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Water reuse is rapidly becoming an integral feature of resilient water systems, where municipal wastewater undergoes advanced treatment, typically involving a sequence of ultrafiltration (UF), reverse osmosis (RO), and an advanced oxidation process (AOP). When RO is used, a concentrated waste stream is produced that is elevated in not only total dissolved solids but also metals, nutrients, and micropollutants that have passed through conventional wastewater treatment. Management of this RO concentrate─dubbed municipal wastewater reuse concentrate (MWRC)─will be critical to address, especially as water reuse practices become more widespread. Building on existing brine management practices, this review explores MWRC management options by identifying infrastructural needs and opportunities for multi-beneficial disposal. To safeguard environmental systems from the potential hazards of MWRC, disposal, monitoring, and regulatory techniques are discussed to promote the safety and affordability of implementing MWRC management. Furthermore, opportunities for resource recovery and valorization are differentiated, while economic techniques to revamp cost-benefit analysis for MWRC management are examined. The goal of this critical review is to create a common foundation for researchers, practitioners, and regulators by providing an interdisciplinary set of tools and frameworks to address the impending challenges and emerging opportunities of MWRC management.

The water sector needs to address viral-related public health issues, because water is a virus carrier, which not only spreads viruses (e.g., via drinking water), but also provides information about the circulation of viruses in the community (e.g., via sewage). It has been widely reported that waterborne viral pathogens are abundant, diverse, complex, and threatening the public health in both developed and developing countries. Meanwhile, there is great potential for viral monitoring that can indicate biosafety, treatment performance and community health. New developments in technology have been rising to meet the emerging challenges over the past decades. Under the current coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the world’s attention is directed to the urgent needto tackle the most challenging public health issuesrelated to waterborne viruses. Based on critical analysis of the water viral knowledge progresses and gaps, this article offers a roadmap for managingCOVID-19 and other viruses in the water environments for ensuring public health.

Legionella pneumophilais the species that is most often cultured from the natural environment, while disease-relevant Legionellaspecies, such as Legionella micdadei, Legionella bozemanii, Legionella anisa, and Legionella longbeachaehave yet to be extensively explored in premise plumbing systems. This study examined the concentrations of five pathogenic Legionellaspecies (listed previously) in the influent and the taps of five different large buildings (BPS, ERC, F, FH, and M), undertaken during the start of two semesters (late summer/fall (August–September) and early winter/spring (January)). A total of 37 large-volume samples to examine building water quality (influents to the buildings and exposure sites (taps)) were collected and analyzed using droplet digital™ PCR. Legionellaspp. (23S rRNA) were present in all water samples during both seasons. The majority (66%) of the exposure sites (bathroom taps) were positive for at least one target Legionellaspecies (listed above). Results showed that pathogenic Legionellaspecies were most often detected during the winter/spring sampling event – the percent positives for any one of the pathogenic Legionellaspecies at the hot-water taps was 80% in building F and 40% in BPS, M, FH, and ERC. Legionella pneumophilaand L. longbeachaewere found in the highest concentrations (2.0 log10gene copies (GC)/100 mL) at the hot-water taps in buildings F and ERC, respectively. No strong relationships were found with the physical–chemical parameters. Overall, general Legionellaspp. concentrations increased in the winter/spring samples due possibly to lower water usage (lower occupancy and no use of cooling towers, which led to more water stagnation or time in the system).

Water safety was investigated at a school certified as a green building. The study was conducted during low water use (summer break) to normal water use (after break) periods. The copper plumbed building contained water saving devices, a water softener and four hot water recirculation zones, and received chloraminated water from a public water system. Six sampling events at 19 in-building locations (and extra 19 locations for metal analysis) were conducted (June 2018 to October 2018). At the building entry point, 65% of the samples (n= 74/114) had no detectable disinfectant residue, heterotrophic plate count ranged from 11 to 400 CFU/100 mL, and no copper action level (AL) exceedances were found; the AL is a health-based threshold. Inside the building, almost 70% of first draw cold samples exceeded the AL during summer, while 37% of samples exceeded the AL after classes resumed. Total copper concentration in the building was related to the distance from the building entry point. The softener was an incubator for bacterial growth and nitrification was detected throughout the plumbing (n= 29/29 for hot, n= 17/22 for cold). The state's recommended spot flushing remediation strategy for reducing copper concentration was ineffective. Water chemical and microbiological testing is recommended before new schools are placed into service and during the life of new and existing buildings. Building water system design standards lack explicit consideration of source water quality, plumbing operation, and material-water compatibility. School plumbing was designed and operated in a way that presented a risk to the health of its occupants.

