RESUMO
OBJECTIVES: There is emerging interest and data supporting the effectiveness of community health workers (CHWs) in non-communicable diseases (NCDs) in low/middle-income countries (LMICs). This study aimed to determine whether a CHW-led intervention targeting diabetes and hypertension could improve markers of clinical disease control in rural Mexico. DESIGN AND SETTING: A prospective observational stepped-wedge study was conducted across seven communities in rural Chiapas, Mexico from March 2014 to April 2018. PARTICIPANTS: 149 adults with hypertension and/or diabetes. INTERVENTION: This study was conducted in the context of the programmatic roll-out of an accompaniment-based CHW-led intervention designed to complement comprehensive primary care for adults with diabetes and/or hypertension. Implementation occurred sequentially at 3-month intervals with point-of-care data collected at baseline and every 3 months thereafter for 12 months following roll-out in all communities. OUTCOME MEASURES: Primary outcomes were glycated haemoglobin (HbA1c) and systolic blood pressure (SBP), overall and stratified by baseline disease control. We conducted an individual-level analysis using mixed effects regression, adjusting for time, cohort and clustering at the individual and community levels. RESULTS: Among patients with diabetes, the CHW-led intervention was associated with a decrease in HbA1c of 0.35%; however, CIs were wide (95% CI -0.90% to 0.20%). In patients with hypertension, there was a 4.7 mm Hg decrease in SBP (95% CI -8.9 to -0.6). In diabetic patients with HbA1c ≥9%, HbA1c decreased by 0.96% (95% CI -1.69% to -0.23%), and in patients with uncontrolled hypertension, SBP decreased by 10.2 mm Hg (95% CI -17.7 to -2.8). CONCLUSIONS: We found that a CHW-led intervention resulted in clinically meaningful improvement in disease markers for patients with diabetes and hypertension, most apparent among patients with hypertension and patients with uncontrolled disease at baseline. These findings suggest that CHWs can play a valuable role in supporting NCD management in LMICs. TRIAL REGISTRATION NUMBER: NCT02549495.
Assuntos
Agentes Comunitários de Saúde/organização & administração , Diabetes Mellitus/terapia , Hipertensão/terapia , Atenção Primária à Saúde/organização & administração , População Rural , Idoso , Pressão Sanguínea , Países em Desenvolvimento , Diabetes Mellitus/epidemiologia , Feminino , Hemoglobinas Glicadas , Humanos , Hipertensão/epidemiologia , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Fatores SocioeconômicosRESUMO
BACKGROUND/AIMS: The black population in the USA is a heterogeneous group composed of smaller subgroups from different origins. The definition of black in many colorectal cancer (CRC) risk studies is vague, and differences in CRC risk comparing black subpopulations have not been evaluated. The aim of the study is to compare advanced colorectal neoplasia (ACN) between two subgroups of black populations: African-American (AA) and Afro-Caribbean (AC). A secondary aim was to determine whether there are differences in prevalence of adenomas. METHODS: This was a retrospective study of 3797 AA and AC patients undergoing first time screening colonoscopy in two different institutions in the USA. RESULTS: Overall adenoma prevalence was 29.3% for the entire population with 29.5% in AAs and 29.0% in AC with no statistically significant difference between the study groups (AOR: 1.02; 95% CI 0.88-1.18, P = 0.751). However, ACN was significantly higher in the AA group (11.8%) compared to AC (9.0%) (AOR: 1.30, 95% CI 1.02-1.66, P = 0.034). It was observed that AAs had ACN at a higher BMI than AC. After adjusting for BMI/ethnicity interactions, the difference in ACN between both groups became more significant (AOR: 1.93, 95% CI 1.16-3.23, P = 0.012). CONCLUSIONS: AAs have a higher risk of ACN than AC. Current recommendations to start screening in average-risk AAs at an earlier age may not apply to other black subgroups.
