RESUMO
Type 1 diabetes mellitus (T1DM) refers to a metabolic condition where a lack of insulin impairs the usual homeostatic mechanisms to control blood glucose levels. Historically, participation in competitive sport has posed a challenge for those with T1DM, where the dynamic changes in blood glucose during exercise can result in dangerously high (hyperglycaemia) or low blood glucoses (hypoglycaemia) levels. Over the last decade, research and technological development has enhanced the methods of monitoring and managing blood glucose levels, thus reducing the chances of experiencing hyper- or hypoglycaemia during exercise. The introduction of continuous glucose monitoring (CGM) systems means that glucose can be monitored conveniently, without the need for frequent fingerpick glucose checks. CGM devices include a fine sensor inserted under the skin, measuring levels of glucose in the interstitial fluid. Readings can be synchronized to a reader or mobile phone app as often as every 1-5 min. Use of CGM devices is associated with lower HbA1c and a reduction in hypoglycaemic events, promoting overall health and athletic performance. However, there are limitations to CGM, which must be considered when being used by an athlete with T1DM. These limitations can be addressed by individualized education plans, using protective equipment to prevent sensor dislodgement, as well as further research aiming to: (i) account for disparities between CGM and true blood glucose levels during vigorous exercise; (ii) investigate the effects of temperature and altitude on CGM accuracy, and (iii) explore of the sociological impact of CGM use amongst sportspeople without diabetes on those with T1DM.
Assuntos
Atletas , Automonitorização da Glicemia , Glicemia , Diabetes Mellitus Tipo 1 , Humanos , Diabetes Mellitus Tipo 1/sangue , Automonitorização da Glicemia/instrumentação , Automonitorização da Glicemia/métodos , Glicemia/análise , Glicemia/metabolismo , Monitoramento Contínuo da GlicoseRESUMO
BACKGROUND: Many children and adolescents with Type 1 Diabetes Mellitus (T1DM) don't meet the recommended levels of physical activity. Healthcare professionals (HCPs) have a key role in supporting and encouraging children and adolescents with T1DM to be physically active. This study aims to understand the perspectives of HCPs in relation to supporting physical activity and implementing guidelines relating to physical activity. METHODS: An online mixed methods survey was circulated to HCPs in pediatric diabetes units in England and Wales. Participants were asked about how they support physical activity in their clinic and their perceptions of barriers/enablers of providing physical activity support to children and adolescents with T1DM. Quantitative data were analysed descriptively. An deductive thematic approach was applied to the free text responses using the Capability Opportunity Motivation model of Behaviour (COM-B) as a framework. RESULTS: Responses were received from 114 individuals at 77 different pediatric diabetes units (45% of pediatric diabetes units in England and Wales). HCPs surveyed felt that the promotion of physical activity is important (90%) and advised patients to increase levels of physical activity (88%). 19% of the respondents felt they did not have sufficient knowledge to provide support. HCPs reported limited knowledge and confidence, time and resources as barriers to providing support. They also felt the current guidance was too complicated with few practical solutions. CONCLUSION: Pediatric HCPs need training and support to be able to encourage and support children and adolescents with T1D to be a physical activity. In addition, resources that provide simple and practical advice to manage glucose around exercise are needed.
Assuntos
Diabetes Mellitus Tipo 1 , Humanos , Criança , Adolescente , Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 1/complicações , Exercício Físico , Inglaterra , País de Gales , Pessoal de Saúde/educação , Pesquisa QualitativaRESUMO
AIMS: Type 1 diabetes is characterised by the destruction of pancreatic ß-cells. Significant levels of ß-cells remain at diagnosis. Preserving these cells improves glucose control and protects from long-term complications. We undertook a systematic review and meta-analyses of all randomised controlled trials (RCTs) of interventions to preserve ß-cell function in people newly diagnosed with type 1 diabetes. This paper reports the results of interventions for improving glucose control to assess whether they preserve ß-cell function. METHODS: Searches for RCTs in MEDLINE, Embase, Cochrane CENTRAL, ClinicalTrials.gov and WHO International Clinical Trials Registry. Eligible studies included newly diagnosed patients with type 1 diabetes, any intervention to improve glucose control and at least 1 month of follow-up. Data were extracted using a pre-defined data-extraction sheet with 10% of extractions checked by a second reviewer. RESULTS: Twenty-eight studies with 1662 participants were grouped by intervention into six subgroups (alternative insulins, subcutaneous and intravenous insulin delivery, intensive therapy, glucose sensing, adjuncts). Only three studies demonstrated an improvement in glucose control as well as ß-cell function. These interventions included intensive insulin therapy and use of an alternative insulin. CONCLUSIONS: This is the largest comprehensive review of RCTs in this area. It demonstrates a lack of robust evidence that interventions to improve glucose control preserve ß-cell function in new onset type 1 diabetes, although analysis was hampered by low-quality evidence and inconsistent reporting of studies. Development of guidelines to support the design of trials in this field is a priority.
Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 1/tratamento farmacológico , Controle Glicêmico/normas , Células Secretoras de Insulina/metabolismo , Insulina/administração & dosagem , Diabetes Mellitus Tipo 1/sangue , Jejum , Humanos , Hipoglicemiantes/administração & dosagem , Células Secretoras de Insulina/efeitos dos fármacosRESUMO
Increases in the global use of plastics have caused concerns regarding potential adverse effects on human health. Plastic products contain hundreds of potentially toxic chemical additives, yet the exact chemicals which drive toxicity currently remain unknown. In this study, we employed nontargeted analysis and in vitro bioassays to identify the toxicity drivers in plastics. A total of 56 chemical additives were tentatively identified in five commonly used plastic polymer pellets (i.e., PP, LDPE, HDPE, PET, and PVC) by employing suspect screening and nontargeted analysis. Phthalates and organophosphates were found to be dominant in PVC pellets. Triphenyl phosphate and 2-ethylhexyl diphenyl phosphate accounted for a high amount (53.6%) of the inhibition effect of PVC pellet extract on human carboxylesterase 1 (hCES1) activity. Inspired by the high abundances of chemical additives in PVC pellets, six different end-user PVC-based products including three widely used PVC water pipes were further examined. Among them, extracts of PVC pipe exerted the strongest PPARγ activity and cell viability suppression. Organotins were identified as the primary drivers to these in vitro toxicities induced by the PVC pipe extracts. This study clearly delineates specific chemical additives responsible for hCES1 inhibition, PPARγ activity, and cell viability suppression associated with plastic.
Assuntos
Plásticos , Poluentes Químicos da Água , Hidrolases de Éster Carboxílico , Humanos , Organofosfatos/toxicidade , PPAR gama , Fosfatos , Plásticos/toxicidade , Polietileno , Cloreto de Polivinila/toxicidade , Poluentes Químicos da Água/análiseRESUMO
NEW FINDINGS: What is the topic of this review? This review discusses the evidence of the benefits of exercise training for ß-cell health through improvements in function, proliferation and survival which may have implications in the treatment of diabetes. What advances does it highlight? This review highlights how exercise may modulate ß-cell health in the context of diabetes and highlights the need for further exploration of whether ß-cell preserving effects of exercise translates to T1D. ABSTRACT: Physical exercise is a core therapy for type 1 and type 2 diabetes. Whilst the benefits of exercise for different physiological systems are recognised, the effect of exercise specifically on the pancreatic ß-cell is not well described. Here we review the effects of physical exercise on ß-cell health. We show that exercise improves ß-cell mass and function. The improved function manifests primarily through the increased insulin content of the ß-cell and its increased ability to secrete insulin in response to a glucose stimulus. We review the evidence relating to glucose sensing, insulin signalling, ß-cell proliferation and ß-cell apoptosis in humans and animal models with acute exercise and following exercise training programmes. Some of the mechanisms through which these benefits manifest are discussed.
