Efecto de las membranas con Cu(II) sobre el proceso de filtración y capacidad de biocida contra Escherichia coli / Effect of Cu(II) membranes on the filtration process and biocide capacity against Escherichia coli

Esta investigación estudió la preparación de membranas compuestas de celulosa y quitosano entrecruzadas con Cu(II) para determinar su efecto biocida y eficiencia en la remoción deEscherichia coli. Las membranas de quitosano se obtuvieron por medio de la técnica de evaporación del solvente. Propiedades de absorción de agua, degradación térmica y mecánicas de las membranas fueron evaluadas con el propósito de modificar la estructura química, la superficie y estudiar su impacto como agente biocida. Los resultados muestran que el Cu(II) interactúa con los grupos iónicos de las membranas que inducen un cambio estructural produciendo un aumento de 190% en el módulo G*. Además, el catión provee estabilidad térmica a temperaturas menores de 200 ºC y produce cambios superficiales a la membrana, especialmente a la membrana de celulosa. Adicionalmente, la membrana de celulosa-Cu(II) aumentó su efecto biocida contraE. colihasta un 96%. El proceso de remoción por medio de la filtración aumentó 41% con la incorporación del catión. Esta investigación muestra el efecto de la interacción del catión con grupos iónicos en la membrana que mejoran las propiedades de filtración y efecto biocida contra esta enterobacteria que puede llegar a ser patógena para el ser humano.

This research studied the membrane preparation of Cu(II) crosslinked membranes composed of cellulose and chitosan to determine its biocidal effect and efficiency to remove Escherichia coli. Water absorption, thermal degradation, and G* modulus evaluated the Cu(II) impact on the equilibrium, thermal and mechanical properties. These results showed that Cu(II) incorporation interacts with the ionic groups, inducing a structural change increasing the G* modulus by 190%. Moreover, the cation provides thermal stability at temperatures below 200 ºC and produced surface changes to the membrane, especially to the cellulose mekkmbrane. Additionally, the cellulose-Cu(II) membranes increased 96% their biocidal effect against E. coli. Enterobacter filtration process increased 41% with the cation incorporation into the cellulose membrane. Therefore, this research showed the cation effect on the ionic groups in the membrane that improve the filtration properties and biocidal effect against harmful enterobacteria to humans.

Servicios públicos domiciliarios: ¿derechos humanos o productos para la venta? Caso Medellín / Home utilities: are they human rights or products for sale? The Medellin Case

El presente artículo presenta los resultado de investigación encaminada a demostrar y visibilizar, en la ciudad de Medellín, las múltiples afectaciones a personas por la ausencia de servicios públicos domiciliarios en sus viviendas, aún y la capacidad técnica, operativa y financiera de la empresa prestadora de servicios en la ciudad: Empresa Públicas de Medellín (Epm E.S.P), lo que supone una inadecuada lectura de la realidad de la ciudad, principalmente en las zonas periféricas y zonas de alto riesgo. Esta situación lleva a que los ciudadanos recurran a las vías judiciales o a las vías de hecho para proveerse del servicio y en cualquiera de las dos vías se termina por generarle una serie de dificultades de orden jurídico, social y económico al Municipio que es, según la Ley 142 de 1994, el responsable de garantizar el derecho a los servicios públicos domiciliarios; situaciones que pudiesen contar con una solución más adecuada en tanto que ajustada a las realidad de la ciudad.

This current paper introduces the research results aiming at demonstrating and identifying, in the city of Medellin, the multiple effects to people by the lack of home utilities, still and the technical, operational, and financial capacities of the company providing services in the city: Public Companies of Medellin (EPM -ESP), which supposes an inadequate reading of the reality of the city, mainly on the outskirts and high-risk areas. This situation makes the citizens resort to the judicial routes or assault and battery in order for them to provide with the service, and in either of the two routes, a series of legal, social, and economic difficulties are derived, which becomes a problem to the Municipality, which according to the Law 142 as of 1994, is responsible for ensuring the people the right to home utilities, situations which could have a moreadequate solution to the extent that it can be adjusted to the reality of the city.

