Normalization and Trace Element Contamination of Soils in a Karstic Polje - An Example from the Sinjsko Polje, Croatia

Estimation of the anthropogenic over natural contribution in the chemical content of soils and sediments is very important but not easy to measure. Normalization based on either aluminium or iron, as reference conservative elements having supposed natural distributions, is a useful tool in solving this problem. However, several independent factors can influence the normalization procedure, which if not taken into account could lead to completely erroneous conclusions about the origin of the particular elevated concentrations of certain elements. Therefore, a great deal of caution should be exercised during application of the normalization procedure. Analytical data from 95 soil samples from the Sinjsko polje enabled us to critically apply this procedure. Linear regression analysis, evaluation of enrichment factors and trend surface analysis with the construction of appropriate maps were used to test the procedure. Presuming an existing linear dependence between the conservative element and the heavy metal it is possible with the use of linear regression to simultaneously define the heavy metal geochemical background (baseline) and to isolate natural and/or anthropogenic outliers (anomalies). Coupled with geographic plotting facilities this type of outlier-screening is used to locate areas of man made pollution. Statistical treatment of selected elements included the calculation of means, standard deviations and other estimates of basic statistic parameters. Evaluation of enrichment factors reveals the dependence of this parameter upon four main factors: the choice of reference element; the choice of reference material; the homogeneity of reference element distribution in the study area; and correlation of particular element with reference element. Examination of trends is a common procedure in the analysis of geochemical maps. Its purpose is to segregate the underlying trend that possibly pervades the study area, from the local variations, that is, the “noise” or “background”. Statistical analysis, as suggested by the results in this work, would be more properly used over general areas in the karstic terrain, with different geological, geomorphologic and hydrogeological characteristics, rather than being focused on the relatively small phenomena such as poljes, with many local geologic, hydrogeological and geochemical constraints

Impressions of the Biota Associated With Waterfalls and Cascades from a Holocene Tufa in the Zrmanja River Canyon, Croatia

The following types of calcified deposits characterize Holocene waterfall tufas in the Zrmanja river: mossy deposits, algally laminated crusts and algally coated grains. Petrological examination revealed, that abundant organic remains belonging to mosses and algae provide supporting material, over which tufa accretion takes place, leaving well-defined impressions of the biota. Postgenetic features like meniscus, isopachous and drusy mosaic calcite spar cementation, as well as aggradational neomorphism are only rarely present

Biocorrosion Behavior of High Noble Au-Pt Dental Alloy in Different Solutions and pH Values

Korozijska stabilnost i biokompatibilnost najvažniji su čimbenici za upotrebu neke slitine u ustima. Svrha ovoga rada bila je analizirati otpuštanje metalnih iona iz visoko plemenite zlatno-platinske (Au/Pt) slitine u različite otopine koje oponašaju različite uvjete u usnoj šupljini. Zlatno-platinska (Au/Pt) slitina bila je in vitro izložena otopini koja oponaša slinu (Saliva; fosfatni pufer pH 6.0), u jako kiselome mediju koji oponaša ekstremne uvjete u usnoj šupljini (Ekstrem; fosfatni pufer pH 3.5) i u mliječnoj kiselini pri pH 3,5 što oponaša uvjete ispod dentobakterijskoga plaka (Plak, mliječna kiselina pH 3.5). Po 6 uzoraka tvorničke slitine bilo je uronjeno u slinu, ekstrem i plak 1, 2, 3, 4, 5, 6, 7, 14, 21 i 30 dana. Otopine su analizirane na 15 metalnih iona s pomoću ICP-AES. Rezultati pokazuju da je otpuštanje iona Zn, Cu, Fe i Cr ovisno o vremenu izloženosti i o vrsti otopine i njezina pH (ANOVA, p<0.01 za vrstu otopine, vrijeme ekspozicije i interakcijske uporedbe). Krom i željezo nisu bili deklarirani u Au/Pt slitini, a pronađeni su u otopinama. Nedeklarirani ioni (npr. Cr) vjerojatno mogu biti uzrokom alergija koje se pripisuju zlatu.Corrosion stability and biocompatibility are basic factors for oral use of dental alloys. The aim of this study was to analyse the release of metal ions from Gold/platinum (Au/Pt) dental alloy in the different conditions that may be found in the oral cavity.Gold/platinum (Au/Pt) dental alloy was exposed in vitro to either simulated saliva (Saliva; phosphate buffer pH 6.0), highly acidic medium resembling the extreme conditions in the oral cavity (Acid; phosphate buffer pH 3.5), and in lactic acid at pH which occurs under the dental plaque (Plaque, lactic acid pH 3.5). The alloy was immersed in the Saliva, Acid, and Plaque solution for 1, 2, 3, 4, 5, 6, 7, 14, 21, and 30 days. The solution was analyzed for fifteen metals with the ICP-AES. The results revealed time and solution dependent leaching of Zn, Cu, Fe, and Cr (ANOVA, p<0.01 for solution, time, and interaction comparison). Chromium and iron were not declared in the Au/Pt dental alloy. Undeclared ions (eg. Cr) may be responsible for the allergy attributed to gold

