Implementing risk-based approaches to improve drinking water quality in small water supplies in the Nordic region - barriers and solutions.

Small water supplies face similar problems worldwide, regardless of ownership or management type. Non-compliance with water quality regulations is more frequent in small supplies than in large ones, as are waterborne disease outbreaks. The new European Union Drinking Water Directive requires risk-based approach (RBA) to secure water safety as is recommended in the World Health Organization's Guidelines for drinking water quality through 'water safety plans'. This is already in regulation in the Nordic countries, although less used in small supplies. In this research, we explore the challenges, barriers and possible solutions to implementing RBA and improving compliance in small supplies. This was achieved by conducting and analysing interviews with 53 stakeholders from all eight Nordic countries to produce recommendations for action by the different implicated actors. Our findings suggest the centrality of governmental policy, including support for continuous training, provision of simple RBA guidelines and increasing cooperation in the water sector. The Nordic experience reflects global challenges with small water supplies and the trend towards systematic preventive management epitomized in the framework for drinking water safety advocated by the World Health Organization since 2004.

Development of macrolide resistance in Mycoplasma pneumoniae-infected Swedish patients treated with macrolides.

BACKGROUND: The proportion of Mycoplasma pneumoniae isolates carrying point mutations in the 23S region of the genome associated with macrolide resistance has increased. We evaluated the probability of developing M. pneumoniae macrolide resistance mutations during macrolide treatment. METHODS: M. pneumoniae strains from initial and follow-up oropharyngeal samples from 38 Swedish patients were tested for 23S rRNA mutations by amplifying and pyrosequencing the gene target region. The duration of symptoms and of M. pneumoniae carriage were recorded in cases with and without the macrolide resistance mutation. RESULTS: Macrolide resistance mutations were absent in all baseline strains. Twenty-two patients were prescribed macrolides; the longest M. pneumoniae carriage time in these patients was 7 months and the longest symptomatic period was 7.5 months. Macrolide resistance was detected after macrolide treatment in 1 patient (carriage time 3.5 months and symptomatic period 7.5 months). CONCLUSIONS: M. pneumoniae may develop macrolide resistance during macrolide treatment. A long duration of M. pneumoniae carriage and symptoms is common in patients regardless of the presence of resistance.

Inoculation with adapted bacterial communities promotes development of full scale slow sand filters for drinking water production.

Gravity-driven filtration through slow sand filters (SSFs) is one of the oldest methods for producing drinking water. As water passes through a sand bed, undesired microorganisms and chemicals are removed by interactions with SSF biofilm and its resident microbes. Despite their importance, the processes through which these microbial communities form are largely unknown, as are the factors affecting these processes. In this study, two SSFs constructed using different sand sources were compared to an established filter and observed throughout their maturation process. One SSF was inoculated through addition of sand scraped from established filters, while the other was not inoculated. The operational and developing microbial communities of SSFs, as well as their influents and effluents, were studied by sequencing of 16S ribosomal rRNA genes. A functional microbial community resembling that of the established SSF was achieved in the inoculated SSF, but not in the non-inoculated SSF. Notably, the non-inoculated SSF had significantly (p < 0.01) higher abundances of classes Armatimonadia, Elusimicrobia, Fimbriimonadia, OM190 (phylum Planctomycetota), Parcubacteria, Vampirivibrionia and Verrucomicrobiae. Conversely, it had lower abundances of classes Anaerolineae, Bacilli, bacteriap25 (phylum Myxococcota), Blastocatellia, Entotheonellia, Gemmatimonadetes, lineage 11b (phylum Elusimicrobiota), Nitrospiria, Phycisphaerae, subgroup 22 (phylum Acidobacteriota) and subgroup 11 (phylum Acidobacteriota). Poor performance of neutral models showed that the assembly and dispersal of SSF microbial communities was mainly driven by selection. The temporal turnover of microbial species, as estimated through the scaling exponent of the species-time relationship, was twice as high in the non-inoculated filter (0.946 ± 0.164) compared to the inoculated filter (0.422 ± 0.0431). This study shows that the addition of an inoculum changed the assembly processes within SSFs. Specifically, the rate at which new microorganisms were observed in the biofilm was reduced. The reduced temporal turnover may be driven by inoculating taxa inhibiting growth, potentially via secondary metabolite production. This in turn would allow the inoculation community to persist and contribute to SSF function.

