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BACKGROUND: In medical students' workplace learning, feedback is important for effective learning regarding communication and clinical skills. The provision of multisource feedback (MSF) in clinical practice with focus on the patient's perspective is rarely addressed in the literature. The overall objective was to explore the experience of MSF in medical students' clinical learning in primary healthcare (PHC). METHODS: In the study, patients provided feedback by use of the Patient Feedback in Clinical Practice (PFCP) questionnaire. By use of adapted PFCP questionnaire versions peers and clinical supervisors provided feedback and students performed a self-evaluation. The MSF learning activity was evaluated using surveys (4-point Likert scale/open-ended questions), (students (n = 26), peers (n = 9) and clinical supervisors (n = 7)). Data were analysed using descriptive and qualitative content analysis. RESULTS: Results (mean 4-point Likert scale) from participants evaluation of the MSF learning activity visualises the value of feedback in terms of patient-centred communication (students 3.50, peers 2.44 and clinical supervisors 3.57), guidance for further training (students 3.14, peers 2.89 and clinical supervisors 3.00) and clarification of pedagogical assignment (students 3.14, peers 2.89 and clinical supervisors 3.00). Thematic analysis of participants' free-text answers in the evaluation surveys resulted in three themes: (1) applicability of the MSF, (2) MSF - collaborative learning process and (3) MSF as a facilitator in students' clinical skills development. The participants experienced that the written MSF provided multi-facetted perspectives, which contributed to students' and peers' clinical and communication learning. MSF experience also enhanced clinical supervisors' feedback regarding communication skills, targeting the supervisors' pedagogical assignment. CONCLUSION: Our findings indicate that MSF provided directly after a patient encounter, using the PFCP questionnaire as feedback provider, could be an adequate learning activity for medical students' workplace learning. The MSF, provided through the PFCP questionnaire, was experienced to neutralise and operationalise the provision of concrete feedback, facilitating peers' learning and clinical supervisors' tuition. The results visualise the importance of patients in MSF, as a valuable resource in students' workplace learning. Our study implies that this learning activity could be an applicable tool to facilitate learning and pedagogic development in clinical education in PHC.
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Educação Médica , Estudantes de Medicina , Competência Clínica , Retroalimentação , Humanos , Atenção Primária à Saúde , Local de TrabalhoRESUMO
METHODS: Fifty-nine medical students evaluated their learning experience of receiving patients' written feedback obtained from the PFCP questionnaire. Students (N = 57) evaluated their experiences by applying a nine-question evaluation survey (Likert scale N = 3 and free-text questions N = 6) and/or participated in a semi-structured interview (N = 6 students). Data were analyzed using descriptive statistics and qualitative content analysis. RESULTS: The analysis of data from the students' evaluation survey was performed using 4-point Likert scale questions presented in mean, SD and range; ability to apply patient-centred communication (3.3, 0.74, 2-4), guidance for further clinical training of clinical skills (3.2, 1.31, 1-4) and visualization of the pedagogical assignment during an encounter (3.0, 1.68, 1-4). A content analysis of the free-text questions from the students' evaluation surveys and interviews resulted in three themes: (1) confidence in clinical practice, (2) application of patient-centred communication and (3) identification of learning needs. CONCLUSIONS: The results indicate that patients' feedback facilitated a reflective self-directed learning process with the identification of learning needs and increased awareness of the patient as a collaborative partner during the encounter. Patients' written feedback adjacent to a patient encounter is identified as a valuable additional learning tool in medical students' workplace learning. Further studies are required to explore how patients' written feedback can be operationalized in different clinical contexts, for example, in in-patient care.
