News Items Archive 2019

Please note that, for some of the older entries, links may no longer be functional.

Fluoride and ADHD (Posted 11/12/2019)
A Mexican study measuring urinary fluoride in 214 gestational mothers and assessing offspring for symptoms of ADHD observed a positive association between higher prenatal fluoride exposure and behavioral symptoms of inattention, but not hyperactivity or impulse control. The study recognises that it has limitations.

Potential risks from microplastics in water. (Posted 05/12/2019)
UKWIR has produced a timely review on microplastics and nanoplastics in water. The study, following a comprehensive literature review, measured microplastics at 8 water treatment and 8 water reclamation plants. The study concluded that water treatment removed 99.99% of microplastic particles and water reclamation 99.9%. There is a need for standard methods with proper analytical controls and more work on the topic is required.

Describing tastes and odours (Posted 29/11/2019)
This review finds that while some taste and odour chemicals are effectively described by a few descriptors ( such as “salty” or “chlorinous”) for others there can be ten or more descriptors with no concensus.)

Distribution impacts of changing supply quality Posted 20/11/2019)
This extremely comprehensive review looks at the possible impacts of changing the quality of water fed into established distribution systems including destabilisation of existing deposits. It presents a framework for the evaluation of potential transition. effects. (More...)

U-V disinfection – a statement. Posted 20/11/2019)
CIWEM has issued a policy statement on u-v disinfection of drinking water supplies.

A new disinfection approach to control halogenated disinfection byproducts (Posted 18/11/2019)
Laboratory studies carried out in China showed that chlorination by-products (DBP) could be very much reduced by a novel disinfection approach using a combination of ion-exchange with a chloride-exchange resin followed by electrolysis. The treated water showed a reduction in cytotoxicity, and effective inactivation of seeded bacteria including E.coli.

Distribution impacts of changing supply quality (Posted 18/11/2019)
This extremely comprehensive review looks at the possible impacts of changing the quality of water fed into established distribution systems including destabilisation of existing deposits. It presents a framework for the evaluation of potential transition effects.(Ref 1; Ref 2)

Non-tuberculous Mycobacteria in drinking water systems (Posted 14/11/2019)
This review article summarizes the information and data published up to now on the factors favoring the presence of these bacteria in natural and artificial water systems and the effectiveness of water treatment . These bacteria are generally referred to as Mycobacterium avium complex (MAC) although the two terms are not synonymous.

Endocrine disruptors in pregnancy and IQ. (Posted 11/11/2019)
A recent study has shown that exposure during the first trimester of pregnancy to mixtures of suspected endocrine-disrupting chemicals found in consumer products is related to lower IQ in children by age 7. While drinking water is not considered it is significant that bisphenol F (BPF), a BPA-replacement compound, made the highest contribution to lowering children's IQ, suggesting that BPF is not any safer for children than BPA.

Fluoride in drinking water and ADHD (Posted 11/11/2019)
A study using data collected by Health Canada showed that higher tap water fluoride was associated with higher odds of an ADHD diagnosis and more ADHD-type symptoms for adolescents. .A 1 mg/L increase in tap water fluoride level was associated with a 6.1 times higher odds of an ADHD diagnosis.

Discolouration risk in drinking water distribution systems (Posted 11/11/2019)
This study shows that flow conditioning, the careful regular increase in flows to mobilise small amounts of material from cohesive layers formed at the pipe wall, provides immediate risk mitigation and system resilience benefits. Whilst the flow conditioning produced an acute but short duration controlled mobilisation of material from the trunk main, longer term downstream monitoring showed reduced chronic or background material loading.

Effect of fluoride in pregnancy on IQ. (Posted 31/10/2019)
A recent Canadian study shows that fluoride exposure during pregnancy was associated with lower IQ scores in children aged 3 to 4 years. Although most expert commentators have described the study findings as inconclusive, and cautioned against changing public health policy on water fluoridation on the basis of these results, it can be expected that the anti-fluoridation lobby will promote the study.

A detailed critique is available in Issue 95 of Health Stream, a subscription service publication of Water Research Australia.

Impact of Climate Change on Trihalomethanes Formation (Posted 31/10/2019)
Monitoring data from five full-scale Scottish drinking water treatment plants (DWTPs) showed that significant correlations exist between trihalomethanes (THMs) levels, water temperature (r = 0.812, p = 0.0013) and dissolved organic carbon (DOC) (r = 0.892, p < 0.0001), respectively. The strong seasonality of these parameters demonstrated how climate can influence THMs formation. An increase in mean summer temperatures will likely increase THM formation, with a 1.8 ░C temperature increase and 39% THMs increase by 2050.

Nitrate in drinking water and the risk of congenital anomalies. (Posted 31/10/2019)
A study in Missouri of almost 350,000 live births found that even though nitrate levels in drinking waters were generally.below 10mg/l, after allowing for private well supplies nitrate exposure was associated with a significantly increased risk of limb deficiencies Nitrate was also weakly associated with an increased risk of congenital heart defects . The authors add that the results of the study should be interpreted with caution given limitations in our ability to estimate exposures and the lack information on some risk factors for congenital abnormalities.

