Lead-zinc mining and home-grown foodstuffs (Eastern FYR Macedonia)

Comunicação oral da qual só está disponível o resumo.Mining accompany our civilization since evolution. Since the “Copper (Chalcolithic) Age” and later “Golden Age”, mining activities have created great wealth. Unfortunately, beside wealth the exploitation of metal rich ores, have been almost always correlated with a negative impact to the nearby ecosystems. In this study a broad area around the active Pb-Zn Sasa mine (NE FYR Macedonia) was characterized, to evaluate the contents of some Potentially Toxic Elements (PTE). The PTE were determined in the surrounding fresh waters (lake and rivers), soils and the home-grown vegetables. The evaluation of the potential hazardous ef ects of the PTE, especially on humans, is a key goal. The PTE’s were determined by ICP-AES and ICP-MS. Furthermore also detailed questionnaires were applied among the local inhabitants. Sequential extraction analyses of selected soil samples revealed that the majority of PTE was bounded to water soluble and exchangeable fraction, which shows that those elements (Ag, As, Cd, Cu, Mo, Ni, Pb, Sb and Zn) are therefore very easily mobile and consequently available to plants. According to the applied questionnaires, the consumption of home-grown foodstuf s is high, and certain vegetables, such as tomatoes, peppers, salads, etc., are consumed every day or even more than once a day. Chemical evaluation of PTE in home-grown vegetables revealed that the most crucial PTE’s (those which heavily exceed upper allowable limits) are Cd, Co, Cu, Pb and Zn, and are closely followed by Cr and As. The calculated Health Risk Index (HRI) shows extremely high estimated values, both for adults and children. As the study area is surrounded by rich metallogenic ore deposits, is expected that the natural background is slightly higher than elsewhere. Nevertheless, the concentrations of PTE’s in waters used for irrigation which were increased and the wind-blown (aeorogenic) PTE’s pollution from the nearby tailings dam, both increases the PTE contents in the studied foodstuf s. Thus, the health of inhabitants in this area is of high concern

Spatial distribution and associated spatial uncertainty of potential toxic elements - the Lake Kalimanci case study (Republic of Macedonia)

Pollution from mining activities is a significant problem in various regions of the Republic of Macedonia. A geochemical survey of the surface deposits of Lake Kalimanci in the easterly region of the Republic of Macedonia was carried out before (2001) and later (2007) the dam failure and thus allowing the measurement of the tailings’ material from Sasa Pb-Zn Mine-Osogovo Mountains (Eastern Macedonia). The concentrations of potentially toxic elements (PTE): Ag, Au, Cd, Co, Cu, Pb, Sb, Th, S, U and Zn were obtained by ICP Mass Spectrometry (ACME Laboratories in Vancouver, Canada). Data analysis, through Principal Component Analysis (PCA), was performed in order reduce the space of analyses by the construction of synthesis variables (Principal Factors). Geostatistical modeling was used, throughout conventional variography and the Sequential Gaussian Simulation algorithm (SGS), to model the new factors' spatial distribution. A hundred simulations, differing in their initial random-number seed, were performed and a Mean Image (MI) obtained. Spatial uncertainty evaluation (simulation’s Standard Deviation) allowed the definition of future monitoring and sampling strategies as well as the measurement of remediation possibilities

Numerical Model for Determining the Magnetic Loss of Magnetic Fluids

Magnetic fluid hyperthermia (MFH) is a medical treatment where the temperature in the tissue is increased locally by means of heated magnetic fluid in an alternating magnetic field. In recent years, it has been the subject of a lot of research in the field of Materials, as well as in the field of clinical testing on mice and rats. Magnetic fluid manufacturers aim to achieve three objectives; high heating capacity, biocompatibility and self-regulatory temperature effect. High heating power presents the conversion of magnetic field energy into temperature increase where it is challenging to achieve the desired therapeutic effects in terms of elevated temperature with the smallest possible amount of used material. In order to carry out the therapy, it is primarily necessary to create a fluid and perform calorimetric measurement for determining the Specific Absorption Rate (SAR) or heating power for given parameters of the magnetic field. The article presents a model based on a linear response theory for the calculation of magnetic losses and, consequently, the SAR parameters are based on the physical parameters of the liquid. The calculation model is also validated by calorimetric measurements for various amplitudes, frequencies and shapes of the magnetic field. Such a model can serve to help magnetic fluid developers in the development phase for an approximate assessment of the heating power