scholarly journals Evaluation of Recommended Water Sample Collection Methods and the Impact of Holding Time on Legionella Recovery and Variability from Healthcare Building Water Systems

2020 ◽  
Vol 8 (11) ◽  
pp. 1770
Author(s):  
Marisa B. Hirsh ◽  
Julianne L. Baron ◽  
Sue M. Mietzner ◽  
John D. Rihs ◽  
Mohamed H. Yassin ◽  
...  

Water safety and management programs (WSMP) utilize field measurements to evaluate control limits and monitor water quality parameters including Legionella presence. This monitoring is important to verify that the plan is being implemented properly. However, once it has been determined when and how to sample for Legionella, it is important to choose appropriate collection and processing methods. We sought to compare processing immediate and flushed samples, filtration of different volumes collected, and sample hold times. Hot water samples were collected immediately and after a 2-min flush. These samples were plated directly and after filtration of either 100 mL, 200 mL, or 1 L. Additionally, unflushed samples were collected and processed immediately and after 1, 24, and 48 h of hold time. We found that flushed samples had significant reductions in Legionella counts compared to immediate samples. Processing 100 mL of that immediate sample both directly and after filter concentration yielded the highest concentration and percent sample positivity, respectively. We also show that there was no difference in culture values from time 0 compared to hold times of 1 h and 24 h. At 48 h, there were slightly fewer Legionella recovered than at time 0. However, Legionella counts were so variable based on sampling location and date that this hold time effect was minimal. The interpretation of Legionella culture results depends on the sample collection and processing methods used, as these can have a huge impact on the success of sampling and the validation of control measures.

2002 ◽  
Vol 26 (2) ◽  
pp. 236-270 ◽  
Author(s):  
Gary Beasley ◽  
Pauline Kneale

Pollution-free stream water and sediments are crucial to support healthy stream flora and fauna, but urban surface runoff impairs water quality and leaves a legacy of pollution in the sediments. Pollution in sediments influences the development of macroinvertebrates, the lowest members of the food chain, leading to modification of the whole ecological structure. This review focuses on the sources and impacts of zinc, nickel, copper and oil derivative polycyclic aromatic hydrocarbon (PAH) contaminants on macroinvertebrates in urban streams. Land use, and the connectivity of the runoff and sediment are seen to have an effect on the ecological integrity of the watercourse but case examples are sparse. The literature indicates that while reduced species diversity has been identified at a number of sites the dynamics are neither well understood nor well modelled. The literature evidence is compared with field evidence from a study of 62 source areas in headwater catchments with residential, urban, industrial and motorway land uses. From the review and field results it is evident that there is still an important need for process-based field measurements of urban water quality parameters. It is suggested that forecasting the ecological status of watercourses would benefit from data on sediment chemistry and the interaction effects of metals and PAHs.


2014 ◽  
Vol 35 (3) ◽  
pp. 293-299 ◽  
Author(s):  
Beatrice Casini ◽  
Andrea Buzzigoli ◽  
Maria Luisa Cristina ◽  
Anna Maria Spagnolo ◽  
Pietro Del Giudice ◽  
...  

Objective and Design.Legionellacontrol still remains a critical issue in healthcare settings where the preferred approach to health risk assessment and management is to develop a water safety plan. We report the experience of a university hospital, where a water safety plan has been applied since 2002, and the results obtained with the application of different methods for disinfecting hot water distribution systems in order to provide guidance for the management of water risk.Interventions.The disinfection procedures included continuous chlorination with chlorine dioxide (0.4–0.6 mg/L in recirculation loops) reinforced by endpoint filtration in critical areas and a water treatment based on monochloramine (2-3 mg/L). Real-time polymerase chain reaction and a new immunoseparation and adenosine triphosphate bioluminescence analysis were applied in environmental monitoring.Results.After 9 years, the integrated disinfection-filtration strategy significantly reduced positive sites by 55% and the mean count by 78% (P< .05); however, the high costs and the occurrence of a chlorine-tolerant clone belonging toLegionella pneumophilaST269 prompted us to test a new disinfectant. The shift to monochloramine allowed us to eliminate planktonicLegionellaand did not require additional endpoint filtration; however, nontuberculous mycobacteria were isolated more frequently as long as the monochloramine concentration was 2 mg/L; their cultivability was never regained by increasing the concentration up to 3 mg/L.Conclusions.Any disinfection method needs to be adjusted/fine-tuned in individual hospitals in order to maintain satisfactory results over time, and only a locally adapted evidence-based approach allows assessment of the efficacy and disadvantages of the control measures.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1403
Author(s):  
Diego E. Casas ◽  
Rosine Manishimwe ◽  
Savannah J. Forgey ◽  
Keelyn E. Hanlon ◽  
Markus F. Miller ◽  
...  