Cryptosporidium spp. linked to human outbreaks of cryptosporidiosis in England and Wales, 2009 to 2017 (Posted 31/10/2019)
Of the 178 outbreaks investigated in this period only 2 were associated with drinking water supplies.

Norovirus risk in direct potable reuse (Posted 31/10/2019
Conventional quantititive microbial risk assessment (QMRA) uses static models in which the probability of infection is calculated as a single exposure event with minimal (if any) time dependence or system feedback. This results in a disconnect between the number of shedding individuals at any given time, the pathogen load to the environment and the water/wastewater treatment infrastructure, and the implications for public health risk. This disconnect also makes it particularly difficult to fully characterize risks associated with highly contagious pathogens, such as norovirus (NoV), which often involve numerous ‘secondary’ infections. Ultimately, static QMRAs may underestimate the true risk of waterborne disease within a community by not capturing the effects of secondary transmission. A study using dynamic quantitative microbal risk assessment (QMRA), which accounts for the above deficiencies, concludes that secondary and foodborne transmission dominate the overall risk calculation and that waterborne NoV likely contributes no appreciable public health risk.

Asssesing effects of changing supply source on water quality. (Posted 26/10/2019
Following upgrade of treatments in an unchlorinated drinking water supply system in the Netherlands, transition effects caused by changing the supply water quality that resulted from destabilization of biofilm and loose deposits in DWDS were investigated by analyzing the physiochemical and microbiological characteristics of suspended particles before , during ( after 3 weeks) and 6 months after upgrading the treatments (T6-months).. Although some quality deterioration was apparent after 3 weeks, after 6 months water quality was improved and sustained. At no stage was consumer perception adversely affected.

Hepatitis E virus in raw and treated waters. (Posted 22/10/2019)
This extremely detailed and thorough Swedish paper does not make light reading for anyone not extremely well-versed in the latest genetic tools. This reviewer, having been raised on agar plates and inoculating loops, is not equipped to look critically at the paper. Using genetic sequencing the authors found viruses from 12 to 18 families were still tap water with Hepatitis E virus 3 strains present in tap water in low level. They conclude that the risk for getting infected by viruses in the concentrations detected in the drinking water is probably negligible. Howeverthey also conclude that further studies are necessary to investigate the viability of the viruses identified in water.

Water network resilience (Posted 30/09/2019)
USEPA and Sandia National Laboratories have launched the Water Network Tool for Resilience, a comprehensive scientific software package to help assess a drinking water systems resilience to natural disaster. The software improves upon already available capabilities by fully integrating hydraulic and water quality simulation, damage estimates and response actions, and resilience metrics into a single platform. The software is available as an open source software package and can be applied to a wide range of disruptive incidents and repair strategies.

Revision of WHO Guidelines for Drinking Water Quality (Posted 30/09/2019)
As part of the development programme for the second addendum of the GDWQ, WHO is inviting comments by 7 November on draft documents for Chromium, Iodine, and Nickel.

Carcinogenic contaminants in US Drinking Water (Posted 24/09/2019)
Cumulative risk analysis of contaminant occurrence in United States drinking water for the period of 2010–2017 indicates that over 100,000 lifetime cancer cases could be due to carcinogenic chemicals in tap water. The majority of this risk is due to the presence of arsenic, disinfection byproducts and radioactive contaminants.

Burst pipe location. (Posted 18/09/2019)
A novel approach using a newly developed algorithm enabled correct location of 57 of the total 58 synthetic bursts in the potential burst district when the top five most possible pipes were considered.

Potential risks from nanoparticles and microplastics (Posted 18/09/2019)
UKWIR has carried out the first study of its kind in the UK to develop a robust approach to sampling and detection of microplastic particles in the treated water cycle. This included accurately measuring the presence of microplastic particles in potable (drinking) water, treated wastewater and in the solid residues (sludge) produced by both the water and wastewater treatment processes.

This research has confirmed that both the water and the wastewater treatment processes effectively remove 99.9% of microplastic particles from the final product i.e. the potable water and treated wastewater. It also demonstrates that a robust process for sample collection and analysis, free from airborne contamination, is vital to ensure accurate results.

For the project, microplastics were defined as particles >25 Ám that had been captured on 10 Ám filters.

Distribution impacts of changing supply quality (Posted 11/09/2019)
This extremely comprehensive review looks at the possible impacts of changing the quality of water fed into established distribution systems including destabilisation of existing deposits. It presents a framework for the evaluation of potential transition effects.

Booster chlorination design (Posted 11/09/2019)
This paper presents a scenario-based robust optimisation approach which was developed to obtain booster chlorination designs that withstand uncertain network operations and water demand conditions in the distribution system. It develops robust booster chlorination (RBC) designs, which indicate the number of boosters, locations and injection rates in the network.

Potable water reuse (Posted 31/08/2019)
Water Research Australia has published a comprehensive report providing a summary of key developments and the current status of potable reuse practice, identifying and understanding the drivers and incentives that have underpinned progress. In particular the report includes an overview of recently produced guidelines and best practice documents, with a particular focus on the ways in which international and Australian regulators have approached regulation of potable reuse for the prime purpose of ensuring full protection of public health.