Assuntos
Adenoma/etnologia , Negro ou Afro-Americano/estatística & dados numéricos , Neoplasias do Colo/etnologia , Idoso , Região do Caribe/etnologia , Feminino , Florida/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Ohio/epidemiologia , Prevalência , Estudos RetrospectivosRESUMO
RESUMEN Se resumen las diferentes experiencias en la aplicación de las técnicas nucleares y conexas en el estudio de diversos problemas ambientales de la Ciudad de La Habana. El análisis medioambiental mediante las técnicas de Análisis por Activación Neutrónica (AAN) y Gamma (AAG), Fluorescencia de Rayos X (FRX), Espectrometría por Absorción Atómica (EAA) y por Inducción de plasma acoplado (ICP), así como la Espectrometría Gamma de Bajo Fondo (EGBF), han permitido obtener información muy relevante sobre el comportamiento de los metales pesados, antibióticos y radionúclidos en los sedimentos marinos y fluviales, suelos urbanos y agrícolas, aguas, arenas de balnearios, polvos urbanos y productos de la agricultura urbana de la ciudad de La Habana.
ABSTRACT Various nuclear and related analytical techniques applied to study different environmental problems in Havana city are presented. The environmental analysis by means of Neutron and Gamma Activation analyses, X-ray Fluorescence Atomic Abortion and Induced Coupled Plasma spectroscopies and Low Background , Gamma Spectrometry, have allowed to obtain important information about the behavior of heavy metals, antibiotics and radionuclides in sediments, urban and agricultural soils, waters, beach sands, urban dusts and agricultural products farmed in the Havana city.
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Sugarcane is one of the main crops worldwide, and it has an important impact on environmental issues. A bibliometric mapping analysis of the research on sugarcane was carried out, using data on the titles, abstracts, and keywords of articles published in leading journals and other peer-reviewed documents available in the SCOPUS database from 1858 to 2019 (27 August), and this was subsequently analyzed with the software VOSviewer. The three most important countries that publish research and were most-cited regarding sugarcane were Brazil, the USA, and India. The analysis of the co-occurrence of terms shows that the main research areas were sugarcane bagasse and terms related to bioenergy, and on a second level of relevance agronomy topics related to increasing crop yields. This first attempt to visualize the abundance of publications regarding sugarcane in their totality is in itself a good starting point for further scientific discussion.
Assuntos
Bibliometria , Publicações Periódicas como Assunto , Saccharum , Celulose , Produtos Agrícolas , Bases de Dados Factuais , HumanosRESUMO
Phania matricarioides (Spreng.) Griseb. is a traditionally used plant with various pharmacological properties. However, there are only scarce reports about the phytochemistry and biological activity of this plant. In this work, P. matricarioides was collected from three different localities of Cuba: PmB (collected in Bauta, Artemisa), PmC (collected in Cangrejeras, Artemisa), and PmI (collected in La Lisa, Havana), extracted with aqueous ethanol, and analyzed macroscopically and microscopically. The extracts were screened for phytochemical contents, analyzed by TLC and HPLC, and screened for antioxidant activity using the FRAP and DPPH assays. Macroscopic analysis showed similar results for all samples; however, microscopic, physicochemical and phytochemical studies showed appreciable differences. In particular, the total solid of PmC extract was higher (1.94 ± 0.03%) than the other samples. In HPLC profiles, quercetin was identified in the three samples and a greater similarity between samples PmB and PmI was observed. All samples demonstrated radical-scavenging antioxidant activity by the DPPH assay, which PmC also demonstrated the smaller (p < 0.05) value (IC50 = 27.4 ± 0.1 µg/mL), but was statistically superior (p < 0.05) to vitamin C (IC50 = 23.7 ± 0 µg/mL). Also, in the FRAP assay, a higher vitamin C equivalent of PmC was significantly superior (p < 0.05) to the other extracts at the evaluated concentrations, which is likely due to a higher concentration of quercetin. In conclusion, P. matricarioides could constitute a potential resource in the field of phytotherapeutic products, and the results obtained can contribute to the development of the quality control norms for this species.
