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Artificial objects, particularly tunnels used for water transport under pressure, impact the geological and hydrogeological environment to a greater or lesser extent, and it is vital to assess their contributions to groundwater quality. Although tunnels are typically lined with concrete, their interaction with the hydrogeological environment intensifies over time. In this study, the detailed spatiotemporal monitoring of all hydrogeological features within the potential influence zone of the hydraulic tunnel of the Pirot Hydropower Plant has been conducted in order to determine the degree of interaction between the artificial object and the natural environment in real time, and to assess the correlation between monitored parameters. Natural conditions of the environment were defined, as well as potential changes through the observing groundwater regimes. The monitoring network included observations of groundwater regimes at seven springs located in close proximity to the hydraulic tunnel, within the tunnel, at three piezometers, and along the river, while methods employed were hydrological monitoring, physicochemical monitoring, and groundwater piezometer sensing. Cross-correlation analysis has been applied for assessing the impact of precipitation dynamics on the spring discharge regime. The results indicate a direct influence of the tunnel on the hydrogeological environment, proving the consistency and high correlation between the monitored parameters. [ABSTRACT FROM AUTHOR]

Background/Aim. Fluoride has beneficial effect on dental caries prevention and enables high hardness of enamel. However, fluoride intake above optimal levels can have adverse effects on teeth and bones, especially in young children during the period of intense growth and teeth development. The aim of this study was to assess fluoride intake from water and toothpaste among 3-year-old children in Belgrade, Serbia, in the municipalities of Vračar and Novi Beograd. Methods. A questionnaire for the parents (n = 40) was used to provide information on the water consumption (tap and/or bottled water) and the brand of toothpaste used by children as well as the frequency of tooth brushing and the amount of toothpaste during brushing. Fluoride concentrations in water and toothpaste samples were determined electrochemically by using fluoride-selective electrode. Fluoride intake was estimated through a mathematical model commonly used by the U.S. Environmental Protection Agency. Results. The obtained results indicate no significant difference in daily fluoride intake through drinking water and toothpaste in 3-year-old children in Vračar (n = 19) compared to Novi Beograd (n = 21) (p > 0.05). However, all estimated fluoride levels (0.089–0.625 mg/day) are significantly lower than the optimal daily intake level for caries protection (0.7 mg/day for children up to 4 years, FNB-USA National Institute of Medicine) and two to six times lower than tolerable upper fluoride level for the children of same age (1.3 mg/day, FNB-USA National Institute of Medicine). Furthermore, calculated daily fluoride intake per kilogram body weight confirm very low fluoride intake by water and toothpaste in children of investigated municipalities in Belgrade, being significantly below the recommended an adequate intake (0.05 mg/kg/day, EFSA). Conclusion. This preliminary study has shown that daily fluoride intake in 3-year-olds is lower than tolerable upper fluoride level, even not sufficient for the prevention of dental caries. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III46009]

In analytical methods used for monitoring of what special attention is paid to sample preparation. Therefore, the objective of this study was testing the efficiency of immunoaffinity columns (IAC) that are based on solid phase extraction principles used for samples preparation in determining aflatoxins and ochratoxins. Aflatoxins and ochratoxins concentrations were determined in totally 56 samples of food items: wheat, corn, rice, barley and other grains (19 samples), flour and flour products from grain and additives for the bakery industry (7 samples), fruits and vegetables (3 samples), hazelnut, walnut, almond, coconut flour (4 samples), roasted cocoa beans, peanuts, tea, coffee (16 samples), spices (4 samples) and meat and meat products (4 samples). Obtained results indicate advantage of IAC use for sample preparation based on enhanced specificity due to binding of extracted molecules to incorporated specific antibodies and rinsing the rest molecules from sample which could interfere with further analysis. Additional advantage is the usage of small amount of organic solvents and consequently decreased exposure of staff who conduct micotoxins determination. Of special interest is increase in method sensitivity since limit of quantification for aflatoxins and ochratoxins determination method is lower than maximal allowed concentration of these toxines prescribed by national rule book.

Human immunodeficiency virus (HIV), isolated in 1983 by Paster Institute researches, has been recognised as the cause of million fatalies in 21st century. Initial monotherapy failed to show promising results, however, with the development of highly active antiretroviral therapy new era of HIV treatment has started. This new approach resulted in extended life time, reduced development of virus resistance as well as morbidity and mortality of HIV patients. Antiretroviral therapy is longlife and connected with serious adverse and toxic effects. Mitochondrial toxicity can be manifested as periferal lipoathrophy, hepatic steatosis, lactic acidosis, neuropathy and miopathy. Metabolic features associated with lipodystrophy include hypertriglyceridaemia, hypercholesterolaemia, insuline resistance and abnormal glucose tolerance. Hepatotoxicity, nephrotoxicity, osteopenia, rash and gastrointestinal symptoms can also occur during antiretroviral therapy. The aim od this work was to present the most important adverse and toxic effects of drugs used in HIV therapy.

