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This work focuses on the heavy metals contents of the size-segregated urban aerosol of the continental area of Balkans. The distribution of nano/micron heavy metals in the size-segregated urban aerosol of Belgrade center was studied during the summer–autumn of 2008. The particle size distribution in the size ranges Dp ≤ 0.49 μm, 0.49 ≤ Dp ≤ 0.95 μm, 0.95 ≤ Dp ≤ 1.5 μm, 1.5 ≤ Dp ≤ 3.0 μm, 3.0 ≤ Dp ≤ 7.2 μm and Dp ≥ 7.2 μm was measured. The aerosol samples were submitted to gravimetric and chemical analyses. The obtained mean mass concentration of the PM fractions was in accordance with an urban aerosol distribution. The aerosol mass concentrations were determined by gravimetric measurements (mGM) and, for heavy metals analyzed by ICP/MS.

We use conventional, microwave and ultrasound assisted sequential extraction, of defined time and power, techniques for extractions of Cd, Cu, Cr, Ni, Pb and Zn in sediments and certified material. We did not change the conditions of extractions through steps, cause we what to see is there difference in extraction results for the certified material and sediments. We use lower powers and time from microwave and ultrasound extraction in order to avoid additional heating and boiling of the samples. Steps 1–3 of the BCR (Community Bureau of Reference), excluding the hydrogen peroxide digestion in step 3, were completed in 16 h in the conventional, in 120 s with 90 W power of microwave and in 30 min of 42 kHz of an ultrasonic frequency. Digestion of organic matter with hydrogen peroxide was performed the same for all techniques. The fourth step, the pseudo-total content, was performed the same on samples remaining after performing the extraction of the previous three phases either conventionally, microwave-assisted or with ultrasound. The precision and accuracy of the proposed procedures were evaluated using a certified reference material BCR701. Acceptable accuracy for most of the metals was observed for all three steps of BCR protocol applying a 16 h total shaking period. Metals were determined with an acceptable accuracy after the pseudo-total step; expect Cr. Results obtained after the application of different techniques on sediments were comparable with ANOVA test for the 95 % of confidence level.

The accumulation of potentially toxic elements (PTEs) in agricultural soils and their subsequent uptake by plants, posing risks to agricultural products and con­sumers is of particular concern for investigation. Vineyard soils are especially vulnerable to pollution from various sources, including agrochemicals, fertilizers and surrounding polluting activities. This research is based on the BCR sequential extraction method to assess PTE speciation in vineyard soil samples. Additionally, it investigates the bioaccumulation of PTEs in grapevines (Cabernet sauvignon and Sauvignon blanc) and evaluates potential health risks for consumers of grapevine products based on each investigated PTE. The find­ings reveal that certain PTEs, Cd, Mn, Ba, Co, Pb and Cu exhibit significant mobility and bioavailability in vineyard soils, emphasizing the importance of continuous monitoring for food safety. The bioaccumulation potential, based on calculated biological accumulation concentration (BAC), exists for some elements, especially for Cu and Zn from easily avail­able soil phase. The human health risk assessment indicates that the consumption of grape­vine products poses minimal risk (HQ < 1) to consumers. Anyhow, among the investigated PTEs, Ba and Cu have the highest HQs. This research contributes to a better understanding of PTE dynamics in vineyard environments, emphasizing the need for ongoing monitoring and control measures to ensure agricultural product safety and protect consumers’ health.

Presented research aimed to develop an alternative approach for the estimation of biosorption capability of sunflower husk. The acid-pretreated sunflower biomass was characterized by scanning electron microscopy combined with energy dispersive X-Ray spectroscopy (SEM-EDX) analysis and Fourier transform infrared (FTIR) spectroscopy. Biosorption efficiency has been evaluated using inductively coupled plasma optical emission spectroscopy (ICP-OES) and laser-induced breakdown spectroscopy (LIBS). The adsorption capacity of the adsorbent was determined as the function of the pH of the solution, the initial concentration of heavy metal solutions, and contact time. The optimal conditions were achieved after 15 min of contact at pH 6, while the percentage of the removal was from 80.0–98.7 %, depending on the element. The results obtained from the kinetic and isotherm studies show that maximum adsorption of ions was quickly reached and followed the pseudo-second-order kinetic model. Real samples were tested and obtained Ni values by LIBS method were 3100±200 and 1240±100 mg kg-1, while estimated values by the ICP-OES were 2995±20 and 1130±10 mg kg-1, respectively. The obtained results prove that LIBS method can be used as a “green alternative” for the evaluation of biosorption efficiency.

In order to further define the potential use of FTIR-ATR spectroscopy, as a non-destructive and reliable technique, for the analysis of the characteristics of post stamps, certified originals of the Principality of Serbia stamps (“Prince Michael issues”) issued in 1866 and 1868 as well as their forgeries were analyzed. Spectra enabling the comparison of the paper, dye and glue of stamps of so-called “Vienna issues”, having denominations of 10 (orange-yellow), 20 (pink) and 40 para (blue) and “Belgrade issues” (1 para-green and 2 para-reddish brown), as well as 24 expert-certified forgeries, were taken. It was shown that the applied technology was, in most of the cases, a fast and suitable technique for establishing clear differences between the spectral characteristics of the paper and dye used for the original stamps, and forgeries that were most probably made decades after the printing of the genuine stamps. The differences between printings of the same issues of the genuine stamps were also elaborated. It is proposed, for the first time in philatelic history, the possibility that “Vienna issues” stamps may have been printed on two different papers, and, having in mind the technology of printing in the 19th century, potentially, not even at the same time or in the same printing house.

This work presents characteristics of atmospheric aerosols of urban central Balkans area, using a size-segregated aerosol sampling method, calculation of mass distributions, SEM/EDX characterization, and ICP/MS analysis. Three types of mass distributions were observed: distribution with a pronounced domination of coarse mode, bimodal distribution, and distribution with minimum at 1 μm describing the urban aerosol. SEM/EDX analyses have shown morphological difference and variation in the content of elements in samples. EDX spectra demonstrate that particles generally contain the following elements: Al, Ca, K, Fe, Mg, Ni, K, Si, S. Additionally, the presence of As, Br, Sn, and Zn found in air masses from southeast segment points out the anthropogenic activities most probably from mining activities in southeastern part of Serbia. The ratio Al/Si equivalent to the ratio of desert dust was associated with air masses coming from southeastern and southwestern segments, pointing to influences from North Africa and Middle East desert areas whereas the Al/Si ratio in other samples is significantly lower. In several samples, we found high values of aluminum in the nucleation mode. Samples with low share of crustal elements in the coarse mode are collected when Mediterranean air masses prevailed, while high share in the coarse mode was associated with continental air masses that could be one of the approaches for identification of the aerosol origin. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The association patterns of xylene and of total phosphorus with sediment constituents in an alluvial aquifer consisting of clays and sands which had been contaminated by a spill of technical grade xylene were investigated with the aim of assessing the dependence of in situ xylene degradation on the P-availability. The investigated alluvial sediments of the Makiš Plain (Sava river alluvion, Quaternary age, Serbia and Montenegro) are relatively poor in P. The most reliable associations were proposed by analyzing the quality of the correlations of xylene- and of P-contents with 32 sediment characteristics. The association patterns depend on the mineralogical and granulometrical composition of sediments, the structural characteristics of the organicmatter (N/C-ratio) and the redox-conditions. Differing association patterns in the clays and the sand had been developed, and these characteristics influence the intrinsic xylene degradation. The main proof for the occurrence of xylene degradation is the percentul share of bacteria which oxidize xylene as a single carbon-source.

