Are contaminated soil and groundwater remediation with nanoscale zero-valent iron sustainable? An analysis of case studies.

Nanoscale zero valent iron (nZVI) is globally the main nanomaterial used in contaminated site remediation. This study aims to evaluate the sustainability of using nZVI in the nanoremediation of contaminated sites and to determine the factors that affect the sustainability of the use of nZVI in remediation. Five case studies of nZVI use on a pilot scale were selected. Life cycle analysis tools were used to evaluate environmental, economic, social impacts, and sustainability. The functional unit of the life cycle analyses was 1.00 m3 of remediated soil and groundwater. Case study of Brazil was the least sustainable, while case study of United States was the most sustainable. Only the modification of the functional unit results in variations in the sustainability index. Different factors influence the sustainability of nZVI in remediation, the main factor being the amount of nZVI used in the processes. Finally, this work contributes significantly to the state-of-the-art sustainable use of nZVI in remediation. This is a pioneering study in the detailed and comprehensive assessment of the sustainability of the use of nZVI in remediation. Through the analysis of case studies, it is possible to determine the main factors that influence the sustainability of the nZVI remediation life cycle.

Social life cycle assessment of the nanoscale zero-valent iron synthesis process for application in contaminated site remediation.

Nanoscale zero-valent iron (nZVI) is the main nanomaterial used in environmental remediation processes. However, as with any remediation technique, the production and the use of nanomaterials can also cause environmental, economic, and social impacts. Thus, the present study investigated the social life cycle analysis (S-LCA) of nZVI production methods applied in environmental remediation. Three production methods of nZVI were selected for analysis: milling, reduction with sodium borohydride, and reduction with hydrogen gas. The social life cycle analysis was developed based on the ISO 14040 standard steps. Limits of the S-LCA system involve the stages of raw material extraction and manufacturing when not considering the use of nZVI postproduction. The analysis of social impact was conducted considering the involved stakeholders, through the application and improvement of an existing methodology and through the following procedures: characterization of social indicators according to a normalized scale, identification of the normalization factor for the indicators, employment of a social questionnaire, calculation of the total points in each impact subcategory (midpoint), calculation of the total points in the impact categories (endpoint), and calculation of the Social Index. The three production methods of nZVI result in significantly equal Social Indices. All methods were classified as socially sustainable according to the implemented methodology. The sensitivity analysis demonstrates the results dependent with the geographic location of the inventory data, while changes in the weighting can affect the Social Index results. Overall, this study significantly contributed to the state-of-the-art application of S-LCA in studies using nanomaterials; however, several limitations were also observed, and thus, steps for future development were suggested to future researches. In addition, this study improved the S-LCA methodology which can be used to assess the social impact of any product.

Life cycle sustainability assessment of the nanoscale zero-valent iron synthesis process for application in contaminated site remediation.

Nanoscale zero-valent iron (nZVI) is the main nanomaterial used in environmental remediation processes. The present study aims to evaluate the life cycle sustainability of nZVI production methods applied in environmental remediation. Three production methods of nZVI were selected for analysis: milling, liquid reduction with sodium borohydride, and chemical reduction with hydrogen gas (in two approaches: considering the goethite and hematite synthesis and after using in nZVI production and, using goethite and hematite particles already synthesized for nZVI production). The life cycle sustainability assessment was carried out based on a multi-criteria and multi-attribute analysis. The multi-criteria analysis was used to determine impact category preferences of different specialists in sustainability and remediation, and calculate the sustainability score through a linear additive model. Finally, a Monte Carlo simulation was used to quantify the results uncertainty. The functional unit considered was 1.00 kg of nZVI produced. The milling method and the hydrogen gas method in approach considering the use goethite and hematite particles already synthesized were the most sustainable. Moreover, the sustainability index was found to be influenced by the considered location scenarios as well as the perspectives of the different specialists, which was essential in producing a more accurate and comprehensive evaluation of the aforementioned sustainability methods. Overall, this study significantly contributed to applications of the state-of-the-art life cycle sustainability assessment in studies regarding nanomaterials, employing a simple methodology that included an analysis of different specialists. In addition, this is the first article that uses life cycle sustainability assessment in nanomaterials.

Nano scale zero valent iron production methods applied to contaminated sites remediation: An overview of production and environmental aspects.

