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A part of the Raša Bay (western Croatia) is an estuary that is fed by the sediment load from the Raša River. The local area had been affected by the former Raša coal industry. The aim of this study was to determine levels of hazardous trace elements (HTEs) in bottom estuarine sediments, fish and mussels collected from two sites downstream of the Raša River mouth, and a wild boar’s kidney donated by hunters. The pseudo-total concentrations of 21 HTEs in sediments were obtained by the X-ray fluorescence (XRF) technique. The results showed that sediment collected closest to the former Raša coal separation unit Štalije was enriched in V, Sr, Ni, Cu, and Pb. Concentrations of HTEs in flathead grey mullet, wild blue mussels, and wild boar were obtained by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that Pb, Cd and Hg in fish and wild mussels were not elevated compared to the Regulation levels of contaminants in food. Lead and Cd in the kidney of a wild boar exceeded the prescribed maximum values for food. This study warrants further geochemical investigations of the Raša Bay environment., Nanos rijeke Raše gomila se na ušću koje čini dio Raškoga zaljeva (zapadna Hrvatska). Na lokalno područje prije nekoliko desetljeća neekološki je utjecala raška industrija ugljena. Cilj istraživanja bio je utvrditi razine opasnih elemenata u tragovima (HTE) u sedimentima donjega ušća, ribama i dagnjama prikupljenim s dvaju lokaliteta nizvodno od ušća rijeke Raše te doniranome bubregu ulovljene divlje svinje. Pseudototalne koncentracije 21 elementa u sedimentima određene su pomoću fluorescencije X-zrakama (XRF). Rezultati su pokazali da je sediment uzorkovan najbliže nekadašnjemu postrojenju za separaciju ugljena Štalije obogaćen V, Sr, Ni, Cu i Pb. Koncentracije elemenata u ribama, dagnjama i u bubregu divlje svinje određene su primjenom induktivno spregnute plazme – masene spektrometrije (ICP-MS tehnike) nakon digestije. Rezultati su pokazali da Pb, Cd i Hg u ribi i divljim dagnjama nisu povišeni u odnosu na razine onečišćenja u hrani propisane Uredbom. Olovo i kadmij u bubrezima divlje svinje premašili su propisane maksimalne vrijednosti za hranu. Ova studija opravdava daljnja geokemijska istraživanja okoliša Raškoga zaljeva.

IntroductionCroatian superhigh-organic-sulfur Raša coal had been mined for nearly 400 years. The release of hazardous trace elements (HTEs) and toxic organic pollutants (TOPs) into the local environment by coal mining, preparation, and combustion activities has resulted in pollution.MethodsIn this study, the diversity and composition of microbial communities in estuarine sediment and soil samples as well as community function responses to the pollutants were investigated.ResultsThe results showed that PAH degradation does occur following 60 years of natural attenuation, the location is still heavily polluted by polycyclic aromatic hydrocarbons (PAHs) and HTEs. Microbial analyses have shown that high concentrations of PAHs have reduced the diversity and abundance of microbial communities. The pollution exerted an adverse, long-term impact on the microbial community structure and function in the brackish aquatic ecosystem. Microorganisms associated with the degradation of PAHs and sulfur-containing compounds have been enriched although the diversity and abundance of the microbial community have reduced. Fungi which are believed to be the main PAH degrader may play an important role initially, but the activity remains lower thereafter. It is the high concentrations of coal-derived PAHs, rather than HTEs, that have reduced the diversity and abundance of microbial communities and shaped the structure of the local microbiota.DiscussionThis study could provide a basis for the monitoring and restoration of ecosystems impacted by coal mining activities considering the expected decommission of a large number of coal plants on a global scale in the coming years due to growing global climate change concerns.

Assessing the environmental quality of coastal systems is important not only for the management and protection of such areas, but also for improving the quality of water resources. Since sediment itself can often be a source of certain toxic elements, in addition to information on the distribution of metals in the water column and in the sediment itself, it is useful to determine the bioavailable forms of individual elements, particularly toxic ones. In this study, water and sediment geochemical data were supplemented with oxyanion mobility in sediments estimated by diffusion gradients in thin film (DGTs). The data obtained indicate that the chemical composition of the water in the Raša River estuary primarily reflects the high input of suspended sediment from the catchment, the mixing of freshwater and seawater, and to a lesser extent the effects of anthropogenic activities. Although sediment composition is primarily determined by geological and hydrodynamic conditions in the catchment, it also indicates moderate enrichment in Co, Cr, Mo and Ni. In contrast, the distribution of oxyanions in sediment pore water indicates the influence of sediment as a source of some elements in the bottom water, e.g., sediment contributes to 40% of the arsenic bottom water budget. The obtained depth profiles of the oxyanion distribution in the sediment pore water indicate an early onset of suboxic to anoxic conditions in Raša Bay, which is prone to rapid sedimentation. All this demonstrates the need to consider the bioavailable forms of elements when assessing environmental quality, as the lack of such information can lead to an incomplete assessment, especially in dynamic coastal systems such as estuaries.