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Estudantes de Medicina , Competência Clínica , Retroalimentação , Humanos , Aprendizagem Baseada em Problemas , RedaçãoRESUMO
BACKGROUND: Adequate communication and maintaining a patient-centered approach throughout patient encounters are important skills for medical students to develop. Feedback is often provided by clinical teachers. Patients are seldom asked to provide feedback to students that systematically addresses knowledge and skills regarding communication and patient-centeredness during an encounter. One way for patients to provide feedback to students is through a questionnaire; there is, however, a lack of such validated feedback questionnaires. This study aimed to compose and validate a feedback questionnaire for patients' feedback to medical students regarding students' ability to communicate and apply patient-centeredness in clinical practice. METHOD: This study comprises (a) composition of the questionnaire and (b) validation of the questionnaire. The composition included (1) literature review, (2) selection and composition of items and construction of an item pool, (3) test of items' content, and (4) test of the applicability of the questionnaire. The items originated from the Calgary-Cambridge Guide (Kurtz S, Silverman J, Benson J and Draper J, Acad Med 78:802-809, 2003), the 'Swedish National Patient Survey' (National Patient Survey, Primary Health Care, 2020), patient evaluation form by Braend et al. (Tidsskr Nor Laegeforen 126:2122-5, 2006), and additional developed items. The items were further developed after feedback from 65 patients, 22 students, eight clinical supervisors, and six clinical teachers. The validation process included 246 patients who provided feedback to 80 students. Qualitative content analysis and psychometric methods were used and exploratory factor analysis assessed internal validity. Cronbach's alpha was used to test the reliability of the items. RESULTS: The process resulted in the 19-item 'Patient Feedback in Clinical Practice' (PFCP) questionnaire. Construct validity revealed two dimensions: consultational approach and transfer of information. Internal consistency was high. Thematic analysis resulted in three themes: ability to capture the personal agenda of the consultation, alignment with the consultation, and constructs and characteristics. Students reported that the PFCP questionnaire provided useful feedback that could facilitate their learning in clinical practice. CONCLUSIONS: The results of this study indicate that the questionnaire is a valid, reliable, and internally consistent instrument for patients' feedback to medical students. The participants found the questionnaire to be useful for the provision of feedback in clinical practice. However, further studies are required regarding the PFCP questionnaire applicability as a feedback tool in workplace learning.
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Estudantes de Medicina , Retroalimentação , Humanos , Psicometria , Reprodutibilidade dos Testes , Inquéritos e Questionários , SuéciaRESUMO
In urban environments, particularly areas under reconstruction, metals, organic pollutants (OP), and microplastics (MP), are released in large amounts due to heavy traffic. Road runoff, a major transport route for urban pollutants, contributes significantly to a deteriorated water quality in receiving waters. This study was conducted in Gothenburg, Sweden, and is unique because it simultaneously investigates the occurrence of OP, metals, and MP on roads and in stormwater from an urban area under reconstruction. Correlations between the various pollutants were also explored. The study was carried out by collecting washwater and sweepsand generated from street sweeping, road surface sampling, and flow-proportional stormwater sampling on several occasions. The liquid and solid samples were analyzed for metals, polycyclic aromatic hydrocarbons (PAH), oxy-PAH, aliphatics, aromatics, phthalates, and MP. The occurrence of OP was also analyzed with a non-target screening method of selected samples. Microplastics, i.e. plastic fragments/fibers, paint fragments, tire wear particles (TWP) and bitumen, were analyzed with a method based on density separation with sodium iodide and identification with a stereo microscope, melt-tests, and tactile identification. MP concentrations amounted to 1500 particles/L in stormwater, 51,000 particles/L in washwater, and 2.6 × 106 particles/kg dw in sweepsand. In stormwater, washwater and sweepsand, MP ≥20 µm were found to be dominated by TWP (38%, 83% and 78%, respectively). The results confirm traffic as an important source to MP, OP, and metal emissions. Concentrations exceeding water and sediment quality guidelines for metals (e.g. Cu and Zn), PAH, phthalates, and aliphatic hydrocarbons in the C16-C35 fraction were found in most samples. The results show that the street sweeper collects large amounts of polluted materials and thereby prevents further spread of the pollutants to the receiving stormwater.
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BACKGROUND: Interprofessional learning activities can contribute to preparing students to function in health care teams. Although the importance of communication is acknowledged, there is still a lack of understanding about how students learn to communicate interprofessionally. AIM: To explore occupational therapist and physiotherapist students learning of skills in interprofessional communication by studying the students' communication while working together with a virtual patient. MATERIAL AND METHODS: The students carried out a virtual patient encounter in pairs of two, using one computer per student, sitting side by side. The students' actions and conversations were recorded as video films, the oral communication was transcribed and analysed using qualitative content analysis. RESULTS: The students created a social learning environment by posing questions, acknowledging each other and clarifying their professional perspective using familiar professional concepts. Comparing their professional views, students related their peers' statements to their own. Departing from their own profession and using the created open environment, the students' communication led to an interprofessional meaning-making process, with students aiming to understand each other. CONCLUSIONS AND SIGNIFICANCE: A reciprocal learning situation was created when students worked together in a virtual setting. Communicating and making shared decisions about a patient can facilitate learning how to communicate interprofessionally and improve students' understanding of their own profession.