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The effects of different drying temperatures between 40 and 80 °C on bioactive constituents and antioxidant activity of edible sub Antarctic brown seaweed, Durvillaea antarctica were studied. Dietary fibre, amino acids profile, pigments (chlorophyll and carotenoids), vitamin E, total phenolics and total flavonoids as well as antioxidant activity were determined, beside a measurement of the chromatic coordinates. The brown seaweed D. antarctica had a high content of dietary fibre and was rich in essential amino acids and drying between 40 and 80 °C did not influence significantly dietary fibre content nor the level of essential amino acids that remained around 44%. However, a significant degradation of the chlorophyll pigments was observed with the lowest level of the initial chlorophyll content occurring at 60 °C (59%). Total carotenoids content was stable during drying between 50 and 70 °C. Vitamin E showed no significant loss during drying at any of the assayed temperatures, which could be due to its occurrence within the lipid fraction. Drying at 40 °C imparted a darker brown colour to the seaweed, while a lighter brown colour was acquired as drying temperature increased. The greatest loss in total phenolics content occurred at 60 °C, while total flavonoids content showed a significant reduction, which declined as drying temperature increased. According to the experimental results, phenolics and flavonoids could be considered as an important source of bioactive compounds with relatively high antioxidant activity. Thus D. antarctica may satisfy the requirements for development of functional foods.
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Heavy metal (Co, Ni, Cu, Zn and Pb) content in muds from some Cuban spas (San Diego, Elguea, Santa Lucía and Cajío) have been studied using X-ray fluorescence. The measured metal contents are in the same order of magnitude as those reported for average Earths upper crust average shales and muds as well as with worldwide reported peloids. The comparison with sediment quality guidelines (SQGs) shows a different degree of pollution for peloids from each studied spa. Nevertheless, the estimated sum of metal/probable effect level value ratios (0.9 - 2.4) correspond to a low potential acute toxicity of contaminants. Therefore, the heavy metal content present in peloids from the studied Cuban spas is not an obstacle for its use with therapeutic purposes
Se estudia mediante la técnica de Fluorescencia de rayos X, el contenido de metales pesados (Co, Ni, Cu, Zn y Pb) en lodos terapéuticos provenientes de varios balnearios cubanos (San Diego, Elguea, Santa Lucía y Cajío). Los contenidos de metales pesados determinados en los lodos terapéuticos se encuentran en el mismo orden que los reportados para lodos y esquistos representativos de la corteza terrestre, así como para lodos utilizados en balnearios internacionalmente. La comparación con las Guías de Calidad de sedimentos muestran diferentes grados de polución para los lodos de cada balneario. Independientemente de ello, los valores de las razones suma de metales/nivel de efecto probable (0,9-2,4) corresponden a un bajo potencial agudo de toxicidad por contaminantes. De esta manera, el contenido de metales pesados presentes en los lodos de los balnearios estudiados no representa impedimento alguno para su uso con fines terapéuticos.
RESUMO
Longissimus dorci (LD) samples of different origin (imported and domestic) with pre-treatments (imported meat stored at -18°C for 6months, domestic meat stored at -18°C for 10days, and domestic meat stored at 4°C for 24h) were cooked as barbacoa and frozen using two treatments (air blast and liquid immersion) and then evaluated after 30days of storage. The results showed that the origin and pre-treatment of meat affected L*, a*, instrumental texture and microstructure; that the storage time affected pH, aw, b* and microstructure; and that the freezing treatments did not affect the meat. Overall, the frozen cooked lamb dish barbacoa could present some problems at the conservation stage due to an increase in pH, aw and changes in microstructure; however, the physical traits (color and texture) remained mostly unchanged and depended more on the quality of the raw meat.
Assuntos
Armazenamento de Alimentos , Carne Vermelha/análise , Animais , Cor , Culinária , Congelamento , Concentração de Íons de Hidrogênio , Masculino , Refrigeração , OvinosRESUMO
Se resumen los principales resultados obtenidos en los últimos 25 años por el Grupo de Aplicaciones Nucleares del InSTEC, en el desarrollo de técnicas nucleares y su aplicación en diferentes sectores de la sociedad. Se presenta el impacto que han tenido las investigaciones aplicadas en la formación de pregrado y posgrado en carreras nucleares y en el reconocimiento social de la comunidad universitaria.
