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The appearance and spread of antibiotic resistance are considered a highly complex process with many factors affecting the resistance mechanisms, including metals. In order to fully understand the spread of antibiotic resistance in different environments, combined studies including geochemistry and microbiology are becoming imperative. So far, very few such studies have been conducted, and none of them involves the southernmost regions. The aim of this study was, therefore, to examine the biogeochemical characteristics of sediments of the southernmost part of Chile. Sediment geochemistry, as well as the presence of heterotrophic and carbapenem- resistant bacteria (CRB) in the Río de las Minas and neighbouring Strait of Magellan in Punta Arenas (Chile), was investigated to assess the anthropogenic impact of untreated urban wastewater on the accumulation of metals and microbial contaminants in this coastal system. Geochemistry of sediments indicated the influence of both natural processes and anthropogenic activities. Although levels of metals in sediments currently do not represent a toxic effect on organisms, the anthropogenic influence on the sediment composition in the study area cannot be denied. Clinically relevant CRB were found in river sediments (1.9 and 2.7 log CFU / mL). Our findings suggest that the Río de las Minas is under the anthropogenic impact of untreated urban wastewater and represent a significant source of potentially pathogenic CRB to the local environment. Resumen: La aparición y propagación de la resistencia a los antibióticos se considera un proceso muy complejo, con muchos factores que afectan a los mecanismos de resistencia, incluidos los metales. Con el fin de comprender plenamente la propagación de la resistencia a los antibióticos en diferentes entornos, es imprescindible realizar estudios combinados que incluyan geoquímica y microbiología. Hasta ahora, se han realizado muy pocos estudios de este tipo y ninguno de ellos afecta a las regiones más meridionales. El objetivo de este estudio fue, por lo tanto, examinar las características biogeoquímicas de los sedimentos del extremo sur de Chile. Se investigó la geoquímica de los sedimentos, así como la presencia de bacterias heterótrofas y resistentes a los carbapenemas (BRC) en el Río de las Minas y el Estrecho de Magallanes en Punta Arenas (Chile), para evaluar el impacto antropogénico de las aguas residuales urbanas no tratadas sobre la acumulación de metales y contaminantes microbianos en este sistema costero. La geoquímica de los sedimentos indicaba la influencia tanto de los procesos naturales como de las actividades antropogénicas. Aunque los niveles de metales en los sedimentos actualmente no representan un efecto tóxico sobre los organismos, no se puede negar la influencia antropogénica sobre la composición de los sedimentos en el área de estudio. Se encontraron CCR clínicamente relevantes en los sedimentos de los ríos (1,9 y 2,7 UFC logarítmicos/ ml). Nuestros hallazgos sugieren que el Río de las Minas está bajo el impacto antropogénico de las aguas residuales urbanas no tratadas y representa una fuente significativa de CRB potencialmente patógena para el medio ambiente local.

The Raša coal from Istria belongs to a special type of superhigh-organic-sulfur coals, with an organic sulfur content of 11%, preserved within the succession of marine carbonates. Previous studies attributed the formation of superhigh- organic-sulfur Raša coal to the seawater percolation [1]. However, recent geochemical data on the rare earth element distribution in Raša coal ashes [2, 3] suggested that the Raša coal- bearing strata, representing the Upper Paleocene lacustrine and brackish facies, were also influenced by the hydrothermal solutions under conditions which led not only to sulfur enrichment but also to the rare earth elements accumulation. To confirm the latter, geochemical and mineralogical analysis were performed on samples of Raša coal seam and surrounding carbonates. Multielement analysis was performed by High Resolution Inductively Coupled Plasma Mass Spectrometry (HR-ICP-MS) using an Element 2 instrument (Thermo, Bremen, Germany). All samples were analyzed for total concentration of 19 elements (Al, Ti, Mn, Fe and the rare earth elements, including Y). Mineral composition of samples was investigated by X-ray diffraction (XRD) and electronic scanning microscopy (SEM). The obtained geochemical and mineralogical data provided new insights into the processes influencing Raša coal formation, confirming the impact of both the seawater and the hydrothermal solutions.