Medición de nitratos y nitritos en agua y saliva de población rural precordillerana de la VIII región / Nitrate and nitrite in water and saliva of rural population in the Andes foothills of the VIII Region

Introducción: Un factor de riesgo para las neoplasias escamosas de faringe son las nitrosaminas, las que derivan de los nitratos salivales que provienen de la dieta y en especial del agua si los niveles están por sobre la norma. Objetivos: Conocer y comparar los niveles de nitratos y nitritos en agua y saliva de habitantes de la región precordillerana y en población urbana de Concepción. Material y método: Estudio prospectivo, tipo caso y control. Determinan niveles de nitratos y nitritos en agua de la zona precordillerana y en agua de Concepción y en saliva de habitantes de la zona rural y de grupo control de Concepción. Resultados: Se obtienen 10 muestras de agua del sector rural y 1 muestra de agua potable de Concepción. Nivel de nitratos en agua rural 23,29 mg/L, en agua urbana 3,6 mg/L (p <0,05). En saliva, grupo estudio (n =15) con nivel de nitritos de 9,58 mg/ml, grupo control (n =24) nivel de 3,8 mg/ml (p <0,05). Conclusión: En la zona rural hay niveles significativamente mayores de nitratos en el agua y nitritos en saliva. Los niveles en agua son superiores a normas nacionales e internacionales. Nuestros resultados resaltan la posible importancia de las nitrosaminas y sus precursores como elementos carcinogónicos en los carcinomas escamosos orofaríngeos.

Introduction: A risk factor for squamous carcinomas of the oropharynx are the nitrosamines, which are derived from salivary nitrate coming from diet and water, especially if the levels are above the allowed levels. Aim: To determine and compare the levels of nitrates and nitrites in drinking water and saliva of people at the foothills of our region and urban population of Concepcion. Material and method: A descriptive cross sectional study. Determination of levels of nitrates and nitrites in drinking water in the Andean foothills and Concepcion and in saliva of people from same locations. Results: We obtained 10 rural water samples and 1 from Concepcion drinking water. Nitrate levels in rural water were 23.29 mg/L and 3.6 mg/L (p <0.05) in urban water. In saliva, the study group (n =15) had 9.58 mg/ml nitrite in saliva, the control group (n =24) 3.8 mg/ml (p <0.05). Conclusion: In rural areas there are significantly higher levels of nitrates in drinking water and saliva. The water levels are higher than national and international standards. Our results confirm high amounts of nitrogen cycle products (nitrites and nitrates) in drinking water and in saliva so it could be considered as carcinogenic elements in oropharyngeal squamous cell carcinomas.

Interrelations of habitual abortion and lead levels in venous blood and abortuses with drinking water lead level in some Egyptian population

In Egypt, one of the main sources of lead exposure is a network of lead pipes used for water supply. Adverse effects of high lead exposure are well known. Many studies have focused on the health effects of low blood lead levels after sharp decline of its exposure levels. Currently, there is a growing concern about threats posed on pregnancy outcomes among women with low to moderate blood lead levels. This study was conducted to evaluate the role of contaminated water as one source of multifactorial lead exposure chain, and to be acquainted if the currently observed lead levels are associated with increased risk of spontaneous abortion in pregnant women in Egypt. The results of this study revealed significant positive correlations between drinking-water lead with both blood lead and abortus lead levels in cases of abortion. Each woman with unexplained spontaneous abortion should be subjected to blood lead estimation. Primary prevention by removing lead from the environment is the only pathway to avoid threats posed on pregnancy outcome since there is no effective remedy to remove lead from the body at levels below 30 microg/dl

Impacto do uso da água de cisternas na ocorrência de episódios diarréicos na população rural do agreste central de Pernambuco, Brasil / The impact of the use of water from water-tanks on the occurrence of diarrhea in the rural population of the Central Agreste region of the Brazilian State of Pernambuco

OBJETIVOS: avaliar o impacto do uso da água de cisternas na ocorrência de episódios diarréicos comparando o número e a duração de episódios entre moradores de domicílios com e sem cisternas, numa mesma área geográfica. MÉTODOS: estudo longitudinal prospectivo aninhado a um estudo de corte transversal com dois grupos de comparação (domicílios com e sem cisternas) realizado, em 21 municípios do Agreste Central de Pernambuco, em 2007. O período de coleta foi de 60 dias, e incluiu 1765 indivíduos. Para análise descritiva utilizou-se modelos mistos hierárquicos, Mann-Whitney e Kaplan-Meyer com nível de significância de 5 por cento. RESULTADOS: entre os 949 indivíduos com cisternas, obteve-se uma redução no risco de ocorrência de episódios diarréicos de 73 por cento quando comparados aos 816 indivíduos sem cisternas (RR=0,27; p<0.001). O número médio de episódios registrados nos residentes de domicílios sem cisternas foi de 0,48 (DP=1,17), contra 0,08 (DP=0,32) nos domicílios com cisternas(z=-10,26; p<0,001). A duração média dos episódios foi 1,5 vezes maior nos domicílios sem cisternas (χ²=8,99; p=0,003). CONCLUSÕES: os achados deste estudo destacam a importância do acesso à água potável na redução de doenças. A ocorrência de diarréia, bem como, seus indicadores de gravidade - número de episódios e duração da diarréia foram consistentemente maiores nos residentes de domicílios sem cisternas.