Origin of bacteria in tap water and distribution systems (Posted 31/08/2019)
Workers in the Netherlands have reported on a very detailed study of composition of bacterial communuities from source water to tap. There was not a detectable contribution of source water to bacterial community in the tap water and distribution system. The planktonic bacteria in the treated water was the major contributor to planktonic bacteria in the tap water They conclude that the tap water bacteria could possibly be managed by selecting and operating the purification process properly and cleaning the distribution system effectively.

Research priorities in water and health (Posted 31/08/2019)
The tenth anniversary meeting of the International Water and Health Seminar in 2018 brought together experts, students, and practitioners, setting the stage for development of an inclusive and evidence-based research agenda on water and health. Their findings present a comprehensive agenda of topics at the forefront of water and health research. This information can frame and inform collective efforts of water and health researchers over the coming decades, contributing to improved water services, public health, and socioeconomic outcomes

Microplastics in drinkinjg water (Posted 31/08/2019)
WHO has published an authoritative report which critically examines the evidence related to the occurrence of microplastics in the water cycle (including both tap and bottled drinking-water and its sources), the potential health impacts from microplastic exposure and the removal of microplastics during wastewater and drinking-water treatment. Recommendations are made with respect to monitoring and management of microplastics and plastics in the environment, and to better assess human health risks and inform appropriate management actions, a number of key knowledge gaps are identified.

Effect of silver nanoparticles on Cryptosporidium oocysts. (Posted 30/08/2019)
Using Cryptosporidium oocysts isolated from tapwater, workers in Egypt have shown that silver nanoparticles at 1ppm resulted in loss of viable C. parvum oocyst to 97.2%. and the activity was dose dependent. They report however a noticeable increase in the oocyst's viability at 2 and 4 h.

Potential toxicity of iron deposits in mains. (Posted 30/08/2019)
Workers in Beijing found that iron particle-dominated loose deposits, which were collected from a real DWDSs through pipe flushing, possessed obvious toxicity to human liver cells. Lab studies using FeOOH crystals grown in conjunction with other compounds showed structure transformation with the coexisting matters which further influenced their toxicity: the samples with sharp surfaces had higher toxicity than those with smooth surfaces.

Manganese deposition and release in drinking water distribution systems. (Posted 27/08.2019)
Field studies on 7 distribution systems in China showed that particulate Mn tended to accumulate in DWDS even at concentrations as low as 10 μg/L . When total Mn concentration in finished water was below 5 μg/L, erosion of Mn deposits occurred in DWDS with a Mn deposit inventory. Soluble Mn release was observed when chlorine or chlorine dioxide concentration was lower than 0.1 mg/L. Ensuring the total Mn concentration is below 10 μg/L and decreasing the particulate Mn concentration to 5 μg/L in finished water are both recommended.

Distrust of public water supplies (Posted 20/08/2019)
A study in Los Angeles County suggests new requirements for systems to report quality contamination in distributional networks and incentives for property owners to upgrade premise plumbing. It also reasserts that infrastructure neglect contributes to rational, but costly decision-making by disadvantaged urban communities to consume tap alternatives.

Improving pipe failure prediction (Posted 20/08/2019)
Pipe failure prediction models are often built by environmental data scientists with limited in-field experience of either fixing pipes or recording data about network failures. As infrastructure data can be inconsistent, incomplete and incorrect, this disconnect between model builders and field operatives can lead to logical errors in how datasets are interpreted and used to create predictive models. To enable data scientists to build more accurate predictive models of pipe failure, this paper summarises typical factors influencing failure for 5 common groups of materials for water pipes.

Flow cytometry applications in water treatment, distribution, and reuse (Posted 20/08/2019)
Numerous papers are currently being published on flow cytometry and water supply and this review identifies and examines nearly 300 studies published from 2000 to 2018 that illustrate the benefits and challenges of using FCM for assessing source-water quality and impacts of treatment-plant discharge on receiving waters, wastewater treatment, drinking water treatment, and drinking water distribution. It discusses options for combining FCM with other indicators of water quality and addresses several topics that cut across nearly all applications reviewed. Finally, it identifies priority areas in which more work is needed to realize the full potential of this approach. Other similar papers can be accessed here and here.

Manganese can increase lead release from pipes (Posted 15/08/2019)
Canadian workers have shown that when manganese comes into contact with chlorine, it's oxidized, turning into manganese oxide. Both in computer models and in experiments that mimicked water pipes -- complete with artificial tap water -- they found that the manganese oxide acted as a catalyst, increasing the rate of conversion from lead carbonate to lead dioxide by two orders of magnitude.

Solar steam generation for clean water production (Posted 15/08/2019)
Canadian researchers have developed a robust solar steam generation system that achieves efficient and continuous clean water production from salty water with almost 100 per cent salt removal. The process uses a disc of super-hydrophilic filter paper with a layer of carbon nanotubes for light absorption. A cotton thread, with a 1mm diameter, acted as the water transport channel, pumping saline water to the evaporation disc.

Through precisely controlling salt crystallisation only at the edge of the evaporation disc, this novel design also can harvest the salts. Continuous steam generation and salt harvesting was achieved during over 600 hours of non-stop operation.