The nano scale zero valent iron (nZVI) is the most used material in the remediation process. The inclusion of sustainability in the remediation process has also been gaining prominence. Sustainable remediation seeks to consider the environmental, economic and social impacts of remediation. Thus, this article aims to: (i) identify and describe nZVI production methods and (ii) evaluate their environmental aspects. Thus, this research was carried out in two stages. The first consisted of systematic bibliographical research to identify and describe nZVI production methods. In the second stage, an environmental analysis of the methods was performed considering the methodology of life cycle inventory assessment. Based on the inventory analysis, a classification of environmental aspects was performed, which included criteria, icons and a color scale. Nine nZVI production methods were identified, which comprised different technologies and processes. All methods had negative environmental aspects, such as high energy consumption, waste, wastewater generation and atmospheric emissions. In the classification of methods with regard to environmental aspects, the milling method had the best score, and the ultrasonic wave method the worst. Overall, this study contributes significantly to the detailed knowledge of nZVI synthesis methods in relation to production processes and their environmental aspects.

Effects of homemade biosurfactant from Bacillus methylotrophicus on bioremediation efficiency of a clay soil contaminated with diesel oil.

Despite constant progress in the understanding of the mechanisms related to the effects of biosurfactants in the bioremediation processes of oily residues, the possibility of antagonist effects on microbial growth and the production in situ of these compounds must be elucidated. The aims of this work were a) to evaluate the effects of the addition of a homemade biosurfactant of Bacillus methylotrophicus on the microbial count in soil in order to determine the possibility of inhibitory effects, and b) to accomplish biostimulation using media prepared with whey and bioaugmentation with B. methylotrophicus, analyzing the effects on the bioremediation of diesel oil and evidencing the in situ production of biosurfactants through effects on surface tension. The homemade bacterial biosurfactant did not present inhibitory effects acting as a biostimulant until 4000 mg biosurfactant/kg of soil. The biostimulation and bioaugmentation presented similar better results (p > 0.05) with the degradation of oil (~60%) than natural attenuation due to the low quantities of biostimulants added. For bioaugmentated and biostimulated soils, a decrease of surface tension between 30 and 60 days was observed, indicating the production of tensoactives in the soil, which was not observed in natural attenuation or a control treatment.

Use of Nanoscale Zero-Valent Iron for Remediation of Clayey Soil Contaminated with Hexavalent Chromium: Batch and Column Tests.

This study investigated the reduction of hexavalent chromium (Cr(VI)) in a clayey residual soil using nanoscale zero-valent iron (nZVI). Five different ratios between nZVI and Cr(VI) were tested in batch tests (1000/11; 1000/23; 1000/35; 1000/70, and 1000/140 mg/mg) with the soil. With the selected proportion resulting best efficiency, the column tests were conducted, with molded specimens of 5 cm in diameter and 5 cm in height, with different nZVI injection pressures (10, 30, and 100 kPa). The soil was contaminated with 800 mg/kg of Cr(VI). The Cr(VI) and Cr(III) analyses were performed following the USEPA 3060A and USEPA 7196A standards. The results show that the reduction of Cr(VI) is dependent on the ratio between nZVI and Cr(VI), reaching 98% of efficiency. In column tests, the pressure of 30 kPa was the most efficient. As pressure increased, contaminant leaching increased. The permeability decreased over time due to the gradual increase in filtration and formation of oxyhydroxides, limiting nZVI mobility. Overall, nZVI is efficient for soil remediation with Cr(VI), but the injection process can spread the contaminated if not properly controlled during in situ application.

Influence of nanoscale zero-valent iron on hydraulic conductivity of a residual clayey soil and modeling of the filtration parameter.

Contaminated clay soils pose problems to public health and the environment in several parts of the world. Very little is known about the transport of decontaminating agents used in remediation process under natural, undisturbed conditions. Nanomaterials, especially those made of nanoscale zero-valent iron (nZVI), have been most frequently used for remediation of contaminated soils because of their higher reactivity, lower toxicity, and lower cost than other metallic nanoparticles. Even though the nanoparticle size is smaller than soil pores, clogging may occur over time due to agglomeration of nanoparticles, which could reduce the soil's natural permeability and thereby cause filtration of the nanoparticles. The use of a stabilizer in the nanoparticles can modify the reactivity but improves their mobility in the soil system. Thus, the objective of this work was to evaluate the hydraulic conductivity of residual clay soil under the injection of different types and concentrations of nZVI with and without surfactant stabilizer (NANOFER 25, NANOFER 25S, and NANOFER STAR in powder at 1 g/L, 4 g/L, 7 g/L, and 10 g/L concentrations), and to model transport of these nZVI suspensions in this soil system. Undisturbed cylindrical soil samples collected from the field were used, and hydraulic conductivity tests were performed using a column apparatus. The results showed that the presence of the stabilizer in the nZVI influenced the nanoparticles' mobility. The nZVI concentrations of 1 and 4 g/L did not affect the natural soil hydraulic conductivity. However, higher concentrations reduced the hydraulic conductivity value, which retarded the migration of nZVI as reflected in the value of filtration parameter.

Bibliometric study of the toxicology of nanoescale zero valent iron used in soil remediation.