Proposed water balance equation for municipal solid waste landfills in Jordan.

This article presents a water balance equation for predicting leachate generation in municipal solid waste (MSW) landfills located in semi-arid areas, using the Akaider landfill in Jordan as an example. HYDRUS-2D/3D software was used to model the effect of co-disposal of wastewater into the landfill on the leachate production rates and for comparison with the results of the simulation of the proposed water balance equation parameters. A series of simulations was carried out for a 30-year period. The suggested water balance equation predicted that leachate will percolate to a depth of 50 m in the simulated period. The result indicates that the co-disposed wastewater plays a major role in controlling the rate and magnitude of the contaminants that percolate from the MSW leachate. As the initial water content of the waste increases, there is greater mobilisation of salts. The concentration of chloride at a given location increased and the time required for the chloride to reach this location decreased as a consequence. However, eliminating the co-disposed wastewater will significantly minimise leachate generation and decrease possible groundwater contamination. This equation is applicable to areas that have geological and hydrological properties similar to Jordan.

Decline of the new Swedish variant of Chlamydia trachomatis after introduction of appropriate testing.

OBJECTIVE: The longitudinal epidemiological development of the new variant of Chlamydia trachomatis was studied after appropriate testing procedures had been introduced when the strain was detected in 2006. METHODS: The number of cases of the new variant of C trachomatis was followed from 2007 through 2011 from the laboratory records. Testing for C trachomatis is centralised to one laboratory with around 80-85 000 persons being tested annually in a population of 1.1 million. RESULTS: During the 5-year period, 410 973 patients were tested of which 25 723 cases were positive. The proportion of the new variant of all positive cases declined from 30% in 2007 to 6% in 2011. While the number of the new variant of C trachomatis declined, the ordinary wild-type strains remained largely unchanged. CONCLUSIONS: A selective decline of the new variant of C trachomatis has occurred after appropriate laboratory testing was introduced. A new balance point between 5% and 10% for the new variant seems to be gradually approached.

Mycoplasma genitalium in cervicitis and pelvic inflammatory disease among women at a gynecologic outpatient service.

OBJECTIVE: We sought to analyze the prevalence and clinical manifestations of Mycoplasma genitalium infection in a heterogeneous population of women. STUDY DESIGN: The study was designed as a cross-sectional case-control study. Women attending a gynecological outpatient service from 2003 through 2008 were invited to participate. RESULTS: The prevalence of M genitalium was 2.1% and of Chlamydia trachomatis was 2.8% among 5519 tested women. A total of 679 women were included. Both pelvic inflammatory disease (PID) and cervicitis were independently associated with M genitalium (odds ratio, 9.00; 95% confidence interval, 1.62-49.89 and odds ratio, 3.80; 95% confidence interval, 2.06-7.03, respectively). Women with C trachomatis had a higher frequency of both PID (18.3% vs 4.9%, P < .001) and cervicitis (33.4% vs 22.3%, P < .001) than women with M genitalium. CONCLUSION: M genitalium was an independent and strong risk factor for both cervicitis and PID although, compared to C trachomatis, clinical manifestations were less frequent.

Frequent detection of respiratory agents by multiplex PCR on oropharyngeal samples in Swedish school-attending adolescents.