Aim: To compare e-professionalism perceptions between medical and dental students, focusing on their awareness and understanding of guidelines for developing e-professionalism., Methods: A cross-sectional quantitative study was conducted at the University of Zagreb School of Medicine (UZSM) and School of Dental Medicine (UZSDM) in 2022/2023. Data were gathered through a questionnaire designed specifically for the survey., Results: Of the 646 questionnaires collected, 626 were analyzed, with a response rate of 33.95% for UZSM and 37.83% for UZSDM. Most respondents (71.4%) were female, with a median age of 21. Medical students significantly more frequently considered it unprofessional to publish posts containing photos of patients/clients (96.5% vs 75.1%), endorsements of health products without conflict-of-interest disclosures (60.6% vs 33.0%), and posts describing patient interactions without revealing identifying information (51.7% vs 27.4%). In contrast, dental medicine students more frequently considered it unprofessional to publish posts with swearing or foul language (81.2% vs 67.4%), critical comments about lecturers (68.0% vs 46.9%), and criticisms of course material or the institution (52.3% vs 36.4%). Only 23.2% of students were aware of e-professionalism guidelines, with 37.9% of those familiar with their content., Conclusion: While medical and dental students recognize the importance of e-professionalism, their perceptions have substantial differences. The need for promoting existing guidelines and integrating e-professionalism into curricula is evident. Continuous monitoring and research in this domain are essential to ensure future health care professionals maintain high standards of online professionalism.

The recognition of certain herbicides as endocrine disrupting compounds has raised concerns due to their ability to interfere with the normal functioning of the endocrine system, which regulates various physiological processes in organisms. The objective of this study was to assess the possible human health risks associated with terbuthylazine and endocrine-disrupting herbicides atrazine, acetochlor, and metolachlor in the drinking, surface, and groundwater of the Zagreb city region, Croatia. We relied on advanced statistical methods and principal component analysis (PCA), which revealed higher levels of atrazine and acetochlor in drinking and groundwater samples and higher presence of metolachlor and terbuthylazine in surface waters. To evaluate the danger to human health, various exposure scenarios have been assessed. The risk of direct human exposure to analyzed herbicides through drinking or bathing with drinking (tap) or groundwater, as well as from recreational activities like swimming in rivers, streams, and lakes, has been quantified. In addition to these direct exposure scenarios, indirect ones based on consumer goods, fruits, and vegetables, treated with surface and groundwater for irrigation, were assessed to investigate the danger to human health. Judging by the reported herbicide levels there was no significant risk of carcinogenic (CR ≤ 1 × 10 -6 ) or non-carcinogenic (HI < 1) diseases, not even when we assessed the so-called "cocktail effect" of combined the herbicide exposure in different waters., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This review article summarizes our research of persistent organic pollutants (POPs) in human milk from Croatian mothers over the last few decades. Our studies make up the bulk of all POPs research in human milk in Croatia and show a state-of-the art in the research area. The first investigations were made in 1970's. Aim of our review article is to document the comprehensive results over several decades as the best tool to: 1.) contribute to understanding of POPs and their potential health risks, 2.) evaluate effectiveness of legislative bans and restrictions on human exposure to POPs in Croatia, and 3.) to suggest further actions. In our review we discuss: 1.) Human milk between 2011 and 2014 - evaluation of interrelations of organochlorine pesticides (OCP) and polychlorinated biphenyls (PCB) in human milk and their association with the mother's age and parity using artificial intelligence methods; and our yet unpublished research data on health risks for infants assessed through daily PCB and OCP intake. 2.) Time trends of PCB and OCP in human milk between 1976 and 2014. 3.) polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofuran (PCDD/F) in human milk in 2000., and yet unpublished data on PCDD/F and polybrominated diphenyl ethers (PBDE) in 2014., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

(1) Background: An increasing use of pharmaceutics imposes a need for the permanent development of efficient strategies, including the tailoring of highly specific new materials for their removal from the environment. Photocatalytic degradation has been the subject of increasing interest of the researchers in the field. (2) Methods: This paper is focused on the investigation of the possibility to deposit a thin metal layer on a TiO 2 surface and study its photocatalytic performance for the degradation of ciprofloxacin using a combination of theoretical and experimental methods. (3) Results: Based on the extensive DFT screening of 24 d-metals' adhesion on TiO 2 , Cu was selected for further work, due to the satisfactory expected stability and good availability. The (Cu)TiO 2 was successfully synthesized and characterized with XRD, SEM+EDS and UV-Vis spectrophotometry. The uniformly distributed copper on the TiO 2 surface corresponds to the binding on high-affinity oxygen-rich sites, as proposed with DFT calculations. The photocatalytic degradation rate of ciprofloxacin was improved by about a factor of 1.5 compared to the bare non-modified TiO 2 . (4) Conclusions: The observed result was ascribed to the ability of adsorbed Cu to impede the agglomeration of TiO 2 and increase the active catalytic area, and bandgap narrowing predicted with DFT calculations.

