Marijan Ahel

Ruđer Bošković Institute | RBI · Division for Marine and Environmental Research

The consumption patterns of five categories of psychoactive substances (PS), including "conventional" illicit drugs, new psychoactive substances (NPS), therapeutic opioids, alcohol and nicotine, were studied in the city of Split, Croatia, using wastewater-based epidemiology (WBE), with an emphasis on the impact of a large electronic music festival....

In this work, a wide-scope liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantitative determination of environmental levels of multiclass drugs and their metabolites in water and fish samples was developed. The method allowed the reliable determination of 44 drugs, covering a rather wide range of chemistries and physicoch...

Biomass dynamics in the marine lake are strongly dependent on seasonal variability in vertical stratification, indicating rapid adaptation of phytoplankton to short-term changes in the water column. A small marine lake (Rogoznica Lake, Croatia), which fluctuates between stably stratified and holomictic euxinic conditions, was used as a model to stu...

Microcystins (MCs) are the most studied cyanotoxins. The uptake of MCs in cells and tissues of mammals and fish species is mostly mediated by organic anion-transporting polypeptides (OATPs in humans and rodents; Oatps in other species), and the Oatp1d1 appears to be a major transporter for MCs in fish. In this study, six MC congeners of varying phy...

Macrolide antibiotics azithromycin (AZI), erythromycin (ERY) and clarithromycin (CLA) have been recently included in the EU Watch List of contaminants of emerging concern in the aquatic environment. However, their comprehensive assessment in different environmental compartments, by including synthesis intermediates, by-products and transformation p...

The main goal of this study was to perform an ecotoxicological profiling of terrestrial and aquatic cyanobacterial strains found in different soils or in toxic cyanobacterial blooms in Vojvodina region, Serbia, using the effect-directed analysis (EDA) approach. The applied procedure was based on a series of in vitro or small-scale bioassays coverin...

The biodegradation of biorecalcitrant opioid drug tramadol (TRAM) was studied in a model biodegradation experiment performed with an enriched activated sludge culture pre-adapted to high concentration of TRAM (20mg/L). TRAM and its transformation products (TPs) were determined by applying ultrahigh- performance liquid chromatography/quadrupole-time...

A one-year study on the occurrence and fate of macrolide antibiotics and their metabolites, synthesis byproducts, and transformation products (TPs) was performed in the wastewater treatment plant of the city of Zagreb (Croatia). The target compounds were found in all analyzed influent and effluent samples with the total concentrations of azithromyc...

This study investigated the occurrence of 48 contaminants of emerging concern (CECs) in wastewater effluents from three Slovenian and three Croatian waste water treatment plants (WWTPs) representing the major inputs into the upper and middle course of the Sava River and simultaneously in the Sava River itself. Two sampling campaigns were carried ou...

The biotransformation study of difficult-to-degrade opioid analgesic methadone (MTHD) was performed by activated sludge culture adapted to high concentration of methadone (10 mg/L). The study included determination of elimination kinetics of the parent compound, taxonomic characterization of microbial culture, identification of biotransformation pr...

A comprehensive study aimed at monitoring of temporal variability of illicit drugs (heroin, cocaine, amphetamine, MDMA, methamphetamine and cannabis) and therapeutic opiate methadone in a large-sized European city using wastewater-based epidemiology (WBE) was conducted in the city of Zagreb, Croatia, during an 8-year period (2009-2016). The study a...

The biotransformation of three prominent macrolide antibiotics (azithromycin, clarithromycin and erythromycin) by an activated sludge culture, which was adapted to high concentrations of azithromycin (10 mg/L) was investigated. The study included determination of removal kinetics of the parent compounds, identification of their major biotransformat...

Although published literature provides a clear demonstration of widespread occurrence of opioid analgesics (OAs) in the aquatic environment, analytical methods suitable for a systematic study of this pharmaceutical class, which would include a broad spectrum of opioid analgesics and their metabolites, are still missing. In this work, a comprehensiv...

Effluents from pharmaceutical industries are recognized as significant contributors to aquatic pollution with antibiotics. Although such pollution has been mostly reported in Asia, knowledge on industrial discharges in other regions of the world, including Europe, and on the effects associated with such exposures is still limited. Thus, we performe...

Macrolide antibiotics are a prominent group of emerging contaminants frequently found in wastewater effluents and wastewater-impacted aquatic environments. In this work, a novel analytical method for simultaneous determination of parent macrolide antibiotics (azithromycin, erythromycin, clarithromycin and roxithromycin), along with their synthesis...