BACKGROUND: Respiratory agents may be detected in the oropharynx of healthy individuals. The extent of this condition and the reasons behind it are largely unknown. The objective of this study was to determine the factors associated with the presence of respiratory agents in the oropharynx of adolescents healthy enough to attend school activities. METHODS: On a single day in December, samples from the posterior wall of the oropharynx of adolescents aged 10-15 y were obtained using cotton-tipped swabs. The samples were analyzed by real-time polymerase chain reaction (PCR) for the presence of 13 respiratory viruses and 2 bacteria (Mycoplasma pneumoniae and Chlamydophila pneumoniae). RESULTS: Out of the 232 adolescents sampled, 67 (29%) had any respiratory symptom. A positive PCR result was found in 50 individuals (22%). Human rhinovirus was the most commonly found agent. Respiratory agents were significantly more frequent in the younger age group (10-13 y) than in the older age group (14-15 y): 26% (38/148) vs 14% (12/84), respectively; p = 0.04. Cough was the only symptom that was more common among individuals with a positive PCR test than among those with a negative PCR test: 8/50 (16%) vs 11/182 (6%); p = 0.02. Family size and class size were not associated with the likelihood of a positive PCR test. CONCLUSIONS: The presence of respiratory agents in the oropharynx is a frequent finding among adolescents healthy enough to attend school activities. The high prevalence was found to be associated with young age, but not with the size of the family or class.

DynSus: Dynamic sustainability assessment in groundwater remediation practice.

Decision-making processes for clean-up of contaminated sites are often highly complex and inherently uncertain. It depends not only on hydrological and biogeochemical site variability, but also on the associated health, environmental, economic, and social impacts of taking, or not taking, action. These variabilities suggest that a dynamic framework is required for promoting sustainable remediation. For this, the decision support system DynSus is presented here for integrating a predeveloped contaminant fate and transport model with a sustainability assessment tool. Implemented within a system dynamics framework, the new tool uses model simulations to provide remediation scenario analysis and handling of uncertainty in various data. DynSus was applied to a site in south Sweden, contaminated with pentachlorophenol (PCP). Simulation scenarios were developed to enable a comparison between alternative remediation strategies and combinations of these. Such comparisons are provided for selected sustainability indicators and remediation performance (in terms of concentration at the recipient). This leads to identifying the most critical variables to ensure that sustainable solutions are chosen. Simulation results indicated that although passive practices, e.g., monitored natural attenuation, were more sustainable at first (5-7 years after beginning remediation measures), they failed to compete with more active practices, e.g., bioremediation, over the entire life cycle of the project (from the beginning of remedial action to achieving the target concentration at the recipient). In addition, statistical tools (clustering and genetic algorithms) were used to further assess the available hydrogeochemical data. Taken together, the results reaffirmed the suitability of the simple analytical framework that was implemented in the contaminant transport model. DynSus outcomes could therefore enable site managers to evaluate different scenarios more quickly and effectively for life cycle sustainability in such a complex and multidimensional problem.

Infection-induced coronary dysfunction and systemic inflammation in piglets are dampened in hypercholesterolemic milieu.

The synergism of infection with conventional cardiovascular risk factors in atherosclerosis is much debated. We hypothesized that coronary arterial injury correlates with infection recurrence and pathogen burden and is further aggravated by hypercholesterolemia. Forty-two Göttingen minipigs were assigned to repeated intratracheal inoculation of PBS, Chlamydia pneumoniae (Cpn), or both Cpn and influenza virus at 8, 11, and 14 wk of age. Animals were fed either standard or 2% cholesterol diet (chol-diet). At 19 wk of age coronary vasomotor responses to acetylcholine (ACh) and adenosine were assessed in vivo and blood and tissue samples were collected. Nonparametric tests were used to compare the groups. In cholesterol-fed animals, total cholesterol/HDL was significantly increased in infected animals compared with noninfected animals [3.13 (2.17-3.38) vs. 2.03 (1.53-2.41), respectively; P = 0.01]. C-reactive protein (CRP) rose in infected animals [10.60 (4.96-18.00) vs. 2.47 (1.44-3.01) µg/ml in noninfected; P < 0.01] without significant difference between the mono- and coinfected groups. Among coinfected animals, both CRP and haptoglobin were lower in those fed chol-diet than in those fed standard diet (P < 0.05). The vasoconstricting response to ACh was most prominent in coinfected animals {769.3 (594-1,129) cm; P = 0.03 vs. noninfected [342 (309-455) cm] and P = 0.07 vs. monoinfected [415 (252.5-971.8) cm]}. Among monoinfected animals, similar to CRP, a trend for less vasoconstriction was observed in those fed chol-diet (P = 0.08). Coinfection of piglets appears to be associated with more pronounced coronary muscarinic vasomotor dysfunction. In monoinfected animals, use of chol-diet seems to dampen both coronary dysfunction and systemic inflammation induced by infection.

