Mercury levels in human population from a mining district in Western Colombia.

A biomonitoring study was carried out to examine the adverse impacts of total mercury in the blood (HgB), urine (HgU) and human scalp hair (HgH) on the residents of a mining district in Colombia. Representative biological samples (scalp hair, urine and blood) were collected from volunteered participants (n=63) to estimate the exposure levels of THg using a Direct mercury analyzer. The geometric mean of THg concentrations in the hair, urine and blood of males were 15.98µg/g, 23.89µg/L and 11.29µg/L respectively, whereas the females presented values of 8.55µg/g, 5.37µg/L and 8.80µg/L. Chronic urinary Hg (HgU) levels observed in male workers (32.53µg/L) are attributed to their long termed exposures to inorganic and metallic mercury from gold panning activities. On an average, the levels of THg are increasing from blood (10.05µg/L) to hair (12.27µg/g) to urine (14.63µg/L). Significant positive correlation was found between hair and blood urinary levels in both male and female individuals. Thus the present biomonitoring investigation to evaluate the Hg levels and associated health issues would positively form a framework for further developmental plans and policies in building an ecofriendly ecosystem.

Mercury distribution in different environmental matrices in aquatic systems of abandoned gold mines, Western Colombia: Focus on human health.

Total mercury (THg), methylmercury (MeHg) in water, sediments, macrophytes, fish and human health risks were analyzed and assessed from abandoned gold mining ponds (AGMPs)/ mining areas in Western Colombia to know its present environmental condition. Concentrations of THg in water (avg. 13.0 ± 13.73 ng L-1) was above the EPA threshold level (12 ng L-1), suggesting possible chronic effects. Sediment sample revealed that the ponds are methylated (%MeHg: 3.3-11). Macrophyte Eleocharis elegans presented higher THg content in the underground biomass (0.16 ± 0.13 µg g-1 dw) than in the aerial biomass (0.05 ± 0.04 µg g-1 dw) indicating accumulation of THg. MeHg was the most abundant chemical species in fish (MeHg/THg: 83.2-95.0%), signifying higher bioavailability and its risk towards human health. Fish samples (15%) indicate that THg were above WHO limit (0.5 µg g), particularly in Ctenolucius beani, Hoplias malabaricus and lowest in Sternopygus aequilabiatus and Geophagus pellegrini. Bioaccumulation and biomagnification of MeHg were higher in the carnivores representing a source of exposure and potential threat to human health. Fulton's condition factor (K) for bioaccumulation indicate a decrease with increasing trophic level of fishes. Overall results suggest, mercury species found in different AGMPs compartments should be monitored in this region.

Distribution of chemical forms of mercury in sediments from abandoned ponds created during former gold mining operations in Colombia.

Total mercury (THg) and methylmercury (MeHg) were studied in sediments from 27 abandoned gold mining ponds (AGMPs) through small-scale artisanal gold mining in the district of San Juan in Chocó region of Colombia. The AGMPs were abandoned in the last century (1997) and were grouped into three distinct groups (2-6; 7-12; 13-20 years). Overall concentration (in ng g-1) pattern of THg in sediments varied from 39.06 to 1271.32 (avg. 209.57) with 174.81 (13-20 years), 205.56 (7-12 years) and 248.33 (2-6 years) respectively. MeHg concentrations accounted for 3.3-10.9% (avg. 6.5%) of THg and were significantly correlated with THg during all periods. Correlations between organic matter (OM) vs MeHg and THg were negative in the oldest pools, signifying a "dilution effect" or "natural burial" of THg and MeHg. Results for sequential extraction indicate that the fraction of elemental Hg (Hg-e) and organo chelated Hg (Hg-o) represent the main chemical forms of Hg in the sediments, regardless of the abandonment period, whereas the bioavailable fraction was only 0.12-1.65% of THg. The significant statistical relationship between MeHg, THg and OM suggests that these parameters control the distribution, mobility, toxicity and bioavailability of Hg in the sediments of these abandoned ponds. Evaluation of THg with sediment quality guidelines indicates that the values are on the higher side for Threshold effect concentration and Upper continental crust. Comparing of MeHg with many other regions outside Colombia is a worrying factor and needs immediate attention to protect the human health.

Deficiencia de cinc en niños con desnutrición aguda grave / Zinc deficiency in children with acute and severe malnutrition

El cinc es uno de los minerales más importantes porque cumple con importantes funciones estructurales, catalíticas y regulatorias en las células humanas, razón por la cual su deficiencia se asocia con retraso en el crecimiento lineal, alteración de los sentidos del gusto y del olfato, del crecimiento y de la maduración neuronal, deterioro de la respuesta inmune y aumento en la incidencia de diarrea y neumonía; condiciones comunes en la desnutrición grave. El indicador más usado para medir el estado corporal del cinc es la concentración en suero o en plasma, la cual fluctúa ampliamente en una variedad de procesos fisiológicos y patológicos, especialmente en condiciones de desnutrición donde es común encontrar hipoalbuminemia, hemoconcentración, sobrehidratación e infección. Las concentraciones plasmáticas de cinc en los niños desnutridos graves se encuentran disminuidas en un 50 porciento respecto a los valores de los niños eutróficos, lo que dificulta la ganancia de tejido muscular y el crecimiento compensatorio cuando ellos se someten a tratamiento de recuperación nutricional; lo anterior justifica por qué este mineral hace parte de la suplementación con micronutrientes para el manejo de estos niños. Este artículo revisa la relación entre la deficiencia de cinc y la desnutrición grave.