School’s indoor air quality (IAQ) is very important as it can affect student’s learning abilities and lead to health issues. Therefore, indoor air quality, and in particular the CO2 concentration, was monitored on a daily basis from mid-November till the end of December 2017, by using several low-cost instruments. The measuring was performed in the physics classroom of a grammar school in Rijeka, Croatia. Detailed CO2 generation rates, air exchange rates, and ventilation rates are calculated and reported in this work, from the experimentally obtained data. Very high concentrations of over 4.000 ppm were recorded, indicating that ventilation rates are far below 5 Ls-1 per person, which is the lowest recommended value of ventilation rate according to the European standard EN 13779. The experimentally obtained data are compared with the theoretical models and a strong correlation are achieved. This is one of the first comprehensive studies of this kind in Croatia; therefore, we hope that it will stimulate interest between health workers, scientists, and school management to implement indoor air quality monitoring practices and perhaps introduce automated ventilation systems in classrooms for the benefit of students’ health and their learning abilities.

Aerosoli se prema Hrvatskom strukovnom nazivlju (STRUNA - Institut za hrvatski jezik i jezikoslovlje ) definiraju u fizici kao čestice raspršene u Zemljinoj atmosferi koje smanjuju optičku prozirnost , dok su u kemiji definirane kao koloidni sustav u kojem je krutina ili kapljevina raspršena u plinu. U fine frakcije aerosola PM2, 5 (particulate matter) pripadaju sve čestice aerodinamičkog promjera do 2, 5 mikrometara. Za stjecanje osjećaja koliko su te čestice malene služi promjer ljudske kose koji iznosi oko 50 mikrometara. Čestice unutar PM2, 5 dopiru u donje dišne putove, stoga je njihova opasnost za zdravlje izuzetna. Procjenjuje se da izloženost PM2, 5 u urbanim sredinama utječe na smanjenje životnog vijeka kao i na povećanje smrtnosti. Posebno je pogođen istok svijeta gdje se u mnogobrojnim znanstvenim radovima dokazuju teze poput smanjenja životnog vijeka do 8 godina , ali ne zaostaju i veliki gradovi Europe i Amerike. Najosjetljivije skupine stanovništva prema WHO (World Health Organization) su ljudi s već razvijenim plućnim i srčanim bolestima te djeca i stariji. Prema IACR (International Agency for Research on Cancer) izloženost ljudi PM2, 5 frakciji utječe na razvoj srčanih i plućnih bolesti te pojave raka. Postoje prirodni i antropogeni (umjetni) izvori fine frakcije. Prirodni izvori su vjetrom nošena morska prašina, zemljana prašina, čestice emitirane požarima i vulkanima. Antropogeni izvori su rad industrija, posebice termoelektrana, industrija nafte, cestovni i pomorski promet itd. Fina frakcija aerosola je uzorkovana u Rijeci i Kostreni pomoću uzorkivača čestica na teflonske filtere. Uzorci su snimani pomoću nekoliko analitičkih tehnika kao što je fluorescencija X zraka (XRF), protonima inducirano x zračenje (PIXE), itd. Određene su koncentracije elemenata u ng/m3 (nanogramima po kubnom metru) od vodika do olova. Svaki taj element ima svoje čvrsto ili meko tkivo gdje se taloži i s vremenom čini štetu. Rezultati pokazuju da tijekom izmaglice za sunčanog dana koncentracije elemenata poput Zn, S, Pb itd. više od 5 puta veće od uobičajenih. Stanovništvo se tad žali na probleme s disanjem kao i na osjećaj tlačenja u prsima. Posebice je problem akumulacije zagađenja zraka u danima bez vjetra. Veliki je problem zagađenja zraka nakon vatrometa ili uporabe pirotehničkih sredstava kad se bilježi više od 55 puta povećanje koncentracija Pb u odnosu na godišnji prosjek. Znamo d as eolovo talođi u kostima i mekim tkivima. Preporuča se učiteljima i nastavnicima da koriste rezultate mjerenja te da odgajaju okolišno osviještene mlade ljude koji će u budućnosti biti donositelji odluka. Nije dovoljno samo znanstveno mjeriti, već treba ukazivati na potrebu održivog razvoja u svim segmentima razvoja društva. Preporuča se učenicima da istražuju dostupne web adrese Državne mreže za trajno praćenje kvalitete zraka, pripadne postaje iz nastavnih zavoda za javno zdravstvo kao i kako bi grafički prikazivali rezultate mjerenja i donosili zaključke (http://iszz.azo.hr/iskzl/podatak.htm? pid=165 ; (http://www.zzjzpgz.hr ; https://aqicn.org/map/world/ …) Ovim predavanjem želi se potaknuti učitelje i nastavnike da motiviraju učenike na istraživanje izvora elektromagnetskog zračenja (poput rentgenske cijevi za tehniku XRF), opisa spektra elektromagnetskog zračenja (kroz primjer XRF spektra aerosola s elementima od S do Pb) primjene elektromagnetskog zračenja (analiza aerosola), što su ishodi iz Kurikuluma nastavnog predmeta Fizika.