The application of nanoscale zero-valent iron is one of the most widely used remediation technologies; however, the potential environmental risks of this technology are largely unknown. In order to broaden the knowledge on this subject, the present work consists of a bibliometric study of all of publications related to the toxicity of zero-valent iron nanoparticles used in soil remediation available from the Scopus (Elsevier) and Web of Science (Thompson Reuters) databases. This study presents a temporal distribution of the publications, the most cited articles, the authors who have made the greatest contribution to the theme, and the institutions, countries, and scientific journals that have published the most on this subject. The use of bibliometrics has allowed for the visualization of a panorama of the publications, providing an appropriate analysis to guide new research towards an effective contribution to science by filling the existing gaps. In particular, the lack of studies in several countries reveals a promising area for the development of further research on this topic.

The psychosocial and economic burden of genital warts among women assisted in sixsexual and reproductive health clinics in Brazil / A carga psicossocial e econômica de verrugas genitais em mulheres atendidas em seis clínicas de saúde sexual e reprodutiva no Brasil

Introduction: World Health Organization estimates that 291 million women worldwide will have a human papillomavirus infection. Treatment for genital warts brings discomfort and may be stressful. Objective: The objectives are to estimate the psychological burden of genital warts and to estimate its economic and burden in six reproductive health clinics in Brazil. Methods: Women visiting BEMFAM'S Clinics form January 2012 until March 2013 filled a self-administrated questionnaire based on psychometric scale. The economic burden was measured with a retrospective study of medical chart review of patients assisted from January 2009 to December 2010. Results: A total of 122 individuals filled the psychosocial questionnaire. Women with normal Pap smear presented lower scores of worries and concerns about gynecological health than women with cervical intraepithelial neoplasia (CIN) or GW and higher scores of satisfaction with sexual life than women with CIN or GW. Feelings of anxiety and surprise with the the last exam were higher in GW group than for normal Pap smear and CIN goups. Each GW episode lasted on average 132 days, had 6 medical visits and costs US$139. Conclusion: The economic burden of GW is closely related to psychosocial burden, and the use of health services after a GW episode should be considered in future resaech. The study of indirect costs is important, considering the number if visits per episode of GW. Additional studies are needed and can help in the advocacy efforts for a comprehensive prevention programs in Brazil.

Introdução: A Organização Mundial de Saúde estima que 291 milhões de mulheres serão infectadas pelo Papilomavírus humano. O tratamento das verrugas genitais pode ser desconfortável e estressante. Objetivo: Estimar a carga psicossocial das verrugas genitais (VG); e estimar a carga econômica das verrugas genitais entre mulheres atendidas em seis clínicas de saúde reprodutiva. Métodos: Voluntárias atendidas nas Clínicas da BEMFAM entre 2010 e 1013 preencheram um questionário baseado na escala psicométrica. A carga econômica foi medida através da análise de prontuários de pacientes atendidas entre 2009 e 2010. Resultados: O questionário psicossocial foi preenchido por 122 sujeitos. Mulheres com Papanicolaou normal apresentaram menores índices de preocupação quanto à saúde ginecológica e maiores índices de satisfação com a vida sexual do que mulheres com neoplasia intraepitelial (CIN) ou VG. Sentimentos de ansiedade e surpresa com o resultado dos exames foram mais observados entre mulheres com verrugas genitais do que nas com Papanicolaou normal ou CIN. Em média, cada episódio de verruga genital durou 132 dias, demandou seis visitas médicas, e custou US$139. Conclusão: Houve relação entre a carga econômica das VG. O presente estudo reforça a importância da análise dos custos indiretos, considerando o número de visitas por episódio de VG. Estudos adicionais podem fortalecer os esforços para programas abrangentes de prevenção no Brasil.

Programa de Transplante Hepático Infantil do Hospital de Clínicas de Porto Alegre: resultados dos doze primeiros transplantes hepáticos intervivos / Pediatric liver transplantation program: results of living liver transplantation

