Human Activity in Antarctica: Effects on Metallic Trace Elements (MTEs) in Plants and Soils

Colobanthus quitensis (Kunt) is one of the two vascular plant species present in Antarctica and develops under severe environmental conditions, being found in both pristine and human-threatened environments. We determined the Cd, Cr, Cu, Mn, Ni, Pb, and Zn levels in C. quitensis roots, leaves, and soils of origin using flame atomic absorption spectroscopy. In January 2017, we collected samples from four geographical zones on the longitudinal gradient along which C. quitensis is distributed, starting from Punta Arenas (PAR) at the extreme south of mainland Chile and moving southwards to the Antarctic territory from King George Island (KGI) to Hannah Point Peninsula (PHA) and finally Lagotellerie Island (LAT). We used certified reference material to validate the plant tissues and soil samples we collected. The highest concentrations of metals that we measured in the soils and in the C. quitensis roots and leaves were in samples we collected at the KGI station, the zone with the greatest human activity. The lowest concentrations we measured were at the LAT station, an island with little human intervention and scarce fauna. The mean concentrations of metals in the roots and leaves of C. quitensis followed a similar order at all sampling locations: Mn > Zn > Cu > Ni > Pb > Cr > Cd. In contrast, in soil, they followed the following order: Mn > Zn > Cu > Cr > Pb > Ni > Cd. The concentration levels obtained for the different metals in the soil and plants tissue samples in this region of Antarctica indicated that the area was non-polluted. However, the metallic trace element (MTE) concentrations may be at an early stage of contamination, as described in other areas of the Antarctic, being a new threat to this continent.

Effects of Urbanization on the Degradation of the Palm Grove Around the City of Marrakech

The city of Marrakech is experiencing a very significant development in terms of urbanization which leads to a significant reduction of the agricultural activity and increase of the rate of metallic pollution in soils. The impact of this metallic pollution on the microbial activity in these soils can negatively affect the growth and the development of the date palm (Phoenix dactylifera L). In addition, the urbanization has direct effects on the degradation of palm groves in the Marrakech region, following a decrease in agricultural and forestry productivity after anthropogenic activities which are at the origin of high metallic trace element (MTE) contents in soils. In order to assess the impacts of this pollution, the authors carried out a study in the rhizospheric soils of the date palm (Phoenix dactylifera L) monitoring the levels of heavy metals (Pb, Zn). Eight sites were chosen: five urban sites (three gardens, two boulevards) and two peri-urban sites (palm groves).

A Practical Trace Element Monitoring System for Intermediate Gas Turbine Fuels

Intermediate fuels (GT-3) are less expensive than distillates and do not cause difficulties in a gas turbine provided the contaminant level of the GT-3 oil is consistently kept below accurately set limits. The key to trouble-free operation is a reliable, relatively inexpensive and fairly fast on-site monitoring system. Experience with such a system was previously reported. The present paper discusses the on-site monitoring systems in some detail. The method provides results for metallic trace element analyses in the order of 10 ppm, within ±0.2 ppm, using the oil ash as the subject of investigation with a flame emission spectrophotometer, a colorimeter and an atomic absorption spectrophotometer. Elimination of interference effects is described and procedures for the appropriate solutions are shown. Investment costs and man-hour requirements are described.