The concentration of magnetic particulate matter (PM) on the leaf surface (an indicator of current pollution) and topsoil (an indicator of magnetic PMs which have geogenic natural signal or historical pollution origin) was assessed in agricultural areas (conventional and organic vineyards). The main aim of this study was to explore whether magnetic parameters such as saturation isothermal remanent magnetization (SIRM) and mass-specific magnetic susceptibility (χ) can be a proxy for magnetic particulate matter (PM) pollution and associated potentially toxic elements (PTEs) in agricultural areas. Besides, wavelength dispersive X-ray fluorescence spectroscopy (WD-XRF) was investigated as a screening method for total PTE content in soil and leaf samples. Both magnetic parameters (SIRM and χ) pinpoint soil pollution, while SIRM was more suitable for evaluating magnetic PM accumulated on leaves. The values of both magnetic parameters were significantly (p < 0.01) correlated within the same type of sample (soil-soil or leaf-leaf), but not between different matrixes (soil-leaf). Differences between magnetic particles' grain sizes among vegetation seasons in vineyards were obtained by observing the SIRM/χ ratio. WD-XRF was revealed to be an appropriate screening method for soil and leaf total element contents in agricultural ambient. For a more precise application of WD-XRF leaf measurements, specific calibration using a similar matrix to plant material is required. In parallel, measurements of SIRM, χ, and element content (by WD-XRF) can be recommended as user-friendly, fast, and eco-sustainable techniques for determining magnetic PM and PTE pollution hotspots in agricultural ambient., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

This study assesses heavy metal content in soil, water, and plant material from sites located around the lignite mine and the power plant "Gacko", Bosnia and Herzegovina. The samples were collected, prepared, and analyzed for heavy metals content using the flame atomic absorption spectrophotometer. Samples were analyzed for cadmium, lead, copper, zinc, manganese, and iron. To identify the relationship among the metals in samples and their possible sources, Pearson's correlation and principal component analysis were performed. Health risk assessment was applied to establish potential health risks posed to humans caused by contaminants in different environmental compartments. The results of our analyses show that most soil samples contain copper, and one of those samples had a copper concentration of more than 70 µg/g, which is a critical upper value for agricultural use. In the soil samples that were analyzed, cadmium was also detected, and its concentration was greater than 2 µg/g. Lead, on the other hand, had a concentration that was higher than the maximum permissible for unpolluted soils in 40% of the soil samples that were analyzed. Lead and cadmium concentrations in surface waters mostly contribute to a non-carcinogenic risk in the scenario of recreational swimming exposure. The presence of Cd, a highly toxic element in water, may be explained by the leaching of artificial fertilizers used in the study area, whereas Pb's origin may be geological. The results of this study recommend routine heavy metal monitoring in samples of soil, water, and plants from the examined area so that, if metal concentrations continue increasing, remedial action should be advised to prevent accumulation in the food chain., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Social media presence among health care professionals is ubiquitous and largely beneficial for their personal and professional lives. New standards are forming in the context of e-professionalism, which are loosening the predefined older and offline terms. With these benefits also come dangers, with exposure to evaluation on all levels from peers, superiors, and the public, as witnessed in the #medbikini movement., Objective: The objectives of this study were to develop an improved coding scheme (SMePROF coding scheme) for the assessment of unprofessional behavior on Facebook of medical or dental students and faculty, compare reliability between coding schemes used in previous research and SMePROF coding scheme, compare gender-based differences for the assessment of the professional content on Facebook, validate the SMePROF coding scheme, and assess the level of and to characterize web-based professionalism on publicly available Facebook profiles of medical or dental students and faculty., Methods: A search was performed via a new Facebook account using a systematic probabilistic sample of students and faculty in the University of Zagreb School of Medicine and School of Dental Medicine. Each profile was subsequently assessed with regard to professionalism based on previously published criteria and compared using the SMePROF coding scheme developed for this study., Results: Intercoder reliability increased when the SMePROF coding scheme was used for the comparison of gender-based coding results. Results showed an increase in the gender-based agreement of the final codes for the category professionalism, from 85% in the first phase to 96.2% in the second phase. Final results of the second phase showed that there was almost no difference between female and male coders for coding potentially unprofessional content for students (7/240, 2.9% vs 5/203, 2.5%) or for coding unprofessional content for students (11/240, 4.6% vs 11/203, 5.4%). Comparison of definitive results between the first and second phases indicated an understanding of web-based professionalism, with unprofessional content being very low, both for students (9/222, 4.1% vs 12/206, 5.8%) and faculty (1/25, 4% vs 0/23, 0%). For assessment of the potentially unprofessional content, we observed a 4-fold decrease, using the SMePROF rubric, for students (26/222, 11.7% to 6/206, 2.9%) and a 5-fold decrease for faculty (6/25, 24% to 1/23, 4%)., Conclusions: SMePROF coding scheme for assessing professionalism of health-care professionals on Facebook is a validated and more objective instrument. This research emphasizes the role that context plays in the perception of unprofessional and potentially unprofessional content and provides insight into the existence of different sets of rules for web-based and offline interaction that marks behavior as unprofessional. The level of e-professionalism on Facebook profiles of medical or dental students and faculty available for public viewing has shown a high level of understanding of e-professionalism., (©Tea Vukušić Rukavina, Lovela Machala Poplašen, Marjeta Majer, Danko Relić, Joško Viskić, Marko Marelić. Originally published in JMIR Medical Education (https://mededu.jmir.org), 09.08.2022.)

Family physicians are burdened with a great number of guidelines considering different conditions they treat. We analyzed opinions of family physicians on electronic tools which help managing chronic conditions and their influence on patient care by cardiovascular disease (CVD) prevention guideline availability, usage and adherence. A descriptive study was performed on a convenient sample of 417 (response rate 56.0%) Croatian family physicians. Data on physician characteristics and availability, usage and adherence to CVD prevention guidelines were analyzed. The χ2-test was used for comparisons. Significance was defined as p<0.05. Family physicians who used additional electronic tools in Electronic Health Record software on more than 80% of their patients had CVD prevention guidelines more available (p<0.01) and used them more frequently (p<0.01). A group who used electronic tools on more than 80% of their patients had CVD prevention guidelines available to them frequently and used them on more than 60% of their patients, also strictly adhering to the guidelines (p<0.01). Physicians who used CVD prevention guidelines on more than 60% of their patients spent more time doing patient education (p=0.036). Using electronic tools helps Croatian family physicians in terms of availability, usage and adherence to the guidelines and quality improvement.