The vast majority of toxicity studies and risk assessments deals with single chemicals. In reality, however, humans are exposed simultaneously to a large number of chemicals, indicating that exposure assessment and safety evaluation should focus on mixtures rather than on single chemicals. This review on the toxicology of chemical mixtures covers widely varying issues, ranging from the basic concepts and terminology of joint action and interaction of chemicals to different designs for studying the toxicity of mixtures. Literature data indicate that exposure to mixtures which contain low levels of chemicals, levels lower than their no observed adverse effect levels (NOAELs), can exert toxic effects whether their components have similar modes of action or not. Different approaches and examples of studies on priority real-life mixtures, strategy and guidelines for mixture risk assessment as well as challenges ahead are also presented.

Cadmium (Cd) is today one of the most significant metal poisons, both in the area of professional as well as of eco toxicology. In the organism, cadmium has a harmful effect on the kidneys, liver, bones, testicles, etc., and, based on evidence in humans that it causes lung carcinoma, it has been placed in the first group of carcinogens. In spite of numerous data in literature on the harmful effects of cadmium, the interactions between cadmium and bioelements as a significant mechanism for cadmium toxicity have still not been sufficiently explained. Since the data so far point to a positive effect of supplementation with certain bioelements regarding toxicity and cadmium content in the organism, the objective of this work was to investigate the effect of increased simultaneous intake of magnesium, zinc and copper on urinary elimination of cadmium in rabbits exposed to cadmium. Rabbits were divided into two groups: Cd group - for a period of 28 days the animals received per os 10 mg Cd/kg b.m/day and Cd+(Mg+Zn+Cu) group - 10 mg Cd/kg b.m. + 40 mg Mg/kg b.m, 20 mg Zn/kg b.m. and 10 mg Cu/kg b.m/day. Daily urine was collected on days 0, 10, 15, 17, 19, 21, 23, 25, and 28 of the experiment. Following decomposition of urine samples with the help of concentrated HNO3 and HClO4 (4:1), the metal concentration was determined using the method of atomic absorption spectrophotometry. Supplementation with magnesium, zinc and copper did not result in significant changes in the elimination of cadmium through urine in animals poisoned with cadmium, in comparison with the animals that were administered only cadmium, while the concentration of all three applied bioelements in urine was significantly increased. It can be concluded that the simultaneous administration of increased doses of zinc, copper and magnesium does not have a positive effect on the elimination of cadmium in conditions when rabbits are poisoned with cadmium.

The field, petrological-mineralogical, geochemical and geochronological data of the metamorphic sole rocks recorded beneath the Fruška Gora, Povlen (Tejići), Stolovi and Banjska ophiolites in the Western Vardar Zone (WVZ) and beneath the Zlatibor, Bistrica, Sjenički Ozren and Brezovica ophiolites in the Dinaridic ophiolite belt (DOB) in Serbia are compared. The focus has been made on metabasic rocks formed in contact with the oceanic crust members: cumulate gabbro and basalts of SSZ-type with E-MORB and OIB-signature and more evolved tholeiitic basalts of MOR-affinity. Amphibole, the major phase formed from the mafic sole components, depending on pressure-temperature conditions exhibits compositional variations. According to mineral assemblages, estimated P-T conditions and ages, the potential P-T paths are given: high pressure - low temperature blueschist facies assemblage (7-9 kbar and ~400°C and 700-850°C), recorded in both domains, the WVZ (Banjska) and the DOB (Bistrica, Sjenički Ozren, Brezovica) and medium pressure - medium temperature amphibolite facies assemblages (~3.5-7 kbar and >350-650°C) recognized in the WZV (Tejići, Devovići) and the DOB (Zlatibor). The peak metamorphic conditions point to depths of the oceanic lithosphere detachment and its initial cooling at 10-30 km, but the ages and tectonic setting of ophiolites remain poorly constrained. The summarized data may be used as an important key in geodynamic evolution of the Mesozoic Tethyan ophiolites. [Projekat Ministarstva nauke Republike Srbije, br. 176019 and br. 176016]