The discovery and study of toxin-antitoxin (TA) systems helps us advance our understanding of the strategies prokaryotes employ to regulate cellular processes related to the general stress response, such as defense against phages, growth control, biofilm formation, persistence and programmed cell death. Here we identify and characterise a TA system...

Caulerpa taxifolia is a marine alga of tropical and subtropical distribution and a well-known invasive species in several temperate regions. Its invasiveness mainly stems from the production of secondary metabolites, some of which are toxic or repellent substances. In this study we investigated the possible inhibitory effects of C. taxifolia second...

The implementation of targeted and nontargeted chemical screening analysis in combination with in vitro and organism-level bioassays is a prerequisite for a more holistic monitoring of water quality in the future. For chemical analysis, little or no sample enrichment is often sufficient, while bioanalysis often requires larger sample volumes at a c...

The discovery and study of toxin-antitoxin (TA) systems helps us advance our understanding of the strategies prokaryotes employ to regulate cellular processes related to the general stress response, such as defense against phages, growth control, biofilm formation, persistence, and programmed cell death. Here we identify and characterize a TA syste...

This paper presents the levels of sulphur, polycyclic aromatic hydrocarbons (PAHs), and potentially toxic trace elements in soils surrounding the Plomin coal-fired power plant (Croatia). It used domestic superhigh-organic-sulphur Raša coal from 1970 until 2000. Raša coal was characterised by exceptionally high values of S, up to 14%, making the dow...

A comprehensive study of spatial and temporal consumption patterns of the selected illicit drugs (heroin, cocaine, amphetamine, MDMA, methamphetamine, cannabis) and therapeutic opioids (codeine, methadone) has been performed in six Croatian cities by applying wastewater-based epidemiology. The investigated cities (Bjelovar, Vinkovci, Varazdin, Karl...

ADP-ribosylation is a post-translational modification that can alter the physical and chemical properties of target proteins and controls many important cellular processes. Macrodomains are evolutionarily conserved structural domains that bind ADP-ribose derivatives and are found in proteins with diverse cellular functions. Some proteins from the m...

In this work extraction by agitation (EA), ultrasound solvent extraction (USE), microwave assisted extraction (MAE) and pressurized liquid extraction (PLE) followed by high performance liquid chromatography with diode array detector (HPLC–DAD) for the determination of eight veterinary pharmaceuticals from different structural groups including one m...

Besides the common illicit drugs, such as cocaine, heroin, and marijuana, there is a growing concern about the use of modern "designer drugs" that have emerged in large numbers over the past few years. In this work, a sensitive and selective method for simultaneous determination of 25 synthetic amphetamine-like psychoactive compounds, including amp...

Power point presentation (27th IAGS, Tucson, Arizona, USA)

Oral presentation abstract presented on the 27th International Applied Geochemistry Symposium (The Association of Applied Geochemists) held in April 2015 · TUCSON, ARIZONA USA

Driving forces related to settlements, agriculture, and release of contaminated untreated effluents from municipalities and industrial facilities that are greatly dominated by old and environmentally unfriendly technologies have always been considered as key elements that exert significant pressure on the ecological status of the Sava River. Despit...

The s-triazine herbicide terbuthylazine (TERB) has been used as the main substitute of atrazine in many EU countries for more than 10 years. However, the ecological consequences of this substitution are still not fully understood. Since the fate of triazine herbicides is primarily dependent on microbial degradation, in this paper, we investigated t...

Poly-ADP-ribosylation is a post-translational modification that regulates processes involved in genome stability. Breakdown of the poly(ADP-ribose) (PAR) polymer is catalysed by poly(ADP-ribose) glycohydrolase (PARG), whose endo-glycohydrolase activity generates PAR fragments. Here we present the crystal structure of PARG incorporating the PAR subs...

Supplementary Figures S1-S6

The initial training network consortium novel tools in effect-directed analysis to support the identification and monitoring of emerging toxicants on a European scale (EDA-EMERGE) was formed in response to the seventh EU framework program call to train a new generation of young scientists (13 PhD fellows and 1 postdoctoral fellow) in the interdisci...

P-glycoprotein (P-gp, ABCB1) is an important part of the multixenobiotic resistance (MXR) defense system in aquatic organisms. The main goal of this study was identification of P-gp inhibitors in contaminated sediments using the effect-directed analysis (EDA) approach. The samples were collected from the Gorjak creek (Zagreb, Croatia), a recipient...

For the first time, an integrated procedure for a quantitative multiresidue analysis of dissolved and particulate illicit drug target residues was developed and validated in three different wastewater matrices. The procedure consists of a comprehensive sample enrichment, fractionation and cleanup followed by the determination of target analytes by...