Quick detection method for paralytic shellfish toxins (PSTs) monitoring in freshwater - A review.

The objective of this critical review was to provide a comprehensive summary of paralytic shellfish toxins (PSTs) producing species and knowledge gaps in detecting PSTs in drinking water resources, with a focus on recent development of PSTs monitoring methods and tools for drinking water monitoring. PSTs, which are also called Saxitoxins (STXs), are a group of neurotoxins not only produced by marine dinoflagellates but also freshwater cyanobacteria. The presence of PSTs in freshwater has been reported from all continents except Antarctica. PSTs in poisoned sea food such as shellfish, molluscs and crustaceans may attack the nerve system after consumption. The high incidences of PSTs occurring in drinking water sources showed another route of potential human exposure. A development of simple and fast screening tools for drinking water surveillance of PSTs is needed. Neurotoxins produced by freshwater cyanobacteria are understudied relative to microcystin and little study is done around PSTs in drinking water monitoring. Some fast screening methods exist. The critical issues for using them in water surveillance, particularly matrix effect and cross-reactivity are summarized, and future research directions are high-lighted. We conclude that monitoring routines at drinking water resources should start from species level, followed by a profound screening of toxin profile. For practical monitoring routine, fast screening methods should be combined with highly sensitive and accurate analytical methods such as liquid chromatography/liquid chromatography-mass spectrometry (LC/LC-MS). A thorough understanding of toxin profile in source water is necessary for screening tool selection.

Utilization of greenhouse effect for the treatment of COVID-19 contaminated disposable waste - A simple technology for developing countries.

Countries with abundant solar radiation have the potential to invest in simple technologies for deactivation of many bacteria and viruses in medical solid waste. In addition to the traditional Infection and Prevention Control (IPC) measures, these simple technologies contribute to better protection of health care workers in countries with compromised solid management schemes. Monitoring of temperature, relative humidity and ultraviolet inside containers soundly designed to collect disposal infectious waste illustrated to deactivate several viruses and bacteria. Casanova et al., 2010, used some surrogate viruses to overcome the challenges of working with SARS-CoV, concluded that by temperature above 40 °C most of viruses become below levels of detection after 90 min. Here we are proposing a model of a simple transparent container almost 200 L in volume that allow solar energy to be accumulated inside. In summer conditions in the testing site, temperature inside the container reached above 50 °C when the ambient air temperature was around 30 °C. The container was built using epoxy glass to guarantee maximum heat penetration. Actual temperature measurement inside the container was measured in real time against ambient air temperature. We present a mathematical model for predication of maximum temperature at different positions inside the container and their relation to different ambient air temperature scenarios. The mathematical formulas used are based on the conservation laws and a good agreement of a full month of field measurements were obtained. Even in winter conditions in many of developing countries air temperature can maintain levels above 20 °C, which will produce temperature around 30 °C and viruses can reach levels below detection limit in maximum 3 h.

The Swedish new variant of Chlamydia trachomatis: genome sequence, morphology, cell tropism and phenotypic characterization.