Assuntos
Exercício Físico/fisiologia , Células Secretoras de Insulina/fisiologia , Condicionamento Físico Animal/fisiologia , Animais , Apoptose/fisiologia , Glicemia/metabolismo , Glucose/metabolismo , Humanos , Insulina/metabolismo , Resistência à Insulina/fisiologia , Células Secretoras de Insulina/metabolismo , Transdução de Sinais/fisiologiaRESUMO
Incorporation of a carbon-based nutrient enhancement strategy for drinking water biofiltration is an attractive option, especially for source waters which contain recalcitrant organics. This study compared biofilters that were operated in parallel and individually enhanced with amino acids (including alanine, phenylalanine, and tryptophan), inulin, and sucrose to increase biomass concentration and promote biodegradation of dissolved organic carbon (DOC) in the source water, including disinfection by-product (DBP) precursors. Biomass activity was characterized by measuring adenosine tri-phosphate (ATP), dissolved oxygen (DO) consumption, and through the use of laccase and esterase enzyme assays. Performance was evaluated in terms of headloss, turbidity, pH, DOC, UV254, and DBP formation potential (DBP FP). The introduction of carbon-based nutrients significantly increased biomass activity, where ATP values peaked at 976â¯ng/g of filter media, 853â¯ng/g, and 513â¯ng/g for amino acids, inulin, and sucrose-spiked biofilters, respectively, while a non-spiked control only reached 104â¯ng/g. DO utilization by the enhanced biofilters was significantly higher than the control, with a strong correlation between ATP and DO uptake observed for all filters (R2â¯>â¯0.74). Laccase and esterase enzyme activities of enhanced biofilters were also elevated (pâ¯> 0.05), suggesting greater biodegradation potential. Operational parameters such as headloss development and turbidity control were not impaired by carbon supplementation strategies or an increase in biomass concentration and activity. However, the enhancement strategy did not provide improvement in terms of source water carbon removal (DOC and UV254) or DBP FP when treated filters were compared to a control.
Assuntos
Carbono/análise , Água Potável/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Biodegradação Ambiental , Filtração/métodosRESUMO
The presence of municipal wastewater at the intake of a major drinking water treatment facility located on Lake Ontario was examined using fluorescence data collected during a period of continuous monitoring. In addition, controlled mixing of lake water and wastewater sampled from a local treatment facility were conducted using a bench-scale fluorescence system to quantify observed changes in natural organic matter. Multivariate linear regression was applied to components derived from parallel factors analysis. The resulting mean absolute error for predicted wastewater level was 0.22% (V/V, wastewater/lake water), indicating that wastewater detection at below 1.0% (V/V) was possible. Analyses of sucralose, a wastewater indicator, were conducted for treated wastewater as well as surface water collected at two intake locations on Lake Ontario. Results suggested minimal wastewater contribution at the drinking water intake. A wastewater detection model using a moving baseline was developed and applied to continuous fluorescence data collected at one of the drinking water intakes, which agreed well with sucralose results. Furthermore, the simulated addition of 1.0% (V/V) of wastewater/wastewater was detectable in 89% of samples analyzed, demonstrating the utility of fluorescence-based wastewater monitoring.
Assuntos
Monitoramento Ambiental , Águas Residuárias/análise , Poluentes Químicos da Água/análise , OntárioRESUMO
BACKGROUND: Diagnosis with Type 2 Diabetes is an opportunity for individuals to change their physical activity and dietary behaviours. Diabetes treatment guidelines recommend theory-based, patient-centred care and advocate the provision of support for patient motivation but the motivational experiences of people newly diagnosed with diabetes have not been well studied. Framed in self-determination theory, this study aimed to qualitatively explore how this patient group articulate and experience different types of motivation when attempting lifestyle change. METHODS: A secondary analysis of semi-structured interview data collected with 30 (n female = 18, n male = 12) adults who had been newly diagnosed with type two diabetes and were participants in the Early ACTID trial was undertaken. Deductive directed content analysis was performed using NVivo V10 and researcher triangulation to identify and describe patient experiences and narratives that reflected the motivation types outlined in self-determination theory and if/how these changed over time. RESULTS: The findings revealed the diversity in motivation quality both between and within individuals over time and that patients with newly-diagnosed diabetes have multifaceted often competing motivations for lifestyle behaviour change. Applying self-determination theory, we identified that many participants reported relatively dominant controlled motivation to comply with lifestyle recommendations, avoid their non-compliance being "found out" or supress guilt following lapses in behaviour change attempts. Such narratives were accompanied by experiences of frustrating slow behaviour change progress. More autonomous motivation was expressed as something often achieved over time and reflected goals to improve health, quality of life or family time. Motivational internalisation was evident and some participants had integrated their behaviour change to a new way of life which they found resilient to common barriers. CONCLUSIONS: Motivation for lifestyle change following diagnosis with type two diabetes is complex and can be relatively low in self-determination. To achieve the patient empowerment aspirations of current national health care plans, intervention developers, and clinicians would do well to consider the quality not just quantity of their patients' motivation. TRIAL REGISTRATION: ISRCTN ISRCTN92162869 . Retrospectively registered.