Sources and distribution of major and trace elements were investigated in the Plitvice Lakes, a pristine cascade hydrological system of sixteen karst lakes situated in a sparsely populated area of the central Croatia. Water and surface sediment samples from 17 locations, including springs, tributaries and lakes, were analyzed for the content of 22...

Comprehensive study on the occurrence and fate of several classes of antimicrobials, including sulfonamides, trimethoprim, fluoroquinolones and macrolides, in Croatian municipal wastewaters was performed using an integrated approach, which comprised analysis of both dissolved and particulate fractions. A nation-wide screening showed ubiquitous occu...

Region-specific contaminant prioritisation is an important prerequisite for sustainable and cost-effective monitoring due to the high number of different contaminants that may be present. Surface water and sediment samples from the Sava River, Croatia, were collected at four locations covering a 150-km-long river section characterised by well-defin...

Poly(ADP-ribosyl)ation is a reversible post-translational protein modification involved in the regulation of a number of cellular processes including DNA repair, chromatin structure, mitosis, transcription, checkpoint activation, apoptosis and asexual development. The reversion of poly(ADP-ribosyl)ation is catalysed by poly(ADP-ribose) (PAR) glycoh...

EDA-EMERGE aims to train a new generation of young scientists in the interdisciplinary techniques required to meet the major challenges in the monitoring, assessment and management of toxic pollution in European river basins considering the enormous complexity of contamination, effects and cause-effect relationships. By integrating innovative mode-...

A total of 866 samples of 28 different kinds of fresh fruits and vegetables from import and domestic production were analyzed. In 67.1% of the samples no residues were found, 27.3% of samples contained pesticide residues at or below maximum residue limit (MRL), and 5.6% of samples contained pesticide residues above MRL. In this study, the exposure...

The Pale Yellow (PY) Naphthalan is potentially a new treatment modality for some oral mucosal and dermatological diseases. Its chemical composition and physical properties were studied by standard and sophisticated methods. Special attention was paid to steranes and hopanes as favorable components and to aromatics as unfavorable compounds. PY Napht...

Post-translational modification of proteins by poly(ADP-ribosyl)ation regulates many cellular pathways that are critical for genome stability, including DNA repair, chromatin structure, mitosis and apoptosis. Poly(ADP-ribose) (PAR) is composed of repeating ADP-ribose units linked via a unique glycosidic ribose-ribose bond, and is synthesized from N...

Removal of numerous classes of pharmaceuticals from the municipal and industrial wastewater, using conventional wastewater treatment, is incomplete and several studies suggested that improvement of this situation would require the application of advanced treatment techniques. This is particularly important for the treatment of industrial effluents,...

Ultrahigh-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry was applied for the identification of transformation products (TPs) of fluoroquinolone (norfloxacin and ciprofloxacin) and macrolide (azithromycin, erythromycin, and roxitromycin) antimicrobials in wastewater effluents from a Zenon hollow-fiber membra...

The anthropogenic impact on the pristine karst lakes was investigated using combination of specific parameters, including multielemental analysis of major inorganic constituents (Al, K, Fe) and trace metals (Li, Ag, Cd, Sn, Pb, Bi, Cr, Co, Ni, Cu, Zn and Sb), polycyclic aromatic hydrocarbons (PAHs) and anionic surfactants of linear alkylbenzene sul...

A comprehensive analytical procedure for a reliable identification of nontarget polar contaminants in aquatic sediments was developed, based on the application of ultra-high-pressure liquid chromatography (UHPLC) coupled to hybrid quadrupole time-of-flight mass spectrometry (QTOFMS). The procedure was applied for the analysis of freshwater sediment...

Prioritization of hazardous chemical contaminants in the Sava River basin using EDA approach Marijan Ahela, Senka Terzica, Roko Zajaa, Ivan Sentaa, Jovica Loncara, Marta Popovica, Iva Mikaca, Knut Erik Tollefsenb, Kevin. V. Thomasb, Tvrtko Smitala a Division for Marine and Environmental Research, Rudjer Boskovic Institute, Bijenicka 54, HR-10000...

A comprehensive study of various psychoactive substances and their metabolites was performed in the wastewater treatment plant of the city of Zagreb (780 000 inhabitants) using liquid chromatography/tandem mass spectrometry (LC-MS-MS). The estimation of drug abuse for five different illicit drugs, including heroin, cocaine, marijuana, amphetamine a...

Analytical procedures using normal-phase high-performance liquid chromatography (HPLC) with fluorescence detection, suitable for the routine determination of alkylphenol polyethoxylate (APnEO) surfactants and their lipophilic metabolites in sewage effluents at sub-microgram per litre level, have been developed. The parent nonylphenol polyethoxylate...