The paper includes the most relevant results obtained by InSTEC´s Group of Nuclear Applications in the last 25 years, in the development of nuclear techniques and its application in different social areas. The impact of applied research on graduated and post graduated education in nuclear careers as well as the social recognition of the university community are presented.
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Concentrations of Cr, Co, Ni, Cu, Zn, Pb and Fe in the street dust from Camagüey city were studied by X-ray .uorescence analysis. The mean Cr, Co, Ni, Cu, Zn and Pb contents in the urban dust samples (97 ± 30, 14 ± 2, 35 ± 36, 94 ± 26, 199 ± 87 and 42 ± 29 mg.kg-1 dry weight, respectively) were compared with mean concentrations in other cities around the world. Spatial distribution maps indicated the same behaviour for Cr-Ni and Pb-Zn-Cu, respectively, whereas the spatial distribution of Co differs from other heavy metals. The metal-to-iron normalization, using Cuban average metal soil contents as background, showed that street dusts from Camagüey city are moderately or significantly Zn-Pb enriched in those areas associated with heavy traffic density and metallurgic plant location. However, the calculation of the potential ecological risk index shows that metal content in Camagüey street dust does not represent any risk for the city population.
Se determinan por fluorescencia de rayos X las concentraciones de Cr, Co, Ni, Cu, Zn y Pb en los polvos urbanos de la ciudad de Camagüey. Los contenidos medios de metales pesados en las muestras de polvos urbanos (97 ± 30, 14 ± 2, 35 ± 36, 94 ± 26, 199 ± 87 y 42 ± 29 mg.kg-1 en peso seco respectivamente) son comparados con las concentraciones medias determinadas en otras ciudades del mundo. Los mapas de distribución espacial indican comportamientos similares para Cr-Ni y Pb-Zn-Cu respectivamente, en tanto la distribución espacial de Co difiere del resto de los metales. La normalización a un metal de referencia, empleando como fondo los valores medios de concentraciones de metales pesados cubanos, mostró que los polvos urbanos de la ciudad de Camagüey tienen un enriquecimiento moderado o significativo de Zn y Pb en aquellas áreas que están asociadas a una elevada densidad del tráfico automotor y a la ubicación de plantas metalúrgicas. El cálculo del índice de riesgo ecológico potencial mostró que el contenido de metales pesados en los polvos urbanos de Camagüey no representa riesgo alguno para su población.
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The effects of the incorporation of PLA-ß-cyclodextrin-inclusion complex (IC) and ß-cyclodextrin (ß-CD) on biopolyester PLA films were investigated. Thermal stability, surface morphology, barrier, and mechanical properties of the films were measured at varying IC (1, 3, 5, and 7%) and ß-CD (1 and 5%) concentrations. The PLA-IC-composite films (IC-PLA-CFs) showed uniform morphological structure, while samples containing ß-CD (ß-CD-PLA-CFs) showed high agglomeration of ß-CD due to poor interfacial interaction between ß-CD and PLA moieties. According to the thermal property analysis, the 5% IC-PLA-CFs showed 6.6 times lower dimensional changes (6.5%) at the temperature range of 20-80°C than that of pure PLA film (43.0%). The increase of IC or ß-CD content in the PLA-composite films shifted the glass transition and crystallization temperature to higher temperature regions. The crystallinity of both composite films improved by increasing IC or ß-CD content. Both composite films had higher oxygen and water vapor permeability as IC or ß-CD content increased in comparison to pure PLA film. All the composite films had less flexibility and lower tensile strength than the pure PLA film. In conclusion, this study shows that the IC technique is valuable to improve the thermal expansion stability of PLA-based films.