Assuntos
Diabetes Mellitus Tipo 2/prevenção & controle , Dieta/psicologia , Exercício Físico/psicologia , Estilo de Vida Saudável , Motivação , Adulto , Idoso , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/psicologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Pesquisa QualitativaRESUMO
BACKGROUND: Bariatric and metabolic surgery is used as a treatment for patients with severe and complex obesity. However, there is a need to improve outcome selection and reporting in bariatric surgery trials. A Core Outcome Set (COS), an agreed minimum set of outcomes reported in all studies of a specific condition, may achieve this. Here, we present the development of a COS for BARIAtric and metabolic surgery Clinical Trials-the BARIACT Study. METHODS AND FINDINGS: Outcomes identified from systematic reviews and patient interviews informed a questionnaire survey. Patients and health professionals were surveyed three times and asked to rate the importance of each item on a 1-9 scale. Delphi methods provided anonymised feedback to participants. Items not meeting predefined criteria were discarded between rounds. Remaining items were discussed at consensus meetings, held separately with patients and professionals, where the COS was agreed. Data sources identified 2,990 outcomes, which were used to develop a 130-item questionnaire. Round 1 response rates were moderate but subsequently improved to above 75% for other rounds. After rounds 2 and 3, 81 and 14 items were discarded, respectively, leaving 35 items for discussion at consensus meetings. The final COS included nine items: "weight," "diabetes status," "cardiovascular risk," "overall quality of life (QOL)," "mortality," "technical complications of the specific operation," "any re-operation/re-intervention," "dysphagia/regurgitation," and "micronutrient status." The main limitation of this study was that it was based in the United Kingdom only. CONCLUSIONS: The COS is recommended to be used as a minimum in all trials of bariatric and metabolic surgery. Adoption of the COS will improve data synthesis and the value of research data. Future work will establish methods for the measurement of the outcomes in the COS.
Assuntos
Atitude do Pessoal de Saúde , Atitude Frente a Saúde , Cirurgia Bariátrica/normas , Humanos , Pacientes/psicologia , Cirurgiões/psicologia , Reino UnidoRESUMO
Certain unregulated disinfection byproducts (DBPs) are more of a health concern than regulated DBPs. Brominated species are typically more cytotoxic and genotoxic than their chlorinated analogs. The impact of granular activated carbon (GAC) on controlling the formation of regulated and selected unregulated DBPs following chlorine disinfection was evaluated. The predicted cyto- and genotoxicity of DBPs was calculated using published potencies based on the comet assay for Chinese hamster ovary cells (assesses the level of DNA strand breaks). Additionally, genotoxicity was measured using the SOS-Chromotest (detects DNA-damaging agents). The class sum concentrations of trihalomethanes, haloacetic acids, and unregulated DBPs, and the SOS genotoxicity followed the breakthrough of dissolved organic carbon (DOC), however the formation of brominated species did not. The bromide/DOC ratio was higher than the influent through much of the breakthrough curve (GAC does not remove bromide), which resulted in elevated brominated DBP concentrations in the effluent. Based on the potency of the haloacetonitriles and halonitromethanes, these nitrogen-containing DBPs were the driving agents of the predicted genotoxicity. GAC treatment of drinking or reclaimed waters with appreciable levels of bromide and dissolved organic nitrogen may not control the formation of unregulated DBPs with higher genotoxicity potencies.
Assuntos
Brometos , Purificação da Água , Animais , Células CHO , Cricetulus , Desinfetantes , Desinfecção , Poluentes Químicos da ÁguaRESUMO
Water quality parameters affecting sodium silicate performance in partial lead service line replacements were examined using a fractional factorial experimental design and static pipe systems. An external copper wire was used to create a galvanic connection between a former lead service line and a new copper pipe. The pipe systems were filled with lab prepared water made to mimic real water quality. Water was changed on a three times per week basis. A 2(4-1) fractional factorial design was used to evaluate the impact of alkalinity (15 mg L(-1) or 250 mg L(-1) as CaCO3), nitrate (1 mg L(-1) or 7 mg L(-1) as N), natural organic matter (1 mg L(-1) or 7 mg L(-1) as dissolved organic carbon), and disinfectant type (1 mg L(-1) chlorine or 3 mg L(-1) monochloramine), resulting in eight treatment conditions. Fractional factorial analysis revealed that alkalinity, natural organic matter and monochloramine had a significant positive effect on galvanic current. Natural organic matter and monochloramine also had a significant positive effect with respect to both total and dissolved lead release. For the treatment conditions examined, 67-98% of the lead released through galvanic currents was stored as corrosion scales and predominantly comprised of particulate lead (96.1-99.9%) for all eight treatments. The use of monochloramine and the presence of natural organic matter (7 mg L(-1)) were not favourable for corrosion control in sodium silicate-treated partial lead service line replacements, although further studies would be required to characterize optimal water quality parameters for specific water quality types. For utilities operating with sodium silicate as a corrosion inhibitor, this work offers further evidence regarding the consideration of chlorine as a secondary disinfectant instead of monochloramine, as well as the value of controlling natural organic matter in distributed water.