Dissolved and particulate carbohydrates (DTCHO and PTCHO) as well as surface-active substances concentrations and relative acidities (SAST and Acr) were studied in the northern Adriatic Sea during the period between 1998 and 2005 with the aim to investigate their temporal and spatial dynamics in the basin and possible links with the mucilage events...

Diatom composition and abundance in biofilm that formed on artificial substrates exposed at several depths in July 2000 were investigated at two stations in Croatia's oligotrophic and highly-stratified Zrmanja Estuary. Chlorophyll a ranged from 2.27 to 92.81 mg m-2. HPLC analysis provided evidence of diatom dominance, while green algae and cyanobac...

A sensitive and highly selective method for the simultaneous determination of sulfonamides, macrolides, fluoroquinolones and trimethoprim in wastewater and river water has been developed. Samples were enriched by solid-phase extraction and analysed by reversed-phase liquid chromatography coupled to electrospray ionisation tandem mass spectrometry....

This paper reports on a comprehensive reconnaissance of over seventy individual wastewater contaminants in the region of Western Balkan (WB; Bosnia and Herzegovina, Croatia and Serbia), including some prominent classes of emerging contaminants such as pharmaceuticals and personal care products, surfactants and their degradation products, plasticize...

The distribution of the dissolved and the particulate carbohydrates in the River Zrmanja estuary was investigated for the first time. Investigations were performed at five stations during a four-year period. In order to reflect stratified character of the estuary sampling was performed at different depths. For that reason, depth was treated as a co...

Phytoplankton distribution and environmental characteristics were determined in a shallow, highly stratified and oligotrophic estuary (Zrmanja, eastern Adriatic). Samples were collected in two contrasting seasons; winter (February 2000), when river discharge was high, and in summer (July 2003), a period of drought. Phytoplankton distribution was cl...

Paper reports the results of landfill leachate treatment with membrane bioreactor, nanofiltration and ozonation. Investigated leachate encompasses a number of specific compounds of pharmaceutical origin, including a suite of by-products deriving from the production of vitamin C and propyphenazone. Low biodegradability was observed in MBR (16%) for...

The Plitvice Lakes National Park is situated in a pristine and sparsely populated area of the northwestern Dinarides, central Croatia. The basic geomorphological phenomenon of the Park consists of 16 karst lakes interconnected by numerous cascades and waterfalls, formed by travertine barriers. During the last century the area experienced significan...

Phytoplankton distribution and environmen-tal characteristics were determined in a shallow, highly stratified and oligotrophic estuary (Zrmanja, eastern Adriatic). Samples were collected in two contrasting seasons; winter (February 2000), when river discharge was high, and in summer (July 2003), a period of drought. Phytoplankton distribution was c...

As a widely spread cyprinid fish species, the European chub (Leuciscus cephalus) has been used extensively in biomonitoring programs. However, no laboratory dose-response and/or time course studies related to applied biomarkers have been reported on chub yet. In order to address this issue, specimens of juvenile chub caught in September 2005 in the...

This work provides an inventory of water resources and presents the current status of water supply, water quality as well as wastewater management in Bosnia and Herzegovina, Croatia and the State Union of Serbia and Montenegro, established after the break-up of the former Yugoslavia. All three countries are very rich in water resources, pertaining...

The organic toxicants present in the effluent of the main sewer of the city of Zagreb, Croatia were isolated and identified through the use of effects-directed characterisation techniques. At the time of investigation, the wastewater effluent received no treatment and was comprised of a mixture of effluent from domestic and industrial sources. The...

Cited By (since 1996):24, Export Date: 18 October 2014

Municipal wastewaters are among the most important sources of waste materials released into the environment. In Croatia, this problem is especially pronounced since only 4.4% of the total wastewaters are subject to complete mechanical and biological treatment. Beside a limited number of regulated organic contaminants, wastewaters contain an extreme...

Landfilling is probably, the most popular disposal method for the management of domestic and industrial waste. Unfortunately, many landfills around the world do not include leachate collection systems and present a considerable risk to the underlying aquifers. There have been numerous reports on groundwater contamination in the vicinity of unprotec...

Seasonal and spatial distributions of dissolved (DTCHO) and particulate carbohydrates (PTCHO) were investigated in the highly stratified estuary of the Krka River over a period of one year. The observed longitudinal and vertical and concentration profiles indicate that the strongest accumulation of DTCHO occurs in the surface layer of during summer...

Landfilling is probably, the most popular disposal method for the management of domestic and industrial waste. Unfortunately, many landfills around the world do not include leachate collection systems and present a considerable risk to the underlying aquifers. There have been numerous reports on groundwater contamination in the vicinity of unprotec...