The impact of ship emissions on air pollution in harbours is probably one of the lesser-understood aspects of anthropogenic pollution. Vessels are often powered by relatively old engines and at the same time quality of fuels is often questionable. These factors have potential to significant increase air pollution in busy harbours. It is well know that V/Ni ratio higher than 2.5 are good indicators of heavy oil combustion from the ship engines. To evaluate this contribution to the air pollution in the harbour of Rijeka the authors measured concentrations of V and Ni in fine aerosols (PM₂.₅). Over the 300 fine aerosol samples were collected during the three years period (February 2012 – June 2015) and analyzed by two analytical techniques; X-ray Fluorescence and Laser Integrated Plate Method at the Laboratory for Elemental-Micro Analysis (Department of Physics University of Rijeka). Concentrations of 18 elements (Si to Pb) were obtained as well as the black carbon (BC) component. The results were statistically evaluated by means of the positive matrix factorization. In nearly 15% of samples, concentration ratio (V/Ni) was found to be around 3 indicating that during those days the source that the authors named “ship emission” was present in fine aerosol pollution with major components such as S, BC and traces K, V, Fe, Cl, Br, Pb and Ni. This anthropogenic source represented approximately 10% from the total fine aerosol mass.

VIBA-Lab is a computer program originally developed by the author and co-workers at the National University of Singapore (NUS) as an interactive software package for simulation of Particle Induced X-ray Emission and Rutherford Backscattering Spectra. The original program is redeveloped to a VIBA-Lab 3.0 in which the user can perform semi-quantitative analysis by comparing simulated and measured spectra as well as simulate 2D elemental maps for a given 3D sample composition. The latest version has a new and more versatile user interface. It also has the latest data set of fundamental parameters such as Coster–Kronig transition rates, fluorescence yields, mass absorption coefficients and ionization cross sections for K and L lines in a wider energy range than the original program. Our short-term plan is to introduce routine for quantitative analysis for multiple PIXE and XRF excitations. VIBA-Lab is an excellent teaching tool for students and researchers in using PIXE and RBS techniques. At the same time the program helps when planning an experiment and when optimizing experimental parameters such as incident ions, their energy, detector specifications, filters, geometry, etc. By “running” a virtual experiment the user can test various scenarios until the optimal PIXE and BS spectra are obtained and in this way save a lot of expensive machine time.

The results of a long term, multi elemental XRF and PIXE analysis of fine aerosol pollution in the city of Rijeka, Croatia, are reported for the first time. The samples were collected during a seven months period (6th Aug 2013–28th Feb 2014) on thin stretched Teflon filters and analyzed by energy dispersive X-ray fluorescence (EDXRF) at the Laboratory for Elemental Micro-Analysis (LEMA), University of Rijeka and by Particle Induced X-ray Emission (PIXE) using 1.6 MeV protons at the Laboratory for Ion Beam Interactions (LIBI), Ruđer Boskovic Institute, Zagreb. The newly developed micro-XRF system at LEMA provided results for 19 elements in the range from Si to Pb. The PIXE at the LIBI provided information for the same elements as well for the light elements such as Na, Mg and Al. Black carbon was determined with the Laser Integrated Plate Method (LIPM). The results were statistically evaluated by means of the positive matrix factorization (PMF). The seven major pollution sources were identified together with their relative contributions, these are: secondary sulfates, road traffic, smoke, road dust, sea spray, ship emissions and soil dust.

