Developing Drinking-Water Quality Regulations and Standards

This document provides practical guidance to support the development or revision of customized national or subnational drinking-water quality regulations and standards.The principles and guidance presented are broadly applicable across countries and contexts, including more resource-limited settings. Supporting examples from both lower- and higher-income countries are included.Drinking-water quality regulations and standards developed or revised in accordance with this guidance will reflect the best practices identified in the WHO Guidelines for Drinking-water Quality to most effectively protect public health. Moreover, the regulations and standards will consider local needs, priorities and capacities to ensure that they are realistic and appropriate. Topics covered include:Guiding principlesGetting startedSelecting parameters and parameter limitsSetting out compliance monitoring requirement

Common or independent? The debate over regulations and standards for water reuse in Europe

Although unplanned water reuse has been practised across Europe for decades, multiple stresses on water supply and demand over recent years have led to the development of many planned reuse schemes. Despite this development, the legislative and regulatory regimes required to underpin a growing water reuse sector have arguably failed to emerge. The reasons for this and the cases for and against pan-European water reuse regulations are explored and debated. The conclusions highlight several challenges for politicians and policy makers if appropriate regulatory systems and water quality standards are to be provided which support the embryonic European water reuse sector

Understanding the impact of crop and food production on the water environment ‐using sugar as a model

The availability of fresh water and the quality of aquatic ecosystems are important global concerns, and agriculture plays a major role. Consumers and manufacturers are increasingly sensitive to sustainability issues related to processed food products and drinks. The present study examines the production of sugar from the growing cycle through to processing to the factory gate, and identifies the potential impacts on water scarcity and quality and the ways in which the impact of water use can be minimised. We have reviewed the production phases and processing steps, and how calculations of water use can be complicated, or in some cases how assessments can be relatively straightforward. Finally, we outline several ways that growers and sugar processors are improving the efficiency of water use and reducing environmental impact, and where further advances can be made. This provides a template for the assessment of other crops

Lead in drinking water – an ongoing public health concern?

Lead remains a problem in drinking water in many parts of the world, with millions of properties served by distribution systems containing leaded components. This review considers the latest information on lead in drinking water and presents perspectives on solving the lead problem. Strong links have been established between human exposure to lead and health impacts, both in adults and children. As a result, permissible levels of lead in drinking water have generally become lower. However, achieving these regulations is challenging with the controls available. Future recommendations for aspiring to zero lead in drinking water are i) improved sampling, monitoring and modelling; ii) wider application of point of use devices in the short term; iii) replacement of all lead pipes and plumbing through enforceable regulation and heightened public awareness

A validated reverse-phase LC-MS/MS method for the analysis of haloacetic acids in drinking water: supporting the transition from HAA5 to HAA9

Haloacetic acids (HAAs) are potentially toxic by-products formed from interactions between organic matter and chlorine during disinfection of drinking water, with brominated HAAs forming when bromide is present. Some countries require monitoring of drinking water for five HAAs, but there is increasing health concern related to the more toxic brominated HAAs and monitoring of nine HAAs (HAA9) is becoming more widespread. However, existing methods of analysis for HAA9 are often sub-optimal, involving complex derivatisation steps and/or long analytical run times. This article presents an improved methodology utilising reverse-phase liquid chromatography mass spectrometry (LC-MS/MS) for which sample preparation involves simple pH adjustment and the analytical run takes 10 min. The efficacy of the method was demonstrated by a full validation across four drinking water matrices with good sensitivity (<0.8 μg/L), precision (<7%), and bias (<10%) observed. A direct comparison using real water samples was performed against the widely used existing gas chromatography method. The new LC-MS/MS method was significantly quicker and easier and demonstrated improved performance in terms of accuracy and precision. This has implications for understanding the risk posed by HAAs in chlorinated water by eliminating the possible historical under-estimates of the levels of the more toxic brominated compounds.The work was supported by UK Water Industry Research Ltd (UKWIR) and Engineering and Physical Sciences Research Council (EPSRC) through their funding of the Water Infrastructure and Resilience (WIRe) Centre for Doctoral Training [EP/5023666/1]

Relation of Trihalomethane Concentrations in Public Water Supplies to Stillbirth and Birth Weight in Three Water Regions in England