Chlamydia trachomatis is a major cause of bacterial sexually transmitted infections worldwide. In 2006, a new variant of C. trachomatis (nvCT), carrying a 377 bp deletion within the plasmid, was reported in Sweden. This deletion included the targets used by the commercial diagnostic systems from Roche and Abbott. The nvCT is clonal (serovar/genovar E) and it spread rapidly in Sweden, undiagnosed by these systems. The degree of spread may also indicate an increased biological fitness of nvCT. The aims of this study were to describe the genome of nvCT, to compare the nvCT genome to all available C. trachomatis genome sequences and to investigate the biological properties of nvCT. An early nvCT isolate (Sweden2) was analysed by genome sequencing, growth kinetics, microscopy, cell tropism assay and antimicrobial susceptibility testing. It was compared with relevant C. trachomatis isolates, including a similar serovar E C. trachomatis wild-type strain that circulated in Sweden prior to the initially undetected expansion of nvCT. The nvCT genome does not contain any major genetic polymorphisms - the genes for central metabolism, development cycle and virulence are conserved - or phenotypic characteristics that indicate any altered biological fitness. This is supported by the observations that the nvCT and wild-type C. trachomatis infections are very similar in terms of epidemiological distribution, and that differences in clinical signs are only described, in one study, in women. In conclusion, the nvCT does not appear to have any altered biological fitness. Therefore, the rapid transmission of nvCT in Sweden was due to the strong diagnostic selective advantage and its introduction into a high-frequency transmitting population.

Comparison of the Abbott RealTime CT new formulation assay with two other commercial assays for detection of wild-type and new variant strains of Chlamydia trachomatis.

In an analytical-method comparison study of clinical samples, the Abbott RealTime CT new formulation assay (m2000 real-time PCR), consisting of a duplex PCR targeting different parts of the cryptic plasmid in Chlamydia trachomatis, was compared both with version 2 of the Roche Cobas TaqMan CT assay, comprising a duplex PCR for a target in the cryptic plasmid and the omp1 gene, and with the Gen-Probe Aptima Combo 2 assay (AC2) targeting the C. trachomatis 23S rRNA molecule. First-catch urine samples from Sweden were tested in Malmö, Sweden, for C. trachomatis with the m2000 real-time PCR assay and with an in-house PCR for the new variant C. trachomatis strain with a deletion in the cryptic plasmid. Aliquots of the urine samples were sent to Aarhus, Denmark, where they were further examined with the TaqMan CT and AC2 assays. A positive prevalence of 9.1% (148/1,632 urine samples examined) was detected according to the combined reference standard. The sensitivities and specificities of the three assays were as follows: for the Abbott m2000 assay, 95.3% (141/148) and 99.9% (1,483/1,485), respectively; for the Roche TaqMan assay, 82.4% (122/148) and 100.0% (1,485/1,485); and for the Gen-Probe AC2 assay, 99.3% (147/148) and 99.9% (1,484/1,485). The plasmid mutant strain was detected in 24% (36/148) of the C. trachomatis-positive samples. There is a difference in sensitivity between the new formulations of the Abbott and the Roche assays, but both assays detected the wild-type and new variant C. trachomatis strains equally well.

Clinical severity of Mycoplasma pneumoniae (MP) infection is associated with bacterial load in oropharyngeal secretions but not with MP genotype.

