lunes, 13 de diciembre de 2010

Elementos traza en el Monte Everest/Trace elements on Mount Everest

Los científicos han encontrado niveles dañinos de metales pesados contaminantes en lugares remotos del monte Everest, una indicación de las grandes distancias que la contaminación atmosférica industrial puede recorrer.
Según los investigadores de la Universidad de Southern Maine en Gorham, todas las muestras de nieve recogidas entre los 5.334 y 7.772 metros metros de altitud contienen niveles de cadmio y de arsénico superiores a los valores permitidos en los E.E.U.U., mientras que las muestras de suelo contienen niveles perniciosos de cadmio.
De acuerdo al estudio, publicado en la revista Soil Survey Horizons, los niveles de las toxinas son mayores según nos acercamos a la cumbre de la montaña, lo que parece indicar que fueron transportados por vientos de gran altitud desde zonas industriales asiáticas.
Los investigadores señalan que estos resultados son preocupantes porque los escaladores y montañeros utilizan nieve derretida para obtener agua potable y porque los fuertes vientos pueden también levantar las toxinas desde el suelo.
En este caso, la cuestión no radica en la ingestión temporal de agua contaminada con elementos tóxicos. El problema es que uno de los rincones más salvajes e inaccesibles de nuestro planeta ha sido ya contaminado por la mano del hombre.

Scientists have found harmful levels of heavy metal pollutants on remote reaches of Mount Everest, an indication of the great distances industrial air pollution can travel.
Every snow sample collected at altitudes between 5,334 and 7,772 meters (17,500 to 25,498 feet) contained levels of cadmium and arsenic that exceeded U.S. safety standards, according to researchers at the University of Southern Maine in Gorham, while every soil sample contained unsafe levels of cadmium.
According to the study, published in the journal Soil Survey Horizons, toxin levels were highest toward the top of the mountain, which suggests that high-altitude winds had carried the toxins from Asian industrial sites.
Researchers called the results a reason for concern because mountaineers rely on melted snow for drinking water and high winds may also kick up toxins located in the soil.
In this case, the question is not the temporal comsuption of water polluted with toxic elements. The problem is that one of the more inaccessible and wild places of our planet is also polluted by anthropogenic causes!

Tomado de/Taken from Environment360

Abstract of the paper
Trace Element Deposition on Mount Everest
B. Yeo and S. Langley-Turnbaugh
Soil Survey Horizons
The objective of this study of the North Ridge of Everest was to examine trace element concentrations and altitudinal trends in soil and snow. Mount Everest was selected because its remote location and extreme elevation isolates it from localized pollution sources. Soil samples were collected on the Rongbuk glacier of Mount Everest (Qomolangma) from 5334 to 6553 m, and fresh surface snow samples (0–10 cm) were collected along the climbing route of the northeast ridge from 6858 m to 7752 m. The samples were analyzed for Pb, Zn, Cd, Ni, Cr, Co, Cu, As, Mn, Hg, and V using inductively coupled plasma spectroscopy. Results show that As and Cd are both above USEPA drinking water guidelines in all snow samples, and arsenic is above the USEPA soil screening guidelines in all soil samples. There was a clear trend in element variation in the soil samples, with the highest concentrations found at 5944 m. There was no clear trend detected in the snow samples, possibly due to vertical mixing of surface snow. Anthropogenic sources are suspected to have contributed to the elevated concentrations of both cadmium and arsenic.

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