The Prašnik forest, located in the south-western part of the Pannonian Basin (Croatia), is a temperate rainforest and the last remnant of the Slavonian rainforest. As a unique phytocoenosis, it was recognized and protected as a special forest vegetation reserve since 1965. Focus of the present study were soil, mushroom and moss samples from this forest. The principal objectives of the study were determination of (i) levels of metals/metalloids in soil, moss and mushroom samples, and (ii) radionuclide activities in soil samples. The main aims of the presented study were to assess: 1) the influence of pedological substrate on the element composition in mosses and mushrooms, as sensitive bioindicators of air quality and environmental health, and 2) the influence of atmospheric deposition on the soil radionuclide composition in this area. Due to its position in the area of warfare during 1990s, the Prašnik rainforest was mined and until 2015 unavailable to visitors. Other than that, as a highly protected area of great biological importance, it was excluded from human exploitation activities since 1928 and is therefore considered free of anthropogenic influence except for contaminants delivered via natural pathways, air or water. Previous studies confirmed only slight and locally restricted influence of the war activities on the soil geochemistry, while the geochemical composition of both mosses and mushrooms showed a prevailing influence of the local substrate and atmospheric deposition. Results of the multielement analysis were in agreement with the data reported in European Geochemical Atlas (FOREGS) for this area. Slightly higher levels than expected by the FOREGS were observed only for Cd, Pb and Zn. The calculated bioaccumulation factors (BAF=Cmoss or mushroom/Csoil ; C - concentration) suggest slight (BAF=10-2 – 10-1) to moderate (BAF=10-1 – 1) accumulation of majority of elements in both mosses and mushrooms. Only Cu in mushrooms exhibited BAF>1. Anthropogenic radionuclides, 137Cs and 134Cs, were present in all samples and reflect the global contamination of the biosphere caused by nuclear tests and accidents in Chernobyl in 1986 and Fukushima in 2011, respectively. Other detected radionuclides are considered to be of natural origin.

Coal mining and coal combustion release environmental contaminants which stay at emission sites for many decades. The paper reports total Se and other potentially toxic elements (As, Cd, Cu, Cr, Hg, Pb, Sr, U, V, and Zn) in lettuce, potato, and tissues (liver, kidney, heart, and muscle) of three non- migratory bird species (pigeon, jay, and black coot) from a Raša Bay area (North Adriatic, Croatia). They have presumably been exposed to elevated levels of the mentioned elements in garden soil, surface water, and aquatic sediment contaminated with superhigh- organic-sulphur (SHOS) Raša coal, highly enriched in S, Se, V, and U. Results point at selenium contamination of stream water (up to 78 μg/L total Se in a non-filtered sample), which is well above the Croatian regulatory threshold of 10 μg/L total Se. The stream drains a site of the former coal- separation unit, and an associated bottom sediment contains up to 10.8 mg/kg total Se, which is also above the safe level of 0.60 mg/kg total Se. Moreover, values of Mo, U, V, and Sr, elements commonly elevated in SHOS coal varieties, were also increased in majority of water samples as well as in analysed vegetables, soil, and aquatic sediments. Although Cu, Zn, Pb, and V were slightly increased in liver samples of birds, more in black coot than the other two birds, selenium values were found to be adequate for their normal growth. The fact that Se can be environmentally hazardous and toxic to life, even in small doses, warrants further research on this topic.