BACKGROUND: Disease severity in Mycoplasma pneumoniae (MP) infection could potentially be related to bacterial factors such as MP genotype (MP1 or MP2; distinguished by different adhesions proteins) or bacterial load in airway secretions. We have compared these parameters in patients who were hospitalized for MP pneumonia, with outpatients with mild MP disease. METHODS: MP bacterial load was measured by real-time PCR in 45 in- and outpatients ("clinical study group") in whom MP DNA had been detected in oropharyngeal secretions by PCR. In addition, genotype and phylogenetic relationships were determined. The phylogenetical assessment was done by partial DNA sequencing of the P1 gene on isolates from 33 patients in the clinical study-group where sufficient DNA was available. The assessment was further extended to isolates from 13 MP-positive family members and 37 unselected MP positive patients from the two subsequent years and two different geographical locations. In total 83 strains were molecular characterized. RESULTS: Mean MP loads were significantly higher in 24 hospitalized patients than in 21 outpatients (1600 vs. 170 genomic equivalents/microL, p = 0.009). This difference remained significant after adjustment for age and days between disease onset and sampling. Hospitalized patients also had higher C-reactive protein levels. Mean levels were 188 vs 20 mg/L (p = 0,001). The genotype assessment showed MP genotype 1 in 17 of the 33 sequenced strains from the clinical study-group, and type 2 in 16 of these patients. Within each genotype, sequence differences were minimal. No association between disease severity and MP genotype was observed. In the extended genotype assessment, MP1 was found in similar proportions. In family contacts it was found in 53% and among patients from the two subsequent years 53% and 40%. CONCLUSIONS: A higher MP bacterial load in throat secretions at diagnosis was associated with more advanced respiratory disease in patients, but MP genotype did not influence disease severity. Both MP genotypes co-circulated during recent outbreaks in Sweden.

Longitudinal clearance of seasonal influenza A viral RNA measured by real-time polymerase chain reaction in patients identified at a hospital emergency department.

To study influenza virus shedding during acute infection, viral load was longitudinally measured by quantitative PCR in nasal flocked swabs from patients with seasonal H3N2 influenza at a Swedish emergency department, including both hospitalized patients and outpatients. Influenza A was detected in 65/184 patients. Sampling was repeated every 3-4 days in 45 patients, with the aim of continuing sampling until day 12 after disease onset. Home visits were offered. Antibodies were measured on paired sera in 95/184 patients. Fifty percent of the patients remained polymerase chain reaction (PCR)-positive 8 days after disease onset in a Kaplan-Meier survival curve. The longest observed duration of viral shedding was 12 days. The average viral load was initially low, peaked on days 2-3 of disease and then declined. Viral decline results remained similar when all 15 (25%) oseltamivir-treated patients were excluded. Significant antibody titre changes were seen in all the 35 PCR verified cases with available paired sera and in 8 of the 58 patients with negative PCR tests on acute phase nasal samples. In conclusion, quantitative PCR testing indicated the presence of influenza virus for up to 12 days, which could have implications for disease transmission and infection control.

Can treated municipal wastewater be reused after ozonation and nanofiltration? Results from a pilot study of pharmaceutical removal in Henriksdal WWTP, Sweden.

The objective of this study was to evaluate the potential of nanofiltration (NF) and ozonation for indirect potable reuse in terms of pharmaceutical residuals. To simultaneously obtain a reasonable retentate volume for further treatment, the tests were performed at a high volume reduction factor (VRF) of 60. The feed to the pilot plant was the effluent from a BNR plant with a final process step of chemical precipitation and rapid sand filtration. Two tests were performed 1) nanofiltration of treated wastewater followed by ozonation and 2) ozonated treated wastewater as feed to NF. Of the 95 pharmaceuticals analysed, three were not removed to the quantification limit, oxazepam in the first test and glibenclamide and ketoprofen in the second. The water quality after the two processes was similar, with an overall removal of pharmaceutical residuals of 99%. There are two advantages of ozonated water as feed to NF-a higher specific flux of 35% and a potential removal of ozonation by-products. The retention of some pharmaceuticals by NF was lower than anticipated, the major removal occurring in the ozonation. A tighter NF or RO is required in order to achieve higher pharmaceutical retention for further treatment of the retentate.

INSIDE: An efficient guide for sustainable remediation practice in addressing contaminated soil and groundwater.