In the present work, we focused on two aspects of mercury (Hg) bioconcentration in the above-ground parts of Neoboletus luridiformis. In the first part, we monitored the bioconcentration potential of individual anatomical parts of a particular fruiting body and evaluated the obtained data by the spline interpolation method. In the second part, we focused on assessing the mercury content in 378 samples of N. luridiformis and associated samples of substrates from 38 localities with different levels of Hg content in Slovakia. From the obtained data of Hg content in samples of substrate and fungi, we evaluated ecological indicators (geoaccumulation index - Igeo, contamination factor - Cf a potential ecological risk - PER), bioconcentration indicators (bioconcentration factor - BCF; cap/stipe quotient - Qc/s) and health indicators (percentage of provisional tolerable weekly intake - %PTWI a target hazard quotient - THQ). Based on the Hg distribution results, the highest Hg content was found in the tubes & pores (3.86 mg/kg DW), followed by the flesh of cap (1.82 mg/kg DW). The lowest Hg content was in the stipe (1.23 mg/kg DW). The results of the BCF values indicate that the studied species can be included in the category of mercury accumulators. The results of the ecological indices representing the state of soil pollution pointed out that two localities (Malachov and Nižná Slaná) stood apart from all monitored localities and showed a state of an extremely disturbed environment. This fact was also reflected in the values of Hg content in the fruiting bodies of the studied mushroom species. In the case of the consumption of mushrooms from these localities, it can be stated that long-term and regular consumption could have a negative non-carcinogenic effect on the health of consumers. It was confirmed by the %PTWI (Malachov: 57.8%; Nižná Slaná: 53.2%) and THQ (Malachov: 1.11 Nižná Slaná: 1.02). The locality Čačín-Jelšovec is interesting from the bioconcentration characteristics point of view, where the level of environmental pollution was the lowest (Hg content in the soil was below the background value) compared to other localities, however, the THQ value was the highest (1.29)., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Benefits and risks of the fish consumption should be assessed to balance the ingestion of healthy omega-3 fatty acids and adverse chemicals. Persistent organic pollutants-POPs (organochlorine pesticides-OCPs and polychlorinated biphenyls-PCB), macro- and micro-elements and fatty acid contents were determined in six fish species from the Adriatic Sea to assess health risks for consumers (worst-case scenario, diseases development risks and benefit-risk). 16 element, 24 POPs and 14 fatty acid contents were determined in six pelagic species which can be used in human diet. Element concentrations were determined by inductively coupled plasma mass spectrometry (ICP-MS), POPs by high-resolution gas chromatography and fatty acid content by gas-liquid chromatography. Diet based on chub mackerel and round sardinella showed lower daily intake (DI) of POPs and highest DI of essential omega-3 fatty acids than other investigated species. Lower ingestion of toxic elements can be observed by consuming anchovy and round sardinella. Based on POP concentrations, there was not observed non-carcinogenic (HI) nor carcinogenic (CR) risks for consumers. Based on element concentrations, there was low HI (0.1 ≥ HI ≥ 1), while the maximum HIs and outlier values (horse mackerel and anchovy samples) implied the presence of HI (HI > 1). The most significant contributor to total non-carcinogenic and carcinogenic risks was inorganic arsenic (inorganic As). Acceptable CR for consumers was assessed, but maximum CR for consumers of horse mackerel and anchovy (CR ≥ 1 × 10-6) showed adverse effects on human health. There were low HIs for developing cardiovascular, nervous, and reproductive diseases, and maximum HIs were higher than 1. Acceptable (1 × 10 -4 ≥CR ≥ 1 × 10 -6 ) risks were observed for developing cancer of nervous system and reproductive organs. Among investigated fish samples, those with higher ƩBR (benefit-risks) and BR for arsenic (As) than median value have a higher risk than benefits in the human diet., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Aim: To describe and compare social media (SM) use habits, and attitudes of medical and dental students toward e-professionalism and to determine their opinion on potentially unprofessional behavior and posts., Methods: In this quantitative cross-sectional questionnaire study, students of the University of Zagreb School of Medicine and those of the School of Dental Medicine completed a survey-specific questionnaire on the use of SM, SM habits, and attitudes toward e-professionalism., Results: Of the 714 collected questionnaires, we analyzed 698 (411 from medical and 287 from dental students). The most commonly used SM were Facebook (99%) and Instagram (80.7%). Unprofessional content was recognized by both groups. Medical students significantly more frequently considered the posts containing patient photos (61% vs 89.8%; P<0.001), describing interaction with a patient not revealing any personal identifiable information (23% vs 41.8%; P<0.001), and containing critical comments about faculty (53% vs 39.7%; P=0.001) to be unprofessional. Dental medicine students were significantly more open to communication through SM (39.7% vs 16.3%; P<0.001), more often reported that they would accept (41.5% vs 12.2%; P<0.001), and had accepted (28.2% vs 5.6%; P<0.001) friend requests/follows/tracks from patients, and sent friend requests/follows/tracks to their patients (5.2% vs 1.2%; P=0.002)., Conclusion: Both groups were highly aware of e-professionalism. Dental students were more desensitized to visual representations of patients, and more prone to SM interactions with patients, which might expose them to the risk of unprofessional behavior.

Background: As we are witnessing the evolution of social media (SM) use worldwide among the general population, the popularity of SM has also been embraced by health care professionals (HCPs). In the context of SM evolution and exponential growth of users, this scoping review summarizes recent findings of the e-professionalism of HCPs., Objective: The purpose of this scoping review is to characterize the recent original peer-reviewed research studies published between November 1, 2014, to December 31, 2020, on e-professionalism of HCPs; to assess the quality of the methodologies and approaches used; to explore the impact of SM on e-professionalism of HCPs; to recognize the benefits and dangers of SM; and to provide insights to guide future research in this area., Methods: A search of the literature published from November 1, 2014, to December 31, 2020, was performed in January 2021 using 3 databases (PubMed, CINAHL, and Scopus). The searches were conducted using the following defined search terms: "professionalism" AND "social media" OR "social networks" OR "Internet" OR "Facebook" OR "Twitter" OR "Instagram" OR "TikTok." The search strategy was limited to studies published in English. This scoping review follows the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) guidelines., Results: Of the 1632 retrieved papers, a total of 88 studies were finally included in this review. Overall, the quality of the studies was satisfactory. Participants in the reviewed studies were from diverse health care professions. Medical health professionals were involved in about three-quarters of the studies. Three key benefits of SM on e-professionalism of HCPs were identified: (1) professional networking and collaboration, (2) professional education and training, and (3) patient education and health promotion. For the selected studies, there were five recognized dangers of SM on e-professionalism of HCPs: (1) loosening accountability, (2) compromising confidentiality, (3) blurred professional boundaries, (4) depiction of unprofessional behavior, and (5) legal issues and disciplinary consequences. This scoping review also recognizes recommendations for changes in educational curricula regarding e-professionalism as opportunities for improvement and barriers that influence HCPs use of SM in the context of e-professionalism., Conclusions: Findings in the reviewed studies indicate the existence of both benefits and dangers of SM on e-professionalism of HCPs. Even though there are some barriers recognized, this review has highlighted existing recommendations for including e-professionalism in the educational curricula of HCPs. Based on all evidence provided, this review provided new insights and guides for future research on this area. There is a clear need for robust research to investigate new emerging SM platforms, the efficiency of guidelines and educational interventions, and the specifics of each profession regarding their SM potential and use., (©Tea Vukušić Rukavina, Joško Viskić, Lovela Machala Poplašen, Danko Relić, Marko Marelić, Drazen Jokic, Kristijan Sedak. Originally published in the Journal of Medical Internet Research (https://www.jmir.org), 17.11.2021.)

