RESUMEN
Otoliths of cultured sea bass (Dicentrarchus labrax) from two different fish farms of Sicily were collected and analyzed by using inductively coupled plasma optical emission spectroscopy. Metal content (Ba, Cd, Fe, Mg, Mn, Sr, and Zn) was measured in order to test the potential use of biogenic carbonates as proxies of dissimilar environmental conditions since the fish farms are implanted in opposite coastal marine areas (Gulf of Castellammare and Gulf of Gela) characterized by different oceanographic features and human activities. Cluster analysis discriminates samples as different groups on the basis of metal content. Results show that concentrations of Sr in the otoliths have a similar range of distribution and not significantly different between the two farms. Otherwise, Fe, Mg, Mn, and Cd show higher concentrations in otoliths collected from fish reared in the farm in the southern coast (Gulf of Gela), an area subject to a great anthropogenic pressure. Zn is the only element with higher values in the otoliths from the farm in the northern coast (Gulf of Trappeto) probably due to industrial effluent. In this work, obtained data confirm the high potential of trace elements measurements in these biogenic carbonates as proxies of different environmental conditions.
Asunto(s)
Acuicultura , Lubina/metabolismo , Monitoreo del Ambiente , Metales/metabolismo , Membrana Otolítica/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Metales/análisis , Alimentos Marinos/análisis , Alimentos Marinos/estadística & datos numéricos , Sicilia , Contaminantes Químicos del Agua/análisisRESUMEN
The mercury (Hg) pollution of sediments is the main carrier of Hg for the biota and, subsequently, for the local fish consumers in Augusta Bay area (SE Sicily, Italy), a coastal marine system affected by relevant sewage from an important chlor-alkali factory. This relationship was revealed by the determination of Mass Dependent (MDF) and Mass Independent Fractionation (MIF) of Hg isotopes in sediment, fish and human hair samples. Sediments showed MDF but no MIF, while fish showed MIF, possibly due to photochemical reduction in the water column and depending on the feeding habitat of the species. Benthic and demersal fish exhibited MDF similar to that of sediments in which anthropogenic Hg was deposited, while pelagic organisms evidenced higher MDF and MIF due to photoreduction. Human hair showed high values of δ(202)Hg (offset of +2.2 with respect to the consumed fish) and Δ(199)Hg, both associated to fish consumption.
Asunto(s)
Isótopos de Mercurio/análisis , Mercurio/análisis , Contaminantes Químicos del Agua/análisis , Animales , Bahías , Ecosistema , Monitoreo del Ambiente , Contaminación Ambiental , Peces/metabolismo , Sedimentos Geológicos/química , Cabello/química , Cabello/metabolismo , Humanos , Italia , Carne/análisis , Mercurio/metabolismo , Isótopos de Mercurio/metabolismo , Contaminantes Químicos del Agua/metabolismoRESUMEN
The first attempt to systematically investigate the atmospheric mercury (Hg) in the MBL of the Augusta basin (SE Sicily, Italy) has been undertaken. In the past the basin was the receptor for Hg from an intense industrial activity which contaminated the bottom sediments of the Bay, making this area a potential source of pollution for the surrounding Mediterranean. Three oceanographic cruises have been thus performed in the basin during the winter and summer 2011/2012, where we estimated averaged Hgatm concentrations of about 1.5±0.4 (range 0.9-3.1) and 2.1±0.98 (range 1.1-3.1) ng m(-3) for the two seasons, respectively. These data are somewhat higher than the background Hg atm value measured over the land (range 1.1±0.3 ng m(-3)) at downtown Augusta, while are similar to those detected in other polluted regions elsewhere. Hg evasion fluxes estimated at the sea/air interface over the Bay range from 3.6±0.3 (unpolluted site) to 72±0.1 (polluted site of the basin) ng m(-2) h(-1). By extending these measurements to the entire area of the Augusta basin (~23.5 km(2)), we calculated a total sea-air Hg evasion flux of about 9.7±0.1 g d(-1) (~0.004 tyr(-1)), accounting for ~0.0002% of the global Hg oceanic evasion (2000 tyr(-1)). The new proposed data set offers a unique and original study on the potential outflow of Hg from the sea-air interface at the basin, and it represents an important step for a better comprehension of the processes occurring in the marine biogeochemical cycle of this element.
Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Mercurio/análisis , Contaminantes Químicos del Agua/análisis , Atmósfera/química , Italia , Estaciones del Año , Agua de Mar/químicaRESUMEN
Our study reports on the total mercury (HgT) concentrations measured in the muscles and livers of several benthic, demersal and pelagic fish species caught inside and outside of Augusta Bay (southern Italy), a semi-enclosed marine area, highly contaminated by the uncontrolled (since the 1950s to 1978s) discharge of the largest European petrochemical plant. Mercury levels in fish tissues are discussed with regard to specific habitat, size and/or age of the specimens and HgT distribution in the bottom sediments. Results suggest a still active Hg release mechanism from the polluted sediments to the marine environment. Also, the high HgT concentrations measured in fishes caught in the external area of the bay imply a potential role of Augusta Bay as a pollutant source for the Mediterranean ecosystem. Finally, values of hazard target quotient (THQ) and estimated weekly intake (EWI) demonstrate that consumption of fishes caught inside the bay represents a serious risk for human health. Also, data indicate that intake of fishes caught from the external area of the bay, especially for that concern demersal and benthic species, could be represent a significant component of risk for the local population.