The only coal-fi red power plant in Croatia is situated near the city of Labin, on the east coast of the Istrian Peninsula (the Northern Adriatic Region). The Raša coal (with super-high content of sulphur, up to 14%) was mined at six localities around the city of Labin for more than a century. Our latest research showed that the soil surrounding the plant is highly polluted with PAHs, and moderately polluted with potentially toxic trace elements Cd and Se. Herewith, the aim of this study was to assess for the fi rst time a health risk for the local inhabitants from Cd and Se caused by ingestion or dermal exposure to soil particles. The hazard index (HI) was used to assess non-carcinogenic human health risk of Cd and Se. Since slope factors for Cd and Se based on oral or dermal exposure of general population are not assigned due to the lack of evidence of carcinogenicity, we were not able to calculate carcinogenic risk from Cd and Se present in soil. The results showed that the calculated non-carcinogenic risk due to Cd (HImax=0.06) and Se (HImax=0.02) in soil were well below the threshold value (HI=1) for both adults and children, indicating that exposed individuals are unlikely to experience adverse health effects. However, further detailed investigation including larger number of potentially toxic and carcinogenic trace elements will be conducted in the future. These results will provide basic information of metal pollution control and environment management in the Labin area.

Croatian forest reserves are among the richest in EU. One of them is the Prašnik rainforest, declared as a special forest reserve since 1928, which is located near the major highway linking Western and Eastern Europe. It has the second tallest oak in Europe (39.6 m), the age and girth of which are 350 years, and 7.82 m, respectively. More than 20 years ago, numerous mines were placed in the area because of Croatian War of Independence, having threatened visitors and scholars to this day. During the late August 2015, soil, moss, and mushroom samples (n = 26) were collected from the protected locality. Following their air-drying, grinding, and digestion in acids, elemental analysis was carried out by HR ICP-MS. Soil element values (mg/kg) were following (mean ± SD, range): Pb 37.3 ± 6.5, 29.2-47.1 ; Al 53, 080 ± 3, 420, 44, 090-56, 070 ; Cr 79.2 ± 6.5, 64.5- 85.1 ; Ni 24.4 ± 2.8, 19.4-28.6 ; Cu 17.2 ± 4.1, 13.1-25.3 ; Zn 127.8 ± 33.2, 101.1-216.4 ; Sr 116.2 ± 5.0, 103.2-121.4 ; Ba 388.1 ± 24.1, 327.2-409.7 ; and As 11.2 ± 3.4, 7.3-16.6. By using Sr values, calculated enrichment factor ranges (based on the regional geochemical map) were following: Pb 1.2-1.7, Al 0.7-0.8, Cr 0.9- 1.0, Ni 0.50.7, Cu 0.6-1.2, Zn 1.2-2.7, Ba 0.8- 0.9, and As 0.8-1.7. Except Zn which is moderately enriched in soil (EF 2-5), all other variables showed defi ciency to minimal enrichment (EF < 2). Element ranges (mg/ kg d.w.) in mosses and mushrooms were following: Pb 2.3-6.9, and 1.1-6.4, As 0.4-1.0, and 0.2-3.7, Cd 0.1-0.3, and 0.02-0.2, and Ni 2.0-4.5, and 1.0-8.1, respectively.

Antifouling biocides, as tributyltin (TBT), have been developed to prevent settlement of organisms on vessels and therefore were directly introduced into the marine environment. Their widespread use caused high levels of contamination and raised concerns about their toxic effects on marine communities. Nowadays, the usage of TBT-based antifouling paints has been banned in many countries worldwide. However, overview of the recently published data demonstrates that marine environment is still polluted with TBT. Obviously, the ban cannot solve the problem of contamination immediately since TBT is highly persistent in sediments, which therefore represent a long term source of TBT in the marine environment. Since TBT degradation in sediments occurs very slowly, with half-lives from several years to decades, it controls the overall persistence of TBT in the entire environment. Consequently, the complete knowledge on degradation process is of crucial importance for the assessment of the time period in which TBT pollution will be present. Here we shown that organic matter, by controlling TBT adsorption/desorption processes, influences the TBT degradation efficiency and consequently defines its persistence in contaminated sediments, which thus increases in sediments rich in organic matter.