Assuntos
Ácido Láctico/química , Nanocompostos/química , Polímeros/química , beta-Ciclodextrinas/química , Varredura Diferencial de Calorimetria , Nanocompostos/ultraestrutura , Poliésteres , Propriedades de Superfície , Temperatura , Resistência à Tração , Termodinâmica , TermogravimetriaRESUMO
Nanocellulose is of research interest due to its extraordinary optical, thermal, and mechanical properties. The incorporation of guest nanoparticles into nanocellulose substrates enables production of novel nanocomposites with a broad range of applications. In this study, gold nanoparticle/bacterial cellulose (AuNP/BC) nanocomposites were prepared and evaluated for their applicability as surface-enhanced Raman scattering (SERS) substrates. The nanocomposites were prepared by citrate mediated in situ reduction of Au(3+) in the presence of a BC hydrogel at 303 K. Both the size and morphology of the AuNPs were functions of the HAuCl4 and citrate concentrations. At high HAuCl4 concentrations, Au nanoplates form within the nanocomposites and are responsible for high SERS enhancements. At lower HAuCl4 concentrations, uniform nanospheres form and the SERS enhancement is dependent on the nanosphere size. The time-resolved increase in the SERS signal was probed as a function of drying time with SERS 'hot-spots' primarily forming in the final minutes of nanocomposite drying. The application of the AuNP/BC nanocomposites for detection of the SERS active dyes MGITC and R6G as well as the environmental contaminant atrazine is illustrated as is its use under low and high pH conditions. The results indicate the broad applicability of this nanocomposite for analyte detection.
Assuntos
Celulose/química , Ouro/química , Nanopartículas Metálicas/química , Nanocompostos/química , Análise Espectral Raman/métodos , Tamanho da PartículaRESUMO
Concentrations of Cr, Co, Ni, Cu, Zn and Pb in the topsoils (0-10 cm) from ten farms located in the vicinity of a steel-smelter plant at Cotorro (Havana, Cuba) were measured by X-ray fluorescence analysis. The concentration ranges of Cr, Co, Ni, Cu, Zn and Pb were 54-186, 15-39, 19-137, 50-945, 91-7739 and 21-731 dry weight respectively. The metal mean contents in the farm topsoil samples were compared with metal contents reported for soils from the vicinity of other smelters worldwide. The Metal-to-Iron normalisation and estimation of the integral pollution indexes allowed observing that most metal polluted soils are from those farms, and that their location coincide with the prevalent wind direction in the studied area. The enrichment index values show that metal concentrations in soils from these farms are above the permissible levels for urban agriculture.
Se determinan por fluorescencia de rayos X las concentraciones de Cr, Co, Ni, Cu, Zn y Pb en los suelos superficiales (0-10 cm) de 10 granjas agrícolas, localizadas en la vecindad de la planta de acero del Cotorro (La Habana, Cuba). Los rangos de concentraciones de Cr, Co, Ni, Cu, Zn y Pb fueron de 54-186, 15-39, 19-137, 50-945, 91-7739 y 21-731 de peso seco respectivamente. Los contenidos medios de metales pesados en los suelos superficiales de las granjas se comparan con los niveles de metales pesados reportados en la literatura para suelos adyacentes a plantas de acero. La normalización de los metales al hierro y la estimación del los índices de polución integral, permitió determinar que los suelos contaminados por metales pesados fueron aquellos, cuya ubicación coincide con la dirección predominante de los vientos en la zona estudiada. Los valores delíndice de enriquecimiento mostraron que las concentraciones de metales pesados en los suelos de esas granjas, superan los niveles permisibles para la agricultura urbana.