Background: Social media permeated everyday life and consequently it brought some changes to behaviour of health professionals. New form of professionalism emerged called e-professionalism depicting professional behaviour while using social media. There are a number of studies conducted in the past several years measuring behaviour of different populations of health professionals on social media and social media sites. Many studies have investigated aspects of e-professionalism of medical or dental students as future health professionals, but there are no validated instruments made for assessing attitude towards e-professionalism of those two populations. Objective of this paper is to validate a newly developed scale for measuring attitudes towards e-professionalism among medical and dental students., Methods: The original 32-item scale was developed and administered to 411 medical students (RR 69%), and 287 dental students (RR 49.7%). Exploratory factor analysis was used to investigate the existence of underlying factors. Principal component analysis was used as an extraction method with oblimin as selected oblique rotation method. Cronbach's alpha was used to assess reliability., Results: Total of 698 student answers entered analysis. The final scale had 24 items that formed seven factors named: ethical aspects, dangers of social media, excluding physicians, freedom of choice, importance of professionalism, physicians in the digital age, negative consequences. Cronbach's alpha indicating scale reliability was .72. Reliability conducted on each factor ranged from .570 to .877., Conclusions: The scale measures seven factors of attitude towards e-professionalism and exhibits satisfactory reliability. Based on insights from validation, some possible improvements are suggested., (© 2021. The Author(s).)

This work investigates the release of toxic elements from wood into the experimental spirit models and the safety risks for consumers. The spirit models were prepared as ethanolic extracts using the procedure which reproduces maturation of spirits. Investigation included staves of wood species commonly used in Balkan cooperage: mulberry, Myrobalan plum, black locust, wild cherry, and various oaks. Potassium was the most abundant element, except in the wild cherry extract where calcium was dominant, and the Myrobalan plum extract where phosphorus was the most abundant. The parameters for the health risk assessment, such as hazard index (HI) and hazard quotient (HQ) were calculated for potentially toxic elements and indicated that all wood extracts would be safe for human consumption. Owing to the proven abundance of phenolics in the investigated wood extracts, relations among elements and phenolics were also studied and conclusions were made based on the statistically significant correlations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

This study was performed in organic vineyard to assess integrated pollution in soil-plant-air system by potentially toxic elements (PTE). Concentrations of 26 PTE were determined in soil, grapevine, and air biomonitors (moss bags) using ICP-OES and ICP-MS. Environmental implication assessment of soil did not show pollution by PTE, except for B in samples collected in the middle of grapevine season (July). Despite low total Cd concentrations in soil, it has the highest influence on increase of environmental risk. Based on biological accumulation concentration (BAC), grapevine is not hyperaccumulator of PTE from soil. Advanced classification algorithm, Kohonen self-organizing map (SOM), was applied to compare environmental implications in organic with conventional vineyards. PTE concentrations were significantly lower in organic than conventional grapevine. PTE concentrations were higher in the outer (leaf and petiole) than in the inner grapevine parts (skin, pulp, and seed). Some airborne elements have an influence on outer grapevine parts, especially on leaves (ratio factor-RF > 1). Moss bag technique testified about lower enrichment of airborne elements compared with the conventional vineyard and urban microenvironments. Environmental and health risk assessments confirmed that organic production is harmless for field workers and grape consumers.

Aim: To predict the future supply and age distribution of physicians with a simulation model, which can be used as an advising tool for policymakers who decide on enrollment and specialization training (ST) quotas at the national level., Methods: A simulation model was created using the system dynamics (SD) method. Changes in the number of physicians and their age distribution were projected in the context of the expected future changes of the Croatian population under different scenarios covering the period from 2017 to 2041., Results: The two scenarios showed that Croatia would not face physician shortage in the future. The scenario 1 projected that Croatia would certainly reach the current European Union (EU) average of 360 physicians per 100 000 inhabitants by 2021, and that this figure would increase to 430 per 100 000 inhabitants by 2041. The scenario 2 suggested a similar trend, with Croatia reaching the current EU average by 2021 and the number of physicians increasing to 451 per 100 000 inhabitants by 2041. Both scenarios indicated that the Croatian physicians' age distribution will recover in favor of younger age groups of specialists., Conclusion: There is no need to increase the enrollment into the medical schools to ensure sufficient number of physicians per capita in Croatia, but it is necessary to keep the recently reached level of 550 licenses for ST per year. The developed dynamic model is available online and can be adapted to the analysis of different scenarios in different health care systems.

We report a qualitative analysis of higher education biomedical informatics (BMI) teachers' opinions on the needs for BMI workforce and employment opportunities in the Croatian health care system. Needs were perceived as considerable; however this was not coupled with adequate employment opportunities. Barriers were identified to correcting this imbalance, including the failure of the health care system planners to recognise BMI experts as an important part of the workforce and lack of adequate educational opportunities.

The objective of this paper is to show how a simple but powerful simulation model can be build up using standard spreadsheet program and used to simulate future, needs and supply of physicians in order to inform policy makers at national level when deciding on enrollment to medical schools and immigration quotas for physicians. The Republic of Croatia is facing a serious shortage of physicians in the healthcare system and simulation results have shown that the gap between needs and supply will even increase if current enrollment qoutas to medical schools would persist. Increasing enrollment quotas, adjusting immigration policy, re-directing physicians from other professions to the healthcare system, task shift and skill mix options are just some of the measures needed to be taken promptly in order to prevent a huge deficit of physicians in the future. Simulation modeling is certainly a method for predicting changes within healthcare systems with a possibility to examine multiple different scenarios and suggest interventions.

The pollution state and health risk assessment of potentially toxic elements (PTE) in soil and sediment samples of the petrochemical industry and its surrounding area are evaluated in this study. The pseudo-total contents of Ba, Cd, Co, Cu, Cr, Mn, Ni, Pb, V, Zn, As, Hg, and Se were measured by inductively coupled plasma-optical emission spectrometry (ICP/OES) in analyzed samples. Instead of determining total content, we performed aqua regia of the samples. The silicate matrix remained, and the quantities of elements that are within the silicate matrix do not represent an environmental danger. The soils from the chlor-alkali plant are highly polluted by Hg (the enrichment factor values were above 6000), and by Cu, Cd, Pb, and Zn, while the sediment samples from the wastewater channel are polluted with Cr, Cd, and Hg. The measured element contents are used for calculating health risk criteria for a composite worker (a worker who is exposed, long-term, during the work day) and for residential people. Hg is the element that mainly contributes to non-carcinogenic risks within the petrochemical area. The highest value of total carcinogenic risk obtained in the sediment sample from the wastewater channel, and the metal that mostly contributes is Cr. The areas closest to the petrochemical industry have higher values of health risk criteria parameters and pollution indices. The areas that are located further to the north and south from the petrochemical industry are less burdened with the analyzed elements, which is significant because the closest city and village are situated in those directions.