Butyltins (BuTs) have been introduced into the marine environment by the use of tributyltin (TBT) as biocide in antifouling paints since 1960s. However, after it was established that TBT has various toxic effects on the non target organisms, like the appearance of imposex in gastropods at very low levels (1-2 ng L-1), the use of TBT-based antifouling paints has been banned in many countries worldwide, including the whole Europe, while in Croatia they are banned since 2006. The first measurements of BuT concentrations in seawater and mussels from the Croatian Adriatic coast, sampled during 2009 and 2010, showed a widespread pollution with TBT suggesting an ongoing use of those paints, despite restrictions (Furdek et al., 2012). In this paper we present the first data on BuT concentrations in sediments from the Croatian Adriatic coast. In order to elucidate factor influencing the level of BuT pollution, locations with different intensity of maritime activities (marinas, ports and reference sites) were selected for sampling of surface sediments. BuTs in sediments ranged from 5 to 1362 ng(Sn) g-1(d.w.), while contamination levels in marinas and ports were significantly higher than at reference sites. The far highest concentrations were found in sediments taken below the service hoists in marinas, where BuTs reached the enormous value of 66344 ng(Sn) g-1(d.w.). In addition to BuTs, the concentrations of total tin in surface sediments were also determined in order to test the hypothesis that elevated levels of inorganic tin in marine environment originate primarily from TBT that is used in antifouling paints. The strong and statistically significant correlations between BuTs and total Sn confirmed this assumption. The assessment of the level of sediment pollution was done using OSPAR criteria for TBT concentrations in sediments and enrichment factor (EF) approach for total Sn. Both criteria indicated that >75 % of sampled sites can be classified as highly polluted. Obviously, the ban of the use of TBT-based antifouling paints cannot solve the problem of BuT pollution immediately, since contaminated sediments represent a long term source of TBT in the marine environment.

Makirina Bay (N. Dalmatia, Republic of Croatia) represents one of the major and most important sites where organic-rich sediments accumulate along the eastern Adriatic coast. According to their organoleptic properties, these sediments (peloids) are suitable for application as a raw material for different therapeutic, cosmetic, and wellness-related purposes. In addition, Makirina Bay peloids are already frequently used by local people and tourists as pomades ; peloids are collected in situ from the bay, applied directly on the skin, and sun dried. Several characteristics of Makirina bay peloids were determined, including their granulometry, cation exchange capacity (CEC), mineral and elemental composition, potentially toxic elements (PTE) mobility/bioavailability and thermal properties (specific heat, thermal conductivity and thermal difussivity) in order to evaluate the suitability of their application for medical/therapeutic purposes in balneotherapy and pelotherapy. Our results showed that Makirina bay peloids are represented mostly by sandy silt and have a relatively high CEC value (63.82 meq/100g). The mineral composition of peloids is dominated by dolomite and quartz, followed by illite/muscovite, aragonite, halite, calcite, and pyrite. Oriented preparations of the clay fraction revealed illite/muscovite, chlorite, and kaolinite as the dominant clay minerals. PTE concentrations in surficial (0-5 cm) peloids are [in mg/kg]: As (14.47), Cd (0.27), Cu (27.64), Mn (232.4), Mo (13.82), Ni (26.51), Pb (23.74) and Zn (47.67). The results of the sequential extraction procedure indicated that majority of PTE (except Cd, Mn and Mo) in Makirina bay peloids are not readily mobile or bioavailable since only a small percentage of PTE is extracted in the first two steps (e.g. water-soluble and exchangeable fraction). Thermal properties of Makirina bay peloids are as follows: specific heat 2050 J/kgK, thermal conductivity 0.99 W/mK and thermal diffusivity 2.84*10-7 m2/s.