The effects of manure application in agriculture on surface water quality has become a local to global problem because of the adverse consequences on public health and food security. This study evaluated (i) the spatial distribution of bovine (cow) and porcine (pig) genetic fecal markers, (ii) how hydrologic factors influenced these genetic markers, and (iii) their variations as a function of land use, nutrients, and other physiochemical factors. We collected 189 samples from 63 watersheds in Michigan's Lower Peninsula during baseflow, spring melt, and summer rain conditions. For each sample, we quantified the concentrations of bovine and porcine genetic markers by digital droplet polymerase chain reaction and measured Escherichia coli, dissolved oxygen, pH, temperature, total phosphorus, total nitrogen, nitrate‐nitrite (NOX), ammonia (NH3), soluble reactive phosphorus, streamflow, and watershed specific precipitation. Bovine and porcine manure markers were ubiquitous in rivers that drain agricultural and natural fields across the study region. This study provides baseline conditions on the state of watershed impairment, which can be used to develop best management practices that could improve water quality. Similar studies should be performed with higher spatial sampling density to elucidate detailed factors that influence the transport of manure constituents. Spatial transport of two fecal markers occurs as the seasons change and flows increase.Streamflow was the strongest predictor of markers during spring melt and baseflow periods.Watersheds with natural land uses were related to the increase of marker concentrations.Impacted rivers with elevated markers could be identified for further study and remediation.

Numerous bacterial genetic markers are available for the molecular detection of human sources of fecal pollution in environmental waters. However, widespread application is hindered by a lack of knowledge regarding geographical stability, limiting implementation to a small number of well-characterized regions. This study investigates the geographic distribution of five human-associated genetic markers (HF183/BFDrev, HF183/BacR287, BacHum-UCD, BacH, and Lachno2) in municipal wastewaters (raw and treated) from 29 urban and rural wastewater treatment plants (750–4 400 000 population equivalents) from 13 countries spanning six continents. In addition, genetic markers were tested against 280 human and nonhuman fecal samples from domesticated, agricultural and wild animal sources. Findings revealed that all genetic markers are present in consistently high concentrations in raw (median log107.2–8.0 marker equivalents (ME) 100 mL–1) and biologically treated wastewater samples (median log104.6–6.0 ME 100 mL–1) regardless of location and population. The false positive rates of the various markers in nonhuman fecal samples ranged from 5% to 47%. Results suggest that several genetic markers have considerable potential for measuring human-associated contamination in polluted environmental waters. This will be helpful in water quality monitoring, pollution modeling and health risk assessment (as demonstrated by QMRAcatch) to guide target-oriented water safety management across the globe.

Viral foodborne outbreaks are a serious threat to public health, and fresh produce is becoming increasingly recognized as a transmission vehicle. To limit foodborne disease, ready-to-eat leafy greens are typically washed with a chlorine-based sanitizer during commercial production. This study assessed the efficacy of a chlorine-based sanitizer against coliphage MS2, as a potential surrogate for foodborne viruses, on fresh-cut romaine lettuce during simulated commercial production using a small-scale processing line. Before processing, romaine lettuce was inoculated to contain approximately 105and 106PFU/g of MS2 for experiments with and without sanitizer, respectively. Lettuce samples were collected following each stage of processing, which included mechanical shredding, 2 min of flume washing (with or without 25 ppm of free chlorine), shaker table dewatering, and centrifugal drying. In addition, the spent centrifuge water and flume wash water were collected, with the flume water concentrated using hollow-fiber ultrafiltration. MS2 was recovered from lettuce in Tris-glycine buffer and quantified as PFUs in a double-agar overlay assay. The greatest reduction in MS2 occurred between shredding and flume washing, with levels remaining relatively stable following flume washing with or without 25 ppm of free chlorine. Average total reductions of 0.8 and 1.0 log PFU/g were seen after processing with and without the sanitizer, respectively, with no statistical difference observed between the two treatments (P> 0.05). The average MS2 level in the spent centrifugation water started at 4.0 log PFU/ml for experiments with sanitizer and the average MS2 reduction in the flume wash water was 4 log (PFU) for experiments with sanitizer, demonstrating that removals could be achieved in the water itself. These findings suggest that the currently recommended commercial production practices are unable to effectively decrease viruses once they have attached to leafy greens during commercial processing.

Surveillance of antibiotic resistance genes (ARGs) has been increasingly conducted in environmental sectors to complement the surveys in human and animal sectors under the “One-Health” framework. However, there are substantial challenges in comparing and synthesizing the results of multiple studies that employ different test methods and approaches in bioinformatic analysis. In this article, we consider the commonly used quantification units (ARG copy per cell, ARG copy per genome, ARG density, ARG copy per 16S rRNA gene, RPKM, coverage, PPM, etc.) for profiling ARGs and suggest a universal unit (ARG copy per cell) for reporting such biological measurements of samples and improving the comparability of different surveillance efforts.

Water treatment plants typically issue a boil water order (BWO) to a potentially affected populace when Cryptosporidiumis detected in the finished water. Although BWOs involve costs that may not be justified for very low risks of infection, there is no predetermined risk level or environmental concentration that triggers such an order. In this study, a cost–benefit analysis was used to identify a threshold level of risk for issuing a BWO. A decision tree was constructed, and the threshold level of risk at which the expected benefits of a BWO exceed expected costs was identified. An exponential dose–response model was used to determine the dose of Cryptosporidiumoocysts that corresponds to the threshold risk level. Results suggest that a daily risk of nine illnesses out of 10,000 people exposed would justify a BWO. Given typical 3‐log removal of oocysts during treatment, this risk level would correspond to a finished water concentration of 0.046 oocysts/L and a raw water concentration of 46 oocysts/L.