As the global meat market moves to never frozen alternatives, meat processors seek opportunities for increasing the shelf life of fresh meats by combinations of proper cold chain management, barrier technologies, and antimicrobial interventions. The objective of this study was to determine the impact of spray and dry chilling combined with hot water carcass treatments on the levels of microbial indicator organisms during the long-term refrigerated storage of beef cuts. Samples were taken using EZ-Reach™ sponge samplers with 25 mL buffered peptone water over a 100 cm2 area of the striploin. Sample collection was conducted before the hot carcass wash, after wash, and after the 24 h carcass chilling. Chilled striploins were cut into four sections, individually vacuum packaged, and stored to be sampled at 0, 45, 70, and 135 days (n = 200) of refrigerated storage and distribution. Aerobic plate counts, enterobacteria, Escherichia coli, coliforms, and psychrotroph counts were evaluated for each sample. Not enough evidence (p > 0.05) was found indicating the hot water wash intervention reduced bacterial concentration on the carcass surface. E. coli was below detection limits (<0.25 CFU/cm2) in most of the samples taken. No significant difference (p > 0.05) was found between coliform counts throughout the sampling dates. Feed type did not seem to influence the (p > 0.25) microbial load of the treatments. Even though no immediate effect was seen when comparing spray or dry chilling of the samples at day 0, as the product aged, a significantly lower (p < 0.05) concentration of aerobic and psychrotrophic organisms in dry-chilled samples could be observed when compared to their spray-chilled counterparts. Data collected can be used to select alternative chilling systems to maximize shelf life in vacuum packaged beef kept over prolonged storage periods.


2015 ◽  
Vol 797 ◽  
pp. 377-382
Author(s):  
Kamil Kurpiel

This article refers to the traditional solution of the non-dismantable sampler and to the dismantable sampler applied as a new solution. This research describes the results of a research project on how the structure of the sampler for assembling and storage of LPG samples influences the representativeness of samples under study. The research was carried out in two directions : analysis of gas samples for the current PN-EN 589, PN-EN ISO 4257 standards and analysis of microscopic and macroscopic inner surface of the sampler. It was observed the formation of contamination layers in samplers. The chemical composition of the layers was examined and identified possible impact on changing the quality parameters of LPG. Based on the conducted research and analysis, the impact of the changed structure on the quality parameters of the LPG fuel and its representativeness in reference to the part of the cargo from which it had been taken can be assessed. Allow to conclude the thesis that the structure of the dismantable sampler followed internal cylinder surface treatment affects the representativeness of the samples collected and analyzed type of LPG gas. The construction of the sampler and possible of cleaning sampler is particularly important for qualitative parameters such gases as corrosive to copper and sulfur content of the total. Impurities that may be present in LPG, derived from refinery and petrochemical processes (ammonia, water, sulfur, methanol, higher hydrocarbons, dirt) and the distribution system are causing the occurrence of secondary reactions. Results occurring secondary reactions adversely affect the quality of the LPG. The researched solution on the dismantled sampler was patented, implemented, and applied in practice. The possibility to dismantle and thoroughly clean the sampler prior to sample collection enhances the certainty of obtaining highly representative samples and credible test results.


Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 2984
Author(s):  
João Rafael Bergamaschi Tercini ◽  
Raphael Ferreira Perez ◽  
André Schardong ◽  
Joaquin Ignacio Garcia Bonnecarrère