Asunto(s)
Monitoreo del Ambiente/métodos , Contaminación de Alimentos/análisis , Mercurio/análisis , Alimentos Marinos/análisis , Contaminantes Químicos del Agua/análisis , Animales , Bahías , Peces , Sedimentos Geológicos/análisis , Sustancias Peligrosas/análisis , Humanos , Italia , Medición de RiesgoRESUMEN
Concentrations of rare earth elements (REE), Y, Th and Sc were recently determined in marine sediments collected using a box corer along two onshore-offshore transects located in the Strait of Sicily (Mediterranean Sea). The REE+Y were enriched in offshore fine-grained sediments where clay minerals are abundant, whereas the REE+Y contents were lower in onshore coarse-grained sediments with high carbonate fractions. Considering this distribution trend, the onshore sediments in front of the southwestern Sicilian coast represent an anomaly with high REE+Y concentrations (mean value 163.4 µg g(-1)) associated to high Th concentrations (mean value 7.9 µg g(-1)). Plot of shale-normalized REE+Y data of these coastal sediments showed Middle REE enrichments relative to Light REE and Heavy REE, manifested by a convexity around Sm-Gd-Eu elements. These anomalies in the fractionation patterns of the coastal sediments were attributed to phosphogypsum-contaminated effluents from an industrial plant, located in the southern Sicilian coast.
Asunto(s)
Sulfato de Calcio/análisis , Sedimentos Geológicos/química , Metales de Tierras Raras/análisis , Fósforo/análisis , Contaminantes Químicos del Agua/análisis , Sulfato de Calcio/normas , Monitoreo del Ambiente , Mar Mediterráneo , Metales de Tierras Raras/normas , Fósforo/normas , Agua de Mar/química , Contaminantes Químicos del Agua/normasRESUMEN
An accurate assessment of body iron accumulation is essential for the diagnosis and therapy of iron overload in diseases, such as hemochromatosis, thalassemia and other forms of severe anemias. The magnetic iron detector (MID) is a room-temperature susceptometer, which measures the total iron overload in the liver. Since February 2005, about 600 patients have been assessed using this device. The iron overload is obtained by calculating the difference between the measured magnetization signal of the patient and the patient's background signal. The latter is the magnetization signal that the patient would generate with normal iron content. This study presents the method for calculating the background signal of healthy volunteers and the application of the same method to patients with iron burden in order to evaluate their overload. The present MID sensitivity is 0.8 g and the reproducibility of the iron overload measurement of the same patients is lower than 0.5 g. The MID does not require calibration with liver biopsies. We correlated the MID measurements with the results of 26 biopsies (R = 0.62), 64 superconducting quantum interference device susceptometer measurements (R = 0.79), 666 serum ferritin concentration measurements (R = 0.72), and 41 MRI- R2* measurements (R = 0.71).
Asunto(s)
Sobrecarga de Hierro/diagnóstico , Hígado/química , Magnetismo/instrumentación , Magnetismo/métodos , Procesamiento de Señales Asistido por Computador , Abdomen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Hierro/química , Modelos Lineales , Masculino , Persona de Mediana EdadAsunto(s)
Servicios de Salud Comunitaria , Argentina , Educación en Salud , Legislación Médica , Salud PúblicaRESUMEN
La elemental tarea de delimitación del concepto de biocombustible, encierra en sí misma aspectos problemáticos. Podemos referirlo como noción genérica incluyendo toda substancia orgánica utilizada por el hombre como fuente energética (ej., leña) y/o aludir al fenómeno tal como se desenvuelve en las actuales circunstancias, haciendo alusión al resultante de complejos sistemas de transformación de biomasa (ej., bioetanol, biodiesel). El debate sobre los biocombustibles ha ocupado, desde hace tiempo, un considerable espacio en los medios de divulgación (diarios, revistas, TV), pero la información es exhibida en forma desordenada, como expresión de bandos en pugna. Por un lado están aquellos que sólo parecen manifestar las bondades del modelo, aludiendo a países como Argentina (por sus características) como ejecutores privilegiados de esta nueva iniciativa. Representa una tarea ineludible encarar una visión que trascienda los planteos superficiales, aspirando a brindar evidencias claras de la etapa actual. La sola sospecha de competencia por territorio entre cultivos que tengan como destino la producción energética y aquella que persigue la obtención de alimentos, merece un riguroso examen. El presente trabajo intenta explorar las aristas centrales del fenómeno de biocombustibles, las formas de producción, así como su vinculación con la seguridad alimentaria a partir de la descripción de cuatro dimensiones interrelacionadas: la disponibilidad de los alimentos, el acceso a los mismos, la estabilidad respecto al uso de los recursos naturales y la utilización biológica de los alimentos y nutrientes. El dilema de alimentos versus energía seguirá siendo una incógnita hasta disponer de una plataforma sólida de estudios que analicen todos los factores relacionados al tema. Es menester el incentivo de trabajos interdisciplinarios, siendo los gobiernos los actores fundamentales.