Appropriate treatment of agricultural waste is necessary for the protection of public health in rural areas because land‐applied animal manure may transmit zoonotic disease. In this study, we evaluated the potential of using a pilot anaerobic membrane bioreactor (AnMBR) to treat agricultural waste. The AnMBR system, following a conventional complete mix anaerobic digester (CMAD), achieved high removals of biological and chemical agents. The mean log10removals of Escherichia coli, enterococci, Clostridium perfringens, and coliphage by the AnMBR were 5.2, 6.1, 6.4, and 3.7, respectively, and for the CMAD were 1.5, 1.2, 0.1, and 0.5, respectively. Compared with other indicators, coliphage was observed most frequently and had the highest concentration in effluent samples. Bovine adenoviruses and bovine polymaviruses (BPyV) were monitored in this study using nested PCR methods. All of the CMAD influent and CMAD effluent samples were positive for both viruses, and three AnMBR effluent samples were BPyV positive. The mean removals of total Kjeldahl nitrogen, total phosphate, chemical oxygen demand, total solids, and volatile solids by the entire system were 31, 96, 92, 82, and 91%, respectively, but there was no removal of ammonium. When the AnMBR was operated independent of the CMAD, AnMBR achieved similar E. coliand enterococci removals as the combined CMAD/AnMBR system. The high quality of effluent produced by the pilot AnMBR system in this study demonstrated that such systems can be considered as alternatives for managing animal manure.

This article begins by discussing enteric viruses, specifically those that have been associated with waterborne disease outbreaks. Advances in molecular techniques for virus detection and identification are discussed, specifically polymerase chain reaction (PCR) which is a technique that copies a virus's genetic material (RNA or DNA) for detecting and identifying viruses in water samples. Techniques for sample collection, virus concentration, and cell culturing are discussed, along with coliphage assays. The article includes an inset that provides information on viruses, how they are spread, waterborne viral diseases, and four viruses on the U.S. Environmental Protection Agency's Contaminant Candidate List.

Three water, sanitation and hygiene (WASH) support tools were applied to Kampala city, Uganda, to evaluate areas with the highest health hazard due to poor wastewater and faecal sludge management and to develop interventions to improve sanitation and reduce exposure. The Pathogen Flow and Mapping Tool (PFMT) assessed how different sanitation management interventions influence pathogen emissions to surface water using rotavirus as the indicator pathogen, while the HyCRISTAL health hazard tool evaluated how flooding and drainage infrastructure influence the presence of human excreta in the environment. The SaniPath tool identified common high-risk pathways of exposure to faecal contamination in food, open drains and floodwater. An overlap in high health hazard hotspot areas was identified by the PFMT and the HyCRISTAL tools. Across the city, the most important hazard sources were the indiscriminate disposal of faecal waste into open stormwater drains from onsite sanitation technologies, open defecation and the insufficient treatment of wastewater. The SaniPath tool identified drain water, floodwater, street food and uncooked produce as the dominant faecal exposure pathways for selected parishes in the city, demonstrating the presence of excreta in the environment. Together, the tools provide collective evidence guiding household, community, and city-wide sanitation, hygiene and infrastructure management interventions from a richer assessment than when a single tool is applied. For areas with high spatial risks, those practising open defecation, and for low-lying areas, these interventions include the provision of watertight pit latrines or septic tanks that are safely managed and regularly emptied. Faecal sludge should be emptied before flood events, direct connections of latrines to open storm drains should be prevented, and the safe handling of food and water promoted. The tools enhance decision making for local authorities, and the assessments can be replicated in other cities.

Background:With increasing implementation of enhanced recovery programs (ERPs) in clinical practice, standardised data collection and reporting have become critical in addressing the heterogeneity of metrics used for reporting outcomes. Opportunities exist to leverage electronic health record (EHR) systems to collect, analyse, and disseminate ERP data. Objectives:(i) To consolidate relevant ERP variables into a singular data universe; (ii) To create an accessible and intuitive query tool for rapid data retrieval. Method:We reviewed nine established individual team databases to identify common variables to create one standard ERP data dictionary. To address data automation, we used a third-party business intelligence tool to map identified variables within the EHR system, consolidating variables into a single ERP universe. To determine efficacy, we compared times for four experienced research coordinators to use manual, five-universe, and ERP Universe processes to retrieve ERP data for 10 randomly selected surgery patients. Results:The total times to process data variables for all 10 patients for the manual, five universe, and ERP Universe processes were 510, 111, and 76 min, respectively. Shifting from the five-universe or manual process to the ERP Universe resulted in decreases in time of 32% and 85%, respectively. Conclusion:The ERP Universe improves time spent collecting, analysing, and reporting ERP elements without increasing operational costs or interrupting workflow. Implications:Manual data abstraction places significant burden on resources. The creation of a singular instrument dedicated to ERP data abstraction greatly increases the efficiency in which clinicians and supporting staff can query adherence to an ERP protocol.