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Terapeutas Ocupacionais/educação , Terapeutas Ocupacionais/psicologia , Terapia Ocupacional/educação , Fisioterapeutas/educação , Fisioterapeutas/psicologia , Estudantes/psicologia , Realidade Virtual , Adulto , Comunicação , Comportamento Cooperativo , Feminino , Humanos , Práticas Interdisciplinares , Relações Interprofissionais , Masculino , Grupo Associado , Aprendizagem Baseada em Problemas/métodos , Inquéritos e Questionários , Adulto JovemRESUMO
Urban runoff contains a mixture of both particulate and non-particulate organic pollutants (OPs). Hydrophobic OPs such as higher petroleum hydrocarbons, phthalates, and polycyclic organic hydrocarbons (PAHs) are not exclusively bound to particles, but also present in runoff in colloidal and truly dissolved forms. These hydrophobic compounds can also form nano- and microsized emulsions that may carry pollutants in stormwater. Hence, it is of great importance to develop treatment technologies such as sorption filters that can remove non-particulate OPs from contaminated stormwater. A pilot plant using column bed-filters of sand as a pre-filter, in combination with granulated activated carbon, Sphagnum peat or Pinus sylvestris bark, was used to investigate the removal of non-particulate OPs from urban stormwater. Samples from the filter effluents were collected weekly; during or after rain events; and during stress tests when incoming water was spiked with contaminated sediment and petrol or diesel. All sorption filters showed efficient reduction of aliphatic diesel hydrocarbons C16-C35, benzene, and the PAHs phenanthrene, fluoranthene, and pyrene during most of the operation time, which was 18 months. During the stress test events, all sorption filters showed 100% reduction of PAH-16, petrol and diesel aliphatics C5-C35. All sorption filters released DOC and nanoparticles, which may explain some of the transportation of OPs through the filter beds. The recommendation is to use a combination of sand pre-filtration and all the studied sorption materials in stormwater filters in series, to achieve effective removal of different types of OPs. It is also important to improve the hydraulic conditions to obtain sufficient water flows through the filters.
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Microplastics (MP) are transported from land-based sources from rivers to marine waters. However, there is currently little knowledge about MP fate from land sources to marine waters. Traffic is estimated to be one of the largest sources of MP; hence, stormwater is expected to be an important transportation route of MP to marine waters. The aim of this study was to investigate the effect of the size and density of tyre wear particles in road run-off on their fate in the Göta River in Sweden using hydrodynamic modelling. The model of the stretch of Göta River, Sweden's largest river, passing through Gothenburg (Sweden's second largest city) and out to the sea, was set up using MIKE 3 FM software. Literature data were used to define the MP characteristics: concentrations in stormwater, prevalent particle sizes, density of MP commonly occurring in road run-off and settling velocities. Results show that higher concentrations of MP are found on the south side of the river, compared with the north side, due to higher annual average daily traffic loads along the south side of the river. The mixing processes in the river and the MP concentrations were generally influenced by the vertical water density gradient caused by saline water from the Kattegat strait. While most MP with higher density and larger size settle in the river, smaller MP with density close to 1.0 g/cm3 do not settle in the river and therefore reach the Kattegat strait and the marine environments. Further research is needed to describe the fate and transport of microplastics in the stormwater system, including treatment facilities, i.e. biofouling, aggregation, degradation and/or further fragmentation and settling.
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Rios , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Hidrodinâmica , Microplásticos , Plásticos , SuéciaRESUMO
Road areas are pollution hotspots where many metals, organic pollutants (OPs) and nano/microparticles accumulate before being transported to receiving waters. Particles on roads originate from e.g. road, tyre and vehicle wear, winter road maintenance, soil erosion, and deposition. Street sweeping has the potential to be an effective and affordable practice to reduce the occurrence of road dust, and thereby the subsequent spreading of pollutants, but there is currently little knowledge regarding its effectiveness. In this paper we investigate the potential of street sweeping to reduce the amounts of OPs and nano/microparticles reaching stormwater, in a case study sampling road dust and washwater from a street sweeping machine, road dust before and after sweeping, and stormwater. The compound groups generally found in the highest concentrations in all matrices were aliphatics C5-C35 > phthalates > aromatics C8-C35 > PAH-16. The concentrations of aliphatics C16-C35 and PAHs in washwater were extremely high at ≤ 53,000 µg/L and ≤ 120 µg/L, respectively, and the highest concentrations were found after a 3-month winter break in sweeping. In general, fewer aliphatic and aromatic petroleum hydrocarbons and PAHs were detected in road dust samples than in washwater. The relative composition of the specific PAH-16 suggests tyre wear, vehicle exhausts, brake linings, motor oils and road surface wear as possible sources. The study indicates that many of the hydrophobic compounds quantified in washwater are attached to small particles or truly dissolved. The washwater contains a wide range of small particles, including nanoparticles in sizes from just below 1 nm up to 300 nm, with nanoparticles in the size range 25-300 nm present in the highest concentrations. The results also indicated agglomeration of nanoparticles in the washwater. The street sweeping collected a large amount of fine particles and associated pollutants, leading to the conclusion that washwater from street sweeping needs to be treated before disposal.