Investigation of geochemical and sedimentological characteristics of sediments of Zrmanja River estuary was conducted in order to determine the deposition conditions as well as natural and anthropogenic factors of influences on sedimentation in this area. Zrmanja River eastuary is located in the central part of the eastern Adriatic coast, about 20 km from Zadar. It can be divided into three parts: the upper part (downstream part from Jankovic buk to Novigrad Sea), the middle part (Novigrad and Karin Sea) and the lower part (strait that connects the Novigrad Sea and the Velebit Channel) (Viličić et al., 2008). On the right bank of the river canyon, about 8 km upstream from the mouth of Zrmanja River into Novigrad Sea, the ex-alumina factory Jadral is situated. Although the factory had stopped working more than three decades ago, impact of plant activity on the surrounding environment can be seen a few hundred meters from the location of the factory, where the wind and the rain bearable aerosols and particles created infested landscape without vegetation. For purposes of this study, sediment cores were taken at several locations in Zrmanja River, Novigrad Sea, Karin Sea and Velebit Channel. Collected samples were subjected to geochemical and sedimentological analysis and the course of their treatment depended on their final use. The results of the analysis showed that the composition of sediments of Zrmanja River estuary is primarily determined by natural factors: the composition of bedrock, existing hydrodynamic conditions and isolation of studied basin. Nevertheless, antropogenic influence is observed as well. Composition of the Zrmanja River sediments indicates impact of the ex-alumina factory Jadral and transfer by wind of the material from its immediate proximity to the water system of the Zrmanja River. In addition, sedimentation in Zrmanja River was found influenced by the construction of reservoirs and power plant Velebit. The construction of power plant caused the change in the downstream water regime of the river, changing the energy of the water and deposition of finer fraction of sediment more downstream compared to the previous period, which is reflected in the grain size and geochemical characteristics of the sediments. It can be concluded that the composition of sediments of Zrmanja River estuary is still primarily determined by natural factors, although sporadically we find the impact of anthropogenic activities.

Istraživanje sedimentoloških, paleontoloških i mineraloških značajki površinskih sedimenata područja Novigradskog i Karinskog mora te rijeke Zrmanje provedeno je u svrhu određivanja podrijetla materijala i uvjeta taloženja sedimenata u Novigradskom akvatoriju. Rezultati istraživanja su pokazali kako je sastav sedimenata Novigradskog i Karinskog mora uvjetovan sastavom geološke podloge drenažnog sustava, postojećim hidrodinamičkim uvjetima te izoliranošću bazena. Krška podloga drenažnog područja uvjetuje zanemariv donos sitnozrnatog materijala rijekom Zrmanjom u usporedbi s manjim i/ili povremenim vodotocima koji dreniraju fliške naslage eocena u zaleđu i donose znatnije količine sitnozrnastog materijala u Novigradsko i Karinsko more. Krupnozrnasta frakcija materijala donešenog rijekom Zrmanjom taloži se neposredno na ušću rijeke u Novigradsko more, dok se neistaloženi materijal u suspenziji odnosi dalje te taloži u dubljim dijelovima bazena, što za posljedicu ima formiranje prodelte. Iako znatno manjeg protoka od rijeke Zrmanje, Karišnica u Karinsko more donosi znatne količine siltnog i glinovitog materijala nastalog trošenjem okolnih naslaga eocenskog fliša. Navedeno potvrđuju vrste vapnenačkog nanoplanktona pronađene samo u uzorcima sedimenata Karinskog i Novigradskog mora. Raspodjela veličinskih frakcija, odnosno sedimenti klasificirani kao silt također potvrđuju značajniji donos terigenog materijala manjim i/ili povremenim vodotocima. Povišen udio muljevite frakcije u tim bazenima posljedica je njegovog direktnog donosa u mirni taložni okoliš, odnosno smanjene mogućnosti njegovog odnošenja iz sustava uslijed ograničene komunikacije s otvorenim morem. Identificirani karbonatni minerali pokazuju da se u oba morska bazena talože biogene, ali i karbonatne čestice terigenog porijekla. Porijeklo kalcita i dolomita u istraživanih sedimentima najvjerojatnije je vezano uz karbonatne stijene, gornjokredne vapnence i dolomite te gornjoeocenske Promina-naslage, dok magnezijem bogati kalcit i aragonit ukazuju na biološko porijeklo. Prisutnost Al-Fe-oksida i hidroksida u istraživanim sedimentima odraz je utjecaja blizine boksitnih ležišta. Glavni izvor manje zastupljenih minerala glina su eocenske naslage fliša te okolna tla, uključujući i boksitnu zemlju.