Assuring access to high-quality water for its multiple uses is increasingly difficult and relevant, as climate changes are gradually altering the hydrologic cycle and impacting traditional and well-established techniques of water resource management. This manuscript proposes a methodology to assess the impact of climatic variability in pre-established management rules, using spatially interpolated rain gauged data for two future emission scenarios. With them, water allocation and water quality parameters are simulated for the Piracicaba, Capivari, and Jundiaí watersheds (PCJ watersheds) in São Paulo, Brazil, employing comparisons among scenarios of historical and climate modified hydrological series. Five selected water quality indicators are used to confirm that the introduction of climate variation signals worsens water quality parameters, along with a decrease in the capability to meet water demand. This finding suggests the importance of including climate change impact in similar studies in management plans. The results indicate higher stress levels on the watershed when changes in the hydrological regime are introduced by the future conditions modeled and driven by the regional climate model (RCM). Water availability decreases and water quality deteriorates, indicating that stakeholders must take action to progressively implement stricter control measures to achieve the goals established by the watershed master plan regarding the limits or classification set by the body governing the watershed in question. On average, there was an increase of about four times the amount of river stretches (in kilometres), from 29.6 km to 161.9 km outside the limits of the established framework. The average was taken for all parameters as presented in the discussion.


2002 ◽  
Vol 68 (6) ◽  
pp. 2711-2715 ◽  
Author(s):  
Yu-sen E. Lin ◽  
Radisav D. Vidic ◽  
Janet E. Stout ◽  
Victor L. Yu

ABSTRACT Copper-silver (Cu-Ag) ionization has effectively controlled Legionella spp. in the hot water systems of numerous hospitals. However, it was ineffective at controlling Legionella in one Ohio hospital despite the confirmation of adequate total concentrations of copper and silver ions. The pH of the water at this hospital was found to be 8.5 to 9.0. The purpose of this study was to investigate the impact of pH and other water quality parameters, including alkalinity (HCO3 −), hardness (Ca2+ and Mg2+), and amount of dissolved organic carbon (DOC), on the control of Legionella by Cu-Ag ionization. Initial concentrations of Legionella and copper and silver ions used in batch experiments were 3 × 106 CFU/ml and 0.4 and 0.08 mg/liter, respectively. Changes in bicarbonate ion concentration (50, 100, and 150 mg/liter), water hardness (Ca2+ at 50 and 100 mg/liter; Mg2+ at 40 and 80 mg/liter), and level of DOC (0.5 and 2 mg/liter) had no significant impact on the efficacy of copper and silver ions in killing Legionella at a neutral pH. When the pH was elevated to 9 in these experiments, copper ions achieved only a 10-fold reduction in the number of Legionella organisms in 24 h, compared to a millionfold decrease at pH 7.0. Silver ions were able to achieve a millionfold reduction in 24 h at all ranges of water quality parameters tested. Precipitation of insoluble copper complexes was observed at a pH above 6.0. These results suggest that pH may be an important factor in the efficacy of copper-silver ionization in controlling Legionella in water systems.


Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6707
Author(s):  
Małgorzata Szulgowska-Zgrzywa ◽  
Ewelina Stefanowicz ◽  
Krzysztof Piechurski ◽  
Agnieszka Chmielewska ◽  
Marek Kowalczyk

This paper presents the results of measuring the final energy consumption for heating and domestic hot water (DHW) preparation and indoor conditions in 15 apartments located in pre-war tenement houses. The measurements were compared to the computed energy consumption. The calculations ware made based on the model calibrated by field measurements. The discrepancies between measurements and calculations were assessed using the energy performance gap (EPG). Calculations were made separately for energy for heating and for DHW preparation. Additionally, the results of EPG calculations for different levels of analysis are presented aiming at assessing the impact of weather, temperature in the surrounding zones and users’ behavior. Users’ behaviors influencing the size of the EPG were divided into typical (energy saving or excessive energy consumption) and forced (energy poverty, response to the apartment’s surroundings, technical limitations. The connection between the heating sources and the heating habits has been clearly observed in the research. The former (typical) behaviors were the origin of the energy gap in the apartments heated with natural gas and district heating. The latter (forced) were the origin of the gap in the apartments heated with mostly electricity and solid fuel (with one exception: one apartment that utilized the district heating).