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Poluentes Atmosféricos , Poluentes Ambientais , Hidrocarbonetos Policíclicos Aromáticos , Emissões de Veículos , Poeira , Monitoramento Ambiental , Poluição AmbientalRESUMO
A wide range of organic pollutants (OPs) are emitted from the road and traffic environment and transported with road runoff to receiving waters. To provide an understanding of the transport routes of OPs in the environment, an investigation was carried out with the aim to determine whether OPs are transported with nano- and microparticles in the form of emulsions. Tests were performed on simulated road runoff, using laboratory prepared mixtures of ultrapure water and specific polycyclic aromatic hydrocarbons (PAHs), alkylphenols (APs) and their ethoxylates (APEOs), phthalates, diesel oil (aliphatic hydrocarbons), with and without addition of humic acid (HA) and iron (Fe) colloids. The samples were analysed directly after mixing and after a few days of stabilisation for particle size distribution (PSD) and concentrations of particles in the size range 10â¯nm-100⯵m, and zeta potential >⯱â¯500â¯mV. Further, after long-term storage to achieve stabilisation, selected samples were investigated for the PSD and particle concentrations in the ranges 10â¯nm-2⯵m, to determine whether stable emulsions had formed. The following simulation mixtures, both mixed and stabilised, were identified as potential emulsions: diesel, APs and APEOs, diesel with APs and APEOS, phthalates, and a mixture of all OPs with and without colloids. Measurements with the Zetasizer and Nanosight instruments imply that the majority of particles in the samples were found in the nano-range of 30-660â¯nm respectively, and a smaller portion of particlesâ¯<â¯28% also measured with Coulter Counter were found to be micro-sized. Higher concentrations of the smallest nanoparticles were found in the mixture of all OPs without colloids added, than in the OP mixture with colloids added. The results indicate that the addition of colloids favours the formation of larger micro-sized emulsions that may break down with time into nano-sized particles. In the mixed samples, the number of micro-sized particles decreased, while the number of nanoparticles increased; this process may also occur in road runoff transportation systems during heavy rain events. This is the first study to indicate that emulsions of OPs may be formed in road runoff, and that emulsions may act as carriers of OPs in urban stormwater.
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Monitoramento Ambiental/métodos , Hidrocarbonetos Policíclicos Aromáticos/química , Poluentes Químicos da Água/química , Coloides , Emulsões , Tamanho da Partícula , ChuvaRESUMO
OBJECTIVE: To explore how a student-run clinic (SRC) in primary health care (PHC) was perceived by students, patients and supervisors. DESIGN: A mixed methods study. Clinical learning environment, supervision and nurse teacher evaluation scale (CLES + T) assessed student satisfaction. Client satisfaction questionnaire-8 (CSQ-8) assessed patient satisfaction. Semi-structured interviews were conducted with supervisors. SETTING: Gustavsberg PHC Center, Stockholm County, Sweden. SUBJECTS: Students in medicine, nursing, physiotherapy, occupational therapy and psychology and their patients filled in questionnaires. Supervisors in medicine, nursing and physiotherapy were interviewed. MAIN OUTCOME MEASURES: Mean values and medians of CLES + T and CSQ-8 were calculated. Interviews were analyzed using content analysis. RESULTS: A majority of 199 out of 227 student respondents reported satisfaction with the pedagogical atmosphere and the supervisory relationship. Most of the 938 patient respondents reported satisfaction with the care given. Interviews with 35 supervisors showed that the organization of the SRC provided time and support to focus on the tutorial assignment. Also, the pedagogical role became more visible and targeted toward the student's individual needs. However, balancing the student's level of autonomy and the own control over care was described as a challenge. Many expressed the need for further pedagogical education. CONCLUSIONS: High student and patient satisfaction reported from five disciplines indicate that a SRC in PHC can be adapted for heterogeneous student groups. Supervisors experienced that the SRC facilitated and clarified their pedagogical role. Simultaneously their need for continuous pedagogical education was highlighted. The SRC model has the potential to enhance student-centered tuition in PHC. Key Points Knowledge of student-run clinics (SRCs) as learning environments within standard primary health care (PHC) is limited. We report experiences from the perspectives of students, their patients and supervisors, representing five healthcare disciplines. Students particularly valued the pedagogical atmosphere and the supervisory relationship. Patients expressed high satisfaction with the care provided. Supervisors expressed that the structure of the SRC supported the pedagogical assignment and facilitated student-centered tuition - simultaneously the altered learning environment highlighted the need for further pedagogical education. Student-run clinics in primary health care have great potential for student-regulated learning.