We investigated the association between total trihalomethanes (TTHMs) and risk of stillbirth and low and very low birth weight in three water regions in England, 1992–1998; associations with individual trihalomethanes (THMs) were also examined. Modeled estimates of quarterly TTHM concentrations in water zones, categorized as low (< 30 μg/L), medium (30–59 μg/L), or high (≥60 μg/L), were linked to approximately 1 million routine birth and stillbirth records using maternal residence at time of birth. In one region, where there was a positive socioeconomic deprivation gradient across exposure categories, there was also a positive, significant association of TTHM with risk of stillbirth and low and very low birth weight. Overall summary estimates across the three regions using a random-effects model to allow for between-region heterogeneity in exposure effects showed small excess risks in areas with high TTHM concentrations for stillbirths [odds ratio (OR) = 1.11; 95% confidence interval (CI), 1.00–1.23), low birth weight (OR = 1.09; 95% CI, 0.93–1.27), and very low birth weight (OR = 1.05; 95% CI, 0.82–1.34). Among the individual THMs, chloroform showed a similar pattern of risk as TTHM, but no association was found with concentrations of bromodichloromethane or total brominated THMs. Our findings overall suggest a significant association of stillbirths with maternal residence in areas with high TTHM exposure. Further work is needed looking at cause-specific stillbirths and effects of other disinfection by-products and to help differentiate between alternative (noncausal) explanations and those that may derive from the water supply

Clarifying the absence of evidence regarding human health risks to microplastic particles in drinking-water: High quality robust data wanted

In a recently published article, Leslie and Depledge (2020) raise concerns regarding statements on the risk that microplastic particles represent to human health and which have been attributed to reports published by both the Science Academies’ Group, Science Advice for Policy (SAPEA) (part of the European Commission’s Science Advice Mechanism) and the World Health Organization (WHO) (SAPEA. Science Advice for Policy by European Academies, 2019, WHO, 2019). Leslie and Depledge (2020), for instance, suggest that WHO (2019) conclude that there is ‘no evidence to indicate a human health concern.’ This statement, taken out of context from the WHO report (WHO, 2019), is then used to imply that the WHO conclude there is ‘no risk’ related to the exposure of microplastic particles (Leslie and Depledge, 2020). While, Leslie and Depledge (2020) highlight the importance of debate and systematic assessment of claims related to the assessment of risk, observations that we agree are important to highlight, there are a number of points raised in the article that require clarification

Pancreatic Transcription Factors Containing Protein Transduction Domains Drive Mouse Embryonic Stem Cells towards Endocrine Pancreas

Protein transduction domains (PTDs), such as the HIV1-TAT peptide, have been previously used to promote the uptake of proteins into a range of cell types, including stem cells. Here we generated pancreatic transcription factors containing PTD sequences and administered these to endoderm enriched mouse embryonic stem (ES) cells under conditions that were designed to mimic the pattern of expression of these factors in the developing pancreas. The ES cells were first cultured as embryoid bodies and treated with Activin A and Bone morphogenetic protein 4 (BMP4) to promote formation of definitive endoderm. Cells were subsequently plated as a monolayer and treated with different combinations of the modified recombinant transcription factors Pdx1 and MafA. The results demonstrate that each transcription factor was efficiently taken up by the cells, where they were localized in the nuclei. RT-qPCR was used to measure the expression levels of pancreatic markers. After the addition of Pdx1 alone for a period of five days, followed by the combination of Pdx1 and TAT-MafA in a second phase, up-regulation of insulin 1, insulin 2, Pdx1, Glut2, Pax4 and Nkx6.1 was observed. As assessed by immunocytochemistry, double positive insulin and Pdx1 cells were detected in the differentiated cultures. Although the pattern of pancreatic markers expression in these cultures was comparable to that of a mouse transformed β-cell line (MIN-6) and human islets, the expression levels of insulin observed in the differentiated ES cell cultures were several orders of magnitude lower. This suggests that, although PTD-TFs may prove useful in studying the role of exogenous TFs in the differentiation of ES cells towards islets and other pancreatic lineages, the amount of insulin generated is well below that required for therapeutically useful cells

Chemicals in the water environment: where do the real and future threats lie?

There are many potential sources of chemical constituents and contaminants in water that can reach drinking water. Not all substances will be present in any particular water. Some substances may be of benefit to health but others can be a threat. However, very few have been clearly shown to cause adverse health effects in humans through drinking water and evidence may be complicated by simultaneous exposure through food. Our knowledge of contaminants in water is, however, incomplete as additional contaminants emerge with advancing analytical methods. Most of these emerging contaminants are present as a consequence of day to day use by the wider human population and control requires a different approach to the substance by substance regulation prevalent at present