Classification of soil samples according to their geographic origin using gamma-ray spectrometry and principal component analysis

A principal component analysis (PCA) was used for classification of soil samples from different locations in Serbia and Montenegro. Based on activities of radionuclides ((226)Ra, (238)U, (235)U, (40)K, (134)Cs, (137)Cs, (232)Th and (7)Be) detected by gamma-ray spectrometry, the classification of soils according to their geographical origin was performed. Application of PCA to our experimental data resulted in satisfactory classification rate (86.0% correctly classified samples). The obtained results indicate that gamma-ray spectrometry in conjunction with PCA is a viable tool for soil classification.     

Retrospective monitoring and inventory of soil contamination in relation to systematic monitoring

Retrospective monitoring of soil contamination has been performed in the Czech Republic. This kind of monitoring is based on the comparison of the heavy metals content in soil samples taken during a systematic soil survey (1960–1970) and in samples taken at the present time. The anticipated high degree of soil pollution in the Czech Republic has not been proved. Most of the contaminated soils were found to be loaded just 20–35 years ago. Retrospective monitoring is considered to be an accelerating tool for determining the strategy of the systematic monitoring of soil contamination. This procedure stimulated the development of the multi-step system of soil loading limits.     

Monitoring The Turbidity and Surface Temperature Changes and Effects of the 17 August 1999 Earthquake in the İzmİt Gulf,Turkey by the Landsat TM/ETM Data

The temporal turbidity and surface temperature changes and effects of the 17 August 1999 earthquake in the İzmit Gulf, Turkey have been investigated using Landsat TM/ETM data. The gulf is in the Mediterranean–Black Sea transition climatic zone and is partially surrounded by green vegetation cover and degraded and densely urbanized-industrialized areas. Landsat TM/ETM data acquired in 1990–1999 confirms increase in turbidity. Turbidity is always low in the southern part and high in the northern part of the gulf, because the more urbanized and industrialized areas are located in the northern part. The Landsat-7 ETM data acquired in the same year (1999) shows seasonal changes in turbidity. Moreover, the two high turbidity and surface temperature anomalies, one of which is parallel to the 17 August 1999 earthquake surface rupture (east–west) and the other which is in the northwest–southeast direction were mapped from Landsat-5 TM data acquired the day (18.08.1999) following the earthquake in the east end of the gulf. On the basis of turbidity implying the sea bottom movement, it is possible to state that a second rupture in the northwest and southeast direction could have occurred at the sea bottom during the earthquake. The distribution of the seismicity centers and the orientation of the lineaments in the area support this finding.     

The water quality of the Vrgorska Matica River

The article presents the results of investigations carried out on the 42 km long Vrgorska Matica River, which flows through the 15 km long Vrgorsko polje (polje = field) which covers an areaof 3000 ha, and is at 24 m a.s.l., located in Southern Croatia.It covers the years 1997–2000 after this field had been reclaimed for agricultural use.The purpose of the investigations was to evaluate the influence of the Vrgorska Matica River which is part of the catchment areaof the Trebizat River, on the water quality in Modro Oko Lakeand Prud Spring, which are used for water supply and are locateddownstream of the Vrgorska Matica River on the right bank of theNeretva River.The water quality was evaluated by using the quality index basedon the following nine parameters: temperature, mineralization, corrosion coefficient, K = (Cl + SO₄)/HCO₃, dissolvedoxygen, BOD₅, total N, protein N, total phosphorus and totalcoliform bacteria (100 mL)^-1 (MPN coli (100 mL)^-1) for which concentrations C ₉₅ are calculated. After completingthe nine parameters the results of C ₉₅ were recorded andtransferred to the score table to obtain the q-value. The q-value used is an attempt to quantify environmental factors which would otherwise be qualitative. For each parameter the q-value was multiplied by a weighting factor based upon the relative significance of the parameter. The nine resulting scores values were then added to arrive at an overall water quality index (S₉₅).According to this index the water can be classified into four categories. The first category, according to the Croatian Water Classification Act (Official Bulletin No. 77,1998), includes ground and surface waters used for drinking or in the food industry either in its natural state or after disinfection, and surface water used for raising high-quality species of fish, ranging from 85–100 scores; the second category includes waterused in its natural state for swimming and recreation, sports orfor other species of fish and the treated water used for drinkingand other industrial purposes ranging between 70–85 scores. Thethird category includes water used in industry with no specific requests upon water quality and in agriculture ranging from 50–70 scores; the fourth category includes water used only afterbeing treated in areas with water shortage which is less than 50 scores.According to results obtained by investigations, the water of theVrgorska Matica River and Prud Spring falls into the second (II)category, while water from the Modro Oko Lake belongs to the first (I) category. This means that the Matica River water does not influence the water quality of the Modro Oko Lake. This lakewater quality is influenced by the Rastoka Matica River from theRastoko polje which is located upstream from the Vrgorska MaticaRiver. This has been proved by dyeing tests.     