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Atitude , Educação Profissionalizante/métodos , Satisfação do Paciente , Atenção Primária à Saúde , Clínica Dirigida por Estudantes , Estudantes , Adolescente , Adulto , Idoso , Criança , Competência Clínica , Educação Médica , Educação em Enfermagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Terapia Ocupacional/educação , Satisfação Pessoal , Fisioterapeutas/educação , Psicologia/educação , Inquéritos e Questionários , Suécia , Adulto JovemRESUMO
Adsorption filtration is one of the most promising techniques for removal of dissolved, colloidal and particulate pollutants from stormwater. The aim of this study was to compare the capacity of five filter materials - cellulose, chitosan, chitosan-covered bark, pine bark and polypropylene/polyethylene (PP/PE) fibres - to sorb organic pollutants frequently detected in stormwater, including polycyclic aromatic hydrocarbons (PAHs), alkylphenols and phthalates. In batch tests, synthetic stormwater spiked with a mixture of the organic compounds was contacted with the materials for up to 24â h. The compounds were then liquid-liquid extracted and analysed using GC-MS. Cellulose and chitosan showed very low sorption capacity for the organic contaminants, whereas >70% of the initial concentration of most tested compounds was removed using PP/PE fibres, and >80% with pine bark and chitosan-covered bark. The highest adsorption capacity was found for PAHs (up to 44â µg/g) using PP/PE fibres and bark. For all tested compounds, maximum sorption was approached within 30â min using these materials.
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Poluentes Químicos da Água , Purificação da Água , Adsorção , Filtração , Compostos Orgânicos , Hidrocarbonetos Policíclicos AromáticosRESUMO
The risk from chemical substances in surface waters is often increased during wet weather, due to surface runoff, combined sewer overflows (CSOs) and erosion of contaminated land. There are strong incentives to improve the quality of surface waters affected by human activities, not only from ecotoxicity and ecosystem health perspectives, but also for drinking water and recreational purposes. The aim of this study is to investigate the influence of urban stormwater discharges and CSOs on receiving water in the context of chemical health risks and recreational water quality. Transport of copper (Cu) and benzo[a]pyrene (BaP) in the Göta River (Sweden) was simulated using a hydrodynamic model. Within the 16 km modelled section, 35 CSO and 16 urban stormwater point discharges, as well as the effluent from a major wastewater treatment plant, were included. Pollutant concentrations in the river were simulated for two rain events and investigated at 13 suggested bathing sites. The simulations indicate that water quality guideline values for Cu are exceeded at several sites, and that stormwater discharges generally give rise to higher Cu and BaP concentrations than CSOs. Due to the location of point discharges and the river current inhibiting lateral mixing, the north shore of the river is better suited for bathing. Peak concentrations have a short duration; increased concentrations of the pollutants may however be present for several days after a rain event. Monitoring of river water quality indicates that simulated Cu and BaP concentrations are in the same order of magnitude as measured concentrations. It is concluded that hydrodynamic modelling is a useful tool for identifying suitable bathing sites in urban surface waters and areas of concern where mitigation measures should be implemented to improve water quality.
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Benzo(a)pireno , Cobre , Modelos Teóricos , Qualidade da Água , Monitoramento Ambiental , Humanos , Hidrodinâmica , Chuva , Suécia , Movimentos da ÁguaRESUMO
Bioretention, also known as rain garden, allows stormwater to soak into the ground through a soil-based medium, leading to removal of particulate and dissolved pollutants and reduced peak flows. Although soil organic matter (SOM) is efficient at sorbing many pollutants, amending the bioretention medium with highly effective adsorbents has been proposed to optimize pollutant removal and extend bioretention lifetime. The aim of this research was to investigate whether soil amended with activated carbon produced from sewage sludge increases the efficiency to remove hydrophobic organic compounds frequently detected in stormwater, compared to non-amended soil. Three lab-scale columns (520 cm3) were packed with soil (bulk density 1.22 g/cm3); activated carbon (0.5% w/w) was added to two of the columns. During 28 days, synthetic stormwater-ultrapure water spiked with seven hydrophobic organic pollutants and dissolved organic matter in the form of humic acids-was passed through the column beds using upward flow (45 mm/h). Pollutant concentrations in effluent water (collected every 12 h) and polluted soils, as well as desorbed amounts of pollutants from soils were determined using GC-MS. Compared to SOM, the activated carbon exhibited a significantly higher adsorption capacity for tested pollutants. The amended soil was most efficient for removing moderately hydrophobic compounds (log K ow 4.0-4.4): as little as 0.5% (w/w), carbon addition may extend bioretention medium lifetime by approximately 10-20 years before saturation of these pollutants occurs. The column tests also indicated that released SOM sorb onto activated carbon, which may lead to early saturation of sorption sites on the carbon surface. The desorption test revealed that the pollutants are generally strongly sorbed to the soil particles, indicating low bioavailability and limited biodegradation.