Introdução: O Hospital de Clínicas de Porto Alegre (HCPA) é pioneiro na realização de transplante hepático infantil (THI) no RS. A menor oferta de doadores falecidos tem estimulado a realização de transplante hepático (TxH) intervivos. Objetivo: Descrever os resultados do THI intervivos do programa THI-HCPA. Método: Estudo descritivo. Incluídos: receptores de TxH intervivos, 18 anos, ambos os sexos e respectivos doadores, voluntários, ambos os sexos. Excluídos: insufi ciência hepática aguda. Variáveis: receptores: características clínico-demográficas, antropométricas; sorologias para Citomegalovírus (CMV) e Epstein-Barr (EBV); incidência de complicações pós-operatórias, tempo de internação, sobrevida 12 meses; doadores: características clínico-demográficas, sobrevida 12 meses. Todas as cirurgias foram realizadas pelo mesmo cirurgião e os dados, coletados prospectivamente. Estudo aprovado pelo Comitê de Ética em Pesquisa do HCPA (13-0208). Resultados: Doze TxH intervivos incluídos. Idade dos receptores: mediana=2 anos (sexo feminino:7). Espera em lista: 141,4±10,3d. Indicação de TxH: 83,3% atresia biliar. IMC normal: 100%. Child- -Pugh: C:7/12(58%). PELD: mediana=11,9a. Pré-TxH:IgG+CMV (10); IgG+EBV(4); ascite (7); peritonite bacteriana espontânea (3), hiponatremia dilucional (7); encefalopatia hepática (2); varizes esofágicas (4); hemorragia digestiva alta (3). Idade dos doadores: 31,8±8,4a. Sexo feminino=50%; 92% aparentado. Pesos receptor/doador: 19,2±8,9%. Implante do segmento hepático lateral esquerdo: 100%. Tempo de isquemia total: 1,34±0,67h. Duração da cirurgia: 5,94±2,58h. Duração da internação (receptores): 30,6 ± 25,2d. Complicações receptores: vascular (4), biliar (3), steal syndrome (1), small for size (2), sepse (1). Reintervenções cirúrgicas: 5. Tempo de permanência em UTI: mediana=9d. Primo-infecção: CMV (1), EBV (3). Rejeição celular aguda (4). Sobrevida em 1 ano: 76,7%. Tempo de internação(doadores): 8,1±4,0 d. Complicações ao doador: dor pós-operatória (80%). Conclusão: Os nossos resultados se assemelham àqueles da literatura no que se refere à incidência de complicações. A cirurgia tem se mostrado segura para o doador (AU)

Introduction: Hospital de Clínicas de Porto Alegre (HCPA) is a pioneer in conducting child liver transplantation (CLT) in RS. The lower supply of deceased donors has stimulated living liver transplant (LTx). Aim: To describe the results of living CLT in the THI-HCPA program. Methods: A descriptive study that included: LTx recipients from living donor, ≤ 18 years old, both sexes and their donors, volunteers, both sexes; and excluded: acute liver failure. Variables: Receptors: clinical, demographic and anthropometric characteristics, serology for cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infection, incidence of postoperative complications, length of stay, 12-month survival; Donors: demographic and clinical characteristics, 12-month survival. All surgeries were performed by the same surgeon and the data were collected prospectively. This study was approved by the Research Ethics Committee of the HCPA (13-0208). Results: Twelve LTx from living donors were included. Age of recipients: median = 2 years (female: 7). Waiting in list: 141.4 ± 10.3 d. Indication for liver transplantation: 83.3% biliary atresia. Normal BMI: 100%. Child-Pugh C:7/12 (58%). PELD: median = 11.9a. Pre-LTx: CMV+IgG (10), EBV+IgG (4), ascites (7), spontaneous bacterial peritonitis (3), dilutional hyponatremia (7), hepatic encephalopathy (2), esophageal varices (4), high gastrointestinal bleeding (3). Donor age: 31.8 ± 8.4. Female = 50%, 92% related. Receiver/giver weights: 19.2 ± 8.9%. Implantation of left lateral hepatic segment: 100%. Total ischemic time: 1.34 ± 0.67 h. Length of surgery: 5.94 ± 2.58 h. Duration of hospitalization (receivers): 30.6 ± 25.2 d. Complications in receptors: vascular (4), bile (3), steal syndrome (1), small for size (2), sepsis (1). Surgical re-interventions: 5. Time in ICU: median = 9d. Primary infection: CMV (1), EBV (3). Acute cellular rejection (4). 1-year survival: 76.7%. Length of hospital stay (donors): 8.1 ± 4.0d. Donor complications: postoperative pain (80%). Conclusion: The results resemble those of the literature regarding the incidence of complications. The surgery has been shown to be safe for the donor (AU)

Tosse na criança / Cough in children

A tosse crônica é um problema bastante freqüente no consultório do pediatra generalista. A tosse näo é uma doença, mas apenas um sintoma de alguma patologia subjacente e a busca de um diagnóstico etiológico específico é de vital importância nesses casos. Os autores propöem uma abordagem eminentemente clínica que facilita a elucidaçäo diagnóstica e o tratamento específico de causa básica, enfatizando o papel limitado dos medicamentos sintomáticos

Reidrataçäo oral: tópicos importantes / Oral rehydration: important topics

Desidrataçäo, devido a diarréia aguda, é uma causa comum de morbidade e de mortalidade nos países em desenvolvimento. O conhecimento da terapêutica e dos cuidados iniciais com esses pacientes säo muito importantes para todo o pessoal médico. Este trabalho pretende demonstrar as indicaçöes, complicaçöes mais freqüentes e crenças a respeito da terapia de reidrataçäo oral