Cambios en la concentración sérica de hierro "libre" en niños con desnutrición aguda grave bajo tratamiento de recuperación nutricional. Turbo -Colombia / Serum 'free' iron level changes in children with severe malnutrition after nutritional treatment support. Turbo - Colombia

Introducción: Se recomida suplemento de hierro en niños con desnutrición aguda grave cuando recuperanel apetito, aun cuando existen evidencias de que en ese momento,aún hay presencia de hierro“libre” y es insuficiente la concentración de transferrina para transportarlo. Objetivo: Evaluar el cambio en las concentraciones séricas de hierro libre, transferrina y ferritina en niños con marasmo y kwashiorkor entre el momento uno, al ingreso y el momento dos, después, cuando el niño recuperó el apetito. Materiales y métodos: Estudio longitudinal, prospectivo, de tipo antes y después. Se realizó en Turbo, con 40 niños menores de cinco años de los cuales 20 tenían marasmo y 20 kwashiorkor. Se determinaron en ambos momentos: hierro 'libre' por electroforesis capilar, transferrina y su índice de saturación, capacidad de fijación de hierro, ferritina, proteínas totales, albúmina, hierro total y proteína C reactiva (PCR) en suero. Resultados: Los niños desnutridos presentaron hierro 'libre' antes de iniciar el tratamiento nutricional sin diferencias significativas entre marasmáticos y edematosos, para el momento dos la concentración de hierro ôlibreõ disminuyó significativamente en ambos grupos pero aun se encontraban valores del metal. La PCR disminuyó significativamente en ambos grupos y en edematosos la ferritina se mantuvo alta al recuperar el apetito. Conclusiones: La recuperación del apetito no es el momento oportuno para dar suplementos de hierro a los edematosos porque aun tienen hierro 'libre', persiste una baja concentración de transferrina y alta de ferritina; se debe esperar la resolución del edema y de la infección.

Introduction: Iron suplementation is recomended for children with severe mal nutrition (Kwashiorkor),when they have recovered the apetiteafter nutritional support. However there is evidence suggesting thateven when the apetite has been recovered, children still present serum“free” iron traces. Objective: To evaluate serum “free” iron, transferrin, and ferritin levels in children with severe malnutrition (kwashiorkpor) in two different periods of time: at baseline before the Serum “free” iron level changes in children withsevere malnutrition after nutritional treatment support. Turbo - Colombia.nutritional therapy starts, and the moment when children recover the apetite. Methods and materials: Longitudinal, prospective study was setting in Turbo-Antioquia. A total of 40children aged < 5 Y, who 20 presentedmarasmus and 20 kwashiorkor.Meassurements like: serum “free”iron by capillary electrophoresis, serumtransferrin, total proteins, albumin,iron and C-reactive protein(CRP) were obtained at baseline,and the time when children recover the apetite. Longitudinal analysis was used to evaluate changes in the malnourished group.Results: No significant diferences were found in both groups of malnourish children who had serum free iron before at baseline, andwhen they recieved nutritional treatmentand recovered the appetite.Eventhought significant decreaseon Serum free iron level were observedin both groups, there wassome remanent trace of the metalin serum. Significant decrease onPCR level was also obtained andserum ferritin level stayed high in the edematous group when they recovering the apetite. Conclusions: Iron supplement is not recomended for children who had recovered the apetite, because they continuing presenting edema and some level of serum “free” iron, low transferrin and high ferritin levels. Iron suplement should begiven when edema and infection have disappeared.

El papel del hierro "libre" y el estrés oxidativo en la etiología del edema de los niños con Kwashiorkor / Role of free iron and oxidative stress in the etiology of oedema in children with Kwashiorkor

El Kwashiorkor es una forma grave de malnutrición proteico energética que se diferencia del marasmo, principalmente, por la presencia de edema. Las teorías iniciales que explican esta alteración, sostienen que el bajo consumo de proteína dietaria ocasiona el descenso de la albúmina plasmática y por consiguiente la disminución de la presión oncótica, provocando la salida de agua al espacio intersticial. Estudios comparativos realizados a partir de 1980, no encontraron diferencias significativas en el contenido de proteínas de las dietas ingeridas por niños con marasmo y kwashiorkor y demostraron que el consumo de cantidades mínimas de este nutriente, no siempre desencadena el edema. Al mismo tiempo, varios investigadores hallaron algunas alteraciones bioquímicas en los niños con kwashiorkor pero no en los niños con marasmo, como mayor producción de especies reactivas del oxígeno, menor defensa antioxidante, altas concentraciones de ferritina y disminución de transferrina séricas y hierro 'libre' en plasma. Lo anterior sugiere que la deficiencia de proteínas, no es el único factor determinante del curso de la desnutrición aguda grave hacia kwashiorkor y que el exceso de agua corporal también puede ser consecuencia del daño oxidativo a biomoléculas orgánicas, ocasionado por la infección y por la presencia de hierro 'libre'.

Kwashiorkor is a serious form ofenergy-protein malnutrition, differentof marasmus in which edema is amajor feature. Initial theories explaining this disorder state that low protein in take cause serum albumin deficit, resulting in decreased oncoticpressure, causing water drains into interstitial space. Starting from 1980, several comparative studies had proved that diets of children suffering of eithermarasmo or Kwashiorkor do notshow significant differences in proteincontent, and a very low proteinintake doesn’t result in edematousmal nutrition. At the same time researchers found some biochemical alterations in children suffering from kwashiorkor but not in thosewith marasmus, such as: higher production of oxygen reactivate species, lower antioxidant protection,high ferritine levels, low transferrine levels, and free iron in serum.The above mentioned, allows us to suggest that protein deficiency is not the only decisive factor in the course of severe malnutrition toward kwashiorkor, and that edema could bea consequence for the oxidative damagecaused to organic biomolecules by infection and free serumiron.