The article relates the author's experience of testing the waters in Phang Nga Province, southern Thailand, after the tsunami disaster. According to the author, the waters were filled with materials from the wreckage that lined the slopes and it is likely that septic tanks contributed to the water degradation. The drinking water samples that the author brought back to Singapore tested negative for all bacterial contamination.

Virus contamination of the water environment through disposal of human wastewater remains a concern for the water industry. Coxsackieviruses are the most common nonpolio enteroviruses found in domestic wastewater and in contaminated surface water, groundwater, and drinking water. Although most infections result in mild febrile illness, coxsackieviruses are capable of causing a wide range of serious illnesses (including aseptic meningitis, myocarditis, and respiratory illness) and are associated with cases of insulin‐dependent diabetes mellitus. A risk assessment approach was used to evaluate the potential public health effects associated with contaminated drinking water and recreational waters. An exponential model developed from human dose–response studies was used to describe the infectivity of coxsackievirus type B and estimate daily and yearly risks of infection, morbidity, and mortality. Concentrations of coxsackievirus reported in the literature were used to examine potential exposure. Although risks of infection for coxsackievirus are lower than for rotavirus, levels detected during outbreaks resulted in risks of 10–1annually for drinking water. Risks assuming an ingestion of 100 mL per swim were 10–2for a 10‐day exposure to freshwater. The severity of the diseases associated with this type of virus and its widespread contamination emphasize the importance of maintaining reliable wastewater and drinking water treatment.

SUMMARYThis review addresses both historical and recent investigations into viral contamination of marine waters. With the relatively recent emergence of molecular biology-based assays, a number of investigations have shown that pathogenic viruses are prevalent in marine waters being impacted by sewage. Research has shown that this group of fecal-oral viral pathogens (enteroviruses, hepatitis A viruses, Norwalk viruses, reoviruses, adenoviruses, rotaviruses, etc.) can cause a broad range of asymptomatic to severe gastrointestinal, respiratory, and eye, nose, ear, and skin infections in people exposed through recreational use of the water. The viruses and the nucleic acid signature survive for an extended period in the marine environment. One of the primary concerns of public health officials is the relationship between the presence of pathogens and the recreational risk to human health in polluted marine environments. While a number of studies have attempted to address this issue, the relationship is still poorly understood. A contributing factor to our lack of progress in the field has been the lack of sensitive methods to detect the broad range of both bacterial and viral pathogens. The application of new and advanced molecular methods will continue to contribute to our current state of knowledge in this emerging and important field.

The Metropolitan Water District of Southern California recently completed construction of an 800,000 acre‐ft (1 × 109m3) drinking water reservoir. Recreational activities, including swimming and other sports involving direct body contact (BC) with the water, have been the subject of considerable interest by local community members. Consequently, a modeling‐based risk assessment study was conducted to assess the potential public health consequences to downstream potable water users consuming water from this reservoir if BC recreation was permitted. Results of the study indicated that the annual risk of waterborne illness would increase three times above background, despite conventional treatment. Moreover, the occurrence of high‐loading pathogen events associated with BC recreation was observed to significantly increase the daily risk of waterborne illness to downstream consumers. The study also considered the cost of additional treatment that would be necessary to address the increased risk. The modeling approach used in this study provides guidance for policymakers and stakeholders who are examining issues associated with BC recreation and drinking water reservoirs.

The Upper Occoquan Sewage Authority (UOSA) Water Reclamation Plant, Centreville, Virginia, is a state-of-the-art wastewater treatment plant that was created to treat area wastewater and provide protection for the Occoquan Reservoir. This study investigated UOSA's unit processes as barriers to pathogenic as well as alternative and traditional indicator microorganisms. Samples were collected once a month for 1 year from eight sites within UOSA's advanced wastewater reclamation plant. The eight sites were monitored for indicator bacteria total and fecal coliforms, enterococci, Clostridium, coliphage (the virus that infects Escherichia coli), human enteroviruses, and enteric protozoa.
Overall, the plant was able to achieve a 5- to 7-log10reduction of bacteria, 5-log10reduction of enteroviruses, 4-log10reduction for Clostridium, and 4.6-log10reduction of protozoa. Total coliforms, enterococci, Clostridium, coliphage, Cryptosporidium,and Giardiawere all detected in four or fewer samples of the final effluent. No enteroviruses or fecal coliforms were detected in the final effluent. The microbiological quality of reclaimed water and the reservoir water were compared. In every case, the treated wastewater was of a better quality than the ambient water in the reservoir, thus indicating that the reclaimed water will not adversely affect the water quality for downstream users.