Prevalence and public health implications of mycotoxigenic fungi in treated drinking water systems (Posted 06/08/2019)
This very comprehensive paper provides a review on the prevalence of mycotoxigenic fungi and their implications to public health in treated drinking water, and the need for inclusion in treated drinking water quality regulations.

To date, no conclusive correlation has been found between indicator organisms such as E. coli and other coliforms to fungi in treated drinking water system This is because fungi can resist disinfection while coliform bacteria would be eradicated. This lack of correlation between coliforms and fungi presence in drinking water distribution systems may mean that there is a possibility for bacteriologically safe water to contain some pathogenic fungi. The growing list of documented pathogenic fungi from treated drinking water can no longer be ignored as water contaminants although the potential health impact of waterborne fungi is still not clear.

App for detecting cyanobacterial blooms (Posted 06/08/2019)
USEPA is developing an app which uses satellite data to detect and predict harmful cyanobacterial blooms.

Flow cytometry v heterotrophic plate counts. (Posted 06/08/2019)
It has long been recognised that conventional plate counts(HPC) only detect a fraction of bacteria present. This study shows that flow cytometry(FCM) has many advantages over plate counts, providing a faster, more descriptive and more representative quantification of bacterial abundance in drinking water. No good correlation was found between HPC and FCM but FCM correlated well with ATP. FCM measurements are reproducible with relative standard deviations below 3% and can be available within 15ámin of samples arriving in the laboratory. High throughput sample processing and complete automation are feasible and FCM analysis is arguably less expensive than HPC when measuring more than 15 water samples per day, depending on the laboratory and selected staining procedure(s).

Household Water Treatment Evaluation Scheme (Posted 06/08/2019)
Since the establishment of the International Scheme to Evaluate Household Water Treatment Technologies (the Scheme) in 2014, WHO has been independently evaluating the performance of household water treatment (HWT) technologies in removing microbial contaminants from drinking-water. The results of the evaluation are intended to guide procuring United Nations (UN) agencies and Member States in HWT selection.

This report summarizes the results of 19 of 20 HWT products evaluated in Round II of the Scheme . These represent a range of treatment methods, including chemical, solar and ultraviolet (UV) disinfection, and ceramic and membrane filtration. The report highlights that among the products that do not meet WHO performance criteria, manufacturing quality is weak, and needs to be strengthened

Effect of pipewall material on DBP formation (Posted 01/08/2019)
A study of the effect of different materials, wall effects, bulk reactions, and water movement showed that on average, the choice of polyvinyl chloride (PVC) and ductile iron can account for as much as 36% difference in trihalomethane (TTHM) formation and 60% difference in chlorine residual decay over time. In ductile iron pipe systems there is a net loss of TTHM yield due to non-TTHM forming chlorine demand imposed by the pipe environment, whereas in PVC pipe, pipe effect is >1. In PVC systems there is an overall increase in TTHM formation as a result of pipe wall surface reactions.

Atrazine standard for drinking water (Posted 01/08/2019)
A recent paper suggests that adverse effects can occur in male mice at the NOAEL (No Observed Adverse Effects Level) used in Australia.. This might cause a reconsideration of the WHO Guideline value for drinking water.

1,4-Dioxane as an emerging water contaminant (Posted 29/07/2019)
Over one-fifth of U.S. public drinking water supplies contain detectable levels of 1,4-dioxane. Although the U.S. Environmental Protection Agency has listed 1,4-dioxane as a high priority chemical and classified it as a probable human carcinogen there are as yet no federal or state maximum contaminant levels for 1,4-dioxane. A review by a veritable army of authors highlights the current state of knowledge, key uncertainties, and data needs for future research on 1,4-dioxane. However WHO has set a guideline value for drinking water of 0.05 mg/l since 2005. As 1,4-dioxane is not a pesticide it does not appear to be covered specifically by the Water Supply (Water Quality) Regulations although Regulation 4 (2) (a) may apply.

Recent drinking water disease outbreaks in affluent nations (Posted 29/07/2019)
An excellent review of the 24 outbreaks of disease due to drinking water which have been reported in the scientific literature since 2000 has been published. The review highlights common themes contributing to the outbreaks which include complacency, naivetÚ and ignorance, failure to learn from experience and chemophobia. This latter refers to a disproportionate concern over chemicals which are of limited significance. It is most concerning when worries regarding disinfection byproducts for which there is very little evidence for adverse health effects have led to inadequate disinfection and documented disease outbreaks.

Real time control of distribution networks (Posted 29/07/2019)
This paper presents a review of the current state of the art of real time control (RTC) of water distribution networks Various control methodologies recently proposed in the scientific literature are presented and discussed, along with experimental and numerical results achieved.

Reducing leakage inAustralia. (Posted 29/07/2019)
The Water Services Association of Australia has published an interesting report on water leakage with a number of interesting case studies which is well worth reading. In particular a section on the use of a leak detection dog!

Gadolinium in drinking water. (Posted 29/07/2019)
Gadolinium is used in MRI scans and is subsequently excreted. It is not well removed in wastewater treatment, can be detected in water resources and some workers are expressing concern over its possible health significance.