Background/Aim. Cyanobacterial toxins befall a group of various compounds according to chemical structure and health effects on people and animals. The most significant in this large group of compounds are microcystins. Their presence in water used for human consumption causes serious health problems, liver beeing the target organ. Microcystins are spread all over the world. Waterblooms of cyanobacterias and their cyanotoxins are also common in the majority of surface waters in Serbia. The aim of this study was to propose HPLC method for determination of mikrocystin-LR, to validate the method and to use it for determination of microcystin-LR in the surface water of the river Ponjavica. The Ponjavica is very eutrophic water and has ideal conditions for the cyanobacterial growth. Methods. Sample of water form the Ponjavica river were collected during the summer 2008. Coupled columns (HLB, Sep-Pak), were used for sample preparation and HPLC/PDA method was used for quantification of microcystin- LR. Results. Parameters of validation show that the proposed method is simple, fast, sensitive (0.1 mg/L) and selective with the yield of 89%-92%. The measuring uncertainty of

Background/Aim. The beneficial effects of medicinal plants are well-known from the ancient times. However, expansion of phytopharmacy and phytotherapy occured during the last decades. Medicinal plants can absorb environmental contaminants from the ground and consequently may cause harmful effects on human health. Quality control usually comprises standard methodology which includes macroscopic identification and examination of active ingredients. Additionaly, there is a permanent need to control the level of pollutants in herbs, with a particular attention to the level of toxic metals. In this study we estimated the level of contamination by determining the content of cadmium (Cd) in the herbs of Hypericum perforatum and Thymus serpyllum collected from the different localities of the mountains Rtanj and Ozren. Methods. Herbs of investigated plants were collected during July 2005 from various localities of Rtanj and Ozren mountains. After drying, homogenization and mineralization, Cd content was determined by atomic absorption spectrophotometry. Results. The obtained results show that Cd content varies significantly in Hypericum perforatum samples collected. The lowest Cd level was found in samples from the one of Rtanj localities (0.25 mg Cd/kg), while the highest was observed in Hypericum perforatum from Ozren locality (1.24 mg/kg). Levels of Cd in the three of four investigated localities were higher than pro posed by WHO (0.3 mg/kg dried herb material). In all investigated samples of Thymus serpyllum herbs Cd levels were below the limit of detection of analytical method (0.2 mg Cd/kg dried materials). Conclusion. This work contributes to the issue of Cd content in Hypericum perforatum and Thymus serpyllum grown in localities of Rtanj and Ozren, and implies the importance for systemic control of Cd content in Hypericum species in order to provide safety of their preparations. Furthermore, regarding Cd toxicity, maximal permissible level of Cd in plant material should be evaluated and established concerning national legislative frame.

The Struganik limestone has been increasingly popular in recent years for interior and exterior building applications, due to easy workability, low cost and multi purpose suitability. The quality of limestone is determined by its mineralogical and textural characteristics and physico-mechanical properties. The Struganik stone corresponds to marl, clayey limestone and limestone (micritic and allochemical). The limestone is commonly layered, either thinly bedded or banked. Chert concretions are present in all varieties. The Upper and the Lower Campanian age were deduced by the abundant foraminifers. Micrite limestone is an autochthonous rock generated in a deep marine environment, whereas allochemical limestone is related to a shallow marine environment but subsequently brought into a deep-water system. The mass quality of the Struganik limestone is controlled by variability of lithology and layering. The values of physico-mechanical properties, such as density, porosity, water absorption and strength, were statistically analyzed and the obtained data were used to assess the rock quality in the quarry. The relationship among the quantified properties is described by regression analyses and the equations of the best-fit line. The Struganik limestone was qualified by its petrological and engineering properties coupled with statistical analysis. It satisfies the majority of the requirements of the Main National Standard as a decorative stone, but with a limiting factor regarding abrasive resistance.

Reverse-phase HPLC methods for determination of 5’-O-acetyl-tiazofurin (AT) and 5’-O-benzoyl-tiazofurin (BT) in rat plasma were developed and validated in terms of specificity, linearity, precision, accuracy and sensitivity. Linear calibration curves were constructed in the concentration range of 2.50 – 100.00 μmol/L for both compounds. The separations were achieved on a Supelcosyl LC-18-DB analytical column (250x4.6 mm; 5_μm particle size) by isocratic elution, with a mixture of 0.1Mdisodium hydrogen phosphate – methanol. UV detection was performed at a wavelength of 254 nm. The proposed methods enable the detection and quantification of nanomolar concentrations of AT and BT in rat plasma.