An integrated approach to the investigation of potentially toxic elements (PTEs) was applied to the soil and grapevine leaf samples collected from vineyard environment through the grapevine season. To investigate mobile and bioavailable concentrations of PTEs, six single extraction procedures and pseudo-total digestion were applied to the samples. The element concentrations in the samples were measured using inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS). To assess atmospheric particle deposition, saturation isothermal remanent magnetisation (SIRM) was applied to the leaf samples. The obtained PTE concentrations in samples were used for calculating various ecological implications in the vineyard environment. The notable environmental pollution implications were estimated for As, B, Cd, Co, Cr, Cu, Mn, Ni and Sr. The environmental risk (RI) of the elements soluble under low-acid conditions influenced soil bioavailability risk. The most bioavailable elements from soil to leaves were Mn, Ni and Sr, followed by Cr and Cu. Cadmium and Co were strongly-bonded in the soil and were not bioavailable. The most suitable extractants for assessing bioavailability in the soil-leaf system were chelating agent Na 2 EDTA, and weak salt solutions CaCl 2 and NH 4 NO 3 . The biological accumulation concentrations (BACs) of B, Ba, Cd, Co, Ni and Zn were decreasing in the leaves through the grapevine growing phases, that is contributed to the decreasing agrochemical application through the season. The BACs of Co, Cr, Sb and Pb, in July (veraison), were higher than in other phases, which indicate anthropogenic activities. According to correlations between biogeochemical index (BGI) and BAC, Cu and Na were mostly bioaccumulated from soil to leaves due to agrochemical applications, while bioaccumulation of B, Cd, Sb and Sr could be influenced by the other anthropogenic sources. Significant correlations between PTE concentrations and SIRM imply that leaves indicate Co, Cr and Ni air pollution in the vineyard environment., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Monitoring of potentially toxic elements in agricultural soil represents the first measure of caution regarding food safety, while research into element bioavailability should be a step forward in understanding the element transportation chain. This study was conducted in the grapevine growing area ("Oplenac Wine Route") for investigating element bioavailability in the soil-grapevine system accompanied by an assessment of the ecological implications and human health risk. Single extraction procedures (CH 3 COOH, Na 2 EDTA, CaCl 2 , NH 4 NO 3 and deionised H 2 O) and digestion were performed to estimate the bioavailability of 22 elements (Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sb, Sr, V and Zn) from the topsoil (0-30 cm) and subsoil (30-60 cm) to the grapevine parts (leaf, skin, pulp and seed) and wine. The extractants were effective comparing to the pseudo-total concentrations in following order Na 2 EDTA ˃ CH 3 COOH ˃ NH 4 NO 3  ˃ CaCl 2 , H 2 O 2 h and 16 h. The most suitable extractants for assessing the bioavailability of the elements from the soil to the grapevine parts were CaCl 2 , NH 4 NO 3 and Na 2 EDTA, but deionised H 2 O could be suitable, as well. The results showed that Ba was the most bioavailable element in the soil-grapevine system. Contamination factor implied a moderate contamination (1 < CF < 3) of the soil. The concentrations of Cr, Ni and Cd in the soil were above the maximum allowed concentrations. According to the biological accumulation coefficient (BAC), the grape seeds and grapevine leaves mostly accumulated Cu and Zn from the soil, respectively. Based on ratio factor (RF > 1), the influence of atmospheric deposition on the aerial grapevine parts (leaves and grape skin) was observed. Nevertheless, low adverse health risk effects (HI < 1 and R ≤ 1 × 10 -6 ) were estimated for farmers and grape and wine consumers., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This study aims to compare three extraction techniques of four sequential element extraction steps from soil and sediment samples that were taken from the location of the Pančevo petrochemical industry (Serbia). Elements were extracted using three different techniques: conventional, microwave and ultrasound extraction. A novel procedure - sum of the ranking differences (SRD) - was able to rank the techniques and elements, to see whether this method is a suitable tool to reveal the similarities and dissimilarities in element extraction techniques, provided that a proper ranking reference is available. The concentrations of the following elements Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Si, Sn, Sr, V and Zn were determined through ICP OES. The different efficiencies and recovery values of element concentrations using each of the three extraction techniques were examined by the CRM BCR-701. By using SRD, we obtained a better separation between the different extraction techniques and steps when we rank their differences among the samples while lower separation was obtained according to analysed elements. Appling this method for ordering the elements could be useful for three purposes: (i) to find possible associations among the elements; (ii) to find possible elements that have outlier concentrations or (iii) detect differences in geochemical origin or behaviour of elements. Cross-validation of the SRD values in combination with cluster and principal component analysis revealed the same groups of extraction steps and techniques., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Lack of experts with complementary competences in the field of information technology as well as medicine and health care has been recognised as an important obstacle to successful computerisation of the health care system. Using a questionnaire survey, we aimed to describe the current educational landscape of biomedical informatics in Croatia, focussing on teachers' profiles and attitudes about existing educational opportunities in the field. Our findings show that Croatian institutions of higher education should better recognise the need for education in biomedical informatics. Dedicated programs need to be established and teacher force strengthened. Joint efforts of existing teachers-institutionalised through a working group focussing on education within the Croatian Society for Medical Informatics, for which strong support exists-might contribute to recognition of the field and improvement of educational opportunities.

Since the methodological parameters of moss bag biomonitoring have rarely been investigated for the application in agricultural areas, two mosses, Sphagnum girgensohnii (a species of the most recommended biomonitoring genus) and Hypnum cupressiforme (commonly available), were verified in a vineyard ambient. The moss bags were exposed along transects in six vineyard parcels during the grapevine season (March‒September 2015). To select an appropriate period for the reliable 'signal' of the element enrichment in the mosses, the bags were simultaneously exposed during five periods (3 × 2 months, 1 × 4 months, and 1 × 6 months). Assuming that vineyard is susceptible to contamination originated from different agricultural treatments, a wide range of elements (41) were determined in the moss and topsoil samples. The mosses were significantly enriched by the elements during the 2-month bag exposure which gradually increasing up to 6 months, but Cu and Ni exhibited the noticeable fluctuations during the grapevine season. However, the 6-month exposure of moss bags could be recommended for comparative studies among different vineyards because it reflects the ambient pollution comprising unpredictable treatments of grapevine applied during the whole season. Although higher element concentrations were determined in S. girgensohnii than H. cupressiforme, both species reflected the spatio-temporal changes in the ambient element content. Moreover, the significant correlation of the element (Cr, Cu, Sb, and Ti) concentrations between the mosses, and the same pairs of the elements correlated within the species, imply the comparable use of S. girgensohnii and H. cupressiforme in the vineyard (agricultural) ambient. Finally, both the moss bags and the soil analyses suggest that vineyard represents a dominant diffuse pollution source of As, Cr, Cu, Ni, Fe, and V., (Copyright © 2017 Elsevier Inc. All rights reserved.)