Real-time control of distribution systems (Posted 21/06/2019)
This paper presents a review of the current state of the art of real time control of water distribution networks. Various control methodologies recently proposed in the scientific literature are presented and discussed, along with experimental and numerical results achieved. Also, aspects related to the cost-effectiveness of RTC are critically analyzed.

Water cycle diagrams need improvement. (Posted 21/06/2019)
Examination of 464 watercycle diagrams from around the world showed that only 2% showed climate change or water pollution, two of the central causes of the global water crisis, as significant aspects of the water cycle. Although human freshwater appropriation now equals half of global river discharge, only 15% of the water cycle diagrams depicted human interaction with water. Most diagrams showed only an idealised single catchment. Flaws in water diagrams reflect and reinforce the misunderstanding of global hydrology by policymakers, researchers and the public.

Optimising booster chlorination. (Posted 21/06/2019)
Workers in Botswana have developed a scenario-based robust optimisation approach for obtaining booster chlorination designs that withstand uncertain network operations and water demand conditions in the distribution system.The results present robust booster chlorination (RBC) designs, which indicate the number of boosters, locations and injection rates in the network.

Flow virometry (Posted 21/06/2019)
This review discusses recent developments in flow cytometry (FCM) in the context of water reuse and focusses on its development to the stage that it can now be used to detect viruses. It proposes use of FCM for near realtime monitoring across treatment.

Contaminants migrating from polyethylene pipes and their effect on drinking water odour. (Posted 21/06/2019)
The formation potential of contaminants diffusing from cross-linked polyethylene (PE-X) pipes and their impact on the odour of drinking water was determined. by analysing migration waters. Many pipes exceeded the German odour standard but although a number of compounds were detected no odour was perceived for most of them.

Unintended effects of engineering agents and materials on production of disinfection by-products (DBP). (Posted 21/06/2019)
This very detailed review highlights situations in which the use of engineering agents and materials in drinking water treatment and distribution needs balance against deleterious impacts on DBP formation.

Temporal disinfection byproducts (DBP)variations in a consumer's tap. (Posted 13/06/2019)
Samples taken every 6 hours over a month at selected sites and weekly over a year at more sites showed that DBP levels were highest in summer and lowest in spring. Within one week, higher levels of haloacetic acids (HAAs) were identified on weekdays than those on weekends. Diurnally, trihalomethanes, HAAs, and haloacetaldehydes were found to be higher at noon but lower in the evening. Variations of most DBPs were somewhat positively related to the changes of temperature and organic matter, but negatively related to the quantity of free chlorine.

Non-Tuberculous Mycobacteria (NTM) in drinking water (Posted 13/06/2019)
Pulmonary infections with NTM are a growing concern worldwide This recent review highlights a recent work focused on quantification and characterization of NTM and on understanding the influence of source water, treatment plants, distribution systems, and building plumbing on the abundance of NTM in drinking water.

rRNA sequencing to identify fecal contamination sources (Posted 28/05//2019)
A Canadian study in a community reliant on wells liable to faecal bacteria comtamination used quantitative polymerase chain reaction (qPCR) and high-throughput DNA sequencing to trace faecal contamination sources and identified Campylobacteraceae as a fecal contamination DNA marker in septic tank effluents. Using human specific Bacteroidales markers, it identified leaking septic tanks as the likely primary fecal contamination source in some of the community's groundwater.

Emerging pathogens and deliberate attacks on European water supplies (Posted 28/05//2019)
A group of experts met recently and developed qualitative scenarios on potential threats posed by either an emergent pathogen in or a microbiological attack on drinking water supplies in a European country. Five scenarios in outline form are reported which incorporate genuine possible future events as well as pathogens of international concern. Common features that would exacerbate all scenarios were under-investment in public services, inadequate water quality testing, and monitoring and lack of resources to keep water supplies safe.

Unintended effects of drinking water agents and materials on DBP formation (Posted 28/05//2019)
This review concludes that coagulant, ion-exchange resin, nanoparticle or biofilm could serve as the precursors of DBPs while activated carbon or membrane treatment may transform DBPs to more toxic compounds.

Differential absorbance for monitoring DBPs. (Posted 08/05/2019)
The relationship between DBP concentration and differential absorbance is affected by water source and time of year. This paper show that using differential absorbance at two wavelengths and initial absorbance ate one wavelength greatly improves the determination coefficients of the relationships, when compared with the best possible single-wavelength relationships. (See also)

Water loss detection in distribution systems. (Posted 08/05/2019)
This study aims at the development of an optimization model based on a model calibration, using artificial immune systems (description) for quantifying and locating water loss in water distribution networks without using observed pressure data as used by previous studies in the related literature. Laboratory studies showed that the model appeared to be promising in terms of water loss detection in WDNs.

Reproductive toxicity of atrazine. (Posted 08/05/2019)
This recent Australian paper demonstrates that a low dose of atrazine can perturb metabolic and reproductive characteristics in male mice. Exposure to 0.5mg/kg body weight, much lower than the WHO cited NOAEL of 1.8mg/kg, showed some adverse effects on sperm mobility and a higher percntage of dead spermatozoa in the epididymis. The study did not determine reproductive outcomes in terms of offspring.