Recentne morske sedimente iz zaliva Makirina lahko glede na njihove organoleptične lastnosti obravnavamo kot zdravilno blato ali peloid, ki ga nekateri domačini in turisti že uporabljajo v obliki blatnih oblog. Uporaba peloidov v balneoterapiji je namenjena predvsem zdravljenju mišičnih, kostnih in kožnih obolenj ter sproščanju in velnesu. Številne nedavne raziskave peloidov so pokazale, da so eni izmed glavnih dejavnikov, ki pogojujejo (ne)uporabo peloida v balneoterapevtske namene, zrnavost, mineraloška sestava, kationska izmenjevalna kapaciteta (KIK), elementna in mikrobiološka sestava izvornega »geološkega materiala«. Iz rezultatov predhodnih raziskav je razvidno, da peloid iz zaliva Makirina gradi zelo slabo sortiran peščen mulj z visoko kationsko izmenjevalno kapaciteto (63, 82 meq/100g). V mineralni sestavi peloida prevladujeta dolomit in kremen, sledijo ilit/muskovit, aragonit, kalcit, halit in pirit. Povprečne koncentracije potencialno toksičnih elementov (PTE) v peloidu iz zaliva Makirina, določenih v tokratni raziskavi znašajo: As (17, 6 mg/kg), Cr (92, 09 mg/kg), Cu (44, 5 mg/kg), Mo (31, 8 mg/kg), Pb (28, 9 mg/kg) in Zn (69, 2 mg/kg) in so primerljive z rezultati preteklih študij. Koncentracije PTE v bentoški algi Codium bursi (C. bursa) so sledeče: As (8, 8 mg/kg), Cr (15, 7 mg/kg), Cu (5, 6 mg/kg), Mo (0, 7 mg/kg), Pb (3, 6 mg/kg) in Zn (16, 3 mg/kg). Izračunani faktorji prenosa (TF) za PTE iz površinskega peloida (0–5 cm) v bentoško algo C. burso so manjši od 1, kar pomeni, da se PTE iz peloida ne prenašajo oziroma se v C. bursi ne akumulirajo. Rezultati prisotnosti koliformnih bakterij in E. coli se ujemajo s preteklimi rezultati, ki so pokazali, da jih v peloidu ni, kar nakazuje, da peloid ni fekalno kontaminiran. Peloid iz zaliva Makirina ima (z izjemo povišanih koncentracij Cr in Mo) primerljive lastnosti s peloidi, ki se trenutno že uspešno uporabljajo v različnih spa-centrih po svetu, vendar je treba pred potencialno uporabo opraviti dodatne raziskave, kot je na primer določitev mobilnosti Cr in Mo.

The research focuses on determination of Geochemical characteristics and distribution of Rareearth elements (REEs) in Makirina Bay sediments. The overall REEs concentrations in Makirina Bay sediments samplesdetected during study ranged from 123.94 ppm to 188.74 ppm. REEs content showed a gradual increase towardsthe depth of sediments. The average UCC-normalized REEs pattern pointed out negative δCe values and positive δEuvalues, indicating reductive conditions prevailing in Makirina Bay sediments. Calculated enrichment factor values arein the range of natural variability with no addition of different anthropogenic components. According to sequentialextraction procedure results, the studied fractions can be followed from highest to lowest percentage of REEs as: oxidizable> exchangeable > reducible+residual > reducible > water soluble fraction. The calculated transfer factor valuesgenerally confirmed the sequential extraction procedure results. The concentrations of all studied REEs are higherin above-ground than in below-ground biomass of seagrass Cymodocea nodosa.