Shipping is a growing transport sector representing a relevant share of atmospheric pollutant emissions at global scale. In the Mediterranean Sea, shipping affects air quality of coastal urban areas with potential hazardous effects on both human health and climate. The high number of different approaches for investigating this aspect limits the comparability of results. Furthermore, limited information regarding the inter-annual trends of shipping impacts is available. In this work, an approach integrating emission inventory, numerical modelling (WRF-CAMx modelling system), and experimental measurements at high and low temporal resolution is used to investigate air quality shipping impact in the Adriatic/Ionian area focusing on four port-cities: Brindisi and Venice (Italy), Patras (Greece), and Rijeka (Croatia). Results showed shipping emissions of particulate matter (PM) and NOx comparable to road traffic emissions at all port-cities, with larger contributions to local SO2 emissions. Contributions to PM2.5 ranged between 0.5% (Rijeka) and 7.4% (Brindisi), those to PM10 were between 0.3% (Rijeka) and 5.8% (Brindisi). Contributions to particle number concentration (PNC) showed an impact 2-4 times larger with respect to that on mass concentrations. Shipping impact on gaseous pollutants are larger than those to PM. The contribution to total polycyclic aromatic hydrocarbon (PAHs) concentrations was 82% in Venice and 56% in Brindisi, with a different partition gas-particle because of different meteorological conditions. The inter-annual trends analysis showed the primary contribution to PM concentrations decreasing, due to the implementation of the European legislation on the use of low-sulphur content fuels. This effect was not present on other pollutants like PAHs. (C) 2016 Elsevier Ltd. All rights reserved.

PM2.5 daily aerosol samples were collected in Rijeka, Croatia during period from 6th August 2013 to 29th January 2015. In total, 259 samples were collected on Teflon filters and analyzed by PIXE and PIGE techniques to give information on 21 elements from Na to Pb. Additionally, black carbon was determined with the Laser Integrated Plate Method. Results were statistically evaluated using Positive Matrix Factorization (PMF). Eight major pollution sources: auto, smoke, secondary sulfates, heavy oil combustion, sea spray, road dust, industry iron and soil dust were identified together with their relative contributions in total PM2.5 pollution.

The new system for energy dispersive X-ray fluorescence (EDXRF) analysis has been installed at the Laboratory for Elemental Micro-Analysis (LEMA) at the University of Rijeka. Currently the key application of this new XRF system is in the field of environmental science, i.e. in the analysis of fine airborne particles. In this work, results of initial multi-elemental analysis of PM2.5 fraction is reported for the first time in the region of Rijeka, Croatia. Sampling was performed at the Rijeka City center, during a continuous 9-day period in February/March 2012. All samples were collected on stretched Teflon filters in 12 h periods. To check the reliability of the new XRF system, results of XRF analysis are compared with the results obtained by the well-established Ion Beam Analysis (IBA) laboratory at Australian Nuclear Science and Technology Organisation (ANSTO). The concentrations of H, Na, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br and Pb were determined. In addition, black carbon was determined by Laser Integrating Plate Method (LIPM). Very good agreement between XRF and IBA techniques is obtained for all elements detected by both techniques. Elemental concentrations were correlated with the traffic volume and wind speed and direction. The summary of our findings is presented and discussed in this paper.

Analizom sadržaja i ilustracija vezanih uz temu Leće u udžbenicima i zbirkama zadataka na hrvatskom jeziku, ustanovili smo da se funkcija leća, sabiranje ili rasipanje svjetlosnog snopa, pripisuje isključivo njihovom obliku i to tako da izbočena leća sabire, a udubljena rasipa svjetlosni snop. Pojednostavljivanjem sadržaja i zanemarivanjem činjenice da funkcija leća ovisi kako o obliku, tako i o optičkim sredstvima od kojih je leća i njezina okolina, izostaje učeničko razumijevanje svakodnevnih pojava tumačenih pomoću primjene leće te se otvara prostor za stvaranje miskoncepcija. Stoga je nužno, prilikom pojednostavljivanja tumačenja znanstvenih činjenica, kako u literaturi, a tako i u nastavnom procesu, koristiti ispravne znanstvene činjenice na odgovarajućoj razini. U ovom radu ponudili smo metodičku obradu teme Leće, koja se može prilagoditi za različite razine obrazovanja.