Abstract: The importance of the El Niño-Southern Oscillation (ENSO) on regional-scale climate variability is well recognized although the associated effects on local weather patterns are poorly understood. Little work has addressed the ancillary impacts of climate variability at the community level, which require analysis at a local scale. In coastal communities water quality and public health effects are of particular interest. Here we describe the historical influence of ENSO events on coastal water quality in Tampa Bay, Florida (USA) as a test case. Using approximate randomized statistics, we show significant ENSO influences on water quality particularly during winter months, with significantly greater fecal pollution levels during strong El Niño winters and significantly lower levels during strong La Niña winters as compared to neutral conditions. Similar significant patterns were also noted for El Niño and La Niña fall periods. The success of the analysis demonstrates the feasibility of assessing local effects associated with large-scale climate variability. It also highlights the possibility of using ENSO forecasts to predict periods of poor coastal water quality in urban region which local agencies may use to make appropriate prepations.

Exposure to waterborne and foodborne pathogens can occur via drinking water (associated with fecal contamination), seafood (due to natural microbial hazards, toxins, or wastewater disposal) or fresh produce (irrigated or processed with contaminated water). Weather influences the transport and dissemination of these microbial agents via rainfall and runoff and the survival and/or growth through such factors as temperature, Federal and state laws and regulatory programs protect much of the U.S. population from waterborne disease; however, if climate variability increases, current and future deficiencies in areas such as watershed protection, infrastructure, and storm drainage systems will probably increase the risk of contamination events. Knowledge about transport processes and the fate of microbial pollutants associated with rainfall and snowmelt is key to predicting risks from a change in weather variability. Although recent studies identified links between climate variability and occurrence of microbial agents in water, the relationships need further quantification in the context of other stresses in the marine environment as well, there are few studies that adequately address the potential health effects of climate variability in combination with other stresses such as overfishing, introduced species, and rise in sea level. Advances in monitoring are necessary to enhance early warning and prevention capabilities. Application of existing technologies, such as molecular fingerprinting to track contaminant sources or satellite remote sensing to detect coastal algal blooms, could be expanded, This assessment recommends incorporating a range of future scenarios of improvement plans for current deficiencies in the public health infrastructure to achieve more realistic risk assessments. Key words: cholera, climate change, climate variability, cryptosporidiosis, E. coli, foodborne diseases, global warming, shellfish poisoning, waterborne diseases. — Envir... [ABSTRACT FROM AUTHOR]

Abstract: The Charlotte Harbor estuary in southwest Florida was sampled monthly for one year at twelve stations, in the lower reaches of the Myakka and Peace Rivers. The objectives of the study were to address the distribution and seasonal changes in microbial indicators and human pathogen levels in Charlotte Harbor shellfish and recreational waters, and to determine those factors that may be important in the transport and survival of pathogens. Monthly water samples and quarterly sediment samples were analyzed for fecal coliform bacteria, enterococci,Clostridium perfringens, and coliphage. Quarterly samples also were analyzed for the enteric human pathogens,Cryptosporidium spp.,Giardia spp., and enteroviruses. Fecal indicator organisms were generally concentrated in areas of low salinity and high densities of septic systems; however, pollution became widespread during wet weather in, the late fall and winter of 1997–1998, coincident with a strong El Nino event. Between, December 1997 and February 1998, enteroviruses were detected at 75% of the sampling stations; none were detected in other months. Enteric protozoa were detected infrequently and were not related to seasonal influences. Fecal indicators and enteroviruses were each significantly associated with rainfall, streamflow, and temperature. Regression models suggest that temperature and rainfall can predict the occurrence of enteroviruses in 93.7% of the cases. Based on findings in this watershed, factors such as variability in precipitation, streamflow, and temperature show promise in modeling and forecasting periods of poor coastal water quality.

Abstract: Viral tracer studies have been used previously to study the potential for wastewater contamination of surface marine waters in the Upper and Middle Florida Keys. Two bacteriophages, the marine bacteriophage ϕHSIC and theSalmonella phage PRD1, were used as tracers in injection well and septic tank studies in Saddlebunch Keys of the Lower Florida Keys and in septic tank studies in Boot Key Harbor, Marathon, of the Middle Keys. In Boot Key Harbor, both phages were detected in a canal adjacent to the seeded septic tank within 3 h 15 min of the end of the seed period. The tracer was then detected at all sampling sites in Boot Key Harbor, including one on the opposite side of U.S. Highway 1 in Florida Bay, and at an Atlantic Ocean beach outside Boot Key Harbor. Rates of migration based on first appearance of the phage ranged from 1.7 to 57.5 m h−1. In Saddlebunch Keys, ϕHSIC and PRD1 were used to seed a residential septic tank and a commercial injection well. The septic tank tracer was not found in any surface water samples. The injection well tracer was first detected at a site most distant from the seed site, a channel that connected Sugarloaf Sound with the Atlantic Ocean. The, rate of tracer migration from the injection well to this channel ranged from 66.8 to 141 m h−1. Both tracer studies showed a rapid movement of wastewater from on-site sewage treatment and disposal systems in a southeasterly direction toward the reef tract and Atlantic Ocean, with preferential movement through tidal channels. These studies indicate that wastewater disposal systems currently in widespread use in the Florida Keys can rapidly contaminate the marine environment.