DBPs in heated tap water (Posted 08/05/2019)
Studies in 2 Canadian distribution systems showed that residential heating of water resulted in an increase in levels of DBPs in tap water (pp 1735-1741). The difference in the average level of trichloromethane between cold and hot tapwater was statistically significant for each system and each season. The increase in the average trichloromethane levels from residential water heating was found to vary according to the system and the season, from 44% to 438%. The results indicate that populations may be more exposed to DBPs through hot water systems than cold water at the tap- the normal sampling location.

Significance of microplastics (Postrd 08/05/2019)
The European consortium of Science Advice for Policy by European Academies has produced an Evidence Review Report on microplastics and nanoplastics which has concluded that they do not currently pose a widespread risk to humans or the environment, except in small pockets, but that evidence is limited, and the situation could change if plastic pollution continues at the current rate.

It ststes that the evidence shows that microplastics are capable of having negative effects on the food consumption, growth, reproduction and survival of a range of aquatic species, once effect thresholds (no effect levels) are exceeded. ( i.e. have an effect once the no effect level has been exceeded. This can be said of anything!). It concludes that at present there are large differences between measured environmental concentrations and predicted no-effect levels estimated from available knowledge. Therefore, it is probable that ecological risks of microplastics are currently rare, although there may be some heavily impacted locations where predicted or measured environmental levels of NMPs currently exceed the no-effect levels. However, if microplastic emissions to the environment remain the same, the ecological risks of microplastics may be widespread within a century. The lack of quantitative data on many aspects of exposure and potential health effects currently prevents any quantitative attempt at human health risk assessment in relation to nano- and microplastics.

The field of microplastics research has recently seen a robust debate about the often poor methodological quality of published research, and overstatement of the implications for ecological and human health risks in both the scientific literature and the popular media. Some have argued that the resources being devoted to microplastics research and regulation would be better directed to proven and widespread ecosystem risks such as eutrophication that require urgent action, while others contend that the pervasive and increasing nature of plastic pollution necessitates better understanding of exposures and hazards before a conclusion about risk levels can be drawn.

Cost-benefit of point-of-use devices for lead reduction (Posted 08/05/2019)
This paper estimates the individual lifetime cost of reduction in IQ and associated loss of earning potential consequent upon exposure to lead in tapwater. It concludes that POU devices represent a cost-effective option to reduce the impact of lead exposure, particularly when water lead concentrations exceed regulated levels.

Treatment resistant E.coli (Posted 27/04/2019)
Canadian workers have shown a possible global distribution of naturalised wastewater strains of E.coli. These strains contain a plethora of antibiotic resistance genes as well as virulence genes. They suggest that this raises some important concerns about the potential for emergence of E.ácoli pathotypes resistant to water-treatment. (this does not impact on their possible significance as index or indicator organisms but raises other concerns)

Rapid isolation of E.coli (Posted 27/04/2019)
Using “bacteria-sized” gold-coated magnetic microdiscs workers were able to isolate E. coli from up to 100 mL water samples (LOD: 102 CFU/100 mL).within 45 minutes. Viability assays could be carrierd out on the captured discs using fluorescent markers . They suggest the method could be applied to drinking water with an enrichment step.

Flushing of household plumbing systems. (Posted 15/04/2019)
This paper looked at best practice for post-incident flushing of water supply plumbing in single premises. After considering existing guidance and the reading level required of recipients it produces guidance which recommends progressively opening all cold-water taps from the closest to point of entry to the furthest and allowing the water to run for at least 20 minutes while hot-water taps should be opened progressively and run for at least 75 minutes.

Microplastics in raw and treated drinking water (Posted 15/04/2019)
Another paper on this very topical topic. Czech Republic workers studied 3 water treatment works and found microplastics (MP) in all samples of raw and treated water at 3 works. Up to 95% of MP were in the range 1-10μm and the treated waters contained from 338 to 628 particles/litre.

Microplastics in drinking water from groundwater sources. (Posted 15/04/2019)
This study looked for microplastics >20μm and found <1 particle/m3. Clearly agreement is required on what constitutes microplastics and perhaps a size range classification.

Making lead pipes safe (Posted 10/04/2019)
Scientists have described a rapid, cost-effective method to overcome problems when changes in water source or treatment have led to loss of scale. They propose that lead pipes can be made safe by application of an external low-voltage electrical charge to speed up scale formation with phosphate.

How to distinguish urban vs. agricultural sources of persistent organic pollutants (Posted 10/04/2019)
This paper presents a relatively simple and effective method for distinguishing between urban and agricultural sources of anthropogenic chemicals. Application at a number of sites showed some classes of materials, including PCBs, to be mainly urban in origin while others, such as hexachlorocyclohexanes were mainly derived from agriculture. Surprisingly DDT had a strong urban signature.

Microplastics in freshwaters and drinking water. (Posted 09/04/2019)
WHO has commisioned this review of microplastics in freshwaters and drinking water which is intended to inform a report to be published on potential risks to public health from microplastics in drinking water. It proposes best practices for microplastic occurrence studies.