Some Problems of the Radiometric Mapping of Carbonate Terrains - An Example From Istria (Croatia)

The gamma dose rates were calculated from the results of gamma-spectrometric measurements of radionuclide concentrations in soils in the region of the Istrian peninsula, Croatia. Calculated gamma dose rate conversion factors (GDRCF) for external exposure above ground, give external dose rates per unit of natural radionuclide concentration in the soil and bedrock. GDRCF in air at a height of 100 cm above ground are tabulated for 40K, 232Th decay series, 238U - 230Th subseries and 226Ra - 210Pb subseries for various source depths in soil or bedrock up to a maximum depth of 120 cm. The radiometric maps must take into consideration gamma doses from soils as well as from underlying rocks in the first metre of ground profile. This is of crucial importance especially for carbonate terrains, where the differences between natural radionuclide concentrations in carbonate derived soils and carbonate bedrock could be of two orders of magnitude. Furthermore, for soils themselves the role of the drainage network in migration processes is undoubtedly very important. All these dependencies make us believe that gamma-spectrometric measurements and related dose rate conversions in connection with in situ dose measurements could be the best method for radiometric mapping at least for carbonate terrains with numerous rock outcrops, poor drainage and lithological variability on a local scale. Recalculation of natural background dose rate data, collected by airborne or carborne surveys, into radionuclide concentration in the ground in carbonate terrains is possible in two cases only: when soil is completely absent or where soils are well developed (thicknesses of 25 cm or more)

Raspodjela elemenata u tragovima u površinskim sedimentima Vranskog jezera i tlima otoka Cresa