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Carvão Vegetal , Recuperação e Remediação Ambiental , Esgotos/química , Poluentes do Solo/isolamento & purificação , Solo/química , Adsorção , Biodegradação Ambiental , Substâncias Húmicas , Interações Hidrofóbicas e Hidrofílicas , Compostos Orgânicos/química , Compostos Orgânicos/isolamento & purificação , ChuvaRESUMO
Adsorption filters have the potential to retain suspended pollutants physically, as well as attracting and chemically attaching dissolved compounds onto the adsorbent. This study investigated the adsorption of eight hydrophobic organic compounds (HOCs) frequently detected in stormwater - including four polycyclic aromatic hydrocarbons (PAHs), two phthalates and two alkylphenols - onto activated carbon produced from domestic sewage sludge. Adsorption was studied using batch tests. Kinetic studies indicated that bulk adsorption of HOCs occurred within 10 min. Sludge-based activated carbon (SBAC) was as efficient as tested commercial carbons for adsorbing HOCs; adsorption capacities ranged from 70 to 2800 µg/g (Cinitial = 10-300 µg/L; 15 mg SBAC in 150 mL solution; 24 h contact time) for each HOC. In the batch tests, the adsorption capacity was generally negatively correlated to the compounds' hydrophobicity (log Kow) and positively associated with decreasing molecule size, suggesting that molecular sieving limited adsorption. However, in repeated adsorption tests, where competition between HOCs was more likely to occur, adsorbed pollutant loads exhibited strong positive correlation with log Kow. Sewage sludge as a carbon source for activated carbon has great potential as a sustainable alternative for sludge waste management practices and production of a high-capacity adsorption material.
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Carvão Vegetal , Esgotos , Poluentes Químicos da Água , Adsorção , Carbono , CinéticaRESUMO
A large number of organic pollutants (OPs) emitted from vehicles and traffic-related activities exhibit environmental persistence and a tendency to bioaccumulate, and may have detrimental long-term effects on aquatic life. The aim of the study was to establish a list of significant sources of OPs occurring in road runoff, identify the OPs emitted from these sources, select a number of priority pollutants (PP), and estimate the quantity of PPs emitted in a road environment case study using substance flow analysis (SFA). The priority pollutants included in the SFA were selected from a list of approximately 1100 compounds found after comprehensive screening, including literature and database searches, expert judgments, the Ranking and Identification of Chemical Hazards method, and chemical analysis of sediments. The results showed the following priority order: polycyclic aromatic hydrocarbons (PAHs)>alkanes C20-C40>alkylphenols>phthalates>aldehydes>phenolic antioxidants>bisphenol A>oxygenated-PAHs>naphtha C5-C12>amides>amines. Among these, PAHs were chosen for a SFA, which was performed for a highway case study area in Gothenburg (Sweden). The SFA showed that the main sources of PAHs emitted in the area were vehicle exhaust gases, followed by tyre wear, motor lubricant oils, road surface wear, and brake linings. Only 2-6% of the total 5.8-29kg annually emitted PAHs/ha ended up in the stormwater sewer system. The measured PAH loads were found in much smaller amounts than the calculated loads and the outflow to stormwater contained much more of the hazardous PAHs than the total loads emitted in the catchment area.
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Treatment of stormwater via sorption has the potential to remove both colloidal and dissolved pollutants. Previous research shows that activated carbon produced from sewage sludge is very efficient in sorbing hydrophobic organic compounds (HOCs), frequently detected in stormwater. The aim of this research was to determine whether the presence of dissolved organic matter (DOM) has a negative effect on the adsorption of HOCs onto sludge-based activated carbon (SBAC) in batch adsorption tests. Batch adsorption tests were used to investigate the influence of two types of DOM - soil organic matter and humic acid (HA) technical standard - on the sorption of HOCs onto SBAC, and whether preloading adsorbent and adsorbates with DOM affects HOC sorption. The results indicate that soil DOM and HAs do not have a significant negative effect on the adsorption of HOCs under tested experimental conditions, except for a highly hydrophobic compound. In addition, preloading SBAC or HOCs with DOM did not lead to lower adsorption of HOCs. Batch adsorption tests appear to be inefficient for investigating DOM effects on HOC adsorption, as saturating the carbon is difficult because of high SBAC adsorption capacity and low HOC solubility, so that limited competition occurs on the sorbent.
