” (9.3%) and “Excellent” (14.4%) which compromises the idea that faecal indicators can be predictors of pathogens.Attending the high prevalence of Salmonella found (23.1%) it seemed important to improve the efficiency of the conventional analytical method (ISO 6340:1995), comparing its draft with SML-VIDAS Salmonella and two new chromogenic media: AES Salmonella Agar Plate (ASAP) and Simple Method Salmonella (SMS). ASAP showed the higher efficiency and can be recommended for a faster detection and presumptive identification of salmonellae in bathing waters.     

Bacteriological examination of ballast water in Singapore Harbour by flow cytometry with FISH

In this study the concentrations of total bacteria, enterobacteria, Vibrio spp., and E. coli have been compared for ballast water samples taken from ships in Singapore Harbour. The cell concentrations were enumerated using FISH and flow cytometry. The data were highly variable, reflecting the many influences upon ballast water as it is utilized in the shipping industry. The concentration of bacterial species was determined as a proportion of the total concentration of cells for the ballast water sampled. For the ballast water sampled these concentrations were 0.67-39.55% for eubacteria, 0-2.46% for enterobacteria, 0.18-35.82% for Vibrio spp., and 0-2.46% for E. coli. Using FISH and flow cytometry, an informative determination of the bacterial hazards of ship ballast water can be made.