OBJECTIVES: to evaluate the impact of the use of water-tanks on the occurrence of episodes of diarrhea, comparing the number and duration of episodes among the residents of households with and without water-tanks in the same geographical area. METHODS: a longitudinal prospective study, nested in a cross-section study comparing two groups (households with and without water-tanks), was carried out in 21 municipalities in the Central Agreste region of the Brazilian State of Pernambuco, in 2007. Data was gathered over 60 days and included 1,765 individuals. Descriptive analysis was carried out using mixed hierarchical models, Mann-Whitney and Kaplan-Meyer with the level of significance set at 5 percent. RESULTS: among the 949 individuals with water-tanks, there was a reduction in the risk of the occurrence of episodes of diarrhea of 73 percent compared with the 816 individuals without water-tanks (RR=0.27; p<0.001). The mean number of episodes registered among residents of households without water-tanks was 0.48 (SC=1.17), compared with 0.08 (SC=0.32) among households with water-tanks (z=-10.26; p<0.001). The mean during of episodes was 1.5 times greater in households without water-tanks (χ2=8.99; p=0.003). CONCLUSIONS: the findings of this study point to the importance of access to drinking water for the reduction of disease. The occurrence of diarrhea and its concomitant severity indicators-number of episodes and duration-were consistently higher among residents of households without water-tanks.

Dental fluorosis and its association with the use of fluoridated toothpaste among middle school students of Delhi.

Introduction: Fluorosis can manifest as dental fluorosis (seen mostly in secondary dentition), skeletal fluorosis, and systemic fluorosis. Groundwater with high fluoride concentrations, diet rich in fish and tea, indoor air-pollution, and use of fluoride toothpastes may contribute considerably to total exposure. Objective: To assess the prevalence of dental fluorosis and associated factors particularly fluoridated toothpastes, among middle school children of a resettlement colony in Delhi. Materials and Methods: This survey was conducted among the middle school students (VI th -VIII th ) studying in three government schools of Sangam Vihar, South Delhi. Students were examined for dental fluorosis by experts. A pre-structured questionnaire was used to obtain data regarding age, source of drinking water, toothpaste used, etc. Height, weight, and hemoglobin were recorded. Two repeat visits were made. Out of 432 students enrolled in these schools, 413 students were examined. Statistics: Descriptive and chi-square statistics were used. Results: Dental fluorosis was prevalent in 121 (29.3%) study subjects. It was significantly more in children of age 13 years or above, in those who used fluoridated toothpaste for dental cleaning (P=0.033) and in anemic children (P<0.001). However, there was no significant association of disease with gender (P=0.02), source of drinking water (P=0.417), and with BMI (P=0.826). Conclusion: As dental fluorosis is very common (in about one-fourth) among the middle school children, in this resettlement colony of Delhi, various control measures e.g. discouraging the fluoridated toothpastes, educating parents about fluorosis, de-fluoridation of water in the high risk areas, etc may help to tackle this situation.

Prevalência de fluorose dentário em escolares de 6 a 9 anos de Niterói / Prevalence of dental fluorosis in 6 to 9-year-old schoolchidren in Niterói

O presente trabalho se propôs a investigar a prevalência de fluorose em escolares entre 6 a 9 anos, da rede pública de ensino do município de Niterói (RJ), detectando a que possíveis fontes de fluorose estes foram expostos. Foi selecionada um amostra representativa por região de Niterói, perfazendo um total de 1036 crianças. A coleta dos dados foi realizada através de questionário e exame clínico. Foi encontrada baixa prevalência de fluorose dentária na faixa etária estudada e que a concentração de fluoreto na água de consumo de Niterói é irregular, estando algumas localidades com níveis ótimos e outras com deficência