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Carvão Vegetal/química , Esgotos/química , Solo/química , Adsorção , Substâncias Húmicas , Interações Hidrofóbicas e Hidrofílicas , Compostos Orgânicos/química , Poluentes do Solo/química , Solubilidade , Eliminação de Resíduos Líquidos , Poluentes Químicos da ÁguaRESUMO
Conventional stormwater treatment techniques such as sedimentation and filtration are inefficient for removing the dissolved and colloidal phases of hydrophobic organic compounds (HOCs) present in stormwater. Adsorption could be a promising technique for removing colloidal and dissolved pollutants. Five low-cost sorbent materials were investigated in this project, including two minerals vermiculite and perlite and three waste products two pine barks and a sawdust as potential adsorbents for removal of polycyclic aromatic hydrocarbons (PAHs), alkylphenols and phthalates; HOCs commonly found in stormwater. Adsorption capacity and kinetics were studied through batch adsorption tests using synthetic stormwater spiked with a mixture of HOCs. Vermiculite and perlite exhibited insignificant removal of the organic contaminants. The three wood-based materials retained >80% of the initial HOC concentration (10-300 µg/L). The two barks exhibited slightly higher adsorption capacities of HOCs than the sawdust. For all compounds tested, maximum adsorption onto the wood-based media was reached in <10 min. The highest adsorption capacity was found for PAHs (up to 45 µg/g), followed by alkylphenols and phthalates. No correlation was found between adsorption capacity and physical-chemical parameters such as solubility and partition coefficients (log K(ow)). Agreement between empirical data and the pseudo-second order kinetic model suggest chemisorption of HOCs onto a monolayer on wood-based media. This could lead to early saturation of the materials and should be investigated in future studies through repeated adsorption of HOCs, for example in column studies.
Assuntos
Óxido de Alumínio/química , Silicatos de Alumínio/química , Dióxido de Silício/química , Resíduos , Poluentes da Água/química , Purificação da Água/métodos , Adsorção , Filtração , Interações Hidrofóbicas e Hidrofílicas , Ácidos Ftálicos/análise , Ácidos Ftálicos/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/química , Poluentes da Água/análiseRESUMO
Chemicals such as phthalates, parabens, bisphenol A (BPA) and triclosan (TCS), used in a wide variety of consumer products, are suspected endocrine disrupters although their level of toxicity is thought to be low. Combined exposure may occur through ingestion, inhalation and dermal exposure, and their toxic as well as combined effects are poorly understood. The objective of the study was to estimate the exposure to these chemicals in Swedish mothers and their children (6-11 years old) and investigate potential predictors of the exposure. Urine samples from 98 mother-child couples living in either a rural or an urban area were analyzed for the concentrations of four metabolites of di-(2-ethylhexyl) phthalate (DEHP), three metabolites of di-iso-nonyl phthalate (DiNP), mono-ethyl phthalate (MEP), mono-benzyl phthalate (MBzP) and mono-n-butyl phthalate (MnBP), methylparaben (MetP), ethylparaben (EthP), propylparaben (ProP), butylparaben, benzylparaben, BPA, and TCS. Information on sociodemographics, food consumption habits and use of personal care products, obtained via a questionnaire, was used to investigate the associations between the urinary levels of chemicals and potential exposure factors. There were fairly good correlations of biomarker levels between the mothers and their children. The children had generally higher levels of phthalates (geometric mean ΣDEHP 65.5 µg/L; ΣDiNP 37.8 µg/L; MBzP 19.9 µg/L; MnBP 76.9 µg/L) than the mothers (ΣDEHP 38.4 µg/L; ΣDiNP 33.8 µg/L; MBzP 12.8 µg/L; MnBP 63.0 µg/L). Conversely, the mother's levels of parabens (MetP 37.8 µg/L; ProP 13.9 µg/L) and MEP (43.4 µg/L) were higher than the children's levels of parabens (MetP 6.8 µg/L; ProP 2.1 µg/L) and MEP (28.8 µg/L). The urinary levels of low molecular weight phthalates were higher among mothers and children in the rural area (MBzP p=<0.001; MnBP p=0.001-0.002), which is probably due to higher presence of PVC in floorings and wall coverings in this area, whereas the levels of parabens were higher among the children in the urban area (MetP p=0.003; ProP p=0.004) than in the rural area. The levels of high molecular weight phthalates were associated with consumption of certain foods (i.e. chocolate and ice cream) whereas the levels of parabens were associated with use of cosmetics and personal care products.
