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2.
Chemosphere ; 342: 140135, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37690561

RESUMO

Heavy metals' interactions with plumbing materials are complicated due to the differential formation of biofilms within pipes that can modulate, transform, and/or sequester heavy metals. This research aims to elucidate the mechanistic role of biofilm presence on Lead (Pb) accumulation onto crosslinked polyethylene (PEX-A), high-density polyethylene (HDPE), and copper potable water pipes. For this purpose, biofilms were grown on new pipes for three months. Five-day Pb exposure experiments were conducted to examine the kinetics of Pb accumulation onto the new and biofilm-laden pipes. Additionally, the influence of Pb initial concentration on the rate of its accumulation onto the pipes was examined. The results revealed greater biofilm biomass on the PEX-A pipes compared to the copper and HDPE pipes. More negative zeta potential was found for the biofilm-laden plastic pipes compared to the new plastic pipes. After five days of Pb exposure under stagnant conditions, the biofilm-laden PEX-A (980 µg m-2) and HDPE (1170 µg m-2) pipes accumulated more than three times the Pb surface loading compared to the new PEX-A (265 µg m-2) and HDPE pipes (329 µg m-2), respectively. However, under flow conditions, Pb accumulation on biofilm-laden plastic pipes was lower than on the new pipes. Moreover, with increasing the initial Pb concentration, greater rates of Pb surface accumulation were found for the biofilm-laden pipes compared to the new pipes under stagnant conditions. First-order kinetics model best described the Pb accumulation onto both new and biofilm-laden water pipes under both stagnant and flow conditions.

3.
Environ Pollut ; 337: 122520, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37678732

RESUMO

Despite being corrosion-resistant, plastic potable water pipes might accumulate heavy metals on their surface if they convey metal-contaminated tap water. This study examined the influence of water pH and flow conditions on lead (Pb) release from new and biofilm-laden potable water pipes to provide insights regarding decontamination. For this purpose, biofilms were grown onto new crosslinked polyethylene (PEX-A), high-density polyethylene (HDPE), and copper pipes for three months. Lead was then deposited onto the new and biofilm-laden pipes through 5 d exposure experiments under flow conditions. After that, lead release experiments were conducted by exposing the lead-accumulated pipes to lead-free synthetic tap water for 5 d, under both stagnant and water flow conditions. The metal accumulation study showed no significant difference in lead uptake by new pipes and their biofilm-laden counterparts under flow conditions. This could be attributed to the detachment of biofilms that have accumulated lead as water flows through the pipes. Water flow conditions significantly influenced the lead release from new and biofilm-laden water pipes. A lower water pH of 5.0 increased the release of lead from plastic pipes into the contact water, compared to pH 6.0 and 7.8. The greatest percentage of lead was released from biofilm-laden HDPE pipes (5.3%, 120 h) compared to biofilm-laden copper pipes (3.9%, 6 h) and PEX-A (3.7%, 120 h) and after exposure to lead-free synthetic tap water at pH 5.0, under stagnant conditions. On the other hand, under water flow conditions, the greatest lead release was found for new PEX-A pipes (4.4%, 120 h), new HDPE pipes (2.7%, 120 h), and biofilm-laden copper pipes (3.7%, 2 h).


Assuntos
Água Potável , Engenharia Sanitária , Cobre/análise , Chumbo , Abastecimento de Água , Polietileno , Descontaminação , Biofilmes
4.
PLoS One ; 18(7): e0288938, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37471393

RESUMO

INTRODUCTION: The Médecins Sans Frontières (MSF) Goyalmara Hospital in Cox's Bazar, Bangladesh is a referral centre offering the highest level of care available in the Rohingya camps for pediatrics and neonatology. Efforts are underway to integrate pediatric palliative care due to high mortality and medical complexity of patients, yet little is known about the experiences of staff delivering palliative and end-of-life care. The purpose of this study was to understand the moral experiences of MSF staff to inform program planning and implementation. METHODS: This focused ethnography was conducted between March-August 2021 at Goyalmara Hospital. Data collection involved participant-observation, individual interviews (22), focus group discussions (5), and analysis of documents including MSF clinical guidelines, admission and referral criteria, reports, and training materials. Data analysis followed a modified version of the Qualitative Analysis Guide of Leuven and data were coded using NVivo software. RESULTS: The prevailing understanding of pediatric palliative care among national and international staff was care that prioritized comfort for infants and children who were not expected to survive. Staff's views were informed by their sense of obligation to do no harm, to do their best on behalf of their patients, and religious beliefs about God's role in determining the child's outcome. The authority of doctors, international staff, as well as protocols and guidelines shaped palliative care decision-making. Staff saw clinical guidelines as valuable resources that supported a consistent approach to care over time, while others were concerned that palliative care guidelines were rigidly applied. CONCLUSION: When integrating palliative care into humanitarian programs, it is important to emphasize the active role of palliative care in reducing suffering. Advocacy for access to the highest level of care possible should continue alongside palliative care integration. While palliative care guidelines are valuable, it is essential to encourage open discussion of staff concerns and adapt care plans based on the family's needs and preferences.