This preliminary descriptive study describes the temporal and spatial distribution of US waterborne disease outbreaks using a geographic information system approach in relationship to rainfall. Regional climate change and variability and their effect on water resources have not been the subject of much study. Climate predictions suggest that storms will be of greater intensity and that the average precipitation event is likely to be heavier. Rainfall and runoff have been associated with individual outbreaks of waterborne disease caused by fecal‐oral pathogens. Waterborne disease outbreak data from 1971 through 1994 were analyzed for groundwater and surface water in 2,105 US watersheds. Between 20 and 40 percent of outbreaks were associated with extreme precipitation. This relationship with extreme precipitation was found to be statistically significant for both surface water and groundwater, although it was more apparent with surface water outbreaks. The authors offer recommendations for improving the assessment of changes in water quality and the effect that climate variability and environmental factors have on waterborne disease risk.

Analysis of groundwater for the presence of microbiota offers researchers a way to estimate the potential for Giardia and Cryptosporidium contamination. A total of 383 groundwater samples from 166 different sites were analyzed for Cryptosporidium, Giardia, and other microbiota (1–500 μm) using immunofluorescence assay and light microscopy procedures. Analysis of the data showed 11 percent of the sites (19 of 166) were sometimes positive for Cryptosporidium, Giardia, or both. Statistical analyses determined that microbiota in eight major groups were indicative of Cryptosporidiumand Giardiacontamination. These groups include algae, arthropods, rotifers, fungi, nematodes, colorless flagellates, amoebae, and gastrotrichs. Cryptosporidiumand Giardiaoccurrence also correlated positively with the three risk categories developed by the US Environmental Protection Agency to rank direct surface water influence on groundwaters (p= 0.001). However, the specific numerical scores used to determine risk categories provided no better prediction of the pathogens than the three general categories. To determine vulnerability to contamination, researchers first should investigate those groundwater sources with a diversity of microbiota.

The incidence of foodborne disease outbreaks caused by contaminated low-pH fruit juices is increasing. With recent mandatory pasteurization of apple juice and the industry's concerns of food safety, fruit juice processors are showing more interest in alternative nonthermal technologies that can kill >99.99% of microbial pathogens present in foods. The association of the coccidian protozoan, Cryptosporidium, with diarrheal disease outbreaks from contaminated tap water and fruit juice raises a safety concern in the food and beverage industries. The objective of this study was to evaluate the effects of high hydrostatic pressure (HHP) on C. parvumoocysts. Oocysts were suspended in apple and orange juice and HHP treated at 5.5 × 108Pa (80,000 psi) for 0, 30, 45, 60, 90, and 120 s. Oocyst viability was assessed by excystation using bile salts and trypsin while the cell culture foci detection method was used to assess infectivity. Results indicated that HHP inactivated C. parvumoocysts by at least 3.4 log10after 30 s of treatment. No infectivity was detected in samples exposed to ≥60 s of HHP and >99.995% inactivation was observed. This study demonstrated that HHP efficiently rendered the oocysts nonviable and noninfectious after treatment at 5.5 × 108Pa.

Experiments are described in which bare (completely desolvated) ions are separated from their source gas and mixed with a bath gas of any desired temperature and precisely controlled composition. The resulting mixture of ions and bath gas is transported by free jet expansion into a vacuum system for mass analysis to reveal the extent to which the ions have formed adducts with other species in the bath gas. Because the ions are separated from their source gas or vapor before they are mixed with the bath gas, the compositions of the bath gas and source gas are completely independent. Thus, one can examine solvation or adduction by any desired species contained in the bath gas without any interference from other species that might be present in the source gas. Reported here are results obtained on the solvation of electrospray ions of a small peptide, leucine-enkephalin, by water and several alkanols. One provocative finding is that a substantial fraction of ions thought to be singly charged monomers turned out to be doubly charged dimers.

Listeria monocytogenes is a foodborne pathogen internationally and in the U.S. The objective of this work was to develop and validate a dose-response model for infection by this organism. Only animal data was available in the literature. The beta-Poisson dose response model provided good fit to the data, and one of the two data sets was found to be concordant with attack rates noted in human outbreaks. There are differences, however, between the dose-response relationship and endemic illness rates computed from “market basket” surveys of the prevalence of L. monocytogenes. Further work to elucidate the bases for this difference is necessary. [ABSTRACT FROM AUTHOR]

This roundtable gives an overview of Cryptosporidium and its relationship to public water supplies. It discusses the parasite's life cycle, where it is found in the environment, how it differs from Giardia, how it gets into drinking water supplies, its health effects on humans, and treatment technologies used to remove the parasite from water supplies.