Microplastics in drinking water. (Posted 28/03/2019)
An excellent review of current knowledge about microplastics (MP) in drinking water with a bibliography of 52 papers. The review shows that MP can be found in both surface water and groundwater sources and in treated drinking water.

Disinfectant residual stability. (Posted 28/03/2019)
A recent review aims to give an understanding of how disinfectant residual stability in drinking water distribution systems is impacted by various influencing factors such as water quality and operational parameters. Important factors wea identified to include temperature, water age, piping material, corrosion products, pH, hydraulic condition, disinfectant residual type and dosage and microbial activity. Of 1809 relevant papers identified since 1998, 161 were assessed in detail.

Sachet water in Africa (Posted 28/03/2019)
In many African countries continuous fully-treated drinking supplies are not available and many people purchae driniking water in sachets which is widely believed to be “pure and safe” A study of 5 commercially marketed sachet supplies used by students in Ghana showed none to meet WHO Guidelines for coliforms or faecal coliforms, all having faecal coliform counts in excess of 105/100ml.

Antibiotic resistance in drinking water systems (Posted 27/03/2019)
A recent review has critically examined the occurrence of antibiotic resistance in groundwater, surface water, and treated distributed water. It concludes that combining UV-irradiation with advanced oxidative processes (such as UV/chlorine, UV/H2O2, and H2O2/UV/TiO2) may enhance the removal of antibiotic resistant bacteria and genes, while disinfection may promote horizontal gene transfer from environmental antibiotic resistant bacteria to pathogens.

True exposure to lead at the tap (Posted 27/03/2019)
A study in Canada on lead exposure in tapwater in 29 households used proportional sampling as the gold standard to which the other protocols, 5-min flush, 30-min stagnation, 6-h stagnation and random daytime were compared. Random daytime samples provided mean lead levels closest to true exposure in the households monitored overall compared to other sampling protocols. Strikingly, mean lead levels after 5 min of flushing underestimated lead exposure by 47%.

Review of microplastics in fresh and drinking water. (Posted 14/03/2019)
A review of 50 papers on microplastics in fresh and drinking water concludes that only 4 of these met all the criteria the authors proposed for the quality of studies. They conclude that more high quality data is needed on the occurrence of microplastics in drinking water, to better understand potential exposure and to inform human health risk assessments.

Ingested nitrate, disinfection by-products, and risk of colon and rectal cancers in women.(Posted 14/03/2019)
A recent study from the Czech Republic suggests that exposure to TTHM in drinking water is associated with increased risk of rectal cancer. Positive findings for individual THMs and Haloacetic acids (HAAs) for both colon and rectal cancers require replication in other studies. We found no associations for nitrate overall or in subgroups with presumed higher NOC exposure.

Detection of drugs of abuse in drinking water. (Posted (11/03/2019)
Workers at Anglia Ruskin University in Cambridge UK using LC-MS examined tap water for 20 drugs of abuse and pharmaceuticals and detected 5 drugs of abuse and 2 pharmaceuticals including mephedone and methylone which have not been reported in drinking water before. Detections were in the range of 0.14 to 2.81 ng/L.

1-4dioxane in drinking water. (Posted 19/02/2019)
Workers in the USA have published a review of 1,4dioxane in drinking water highlighting recent advances in analytical methods, understanding of occurrence, and treatment processes. Although the WHO Guideline value in drinking water is 50 μg/l the authors cite a “health-based reference concentration of 0.35 μg/L” and suggest “a need for developing and implementing management and treatment approaches that protect drinking water sources and prevent human exposure to 1,4-dioxane through drinking water.”

Phthalates effect on female reproduction in mice (Posted 19/02/2019)
Feeding female mice environmentally relevant concentrations of Di(2-ethylhexyl) phthalate (DEHP) or Diisononyl phthalate (DiNP) ranging from 20 micrograms to 200 milligrams per kilogram of body weight showed that DEHP and DiNP exposure has long-term consequences for female reproduction in mice, even long after cessation of exposure. ( WHO Guidelines note that primates are less susceptible than rodents to oral exposure to DEHP but set a Guideline value of 8μg/l for DEHP in drinking water).

Highly Efficient Metal-free Photocatalyst for Safe Drinking Water (Posted 19/02/2019
Workers in China have developed edge-functionalized graphitic carbon nitride (g-C3N4) as a photocatalytic disinfectant. They show that the pathogen-rich water can be rapidly purified in 30ámin with a disinfection efficiency of over 99.9999% under visible-light irradiation,

New method to simultaneously quantify priority disinfection by-products (Posted 10/02/2019)
A new gas chromatography (GC)-mass spectrometry (MS) method iis described that simultaneously quantifies 39 priority unregulated DBPs from six different chemical classes (haloacetaldehydes, haloketones, haloacetamides, haloacetonitriles, halonitromethanes, and iodinated-trihalomethanes) and analyzes unknown DBPs with mass accuracy<600 ppm under full-scan conditions.

Novel method for enumeration of coliphages (Posted 10/02/2019)
Workers based in Australia have developed the QuantiPhage method which uses a cellulose pad instead of the agar used in the conventional double layer overlay. This enables coliphages to be detected in water in under 3 hours.