A different single extraction procedures (CH 3 COOH, Na 2 EDTA, CaCl 2 , NH 4 NO 3 , deionized water), and pseudo-total digestion (aqua regia) were applied to determine major (Al, Fe, K, Mn, Na, P, S, and Si) and trace (Cd, Co, Cr, Cu, Mo, Ni, Pb, V, and Zn) element bioavailability in a topsoil from the experimental vineyard ("Radmilovac", Belgrade, Serbia). For the first time, the extraction with deionized water during 16 h was tested as an alternative method for isolating bioavailable major and trace elements from the soil. Concentrations of the elements were determined by inductively coupled plasma - optical emission spectroscopy (ICP-OES). The extraction of Cu and S from the soil by deionized water during 16 h extracting, NH 4 NO 3 , and CaCl 2 indicated that these elements could originate from the anthropogenic sources, such as fungicide. In addition according to the soil - plant experiment, performed as a preliminary experiment for future studies in vineyards, deionized water was recommended for isolation of bioavailable elements from grape seed and grape pulp; CH 3 COOH, Na 2 EDTA, CaCl 2 and NH 4 NO 3 for grape skin, while for assessment of leaf bioavailable elements from soil fraction, aqua regia was recommended. In addition, identification of similarities between the plant parts and the plant species were performed. Applying environmental risk assessment formulas, the most polluted vineyard parcel in the vineyard region "Radmilovac" was determined. The leaves of some grapevine species showed the high ability for accumulation some of the potentially toxic trace elements from the soil., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Development of a model for simulation of the needed number of specialists of different specialties in the Republic of Croatia by the year 2035 based on the expected changes in size and age structure of population and experts' estimates of the needs. The model will be implemented in the form of a computer program based on the estimated most potent predictors. The developed model will be used as a tool for the simulation of different scenarios for specialist education combined with other factors like migration flows, changes in retirement age and skill mixing in order to compare different possibilities and options for the renewal of the Croatian healthcare personnel. Results will enable the development of recommendations for decision making and the adoption of a rational plan of referral to specialist training. Indirectly, developed model will be useful for needs assessment and simulation and planning of workforce renewal of other health professionals and for other countries.

In the present study, concentrations of heavy metals (Cd, Cu, Co, Mn, Cr, Ni, Pb, and Zn) were determined at 35 river sediments in Serbia. The anthropogenic heavy metals input and quantification of the metal enrichment degree in sediments were estimated by calculating geo-accumulation indices (I(geo)) and enrichment factors (EF). These pollution indices have been calculated using different background values (continental crust and local background values) and different element used for normalization (Al and Fe), followed by result comparison. The EF values calculated with continental crust as background (minor to extremely severe enrichment) were higher than when regional background values were used (minor to moderate enrichment). Significant influence of background values on the I(geo) values is observed. Values of geo-accumulation index (<2) revealed that studied river sediments are remaining unpolluted to moderately polluted with Co, Mn, Cr, and Ni. Significant pollution in the sediments was observed for Cd, Cu, Pb, and Zn elements. The results of this study confirm the relevance of precise and accurate determining of local background concentrations while assessing sediment pollution. The values of EFs for studied elements were more influenced by the choice of background values than selection of element used for normalization. Our recommendation would be to use the local and regional background content in quantification of metal contamination in sediments, since these values differ and are site and region dependent.

Size segregated particulate samples of atmospheric aerosols in urban site of continental part of Balkans were collected during 6 months in 2008. Six stages impactor in the size ranges: Dp ≤ 0.49 μm, 0.49 < Dp ≤ 0.95 μm, 0.95 < Dp ≤ 1.5 μm, 1.5 < Dp ≤ 3.0 μm, 3.0 < Dp ≤ 7.2 μm, and 7.2 < Dp ≤ 10.0 μm was applied for sampling. ICP-MS was used to quantify elements: Al, As, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, K, Li, Na, Ni, Mg, Mn, Pb, Sb, V, and Zn. Two main groups of elements were investigated: (1) K, V, Ni, Zn, Pb, As, and Cd with high domination in nuclei mode indicating the combustion processes as a dominant sources and (2) Al, Fe, Ca, Mg, Na, Cr, Ga, Co, and Li in coarse mode indicating mechanical processes as their main origin. The strictly crustal origin is for Mg, Fe, Ca, and Co while for As, Cd, K, V, Ni, Cu, Pb, and Zn dominates the anthropogenic influence. The PCA analysis has shown that main contribution is of resuspension (PC1, σ(2) ≈ 30 %) followed by traffic (PC2, σ(2) ≈ 20 %) that are together contributing around 50 % of elements in the investigated urban aerosol. The EF model shows that major origin of Cd, K, V, Ni, Cu, Pb, Zn, and As in the fine mode is from the anthropogenic sources while increase of their contents in the coarse particles indicates their deposition from the atmosphere and soil contamination. This approach is useful for the assessment of the local resuspension influence on element's contents in the aerosol and also for the evaluation of the historical pollution of soil caused by deposition of metals from the atmosphere.

Nikola Tesla B power plant (TENT B), located at the Sava River, in Obrenovac, 50 km west from the Serbian's capital, Belgrade, is the second largest coal-fired power plant in the country, consisting of two blocks, each of 620 MW capacity. In order to investigate the threat polycyclic aromatic hydrocarbons (PAHs) from deposited coal ash, obtained by coal combustion in this power plant, can represent for the surrounding environment, samples of coal ash were submitted to extraction with river water used for transport of coal ash to the dump, as well as with water of different ionic strength and acidity. It was found that, out of 16 EPA priority PAHs, only naphthalene, acenaphthylene, fluorene, phenantrene, fluoranthene, and pyrene were found in measurable concentrations in the different extracts. Their combined concentration was around 0.1 μg/L, so they do not, in terms of leached concentrations, represent serious danger for the surrounding environment. In all cases of established (and leached) PAH compounds, changes of ionic strength, acidity, or the presence of organic compounds in river water may to some extent influence the leached concentrations. However, under the examined conditions, similar to those present in the environment, leached concentrations were not more than 50 % greater than the concentrations leached by distilled water. Therefore, water desorption is likely the most important mechanism responsible for leaching of PAH compounds from filter coal ash.

