The aim of this study was to describe the effects of nickel (NiCl 2 ) on murine testicular structure. Experimental animals were injected intraperitoneally with a single dose of 20 mg NiCl 2 per kg of body mass (group A, n = 5) and 40 mg NiCl 2 per kg b. m. (group B, n = 5). The group without injection (n = 5) was the control (C). Animals were killed 48 hours after administration of nickel. The body mass of animals, the mass of testes and the testes : body mass ratio were not significantly affected. In both experimental groups a significant (p < 0.001) decrease of germinal epithelium in comparison with control group was observed. The relative volume of the interstitium was increased but not significantly in both experimental groups. An increase in the relative volume of the lumen was registered in both experimental groups in comparison with the control group. The qualitative analysis detected a dilatation of blood vessels in the interstitium, undulation of the basal membrane and several empty spaces in the germinal epithelium. The diameter (n = 150) of the seminiferous tubule was markedly (p < 0.05) decreased in both experimental groups (A, B) compared to control group. The height of the germinal epithelium showed a significant decrease (p < 0.05 -0.001) after nickel administration. Evaluation of the lumen diameter in the seminiferous tubule showed a significant increase in both experimental groups. The data of the perimeter of seminiferous tubules corresponded with those of the seminiferous tubule diameter. TUNEL assay detected a higher frequency of localized apoptosis in the interstitium of nickel-administered animals compared to control group. Our findings clearly suggest a negative effect of nickel on the structure as well as on the function of the seminferous epithelium at the site of spermatozoa production.

The problems of soil hygiene and contents of the following heavy metals: cadmium, cobalt and nickel in the productive parts of plants in the location of Agricultural Cooperative Štrba in Poprad County were discussed in the presented work. Above-mentioned location is found in the neighbourhood with a chemical factory Chemosvit Svit. The achieved results show that the soil hygiene in this region is mainly affected by the activity of this chemical factory. This factory is producing many risky substances and their results can be seen in the condition of soil hygiene and in the quality of farmed plants. The results of monitored heavy metals (Cd, Co, Ni) prove that the content of cadmium and nickel is the main polluting factor of soil in this region. The increased contents of these elements in soil produce a high risk of the uptake to plants. This further affects the technological quality along with the quality of hygiene of farmed products and finally the food itself as well. A higher attention needs to be paid to cobalt too, because it proved quite high cumulation ability in soil.

The purpose of this study was to assess the effects of lead administration on the kidney and testicular structure of adult rats. Rats received lead (PbNO(3)) in single intraperitoneal dose 50 mg/kg (group A), 25 mg/kg (group B) and 12.5 mg (group C) per kilogram of body weight and were killed 48 h following lead administration. After the preparation of histological samples the results were compared with control. After the lead administration dilated Bowman's capsules and blood vessels in interstitium of kidney with evident hemorrhagic alterations were noted. Quantitative analysis determined increased relative volume of interstitium and tubules. Also, the diameter of renal corpuscules, diameter of glomeruli and diameter of Bowman's capsule were significantly increased, especially in group A, with the highest lead concentration. In testes, dilatation of blood capillaries in interstitium, undulation of basal membrane and occurrence of empty spaces in seminiferous epithelium were detected. An apoptosis assay confirmed increased incidence of apoptosis in the spermatogenetic cells after the lead administration. Also further morphometric analysis showed significant differences in evaluated parameters between control and treated groups. The number of cell nuclei was decreased in lead-treated groups, which is concerned with the occurrence of empty spaces as well as with the higher apoptosis incidence in germinal epithelium. This study reports a negative effect of lead on the structure and function of kidney and testes.

The consumption of cereals in Slovakia but also worldwide is increasing by every year. From 30000 to 50000 tons of mercury circulates thought the biosphere that gets into the atmosphere degassing of the earth's crust and world oceans. Trace element as copper is one of the most efficient antioxidants in the body, often referred to as an element of beauty. It acts as a powerful catalyst for many enzymes and vitamins, through which already small amounts affects many activities in the body (strengthens immunity, reduces levels of histamine). It accumulates in the barley, beans, cucumber, nuts or milk and so on. The aim of our work was the evaluation of transfer of mercury from sludge to edible part of chosen cereals. The objectives were achieved in simulated conditions of growing pot experiment. We used agricultural soil from the location of Výčapy -Opatovce for the realization of the experiment. The sludge, which was added at various doses, was taken from Central Spiš area from locality of Rudňany near the village where minedironore that contains mainly cooper and mercury during last few decades was. We used three types of cereals: barley (Hordeum sativum L.) variety PRESTIGE, spring wheat (Triticum aestivum L.) variety ISJARISSA and oat (Avena sativa L.) variety TATRAN. The length of growing season was 90 days. From the obtained results of two years can be concluded that the accumulation of cooper by seed follows barley ˂ oat ˂ wheat. Even though that the barley is characterized by the highest accumulation of cooper in the seeds, the content did not exceed the maximum level specified by The Codex Alimentarius of the Slovak Republic (CA SR). The results shows that the suitable cultivation of the cereals in localities, which are contaminated with heavy metals, especially by cooper, that the high content of cooper in soil do not pose a risk of accumulation of the metal into the cereal grain.

Keywords: Groundwater, quality, nitrates, city of Nitra RESULTS AND DISCUSSIONWe collected monthly and define the content of nitrate (NO3 -) in groundwater samples from their individual sources in the period 2012 -2013. The results were processed by the figure 1 and 2, which show that:The content of nitrates (NO3 -) were assessed in the period 2012 -2013 in samples taken from individual groundwater sources (Svorad´s spring, Puškin´s spring, spring on Pivoňková street, spring on Mriánska dolina, spring Šindolka and spring Buganka) in the administrative area of Nitra and Zobor , also used for human consumption. The content of NO 3were assessed by Photocolorimetric method. We also evaluate the results achieved in relation to the current legislation of the area. From the result of the performed analyzes during the whole period shows that the average concentration of NO3represented in samples of water from the source Svorad´s spring 12,1 mg.dm -3 , Puškin´s spring 14,6 mg.dm -3 , from spring St. Martina 117,0 mg.dm -3 , from spring on Pivoňkova street 6,4 mg.dm -3 , from spring Šindolka 39,5 mg.dm -3 and spring Buganka 101,7 mg.dm -3 . The nitrate concentration exceeded the limit value in 16 % of cases in 2012 and it was 17 % of cases in 2013. Based on the measured values, therefore we do not recommend to use the water for human consumption from springs Buganka and St. Martina at the endpoint. ARTICLE INFO