Reducing PFAS in Drinking Water with Treatment Technologies (Posted 10/02/2019)
USEPA has produced a useful review of the ability of water treatment technologies to remove per- and poly-fluorinated substances (PFAs) from water.

Flow cytometry applications in water treatment, distribution, and reuse (Posted 10/02/2019)
Two Californian workers have published a useful review of almost 300 published papers on applications of Flow Cytometry to water. They suggest that more work is needed to realize the full potential of FCM in water treatment, distribution, annd reuse. Nonetheless they suggest that there is now a sufficiently large body of research documenting successful applications of FCM that the approach could reasonably and realistically see widespread adoption as a routine method for water quality assessment.

Bacteria-derived filter inactivates bacteria. (Posted 28/01/2019)
Workers in the USA produced membranes from bacterial cellulose using Gluconacetobacter hansenii bacteria and incorporating reduced graphene oxide (GO). In sunlight the membranes rapidly heated up to inactivate E.coli within 3 minutes whereas similar membranes without the reduced GO did not inactivate E.coli.

Persistent and mobile organic chemicals (PMOC) in water (Posted 28/01/2019)
A group of German annd Spanish workers, using a prioritized list of industrial chemicals that were modeled to be persistent, mobile, and emitted into the environment, successfully developed methods for 57 target PMOCs. Applying these to 14 water samples from three European countries a total of 43 PMOCs were detected in at least one sample, among them 23 PMOCs that have not been reported before to occur in environmental waters. ( There are at present no reasons to believe these compounds are of any significance in water supplies).

Review of non-tuberculous Mycobacteria in water (Posted 22/01/2019)
Epidemiological studies suggest that natural and drinking water are principal sources of infection with these organisms. This review looks at the factors favoring the presence of these bacteria in natural and artificial water systems, and the effectiveness of water treatment.

Analysis of disinfection by-products (DBP) (Posted 22/01/2019)
This review discusses current analytical methods and challenges associated with the identification and measurement of DBPs mainly published in the last two years.

Robots to fix underground pipes (Posted 22/01/2019)
As part of a ú26.6 million Government backed Investment Scheme, scientists from four British universities will use ú7 million government investment to develop 1cm-long robotic devices that use sensors and navigation systems to find and mend cracks in pipes.

Antibiotic resistance genes (ARG) in tap water. (Posted 22/01/2019)
Chinese workers have studied antibiotic resistance genes in small bacteria in tap waters. 265 ARG subtypes belonging to 17 ARG types were detected at abundances ranging from 4.0 Î 10−2 to 1.0 Î 100 copies/cell. Multidrug, bacitracin and aminoglycoside resistance genes were dominant, and 43 ARG subtypes were specifically carried by small-size microbes.

A review of Flow cytometry applications in water treatment, distribution, and reuse. (Posted 10/01/2019)
After reviewing almost 300 recent papers the authors conclude that while more work is needed to realize the full potential of Flow Cytometry in water treatment, distribution, and reuse, substantial progress has been made over the past two decades. There is now a sufficiently large body of research documenting successful applications of FCM that the approach could reasonably and realistically see widespread adoption as a routine method for water quality assessment.

Informing public attitudes to use of recycled water (Posted 10/01/19)
A recent study in London evaluated how different ways of framing messages about the safety of non-potable use of recycled water might impact on public attitudes. The study found a positive impact of water safety communications framed in terms of compliance with water quality requirements. Contrarily, a positive attitudinal impact was not evident for safety message framed in terms of the selection of water treatment technology to remove contaminants nor in terms of non-potable water risks relative to other every-day risks.

Rapid field quantification of Escherichia coli in surface waters (Posted 10/01/2019)
Workers in France have evaluated the ALERT automated monitoring system, which uses defined substrates to measure ▀ glucuronidase ( indicative of E coli) and ▀ galactosidase ( indicative of coliforms) activity in surface waters by comparison with conventional most probable number (MPN) methods using natural river waters. They conclude that ALERT technology is an accurate and rapid bacterial quantification technology, capable of autonomous inásitu measurements with metrological capabilities comparable to those of an approved laboratory using MPN microplate techniques.

Impact of blending for direct potable reuse on premise plumbing microbial ecology. (Posted 10/01/2019)
Bench and pilot scale studies on the impact of introducing treated recycled water into distribution system were carried out by US workers. Measurement of regrowth of total bacteria, opportunist pathogens, and antibiotic resistance genes showed almost no effect from the introduction of recycled water.

Waste Management when supplying bottled water (Posted 10/01/2019)
When bottled water was supplied in Flint, Michigan to c97,000 people, starting in October 2015 it is estimated that some 80 million disposable plastic bottles were used in the first 6 months. At the outset no contingency plans were in place to handle the waste plastic and there is little hard data to firm up estimates.. In addition some households were given point of use filters which meant used cartridges also needed disposal. Alarmingly 8% of households remained unaware that there was a problem with lead in their water supply as information was only supplied in English even to non-English speaking households. (This paper should be essential reading for water suppliers who can learn from the many deficiencies in the handling of this incident and ensure they have adequate plans for major water supply emergencies.)