This paper presents a study of major and trace element distribution and an evaluation of their environmental geochemical aspects in the surface sediments of Vrana Lake and the topsoil within its catchment area. The concentrations of 22 elements were determined in 30 lake sediment samples and 60 topsoil samples covering the lake catchment area and the whole island of Cres. The element to Al ratios fall into three main groups: the group of elements that show no difference in ratios in soils and lake sediments: Ni, Co, Mn, Th, Zn, Ba, Ti, K, V, Na, and H; elements that are enriched in the sediments: Ca, Sr, Cd, Pb, Ba and Mg; and elements that are depleted in the lake sediments: Cu, P, Fe, Cr, and La. Long-range air pollution is probably the main reason why the content of metals, especially lead, is increased in the lake sediments, although a local source, from road transport, as indicated by soil data from the catchment area, could also be an important source of Pb. Some pollutants in the soils of the catchment area, such as Cu and Hg from agro-chemical sources, were not determined in elevated concentrations in the lake sediments. Comparison of element/Al indexes from this study with the other studies of surface materials in the region show mutually similar sources, with loess and flysch as two geochemical end-members.U radu se daje pregled raspodjele glavnih elemenata i onih u tragovima u površinskim sedimentima Vranskog jezera i tlima na otoku Cresu, te se na temelju izra|enih analiza daje pregled mogućih geokemijskih promjena u okolišu. Određene su koncentracije 22 elementa u 30 uzoraka jezerskog sedimenta i 60 uzoraka tla koje pokriva slivno područje jezera i otoka Cresa. Na temelju omjera pojedinih elemenata i aluminija utvrđene su tri geokemijske grupe elemenata; prvu grupu čine elementi koji ne pokazuju razliku u omjerima element/Al u tlima i sedimentima: Ni, Co, Mn, Th, Zn, Ba, Ti, K, V, Na i H; elementi koji pokazuju obogaćenje u sedimentima: Ca, Sr, Cd, Pb, Ba i Mg, te grupa elemenata koja je obogaćena u tlima; Cu, P, Fe, Cr i La. Povišene koncentracije olova u jezerskim sedimentima moguće je tumačiti kao posljedicu atmosferskog taloženja iz udaljenih industrijskih izvora a koncentracije utvrđene u tlima, na lokacijama na širem području prometnice koja prolazi istočnom stranom slivnog područja jezera, upućuju i na mogućnost lokalnog utjecaja automobilskog prometa. Neki potencijalno toksični elementi (Hg i Cu) koji su utvrđeni u povišenim koncentracijama u tlima slivnog područja, nisu utvrđeni kao povišeni u samom jezerskom sedimentu. Usporedbom omjera element/Al dobivenih u ovom radu sa rezultatima istraživanja površinskih materijala drugih autora sa šireg područja pokazuju da detritični materijal potječe iz istih izvora sa lesom i naslagama fliša kao dva krajnja geokemijska člana

Trace Element (TE) Release from Two Different Base Alloys Unde Conditions Imitating Oral Saliva

Electrochemical conditions in the oral cavity lead to a release of metal ions into the patient\u27s saliva. The aim of this study was to examine and compare the types andquantities of metal ions released from two base alloys: Co-Cr-Mo alloy (WironitR, Bego, Germany) and Ni-Cr alloy (Wiron 99, Bego, Germany) under in vitro conditions imitating artificial saliva. We soaked ten sets of each alloy having 497 mm2 exposure surface for 1, 2, 3, 4, 5, 6, 7, 14, 21 and 30 days (six pieces each set) in phosphate buffered saline (pH 6.0). TE in the phosphate buffered saline (saliva) were assessed by ICP-AES (JY 50P, Jobin-Ywon, France) with the detection limit of 10 mg/L. We found detectable amounts (mg/L) of TE (Mean SD) released from Co-Cr-Mo alloy (Mean SD): Co 337 (170), Fe 21 (15) Zn 87 (56), Ni 41 (68), and Cr 49 (42) and detectable amounts of TE released from Ni-Cr alloy (Mean SD): Co 265 (300), Fe 247 (256) Zn 92 (46), Ni 542 (668), and Cr 396 (410). The manufacturer did not indicate the presence of Fe, Zn, and Ni in the Co-Cr-Mo alloy and the presence of Fe, Co and Zn, in the Ni-Cr alloy. A significantly higher amount of Fe, Ni and Cr was released from Ni-Cr alloy (p<0.05), and a considerably higher amount of Co was released from Co-Cr-Mo alloy, although it did not reach a statistically significant level (p>0.05), while there was no significant difference between the two alloys for Fe ion release (p>0.05). We must keep in mind that the amount of the released TE may be much higher than the reported values in this study, after the laboratory procedures (casting, polishing, etc.) and allergenic essential TE Cr, Co, and Ni may be present locally in a considerably higher amount

Mal de Meleda: A Report of Two Cases In One Family

Mal de Meleda is a rare autosomal recessive skin disorder, characterized by transgressive palmoplantar keratoderma, lichenoid skin lesions, perioral erythema, brachydactyly and nail abnormalities. We are reporting two cases of a clinically typical disease in a family. No consanguineous relationship between the parents was known and cases could not be detected in three generations of the patient's family