Modeling criteria interaction in decision-making problems is complex and often neglected. In complicated problems, like contaminated site remediation projects, independency of involved criteria is not a realistic assumption. INfluence based deciSIon guiDE (INSIDE) is a methodology that enables sustainable decision making and management in contaminated site remediation practice. Unlike most previous decision-support methods, INSIDE considers realistic interactions among all involved criteria. The method not only gives a one-time best option for choosing a remediation method for the project at hand, but also a management plan for further improvements of the system. INSIDE recognizes economic, environmental, social, and technological considerations for the most sustainable practice. Eight criteria are defined based on these aspects and they can be interrelated. This means that a criterion, e.g., remediation time, does not need to belong to any pre-defined category such as economic, environmental, social, or technical, but can interact with other criteria. This allows for a system with many degrees of freedom that is more realistic for practical problem-solving. In INSIDE, the DEcision MAking Trial and Evaluation Laboratory (DEMATEL) and Analytic Network Process (ANP) techniques are combined for assigning weights to criteria and scoring of remediation alternatives, respectively. Thus, the proposed methodology gives a managerial cone of influence versus importance for all involved criteria in the system. The method is applied to a data-scarce case study in Iran to prioritize between remediation methods for a contaminated groundwater aquifer. The results show that human health risk and environmental impacts are more influential than other evaluated criteria. The suggested methodology should be further tested on a variety of actual remediation problems for additional evaluation.

Impact of the Sediment Organic vs. Mineral Content on Distribution of the Per- and Polyfluoroalkyl Substances (PFAS) in Lake Sediment.

Contamination of the water and sediment with per- and polyfluoroalkyl substances (PFAS) was studied for the lake impacted by the release of PFAS-containing aqueous film forming foam (AFFF). PFAS concentrations were analyzed in lake water and sediment core samples. ΣPFAS concentrations were in the range of 95-100 ng L-1 in the lake water and 3.0-61 µg kg-1 dry weight (dw) in sediment core samples, both dominated by perfluorohexane sulfonate, perfluorooctane sulfonate; 6:2 fluortelomer sulfonate was inconsistently present in water and sediment core samples. The sediment-water partitioning coefficients (log Kd) were estimated and ranged 0.6-2.3 L kg-1 for individual perfluoroalkyl carboxylates (PFCAs) and 0.9-5.6 L kg-1 for individual perfluoroalkane sulfonates (PFSAs). The influence of the sediment inorganic content and organic matter on PFAS distribution was investigated. In studied sediments, the mineral content (corresponding to <5% of the bulk media mass) was mainly represented by sulfur, iron and calcium. The PFAS distribution was found strongly connected to the sediment mineral content (i.e., Fe, Pb, Rb and As), whereas the sediment organic carbon content did not to have a direct influence on the PFAS distribution. The aim of this study was to improve our understanding of the PFAS distribution in the natural heterogeneous media.

Status of risk-based approach and national framework for safe drinking water in small water supplies of the Nordic water sector.

Reliable safe water supply is a pillar of society and a key to public health. The Nordic countries have an abundance of clean fresh water as a source for drinking water supplies. They have followed developments in safeguarding water, both the recommendations of the World Health Organization framework for safe drinking water and European legislation. Worldwide, including the Nordic countries, small water supplies are less compliant with water safety regulation. The forthcoming EU directive on drinking water require risk-based approaches and improved transparency on water quality. This research looks at the Nordic frameworks for safe water supply, with emphasis on risk-based approaches and smaller systems. We analyzed the legal frameworks for safe water, the structure of the water sector across the Nordic countries and explored how prepared these countries are to meet these requirements. Our findings show that, while legal requirements are mostly in place, delivery of information to the public needs to be improved. Most Nordic countries are in the process of implementing risk-based management in large and medium size water supplies, whereas small supplies are lagging. We conclude that a key to success is increased training and support for small supplies. We suggest wider adoption of the Nordic model of cooperation with benchmarking of safe water for all to transfer knowledge between the countries. This work provides insights into challenges and opportunities for the Nordic countries and provides insights relevant to countries worldwide in their effort towards realization of SDG Target 6.1.