The Quality of Water in the Buško Blato Reservoir

The article presents the results of chemical andmicrobiological measurements of the water quality in theBuko Blato reservoir, the largest in Europe, in the period 1989 to 1998.The aim was to observe possiblechanges in water quality during the past decade and itsinfluence on the downstream section of the Cetina River andits numerous tributaries and reservoirs, where there are twolarge regional water supply systems. This reservoir wasbuilt in order to exploit the high hydro-electric potentialof small streamflows in the karst fields of south-westernBosnia. It has strongly influenced the hydrologicconditions of the downstream section of the Cetina River.Buko Blato is a relatively shallow reservoir with the meandepth of 5 m. It covers an area of 57 km². The waterexchange in the reservoir is slow, occurring from one toseveral years. When the water inflow exceeds the hydroelectric plant demands the excess water is delivered by a reversible channel and pre-pumped into the Buko Blato reservoir. The total and carbonate water hardness in thereservoir is lower than in the Cetina River and in typicalkarst streamflows, since the water in this reservoir comesmainly from surface sources including numerous springs withhigh capacity oscillations, torrents and rainfall.Measurements, carried out during the past years, showed asignificant increase in nitrate content as well as in thecoli bacteria and a less significant increase in totalphosphorus content. The water quality was evaluated asmezotrophic according to the total phosphorus content basedon the Carlson index of trophic level, a lower quality thanin the Perua reservoir, upstream on the Cetina River. Thelatter contains a smaller phosphorus content and wasclassed between oligotrophic and mezotrophic. According tothese data, employing the Vollenweider equation, the totalphosphorus content in this water should not exceed the meanof 20 mg m^-3 P. The results indicate that the water inthe Buko Blato reservoir did not deteriorate the waterquality on the downstream section of the Cetina River.     

Monitoring of krypton-85 activity in the atmosphere around Prague

The results of measurements of Krypton-85 (⁸⁵Kr) concentrations in the ground-level air of Prague between 1983 and 1992 are presented and time-related changes analysed. The long-term trend in activity level of ⁸⁵Kr has been steadily increasing with a growth rate of 0.04 Bq.m^–3 (STP) per year. Some peaks of ⁸⁵Kr activity were observed due to the influence of undispersed radioactive plumes coming from distant sources. Short-term variations within a typical range of concentrations from 0.61 to 1.25 Bq.m^–3 (STP) were found to be seasonally dependent, with the maximum occurring in spring.     

Interaction Between GSM Handset Helical Antenna and User's Head: Theoretical Analysis and Experimental Results

Summary The performance of a cellular phone commercial helical antenna at 900~MHz band, both in free space and in the presence of a human head phantom was studied. Numerical simulation of the phone model for the latter case has been performed giving 3D radiation diagrams. The effect of the phantom head on radiation diagrams is presented. The relative amount of the EM power absorbed in the head was obtained for several distances of the phone. Measurements were carried out in a RF anechoic chamber using standard horn antennas and a calibrated measuring system. Absolute radiation patterns of the antenna gain were obtained in the three principal planes. Significant reduction of the absorbed power could be achieved just by moving the phone 1 cm away from the head.     

Cytotoxicity of gamma irradiated aflatoxin B1 and ochratoxin A

Toxicity of gamma irradiated mycotoxins aflatoxin B₁ (AFB₁) and ochratoxin A (OTA) was investigated in vitro. AFB₁ and OTA stock solutions (50?mM, in methanol) were gamma irradiated (5 and 10 kGy) and non-irradiated and irradiated mycotoxins solutions were tested for cytotoxicity on Pk15, HepG2 and SH-SY5Y cell lines (MTT assay, 1–500?μM concentration range; 24?h exposure). Degradation of mycotoxin molecules was examined by liquid chromatography tandem mass spectrometry (HPLC-MS/MS). AFB₁ and OTA radiolytic products were less toxic than the parent mycotoxins to all of the tested cell lines. Gamma irradiation even at 5 kGy had effect on AFB₁ and OTA molecules however, this effect was dependent on chemical structure of mycotoxin. Since gamma irradiation at low dose reduced initial level of both mycotoxins, and gamma irradiated mycotoxins had lower toxicity in comparison to non-irradiated mycotoxins, it can be concluded that gamma irradiation could be used as decontamination method.     

Root uptake of atenolol,sulfamethoxazole and carbamazepine,and their transformation in three soils and four plants

Soils can be contaminated by pharmaceuticals. The aim of this study was to evaluate the impact of soil conditions (influencing sorption and persistence of pharmaceuticals in soils) and plant type on the root uptake of selected pharmaceuticals and their transformation in plant-soil systems. Four plants (lamb’s lettuce, spinach, arugula, radish) planted in 3 soils were irrigated for 20 days (26) with water contaminated by one of 3 pharmaceuticals (carbamazepine, atenolol, sulfamethoxazole) or their mixture. The concentrations of pharmaceuticals and their metabolites in soils and plant tissues were evaluated after the harvest. Sulfamethoxazole and atenolol dissipated rapidly from soils. The larger concentrations of both compounds and an atenolol metabolite were found in roots than in leaves. Sulfamethoxazole metabolites were below the limits of quantifications. Carbamazepine was stable in soils, easily uptaken, accumulated, and metabolized in plant leaves. The efficiency of radish and arugula (both family Brassicaceae) in metabolizing was very low contrary to the high and moderate efficiencies of lamb’s lettuce and spinach, respectively. Compounds’ transformations mostly masked the soil impact on their accumulation in plant tissues. The negative relationships were found between the carbamazepine sorption coefficients and its concentrations in roots of radish, lamb’s lettuce, and spinach.