Three outbreaks of waterborne disease have been attributed to Cryptosporidium—two linked to drinking water and a third to surface water—yet the risk of waterborne disease is unknown because many factors may contribute to transmission. Of 107 surface water samples collected in six western states, 77 were positive for the presence of Cryptosporidiumoocysts. A high count was found in raw sewage (1,732 oocysts/L), whereas low counts were found in waters without waste discharges (0.04 oocysts/L). Cryptosporidiumhas also been detected in drinking water. Little information is available, however, on oocyst survival in the environment or during sewage and drinking water treatment processes. Further research is necessary to define the variables that will influence the possible presence of infectious oocysts in water. It has been suggested that the epidemiology and transmission of Cryptosporidiumare similar to Giardia.Based on environmental occurrence, the risk of Cryptosporidiumtransmission by the water route may be equal to or greater than that of Giardia.

Reduction of enteroviruses and rotaviruses averaged 81 and 93 percent, respectively, at a full‐scale 205‐mgd (776‐ML/d) plant whose treatment train includes chemical flocculation, sand filtration, and chlorination. The highest reduction of enteroviruses occurred during prechlorination‐flocculation and filtration, whereas the highest reduction of rotaviruses occurred during prechlorination‐clarification and final chlorination. Enteroviruses or rotaviruses occurred in 24 percent of the finished water samples, which had >;0.2 mg free chlorine/L and met coliform bacteria (1/100 mL) and turbidity (1 ntu) standards. Although major plant deficiencies may have been responsible for the occurrence of viruses in the finished water, the results of this study indicate that finished water, with measurable levels of free residual chlorine and meeting standards for coliform bacteria and turbidity, cannot be assumed to be virus free.

Water Chlorination: Essential Process or Cancer Hazard? Bull, R. J., Birnbaum L. S., Cantor, K., Rose, J. B., Butterworth, B. E., Pegram, R., and Tuomisto, J. (1995). Fundam. Appl. Toxicol.28, 155-166.

Groundwater systems need to be carefully monitored until contamination levels and acceptable risk factors are determined. Data generated from the detection of Cryptosporidiumoocysts and Giardiacysts in 463 groundwater samples were compiled. Samples were taken from 199 sites in 23 of the 48 contiguous states. The groundwater sources were vertical wells, springs, infiltration galleries, and horizontal wells. Samples were analyzed using an immunofluorescence technique. Inclusion of data from all sources showed that 12 percent of the sites were positive for Cryptosporidiumor Giardiaor both. Cryptosporidiumoocysts were found in 5 percent of the vertical wells, 20 percent of the springs, 50 percent of the infiltration galleries, and 45 percent of the horizontal wells. Giardiacysts were found in 1 percent of the vertical wells, 14 percent of the springs, 25 percent of the infiltration galleries, and 36 percent of the horizontal wells. These data suggest that springs are at a higher risk for contamination than vertical wells. Because pathogens occur frequently in infiltration galleries and horizontal wells, these sources warrant further study.

USEPA's expert panel concluded that both filtration and watershed protection are necessary for New York City's water supply. Under the Surface Water Treatment Rule (SWTR), New York City is required to filter its Catskill–Delaware water supply unless it can meet the criteria to avoid filtration. A panel was appointed by the US Environmental Protection Agency (USEPA) in the summer of 1992 to advise the agency about whether to grant New York City permission to avoid filtration. The panel concluded that although the water quality criteria were met marginally, the requirements for watershed control were not met. The panel also concluded that the city would probably not be able to meet the water quality requirements of an enhanced SWTR, which would likely include, among other additional requirements, measures to control Cryptosporidium.Despite the panel's recommendation for filtration, USEPA granted New York City an avoidance of filtration first through 1993, then through 1996, 1999, and 2002. Although the city has negotiated a very useful watershed agreement with the upstate communities in the Catskill–Delaware watershed, the issues remain the same. This article assesses the issues involved.

This article discusses the assessment of risk from microorganisms in drinking water, the problems associated with such an analysis, the approach for specific organisms, the monitoring required to demonstrate that risk levels are met, and how risk assessment might be approached for determining whether a given level of risk from Giardia and viruses is avoided. Guidelines are suggested for determining the level of treatment necessary to ensure that consumers receive a finished drinking water with risks of less than one infection per 10,000 people per year from Giardia and enteric viruses.

Dose–response data on human exposure to oocysts of Cryptosporidium were analyzed to determine the dose corresponding to a stated risk level. A recent study of infection and illness in human volunteers subjected to controlled exposure to oocysts of Cryptosporidium parvum provided a suitable data base for dose–response analysis. The authors analyzed the study data, and using exponential and beta‐poisson dose–response models, arrived at an estimate of the waterborne concentrations associated with various risk levels.

A number of approaches offer promise for addressing the limitations of current antibody‐based detection methods. This report was prepared by the Working Group on Waterborne Cryptosporidiosis (Technical Task Force E, Developmental Status of Environmental Sampling, Water Testing, and Surrogate Indicators). Methods for detecting Cryptosporidium oocysts in water have centered around microscopic examination of fluorescent antibody‐stained concentrates from large‐volume water samples. The limitations of these antibody‐based methods include the need for experienced analysts, lengthy analytical time, expense, lack of specificity, erratic efficiency, low precision, and difficulty in determining viability. A number of methods, assays, and procedures that have the potential for ameliorating some of these limitations are currently being evaluated. How successful such processes will be remains to be demonstrated by the scientific community.