In this paper, the main objective was fractionation of Cd, Cu, Ni, Pb, Zn, Ca, Fe, and K in certificate material and sediment samples gathered from and around the Petrochemical Industry using the conventional, microwave and ultrasonic sequential extraction. Microwave oven and ultrasound bath were used as an energy source for achieving faster extraction. Additional heating and boiling of samples were avoided by using lower power and shorter time for microwave and ultrasound extraction. Precision and accuracy of procedure were evaluated by using certificate material (BCR701). Acceptable accuracy of metals (87.0-111.3 %) was achieved for all three-step sequential of conventional extraction protocol. An accuracy of the fourth step has been verified with two certificate materials: BCR143R and 146R. The range of total extracted metal concentrations from sediments was similar for all three extraction techniques. A significant high percentage of Cd, Cu, and Zn were obtained after extraction of the exchangeable and acid soluble sediment fraction. Principal component analysis of values obtained after determination of risk assessment code using conventional and ultrasound sequential extraction show similarity of these values. Accuracy, recovery, and risk assessment code values imply that ultrasound sequential extraction is a more suitable, accelerated sequential extraction procedure (30 min per extraction step) than microwave extraction in applied conditions.

Surface and buried sediments were analyzed for Ba, Ca, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn and V, as well as for total carbon and hydrogen to assess the distribution of sediment pollution due to the vicinity of the petrochemical complex. The samples, collected from 20 locations within the petrochemical complex and from 16 locations outside the complex, were aqua regia extracted and analyzed by ICP/OES. Metals were determined with an acceptable accuracy for certified metals of 82-113%. The precision for the aqua regia extraction was satisfactory, less than 20%, except for Cd where it was 28%. Comparison of the data from the petrochemical with those from the non-petrochemical areas showed different distributions of the metals. Metals that exceeded the baseline range; Ba, Cd, Cu, Zn and Pb, were detected in higher concentrations in sediments that were under the influence of the chlor-alkali plant within the petrochemical complex. Comparison with data from the petrochemical complex and its surroundings and their distribution demonstrated that the metal compositions of the sediments were modified by anthropogenic activities., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Thirty-five alluvial sediments of the River Danube and 12 groundwater samples were taken within the Pančevo Oil Refinery (Serbia). The results for groundwater samples exceed European primary drinking water standards for Fe (obtained results, >200 μg/l) and Mn (obtained results, >50 μg/l), while the levels of the trace metals are below the thresholds for drinking water quality. Sediments were treated by sequential extraction procedure with five different solutions, each having a higher extraction capacity than the previous one. We also wanted to determine the possible relationships among trace metals and between sediment properties and elemental concentrations. These solutions partitioned metals into CH(3)COONH(4) extractable (F1); HCl carbonate extractable and NH(2)OH·HCl easily reducible (F2); (NH(4))(2)C(2)O(4)/H(2)C(2)O(4) moderately reducible (F3); H(2)O(2)-HNO(3) organic/sulfide extractable fractions (F4); and HCl acid-soluble residue (F5). The sum of trace metals Ni, Pb, Cu, and Zn associated with the first two fractions (exchangeable, carbonate, and easily reducible) is significant and extremely important because it represents the proportion of heavy metals that can be easily remobilized by changes in environmental conditions such as pH, redox potential, salinity, etc. Sediments located nearer the groundwater flow are exposed to stronger groundwater fluctuation and had a higher quantity of amorphous and less stable substrates of trace metals. Principal component analysis was used to understand and visualize the associations between the trace metals and certain geological forms within analyzed sediments. The observed association between Cr with total sulfur and Mn from the acid-soluble residue could indicate that Cr is in the form of reduced, less toxic Cr(III), which is from the ecochemical point of view very important.

The region of the investigated receptor is situated in the southern part of the Adriatic Sea in the Mediterranean. The measuring station is located on the seashore, which, being considered as a border area, is representative for the qualitative and quantitative estimation of the influence of marine and continental aerosols on the content of major ions in precipitation. In the sampling period, precipitation in the region of the investigated receptor was more abundant during the summer and autumn than during the winter and spring. The most frequent precipitation heights were up to 20 mm, while high precipitation came exclusively from the continental region. The results of the measurements of ions readily soluble in water were used for the differentiation of marine from continental contributions of primary and secondary aerosols to their content in the precipitation. Using PCA, it was shown that main contribution of Cl(-), Na(+) and Mg(2+) came from primary marine aerosols, while the contribution from continental sources was dominant for the content of SO(4)(2-), NO(3)(-), NH(4)(+) and Ca(2+) in the precipitation. The continental origin of Ca(2+) was from a primary source, while SO(4)(2-), NO(3)(-) and NH(4)(+) were representatives of secondary aerosols produced by reactions between acid oxides and alkaline species in the atmosphere, but SO(4)(2-) and NO(3)(-) also exist in the precipitation as free acids. The origin of the trace elements Cd, Cu, Pb and Zn in the precipitation came from anthropogenic emission sources. The results obtained in this work are based on experimental data from 609 samples collected during the period 1995-2000.

A sequential extraction procedure was applied to identify forms of Ni, Zn, Pb and Cu with Fe- and Mn-oxides associated in alluvial sediments of the River Danube within Pancevo Oil Refinery (Serbia). The five steps of the sequential extraction procedure partitioned metals into: CH(3)COONH(4) extractable (S1); NH(2)OH.HCl carbonate extractable and easily reducible (S2); (NH(4))(2)C(2)O(2)/H(2)C(2)O(2) moderately reducible (S3); H(2)O(2)-HNO(3) organic extractable (S4); and HCl acid soluble residue (S5). Extracted concentrations of trace metals, analyzed after all five steps, were found to be (mg kg(-1)) for Mn: 656, Fe: 26734, Ni: 32.3, Zn: 72.8, Pb: 13.4 and Cu: 27.0. Most of the elements were found in acid soluble residue, characterizing stable compounds in sediments. Non-residual fractions of trace metals (sum of the first four fractions) were analyzed because they are more bioavailable than the residual amount. Correlation analysis and two multivariate analysis methods (principal component and cluster analysis) were used to understand and visualize the associations between the non-residual fractions of trace metals and certain forms, more or less crystalline of Fe- and Mn-oxides within the analyzed sediments, since Fe- and Mn-oxides play an important role in trace metal sorption within aquatic systems, especially within the Danube alluvium where the fluctuations of groundwater are very frequent and the level of groundwater could come close to surface.