Assuntos
Compostos Benzidrílicos/urina , Exposição Ambiental , Parabenos/análise , Fenóis/urina , Ácidos Ftálicos/urina , Triclosan/urina , Adulto , Biomarcadores , Criança , Feminino , Humanos , Masculino , MãesRESUMO
Landfill leachates are repeatedly found contaminated with organic pollutants, such as alkylphenols (APs), phthalates and polycyclic aromatic hydrocarbons (PAHs) at levels exceeding water quality standards. It has been shown that these pollutants may be present in the colloidal and truly dissolved phase in contaminated water, making particle separation an inefficient removal method. The aim of this study was to investigate sorption and degradation of petroleum hydrocarbons (PHCs), selected APs, bisphenol A (BPA), phthalates and PAHs from landfill leachate using sand, granulated activated carbon (GAC) and peat moss filters. A pilot plant was installed at an inactive landfill with mixed industrial and household waste and samples were collected before and after each filter during two years. Leachate pre-treated in oil separator and sedimentation pond failed to meet water quality standards in most samples and little improvement was seen after the sand filter. These techniques are based on particle removal, whereas the analysed pollutants are found, to varying degrees, bound to colloids or dissolved. However, even highly hydrophobic compounds expected to be particle-bound, such as the PHCs and high-molecular weight PAHs, were poorly removed in the sand filter. The APs and BPA were completely removed by the GAC filter, while mass balance calculations indicate that 50-80% of the investigated phenols were removed in the peat filter. Results suggest possible AP degradation in peat filters. No evidence of phthalate degradation in the landfill, pond or the filters was found. The PHCs were completely removed in 50% and 35% of the measured occasions in the GAC and peat filters, respectively. The opposite trend was seen for removal of PAHs in GAC (50%) and peat (63%). Oxygenated PAHs with high toxicity were found in the leachates but not in the pond sediment. These compounds are likely formed in the pond water, which is alarming because sedimentation ponds are commonly used treatment techniques. The oxy-PAHs were effectively removed in the GAC, and especially the peat filter. It was hypothesized that dissolved compounds would adsorb equally well to the peat and GAC filters. This was not completely supported as the GAC filter was in general more efficient than peat.
Assuntos
Compostos Benzidrílicos/química , Petróleo/análise , Fenóis/química , Ácidos Ftálicos/química , Hidrocarbonetos Policíclicos Aromáticos/química , Poluentes Químicos da Água/química , Adsorção , Carbono/química , Filtração/instrumentação , Projetos Piloto , Dióxido de Silício , SoloRESUMO
BACKGROUND: Primary care is an integral part of the medical curriculum at Karolinska Institutet, Sweden. It is present at every stage of the students' education. Virtual patients (VPs) may support learning processes and be a valuable complement in teaching communication skills, patient-centeredness, clinical reasoning, and reflective thinking. Current literature on virtual patients lacks reports on how to design and use virtual patients with a primary care perspective. OBJECTIVE: The objective of this study was to create a model for a virtual patient in primary care that facilitates medical students' reflective practice and clinical reasoning. The main research question was how to design a virtual patient model with embedded process skills suitable for primary care education. METHODS: The VP model was developed using the Open Tufts University Sciences Knowledgebase (OpenTUSK) virtual patient system as a prototyping tool. Both the VP model and the case created using the developed model were validated by a group of 10 experienced primary care physicians and then further improved by a work group of faculty involved in the medical program. The students' opinions on the VP were investigated through focus group interviews with 14 students and the results analyzed using content analysis. RESULTS: The VP primary care model was based on a patient-centered model of consultation modified according to the Calgary-Cambridge Guides, and the learning outcomes of the study program in medicine were taken into account. The VP primary care model is based on Kolb's learning theories and consists of several learning cycles. Each learning cycle includes a didactic inventory and then provides the student with a concrete experience (video, pictures, and other material) and preformulated feedback. The students' learning process was visualized by requiring the students to expose their clinical reasoning and reflections in-action in every learning cycle. Content analysis of the focus group interviews showed good acceptance of the model by students. The VP was regarded as an intermediate learning activity and a complement to both the theoretical and the clinical part of the education, filling out gaps in clinical knowledge. The content of the VP case was regarded as authentic and the students appreciated the immediate feedback. The students found the structure of the model interactive and easy to follow. The students also reported that the VP case supported their self-directed learning and reflective ability. CONCLUSIONS: We have built a new VP model for primary care with embedded communication training and iterated learning cycles that in pilot testing showed good acceptance by students, supporting their self-directed learning and reflective thinking.