Contrasting mobility of arsenic and copper in a mining soil: A comparative column leaching and pot testing approach.

The remediation of legacy metal(loid) contaminated soils in-situ relies on the addition of [organic] amendments to reduce the mobility and bioavailability of metal(loid)s, improve soil geochemical parameters and restore vegetation growth. Two vermicomposts of food and animal manure waste origin (V1 and V2) were amended to an arsenic (As) and copper (Cu) contaminated mine soil (≤1500 mg kg-1). Leaching columns and pot experiments evaluated copper and arsenic in soil pore waters, as well as pH, dissolved organic carbon (DOC) and phosphate (PO43-) concentrations. The uptake of As and Cu to ryegrass was also measured via the pot experiment, whilst recovered biochars from the column leaching test were measured for metal sorption at the termination of leaching. Vermicompost amendment to soil facilitated ryegrass growth which was entirely absent from the untreated soil in the pot test. All amendment combinations raised pore water pH by ∼4 units. Copper concentrations in pore waters from columns and pots showed steep reductions (∼1 mg L-1), as a result of V1 & V2 compared to untreated soil (∼500 mg L-1). Combined with an increase in DOC and PO43-, As was mobilised an order of magnitude by V1. Biochar furthest reduced Cu in pore waters from the columns to <0.1 mg L-1, as a result of surface sorption. The results of this study indicate that biochar can restrict the mobility of Cu from a contaminated mine soil after other amendment interventions have been used to promote revegetation. However, the case of As, biochar cannot counter the profound impact of vermicompost on arsenic mobility.

Pyrolysis temperature influences the capacity of biochar to immobilize copper and arsenic in mining soil remediation.

Biochar is a promising material used for multiple remediation approaches, mainly in polluted soils. Its properties can differ depending on feedstock and pyrolysis temperature. In this context, we tested the capacity of three biochar products made from corncob, pyrolyzed at different temperatures (350, 500, and 650 °C), to remediate a mining soil affected by high levels of Cu and As. We performed an exhaustive characterization of the biochar. We found that biochar showed a higher surface area with increasing pyrolysis temperature, whereas high molecular weight PAHs were detected in biochar produced at the maximum temperature, thus indicating potential ecotoxicological risks. After the application of biochar to the soil, Cu was partially immobilized, especially when using that obtained at 500 °C. This effect is attributed to the structure of this material and an increase in soil pH and organic matter content. Conversely, As was increased in the soluble fraction for all three types of biochar but in a proportion that lacks relevance. On the whole, given its lower PAH content, higher Cu immobilization ratio, and an almost negligible increase in As availability, biochar obtained at 500 °C outperformed the other two products with respect to soil recovery. Of note, data on Cu and As availability were doubled-checked using two extraction methodologies. We propose that this operational approach for determining the most suitable pyrolysis temperature will find application in other soil remediation actions.

Manifestaciones imagenológicas y manométricas en pacientes con estreñimiento funcional / Imaging and manometric manifestations in patients with functional constipation

INTRODUCCIÓN: el estreñimiento es un síntoma o afección que puede comprometer la calidad de vida de los pacientes. Su prevalencia global varía entre 2 % y 28 %. OBJETIVO: evaluar la concordancia entre los resultados de los exámenes imagenológicos y la manometría anorrectal, en pacientes con sospecha de estreñimiento funcional. MÉTODOS: la muestra estuvo conformada por 37 pacientes, a los que se les realizó exámenes radiológicos de cecocolografía secuencial (o colon por ingestión), tiempo de tránsito colónico con marcadores radiopacos, defecografía y examen manométrico. Se calculó el índice de Kappa para determinar la concordancia. RESULTADOS: 62,2 % de los enfermos fueron del sexo femenino, la edad predominante estuvo entre 41 y 60 años (43,2 %), predominó el ciego móvil (54,2 %) como causa de estreñimiento. Se hicieron 14 estudios de tiempo de tránsito colónico con marcadores radiopacos, de ellos 28,6 % presentó un tiempo de tránsito lento. Se realizó defecografía a 4 pacientes y 3 presentaron disfunción del suelo pelviano. Se constató que 94,6 % de las pruebas imagenológicas y 78,4 % de las manometrías resultaron positivas (Kappa p= 0,006). CONCLUSIÓN: las técnicas imagenológicas que se investigaron son apropiadas para diagnosticar el estreñimiento funcional y la concordancia de dichas técnicas con la manometría anorrectal es adecuada.

INTRODUCTION: constipation is a symptom or condition that can compromise the quality of patient's life. Its global prevalence varies between 2 % and 28 %. OBJECTIVE: evaluate the correlation between the results of imaging tests and anorectal manometry in patients with suspected functional constipation. METHODS: the sample consisted of 37 patients, who underwent radiological examinations of sequential cecocolografía (colon or swallowed), colonic transit time with radiopaque markers, defecography and manometric examination. Kappa index was calculated to determine the correlation. RESULTS: 62.2 % of patients were female, the predominant age was between 41 and 60 years (43.2 %), mobile blind predominated (54.2 %) as a cause of constipation. 14 studies of colonic transit time with radiopaque markers, were made, 28.6 % of them presented a slow transit time. 4 patients underwent defecography and 3 had pelvic floor dysfunction. It was found that 94.6 % of imaging tests and 78.4 % of manometries were positive (Kappa p= 0.006). CONCLUSIONS: imaging techniques used in this study are suitable for diagnosing functional constipation and consistency of these techniques is suitable anorectal manometry.

El tabaquismo en alumnos de medicina cubanos y centrosudamericanos / Tobacco addittion in cuban medicina students and students from central america

El estudio mediante encuestas autoaplicadas y anónimas de 200 alumnos de 5to año de Medicina de la Facultad “Calixto García” en Ciudad de La Habana, se orientó a explorar los patrones de consumo de tabaco en estos estudiantes, y los conocimientos sobre los efectos dañinos de dicho tóxico. El porcentaje de consumidores en el orden hombres, mujeres y total fue el siguiente: 34 (40,9(por ciento), 28 (23,9(por ciento) y 62 (31,0(por ciento). El grupo de encuestados que refirió haber cesado el consumo fue de 19 estudiantes que representaron el 9,5(por ciento) del total de encuestados, y dentro de ellos el sexo femenino resultó el más destacado. En el orden cubanos, centrosudamericanos los hombres fumadores actuales alcanzaron por cientos de 34,7 y 43,3, y las mujeres 32,5 y 18,9. La edad promedio global de inicio del consumo fue de 17,5 años y resultó más precoz en los cubanos. Dentro del total de fumadores de la muestra, la proporción que reportó desear suspender el consumo sin haberlo logrado fue de 89,4(por ciento) en hombres y 92,9 en mujeres. La información sobre efectos nocivos tuvo, en orden de frecuencia decreciente: halitosis 31(por ciento), cáncer pulmonar 26(por ciento), daño económico 25(por ciento), dependencia 20(por ciento), arteriosclerosis 20(por ciento) y manchas dentales 19(por ciento) y se reiteró como en estudios anteriores la baja frecuencia de referencia del infarto miocárdico (7(por ciento)