The authors suggest yardsticks to gauge the significance of finished water oocyst densities. From consideration of prior monitoring studies on finished water Cryptosporidium and measurements made during and after detected outbreaks, an action level for Cryptosporidium oocysts is defined. At concentrations within and above 10–30 oocysts/100 L in finished water, the possibility of an outbreak would appear to exist. In the lower range of this region and below, outbreaks may occur but may not be detectable. If a single sample exhibits counts at or above this level, further sampling on an expedited basis or consideration of supplemental performance data to support a decision should be undertaken.

In many arid environments an alternative source of water is needed to meet the growing demands of the community, agriculture, and industry, thus wastewater reuse has become a viable option. Although the use of wastewater for agricultural irrigation has been practiced for centuries, recently a conservative approach in fully utilizing this source of water has been taken. The uncertainty of the health risks to an exposed population through wastewater irrigation practices due to the possible presence of enteric pathogenic organisms is one of the major disadvantages. Pathogenic bacteria, parasites, and viruses are all found in sewage and may survive treatment processes. Once in the environment, many are able to exist for prolonged periods of time and outbreaks associated with wastewater irrigation have been documented. Epidemiological evidence is scarce, however, much has been done to determine the fate of the pathogens in the environment. The incidence, survival, and inactivation of pathogens in environments associated with the wastewater aid in the understanding of the sudden occurrence of epidemics and potential routes of transmission. The scope of this review includes epidemiological studies on populations exposed to wastewater, the microbial survival on crops irrigated with wastewater, and the incidence of some of the pathogens in wastewaters. Because many areas are now utilizing wastewater for a variety of purposes from potable water to landscape irrigation, proposed regulations governing its use are discussed.

The occurrence of waterborne transmission of infectious hepatitis has long been recognized, but only in recent years have methods become available for its assay and propagation in the laboratory. The advent of these techniques have led to the development of methods for the detection of the agent of infectious hepatitis in water. Rotaviruses, Norwalk agent, and related viruses are now recognized as major causes of waterborne nonbacterial gastroenteritis. Rotaviruses have been shown to occur in significant concentrations in domestic wastewater and have been detected in conventionally treated drinking water. Methods are still lacking for the detection of Norwalk agent(s) in water, but they continue to be the major cause of waterborne viral gastroenteritis.

Treatment of the pain that is caused by neuroma in continuity in a digital nerve on the palmar surface of the hand is a challenging problem. Eight digital nerves were covered with intrinsic muscle flaps after neurolysis to obtain relief of symptoms in eight patients. Four of the cases involved intrinsic muscles for digital nerves in the thumb. Four patients had digital nerves in the palm covered by lumbrical muscle flaps, two of which were distally based. All patients had significant relief of their symptoms. This report describes the techniques used and their application.

The fate of coliphage and human enteric viruses on turf grass was studied in order to elucidate the potential risk to public health when grass is irrigated with activated sludge treated sewage effluent. The survival of seeded coliphage MS-2, poliovirus type 1, and rotavirus SA-11 was studied outdoors during winter and summer. Virus inactivation rates were influenced by temperature as well as by type of virus. Coliphage, poliovirus, and rotavirus average inactivation rates (K = log inactivated/hr) were 0.17, 0.06 and 0.10 per hour, respectively, during the winter (4-10°C). In contrast, during the summer (36-41°C) K = 0.45, 0.37 and 0.20 per 'hour for MS-2, poliovirus, and rotavims, respectively. To achieve a 99% (2 log10) virus inactivation on turf grasses after the application of sewage effluents, 8 to 10 hours would be needed during the summer and 16 to 24 hours would be needed during the winter.and 0.10 per hour, respectively, during the winter (4-10°C). In contrast, during the summer (36-41°C) K = 0.45, 0.37 and 0.20 per hour for MS-2, poliovirus, and rotavirus, respectively. To achieve a 99% (2 log10) virus inactivation on turf grasses after the application of sewage effluents, 8 to 10 hours would be needed during the summer and 16 to 24 hours would be needed during the winter.

The article explores the threats to water quality and the importance to start a concerted effort to build large data sets relevant in defining water quality and the efforts toward sustainable future. It states that the quality of water is significant in assessing human health. It highlights the continued degradation of water quality due to climate change, urbanization and population growth. The need to invest on innovative strategies to address water pollution is also mentioned.

The article offers information on the International Collaboratory for Sewage initiative, which is part of the Health-Related Water Microbiology Specialist Group of the International Water Association (IWA). The group is developing a microbial source tracking tool that can be used to monitor and assess human fecal pollution in waters across the globe. Statistics released by the World Health Organization on the extent of sewage contamination and water pollution globally are presented.