Anthropogenic activities that introduce an excess of nutrients and other pollutants into rivers and lakes are causing significant changes in their aquatic environment. Excessive nutrients greatly accelerate eutrophication, and lake marl formed during eutrophication differs from that formed in oligotrophic water. We analyzed recent sediment cores fr...

Municipal wastewaters are among the most important sources of waste materials released into the environment. In Croatia, this problem is especially pronounced since only 4.4 % of the total wastewaters are subject to complete mechanical and biological treatment. Beside a limited number of regulated organic contaminants, wastewaters contain an extrem...

Large-scale mucilage events in the northern Adriatic have become more frequent during the last few decades. Since carbohydrates (CHO) comprise one of the major constituents of the Adriatic mucilage, studying their seasonal and spatial patterns is one of the key prerequisites for the understanding of this phenomenon. This paper reports on the distri...

Behaviour of anionic surfactants of linear alkylbenzene sulphonates (LAS) type and non-ionic surfactants of nonylphenol polyethoxylate (NPnEO) type was studied in the conventional mechanical/biological sewage treatment plant (STP) as well as using a membrane biological reactor (MBR). LAS and NPnEO were determined using high performance liquid chrom...

The main landfill of the city of Zagreb generates several hundreds of cubic meters of heavily contaminated leachate per day. The organic composition of the leachate is particu-larly peculiar because, besides common macromolecular humus-like dissolved organic car-bon, it encompasses a number of specific compounds of pharmaceutical origin, including...

This paper summarizes several studies on input, distribution, and fate of two different types of aromatic surfactants, the anionic linear alkylbenzene sulphonates (LAS) and nonionic alkylphenol polyethoxylates (APnEO), in a karstic estuary characterized by sharp salinity gradients. A combination of reversed-phase and normal-phase HPLC analysis foll...

This study examined the partitioning of organic matter into particulate organic carbon (POC) and dissolved organic carbon (DOC) pools in nutrient-enriched enclosures containing natural plankton from the Gulf of Trieste (northern Adriatic), an area affected by mucilage. The strategy of nutrient additions was to introduce a pulse of new nutrients in...

The Rudjer Boskovic Institute is the largest and most productive scientific institute in Croatia, mainly in the areas of physics, chemistry, biology, ecology and oceanography. The institute also hosts two departments for marine and environmental research located in Zagreb and Rovinj, involving about 160 scientists, technicians and administrative st...

Distribution and behavior of selected pharmaceutical chemicals, including analgesics of the phenazone type and the most popular psychomotor stimulant, caffeine, have been determined in raw sewage and sewage effluents from treatment plants of several Croatian cities using gas chromatography with mass selective detection. The concentration of caffein...

The concentration of folic acid (FA), an important constituent of the vitamin B group, was determined over a period of 2 years in the water column of a small meromictic saline lake on the eastern Adriatic coast (Rogoznica Lake), as well as in the western part of the northern Adriatic Sea. The FA concentration was over the range of 0.1-13.5 nM in th...

Analgesics of the phenazone type, including propyphenazone, aminopyrine, and antipyrine, were determined in solid waste and leachate from the main landfill of the city of Zagreb, Croatia, as well as in soil and groundwater below the landfill. All structural identifications and quantitative analyses were performed using high-resolution gas chromatog...

Distribution and seasonal variability of dissolved organic carbon (DOC) and surface active substances (SAS) were studied along the depth profile (15 m) in a small eutrophicated and periodically anoxic sea lake (Rogoznica Lake, Eastern Adriatic coast) in 1996 and 1997. The range of DOC concentrations was characteristic for productive coastal marine...

An assessment of xenobiotic organic pollutants in solid waste of the city of Zagreb was performed using chemical characterisation of individual compounds by gas chromatography/mass spectrometry (GC/MS), and two biomarker methods. All extracts revealed a significant increase (5 to 16-fold) of the benzo(a)pyrene monooxygenase (BaPMO) activity in live...

Degradation products of nonionic surfactants of the nonylphenol polyethoxylate type (NPnEO) were reported recently to be estrogenic to fish at low microgram per litre concentrations. These estrogenic metabolites, including nonylphenol (NP), nonylphenol monoethoxylate (NP1EO) and nonylphenol diethoxylate (NP2EO) as well as their corresponding carbox...

Background and purpose: HPLC analyses of phytoplankton pigments are used for qualitative and quantitative determination of phytoplankton groups in the sea. The scope of our study was to investigate the phytoplankton distribution from the early spying to early autumn in the year when mucilage appeared (1997) and the years without the mucilage event...