Author(s):  
Mihail Zver'kov

To the article the results of the theoretical and experimental researches are given on questions of estimates of the dynamic rate effect of raindrop impact on soil. The aim of this work was to analyze the current methods to determine the rate of artificial rain pressure on the soil for the assessment of splash erosion. There are the developed author’s method for calculation the pressure of artificial rain on the soil and the assessment of splash erosion. The study aims to the justification of evaluation methods and the obtaining of quantitative characteristics, prevention and elimination of accelerated (anthropogenic) erosion, the creation and the realization of the required erosion control measures. The paper considers the question of determining the pressure of artificial rain on the soil. At the moment of raindrops impact, there is the tension in the soil, which is called vertical effective pressure. It is noted that the impact of rain drops in the soil there are stresses called vertical effective pressure. The equation for calculation of vertical effective pressure is proposed in this study using the known spectrum of raindrops. Effective pressure was 1.4 Pa for the artificial rain by sprinkler machine «Fregat» and 5.9 Pa for long distance sprinkler DD-30. The article deals with a block diagram of the sequence for determining the effective pressure of rain drops on the soil. This diagram was created by the author’s method of calculation of the effective pressure of rain drops on the soil. The need for an integrated approach to the description of the artificial rain impact on the soil is noted. Various parameters characterizing drop erosion are considered. There are data about the mass of splashed soil in the irrigation of various irrigation machinery and installations. For example, the rate (mass) of splashed soil was 0.28…0.78 t/ha under irrigation sprinkler apparatus RACO 4260–55/701C in the conditions of the Ryazan region. The method allows examining the environmental impact of sprinkler techniques for analyzes of the pressure, caused by raindrops, on the soil. It can also be useful in determining the irrigation rate before the runoff for different types of sprinkler equipment and soil conditions.


2021 ◽  
Vol 2 (2) ◽  
pp. 76-86
Author(s):  
Diky Setiawan ◽  
Mochammad Hasymi Somaida

The Corona virus is a virus that originates from China, and spreads rapidly throughout the world andbegan to spread to Indonesia in early March 2020. The impact of Covid-19 has caused losses in all fields,be it economy, education, etc. In the field of education, activities both learning and examinations must bereplaced online due to the impact of the spread of Covid-19. This study aims to determine theeffectiveness of the implementation of UAS which is carried out online using the Google Form applicationmedia at SMP MA'ARIF NU CIMANGGU. This research uses the quantitative survey method whichdescribes the online UAS implementation activities at SMP MA'ARIF NU CIMANGGU during thepandemic. The object consists of 35 student respondents. The data sample collection is done using aquestionnaire / questionnaire containing questions related to the implementation of UAS online using theGoogle Form application at SMP MA ' ARIF NU CIMANGGU. Based on the results of this study, theimplementation of online UAS runs effectively f and good, it can be seen from the results of satisfactorystudent scores. The application used is of course the Googke Form as the main media, and Whatsapp as amedium for interaction between teachers and students. The obstacles experienced are regarding badconnections, limited quota, schedules that frequently change, as well as difficulties in understandingsubject matter.Keywords: Covid-19,impact,effectiveness


2020 ◽  
Vol 7 (04) ◽  
Author(s):  
A B Priyanshu ◽  
M K Singh ◽  
Mukesh Kumar ◽  
Vipin Kumar ◽  
Sunil Malik ◽  
...  

An experiment was conducted at Horticultural Research Centre, SVP University of Agriculture and Technology, Meerut (UP) during Rabi season of 2018-19 to assess the impact of different INM doses on yield and quality parameters of garlic. A total of ten treatments consisting of combinations of inorganic fertilizers, organic fertilizers and bio-fertilizers like T1- (Control), T2RDF (100:50:50 kg NPK ha-1), T3-RDF + 20 kg sulphur + FYM 20 ton ha-1, T4- RDF + 20 kg sulphur + VC 4 ton ha-1, T5- 75% RDF + 40 kg sulphur + 5 ton FYM ha-1+ PSB 5 kg ha-1, T6-75% RDF + 40 kg sulphur + 2 ton VC + Azotobacter 5 kg ha-1, T7- 75% RDF + 40 kg sulphur + FYM 3 ton + VC 1 ton+ PSB 5 kg + Azotobacter 5kg ha-1, T8- 50% RDF + 40 kg sulphur + FYM 5 ton + VC2 ton + PSB 5 kg ha-1, T9- 50% RDF + 40 kg sulphur + FYM5 ton + VC 2 ton+ Azotobacter 5 kg ha-1and T10- 50% RDF + 40 kg sulphur + FYM 5 ton + VC2 ton + PSB 5 kg + Azotobacter 5 kg ha-1 were used in Randomized Block Design and replicated thrice. Out of these an application of T7 (75% RDF + 40 kg sulphur + FYM3 ton + VC 1 ton ha-1 + PSB 5 kg + Azotobacter 5 kg ha-1) was found to be significantly superior in term of yield and attributing parameters of garlic.


Sign in / Sign up

Export Citation Format

Share Document