Assuntos
Hospitais Pediátricos , Cuidados Paliativos , Lactente , Humanos , Criança , Bangladesh , Antropologia Cultural , Princípios Morais
5.
Environ Res ; 212(Pt A): 113183, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35390300

RESUMO

A significant portion of urban litter is plastic which contaminates the environment and threatens ecological safety. The conversion of plastic litter into small fragments called microplastics (MPs) intensifies their critical risks by facilitating their transport and altering their physicochemical features. This study focuses on low density polyethylene (LDPE) and polyethylene terephthalate (PET) as the main components of urban litter. The photodegradation of LDPE and PET MPs due to the accelerated weathering experiments is investigated through surface chemistry and morphology analysis. The influence of MPs' photodegradation on their fragmentation behavior is evaluated through the innovative accelerated mechanical weathering experiments that simulated the abrasion of MPs with the road deposits. Furthermore, the role of MPs as the vehicles to transport the heavy metals from the urban environment to the water resources is evaluated by studying the kinetics of lead (Pb) uptake by new and weathered MPs in synthetic stormwater. The surface morphology investigation revealed the formation of crazes and the crack networks onto the MPs due to the weathering experiments. The surface chemistry analysis revealed the generation of several oxidized carbon surface functional groups onto the photodegraded MPs and their increased susceptibility to fragmentation due to the abrasion with the road deposits. The photodegradation increased the Pb accumulation onto the LDPE and PET MPs from 467 µg/m2 and 21 µg/m2 to 2290 µg/m2 and 725 µg/m2, after five days of metal exposure. The fundamental knowledge developed in this research provides a better conceptual understanding of the mechanisms controlling MPs persistence and contaminant transport within the urban environment, which is crucial to estimate their negative impacts on the ecosystem.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Ecossistema , Chumbo , Microplásticos , Fotólise , Plásticos , Polietileno , Poluentes Químicos da Água/análise
6.
J Emerg Manag ; 17(4): 305-320, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31603521

RESUMO

The critical role of evacuation, particularly for the communities in developing countries exposed to cyclones, has only been realized after some disastrous evacuation experiences in recent cyclones. A profound understanding of the factors influencing the evacuation behavior is necessary to reduce the loss of lives, especially in the cyclone prone communities. The purpose of this research is to identify the key factors influencing households' evacuation decision during a cyclone in developing economies. To this end, the research employs state of the art discrete choice modeling techniques referred to as mixed logit models. The study builds on the data collected in 1991 from the coastal areas of Bangladesh following the cyclone Sidr. The analysis result reveals that the evacuees of developing countries like Bangladesh resort to nearby tall buildings during cyclone due to the insufficient facilities provided by the cyclone centers. In case of mandatory evacuation and for temporary house owner, the households' decision to evacuate is found to be uniform. However, significant heterogeneity is found in the households' decision to evacuate whenever they receive a voluntary notice and also if they live sufficiently far from the sea shore. The factors that are identified to be influencing households' evacuation decision during a cyclone will enable potential evacuees to better evaluate their decision and consequently make more informed decision about the timing as well as the necessity of evacuation. The analysis result will also help emergency managers to decide on the timing and the type of evacuation orders they need to provide for reducing causalities due to landfall caused by cyclones.


Assuntos
Tempestades Ciclônicas , Desastres , Bangladesh , Tomada de Decisões , Emergências , Humanos
7.
J Indian Assoc Pediatr Surg ; 22(4): 232-236, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28974876

RESUMO

AIMS: The aim of this study is to report and analyze results of laparoscopy in impalpable testes performed between 2009 and 2016 and its short-term outcomes. MATERIALS AND METHODS: Demographic data, laterality, laparoscopic findings, operative time, procedure, hospital stay, complications, and follow-up data of 76 patients with 79 impalpable testes from 2009 to 2016 were retrospectively collected and analyzed. Successful outcome was defined as maintenance of intrascrotal position with no atrophy at a follow-up of at least 6 months. RESULTS: Impalpable testes constituted 24% of undescended testes in our series. Mean age was 3.9 years. Forty-two patients had left-sided, 31 right-sided, and three bilateral impalpable testes. Of the 79 clinically impalpable testes, on laparoscopy, 3 were vanishing testes, 52 were intra-abdominal (6 high-lying and 46 low-lying), 18 canalicular and 6 nubbin testes. Ultimately, 52 underwent laparoscopic orchiopexy: 46 single-staged orchiopexy and 6 two-staged Fowler-Stephens procedure. Mean operating time was 77 min. Complications were few and mostly minor. Eleven patients were lost in follow-up. On a mean follow-up of 23 months, one testis that underwent single-staged laparoscopic orchiopexy atrophied whereas good size and intrascrotal position were maintained in the rest. CONCLUSIONS: Laparoscopy in impalpable testes was safe, feasible, and effective. Overall outcome was good which was obtained by minimal use of electrocautery, dissection with wide strip of peritoneum and extensive retroperitoneal dissection for mobilization. There is a need for wide reporting of cases from high-volume pediatric surgery centers in India.

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