RESUMO
Introducción: en el periodonto se presentan procesos inflamatorios agudos, que se enmarcan dentro de las urgencias periodontales por ser dolorosos, de instalación repentina y de corta duración, ellos comprenden un grupo de enfermedades con características bien definidas dentro de las cuales se citan: gingivitis ulceronecrotizante aguda, gingivoestomatitis herpética aguda, estomatitis aftosa, absceso gingival y absceso periodontal. Objetivo: caracterizar el comportamiento de pacientes con urgencias periodontales. Método: se realizó una investigación aplicada de tipo observacional, descriptivo, de corte transversal, en los consultorios odontológicos de la Parroquia Olegario Villalobos, municipio Maracaibo, estado Zulia durante julio de 2008 a junio de 2010. El universo y la muestra coincidieron, y fue de 258 pacientes que presentaron urgencias periodontales. Se estudiaron variables como: edad, sexo, urgencias periodontales y factores de riesgo, se utilizaron como indicadores los números absolutos y porcentajes. Resultados: la mayor cantidad de pacientes estuvo representada por el grupo de 19-34 años de edad con 65 pacientes (25,2 %), y por el sexo femenino con 152 (58,9 %). El mayor número resultó afectado por la estomatitis aftosa con 38 %. La higiene bucal deficiente prevaleció en 202 (78,3 %), sobre todo en el sexo masculino con 129 pacientes (63,9 %). Conclusiones: numerosos pacientes estuvieron afectados por la estomatitis aftosa entre 19-34 años de edad; existió predominio de higiene bucal deficiente en el sexo masculino.Las urgencias periodontales constituyeron un problema de salud bucal en la población de la Parroquia Olegario Villalobos.
Introduction: acute periodontal inflammatory processes, which are part of periodontal emergencies, due to the painful, sudden and short-lived installation, are a group of diseases with different characteristics such as acute necrotizing ulcerative gingivitis, acute herpetic gingivostomatitis, aphthous stomatitis, gingival abscess, periodontal abscess. Objective: to characterize the patients with periodontal emergencies behavior. Method: an applied observational, descriptive, cross-sectional research in Dental offices Olegario Villalobos Parish, Maracaibo, Zulia state during July 2008 to June 2010 was performed. The universe and the sample comprised 258 patients who had periodontal emergencies. The variables: age, sex, periodontal emergency and risk factors were studied; absolute numbers and percentages were used as indicators. Results: most of patients were represented by the group of 19-34 years with 65 of them (25.2 %) and 152 females (58.9 %). The highest number of them was affected by aphthous stomatitis with 38 %. Poor oral hygiene prevailed in 202 (78.3 %), especially in males with 129 patients (63.9 %). Conclusions: many patients were affected by aphthous stomatitis between 19-34 years of age; there was a predominance of poor oral hygiene in males. Periodontal emergencies constituted an oral health problem in the population of the Olegario Villalobos Parish.
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Concentrations of chromium, nickel, copper, zinc and lead in surface sediments from six stations located in Nuevitas Bay (Cuba) were estimated by X-ray fluorescence analysis. The Cr content in sediments shows a strong variation across the studied stations (89-513 ), in contrast with the other elements studied. The application of modified degree of contamination (
) classifies as moderate the contamination of Nuevitas Bay. The comparison with Sediment Quality Guidelines (SQGs) and toxicity mean quotients shows that 100 % of the sediments are associated with the occasional presence of possible adverse effects to human health.
Se determinan, mediante el análisis por fluorescencia de rayos X, las concentraciones de cromo, níquel, cobre, zinc y plomo en sedimentos superficiales de seis estaciones de la Bahía de Nuevitas en Cuba. El contenido de cromo se determinó con un intervalo de gran variación (89-513 ) en las estaciones estudiadas. La aplicación del grado de contaminación modificado (
) clasificó la contaminación de los sedimentos de la Bahía de Nuevitas como de “grado moderado”. La comparación con las Guías de Calidad de Sedimentos y del cociente promedio de toxicidad, mostró que el 100 % de los sedimentos estudiados están asociados a la presencia ocasional de posibles efectos adversos a la salud humana.
RESUMO
Introducing porosity in electrospun scaffolds is critical to improve cell penetration and nutrient diffusion for tissue engineering. Nanofibrous cellulose scaffolds were prepared by electrospinning cellulose acetate (CA) followed by saponification to regenerate cellulose. Using a computer-assisted design approach, scaffolds underwent laser ablation resulting in pores with diameters between 50 and 300 µm without damaging or modifying the surrounding scaffold area. A new mineralization method was employed in conjunction with microablation using commercial phosphate buffered saline (PBS) to soak carboxymethylcellulose surface-modified electrospun scaffolds. The resulting crystals within the scaffold on the interior of the pore had a calcium to phosphate ratio of 1.56, similar to hydroxyapatite. It was observed that porosity of the cellulose scaffolds enhanced osteoblast cell attachment at the edge of the pores, while mineralization enhanced overall cell density.