Assuntos
Chumbo/análise , Silicatos/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Abastecimento de Água , Corrosão , Chumbo/química , Ontário , Qualidade da ÁguaRESUMO
This work investigated the application of several fluorescence excitation-emission matrix analysis methods as natural organic matter (NOM) indicators for use in predicting the formation of trihalomethanes (THMs) and haloacetic acids (HAAs). Waters from four different sources (two rivers and two lakes) were subjected to jar testing followed by 24hr disinfection by-product formation tests using chlorine. NOM was quantified using three common measures: dissolved organic carbon, ultraviolet absorbance at 254 nm, and specific ultraviolet absorbance as well as by principal component analysis, peak picking, and parallel factor analysis of fluorescence spectra. Based on multi-linear modeling of THMs and HAAs, principle component (PC) scores resulted in the lowest mean squared prediction error of cross-folded test sets (THMs: 43.7 (µg/L)(2), HAAs: 233.3 (µg/L)(2)). Inclusion of principle components representative of protein-like material significantly decreased prediction error for both THMs and HAAs. Parallel factor analysis did not identify a protein-like component and resulted in prediction errors similar to traditional NOM surrogates as well as fluorescence peak picking. These results support the value of fluorescence excitation-emission matrix-principal component analysis as a suitable NOM indicator in predicting the formation of THMs and HAAs for the water sources studied.
Assuntos
Acetatos/análise , Desinfetantes/análise , Monitoramento Ambiental/métodos , Espectrometria de Fluorescência , Trialometanos/análise , Halogenação , Modelos Lineares , Análise de Componente PrincipalRESUMO
Exercise is a potent stimulus for release of growth hormone (GH), cortisol, testosterone and prolactin, and prolonged exercise inhibits insulin secretion. These responses seem to be specific to the type of exercise but this has been poorly characterised primarily because they have not been compared during exercise performed by the same individuals. We investigated hormone responses to resistance, sprint and endurance exercise in young men using a repeated measures design in which each subject served as their own control. Eight healthy non-obese young adults (18-25 years) were studied on four occasions in random order: 30-s cycle ergometer sprint (Sprint), 30-min resistance exercise bout (Resistance), 30-min cycle at 70 % VO(2max) (Endurance), and seated rest in the laboratory (Rest). Cortisol, GH, testosterone, prolactin, insulin and glucose concentrations were measured for 60 min after the four different interventions. Endurance and sprint exercise significantly increased GH, cortisol, prolactin and testosterone. Sprint exercise also increased insulin concentrations, whereas this decreased in response to endurance exercise. Resistance exercise significantly increased only testosterone and glucose. Sprint exercise elicited the largest response per unit of work, but the smallest response relative to mean work rate in all hormones. In conclusion, the nature and magnitude of the hormone response were influenced by exercise type, perhaps reflecting the roles of these hormones in regulating metabolism during and after resistance, sprint and endurance exercise.
Assuntos
Teste de Esforço/métodos , Exercício Físico/fisiologia , Hormônios/sangue , Adolescente , Adulto , Glicemia/análise , Glicemia/metabolismo , Hormônios/metabolismo , Hormônio do Crescimento Humano/metabolismo , Humanos , Hidrocortisona/sangue , Hidrocortisona/metabolismo , Insulina/sangue , Insulina/metabolismo , Masculino , Resistência Física/fisiologia , Prolactina/sangue , Prolactina/metabolismo , Treinamento Resistido , Corrida/fisiologia , Testosterona/sangue , Testosterona/metabolismo , Adulto JovemRESUMO
Microplastics and per- and polyfluoroalkyl substances (PFAS) both represent persistent groups of environmental contaminants that have been associated with human health risks. Microcystin toxins are produced and stored in the cells of cyanobacteria and may be released into sources of drinking water. Recent concerns have emerged regarding the ability of microplastics to adsorb a range of organic contaminants, including PFAS and microcystins. This study examined the adsorption of two long-chain and two short-chain PFAS, as well as two common microcystins, by both virgin and weathered microplastics in freshwater. Natural weathering of microplastic surfaces may decrease adsorption by introducing hydrophilic oxygen-containing functional groups. Up to 50% adsorption of perfluorooctanesulfonic acid (PFOS) was observed for virgin PVC compared to 38% for weathered PVC. In contrast, adsorption capacities for microcystins by virgin LDPE were approximately 5.0 µg/g whereas no adsorption was observed following weathering. These results suggest that adsorption is driven by specific polymer types and dominated by hydrophobic interactions. This is the first known study to quantify PFAS and microcystins adsorption when considering environmentally relevant concentrations as well as weathered microplastics.
RESUMO
To assess chloramine decay, this study compared the use of pipe loops, which incorporate continuously flowing water, to static pipe section reactors (PSRs). Unlined cast iron (UCI) and cement-lined ductile iron (CLDI) were harvested from distribution systems. These were directly compared to virgin polyvinyl chloride (PVC) pipe at low (0.03 m/s) and high (0.09 m/s) water velocities as well as hydraulic residence times (HRT) of 6 and 24 h. Pipe material was observed to exert the greatest impact on chloramine decay, followed by flow velocity. First-order decay coefficients obtained using pipe loops were statistically similar to those for PSR trials when considering UCI and CLDI pipe, irrespective of pipe velocity or water age. Overall results suggest that the use of PSRs may serve as a viable and cost-effective alternative to pipe loops for assessing the impact of operational variables on disinfectant decay.
Assuntos
Água Potável , Abastecimento de Água , Cloraminas , Cloro , FerroRESUMO
Biofilms that colonize on the surface of microplastics (MPs) in freshwaters may pose a potential health risk. This study examined factors that influence MP-associated biofilm growth, including polymer type, degree of weathering, and source water quality. Weathered MPs produced in-lab were employed in biofilm trials conducted on site using a passive flow-through system with raw water at drinking water treatment facility intakes. Adenosine triphosphate (ATP) was used to quantify biofilm abundance; biofilm composition was assessed via metagenomic sequencing. Biofilm growth was observed on all polymer types examined and most prevalent on polyvinyl chloride (PVC), where ATP levels were 6 to 12 times higher when compared to other polymers. Pathogen-containing species including Salmonella enterica and Escherichia coli were present on all polymers with relative abundance up to 13.7%. S. enterica was selectively enriched on weathered MPs in specific water matrices. These findings support the need to research the potential accumulation of pathogenic organisms on microplastic surfaces.
RESUMO
The occurrence of microplastics in drinking water has drawn increasing attention due to their ubiquity and unresolved implications regarding human health. Despite achieving high reduction efficiencies (70 to >90%) at conventional drinking water treatment plants (DWTPs), microplastics remain. Since human consumption represents a small portion of typical household water use, point-of-use (POU) water treatment devices may provide the additional removal of microplastics (MPs) prior to consumption. The primary objective of this study was to evaluate the performance of commonly used pour-through POU devices, including those that utilize combinations of granular activated carbon (GAC), ion exchange (IX), and microfiltration (MF), with respect to MP removal. Treated drinking water was spiked with polyethylene terephthalate (PET) and polyvinyl chloride (PVC) fragments, along with nylon fibers representing a range of particle sizes (30-1000 µm) at concentrations of 36-64 particles/L. Samples were collected from each POU device following 25, 50, 75, 100 and 125% increases in the manufacturer's rated treatment capacity, and subsequently analyzed via microscopy to determine their removal efficiency. Two POU devices that incorporate MF technologies exhibited 78-86% and 94-100% removal values for PVC and PET fragments, respectively, whereas one device that only incorporates GAC and IX resulted in a greater number of particles in its effluent when compared to the influent. When comparing the two devices that incorporate membranes, the device with the smaller nominal pore size (0.2 µm vs. ≥1 µm) exhibited the best performance. These findings suggest that POU devices that incorporate physical treatment barriers, including membrane filtration, may be optimal for MP removal (if desired) from drinking water.