Assuntos
Celulose/química , Nanofibras/química , Nanotecnologia/métodos , Alicerces Teciduais/química , Células 3T3 , Animais , Cálcio/metabolismo , Celulose/metabolismo , Celulose/farmacologia , Camundongos , Minerais/metabolismo , Fósforo/metabolismo , Porosidade , Propriedades de Superfície , Engenharia TecidualRESUMO
Zinc content and Zn bioaccumulation in crops (rice and some vegetables and condiments) cultivated in 18 Cuban urban and suburban areas are reported. Zinc content in food and the corresponding farming soil samples was determined by X-Ray Fluorescence analysis and by Atomic Absorption spectrometry. The quality of the analysis was verified using the Certified Reference Materials IAEA 393 «Algae¼, MA-B-3/TM «Fish Tissue Lyophilised¼, IAEA V-10 «Hay¼ and IAEA Soil-7. The obtained results show rice, of the studied crops, as the major Zn bioaccumulator and important Zn source in Cuban human diet.
Se reportan los contenidos de zinc y su bioacumulación en cultivos (arroz, vegetales y condimentos) procedentes de 18 áreas de agricultura urbana y suburbana. El contenido de zinc en los alimentos, así como en sus correspondientes suelos de cultivo, fue determinado por Fluorescencia de Rayos X y por Espectrometría de Absorción Atómica. La calidad del estudio se verificó mediante el análisis de los Materiales de Referencia Certificados IAEA 393 «Algae¼, MA-B-3/TM «Fish Tissue Lyophilised¼, IAEA V-10 «Hay¼ e IAEA Soil-7. Los resultados mostraron al arroz, de los cultivos estudiados, como el cultivo de mayor bioacumulación de zinc y como fuente importante de Zn en la dieta de nuestra población.
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Se determinan las concentraciones de metales pesados y radionúclidos naturales en suelos superficiales (0-10 cm) de la ciudad de Cienfuegos, Cuba, mediante las técnicas de fluorescencia de rayos X y espectrometría gamma respectivamente. Los resultados de la medición de metales pesados mostraron que las concentraciones promedio de Ni, Cu, Zn y Pb en los suelos estudiados son superiores a los valores correspondientes de fondo. El cálculo del Índice de Polución Integral permitió determinar que estos suelos presentan una contaminación severa por metales pesados. Las concentraciones de ,
y
en los suelos urbanos de Cienfuegos se encuentran en los intervalos de 8.3-32.7, 3.7-10.7 y 129-356
, con promedios de 22.6, 6.3 y 272
respectivamente, valores que son similares a los reportados para la zona Centro-Sur de Cuba. La tasa de dosis absorbida en aire y la dosis equivalente efectiva anual que recibe la población local producto de la radiación natural es inferior a los límites establecidos internacionalmente. Se determinaron correlaciones positivas significativas de
-Cu y
-Zn, indicando la posible presencia de una fuente de contaminación por estos elementos en la zona.
Concentrations of heavy metals and natural radionuclides in topsoil (0-10cm) from Cienfuegos city, Cuba, were determined by using X-ray fluorescence analysis and gamma ray spectrometry, respectively. The measured results of heavy metals show that the mean concentrations of Ni, Cu, Zn and Pb in the studied soil samples are higher than their corresponding background values. The calculated results of integrated pollution index of heavy metals indicate that the studied soils present severely heavy metal contamination. The concentrations of ,
and
in the studied soil samples range from 8.3 to 32.7, 3.7 to 10.7 and 129 to 356
with an average of 22.6, 6.3 and 272
, respectively, which are similar than the average concentrations reported for South-central Cuban soils. The air absorbed dose rate and the annual effective dose equivalent received by the local residents due to the natural radionuclides in soil are lesser than the worldwide established limits. A significantly positive
-Cu and
-Zn correlations were determined, indicating the possible existence of a source of pollution due to the presence of these elements in the area.