RESUMO
BACKGROUND: Type 2 diabetes mellitus (T2DM) and its associated complications puts considerable strain on healthcare systems. With the global incidence of T2DM increasing, effective disease management is essential. Physical activity (PA) is a key component of T2DM management; however, rates of PA engagement are low in this population. Developing effective and sustainable interventions that encourage PA is a high priority. Electrically assisted bicycles are becoming increasingly popular and may increase PA in healthy adults. This study aimed to provide evidence of the feasibility of conducting a randomized controlled trial to evaluate the efficacy of an e-cycling intervention to increase PA and improve health in individuals with T2DM. METHODS: A parallel-group two-arm randomized, waitlist-controlled pilot study was conducted. Individuals were randomized to either an e-bike intervention or standard care. The intervention incorporated two one-to-one e-bike skills training and behavioural counselling sessions delivered by a community-based cycling charity, followed by a 12-week e-bike loan with two further sessions with the instructors. Feasibility was assessed via measures related to recruitment, retention and intervention implementation. Post-intervention interviews with instructors and participants explored the acceptability of the study procedures and intervention. Clinical, physiological and behavioural outcomes were collected at baseline and post-intervention to evaluate the intervention's potential. RESULTS: Forty participants (Mage = 57) were randomized, of which 34 were recruited from primary care practices. Thirty-five participants were retained in the trial. The intervention was conducted with high fidelity (> 80% content delivered). E-bike training provided participants with the skills, knowledge and confidence needed to e-bike independently. Instructors reported being more confident delivering the skills training than behavioural counselling, despite acknowledging its importance. The study procedures were found to be acceptable to participants. Between-group differences in change during the intervention were indicative of the interventions potential for improving glucose control, health-related quality of life and cardiorespiratory fitness. Increases in overall device measured moderate-to-vigorous PA behaviour following the intervention were found, and there was evidence that this population self-selected to e-cycle at a moderate intensity. CONCLUSIONS: The study's recruitment, retention, acceptability and potential efficacy support the development of a definitive trial subject to identified refinements. TRIAL REGISTRATION: ISRCTN, ISRCTN67421464 . Registered 17/12/2018.
RESUMO
To date, no standardized methods have been proposed for conducting microplastic analyses in treated drinking waters, resulting in challenges associated with direct comparisons among studies. This study compares known methods for collecting and extracting microplastics from drinking waters: an in-laboratory (in-lab) filtration method and an in-line filtration method (i.e., water filtered on-site without an intermediate storage and/or transportation step). In-lab methods have been the predominant method for sample collection in drinking water matrices, and in-line methods are emerging due to the potential to sample large volumes of water on site and minimize contamination from airborne particles, but the two methods have yet to be directly compared using real samples. In response, this study evaluates both methods in terms of recovering spiked reference microplastics, collecting microplastics from tap water samples using the same water volume, and quantifying the removal of microplastics through a full-scale ultrafiltration system. In-line filtration was shown to have higher recoveries for all the reference microplastics examined (+37 % for PVC fragments, +23 % for PET fragments, +22 % for nylon fibers and +7 % for PET fibers) and a greater potential to reduce microplastic contamination. It also resulted in lower standard deviations for total microplastic counts in the tap water and UF influent and effluent samples. The filtration capacity of the proposed in-line filtration method could exceed 350 L of treated water, but this is highly dependent on the water quality. This study therefore supports the use of in-line filtration methods towards the standardization of microplastic collection procedures in drinking water.
Assuntos
Água Potável , Poluentes Químicos da Água , Monitoramento Ambiental , Microplásticos , Plásticos , Poluentes Químicos da Água/análiseRESUMO
Concern exists regarding potential health impacts associated with contaminants of emerging concern (CECs) that adsorb to microplastics (MPs). Previous studies have examined MPs as potential contaminant vectors in marine environments as opposed to freshwaters that represent drinking water sources. This study examined adsorption of two polycyclic aromatic hydrocarbons (PAHs), phenanthrene and fluoranthene, by virgin and weathered polyethylene (PE) in both artificial and natural freshwater matrices. Adsorption kinetics and isotherms conducted in artificial freshwater (AFW) consistently showed higher adsorption onto smaller (200 µm) PE when compared to 1090 µm PE. Adsorption mechanisms were primarily associated with hydrophobic interactions and monolayer chemisorption. As well, environmental factors including dissolved organic matter (DOC), pH, and polymer weathering also impacted adsorption. This work provides new insights regarding the adsorption of organic pollutants to better understand the risk of MPs in drinking water sources.