Uptake/depuration kinetics, bioaccumulation potential and metabolic transformation of a complex pharmaceutical mixture in zebrafish (Danio rerio)

Uptake and elimination kinetics, bioconcentration factors (BCFs), and metabolic transformation of 20 different pharmaceutically active compounds (PhACs), covering a wide range of therapeutic categories and physico-chemical properties, were studied using zebrafish (Danio rerio). The fish were exposed to the mixture of the selected PhACs at environmentally relevant concentrations similar to 10 µg L-1. The experiments were performed in semi-static conditions and comprised a 7-day uptake period followed by a 7-day depuration period. Most of the PhACs reached a concentration plateau within the 7-day uptake-phase which was followed by an efficient depuration, with the observed uptake (ku) and depuration rate constants (kd,) ranging between 0.002 and 3.752 L kg-1 h-1, and 0.010 to 0.217 h-1, respectively. The investigated PhACs showed low to moderate BCFs. The highest BCFs of 47.8, 28.6 and 47.6 L kg-1 were determined for sertraline, diazepam and desloratadine, respectively. A high contribution of metabolic products to the total internal concentration was observed for some PhACs such as codeine (69%), sulfamethoxazole (51%) and verapamil (87%), which has to be taken into account when assessing the bioconcentration potential. Moreover, most of the metabolites exhibited significantly longer half-lives in zebrafish than their parent compounds and affected the overall depuration kinetics.

Assessing the impact of a major electronic music festival on the consumption patterns of illicit and licit psychoactive substances in a Mediterranean city using wastewater analysis

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. The study involved the analysis of 57 urinary biomarkers of PS in raw municipal wastewater samples collected in three characteristic periods, including the festival week in the peak-tourist season (July) and reference weeks in the peak-tourist season (August) and the off-tourist season (November). Such a large number of biomarkers allowed the recognition of distinct patterns of PS use associated with the festival, but also revealed some subtle differences between summer and autumn seasons. The festival week was characterized by markedly increased use of illicit stimulants (MDMA: 30-fold increase; cocaine and amphetamine: 1.7-fold increase) and alcohol (1.7-fold increase), while consumption of other common illicit drugs (cannabis and heroin), major therapeutic opioids (morphine, codeine and tramadol) and nicotine remained rather constant. Interestingly, NPS and methamphetamine clearly contributed to the festival PS signature in wastewater, but their prevalence was rather low compared to that of common illicit drugs. Estimates of cocaine and cannabis use were largely consistent with prevalence data from national surveys, whereas differences were found for typical amphetamine-type recreational drugs, particularly MDMA, and for heroin. The WBE data suggest that the largest proportion of morphine came from heroin consumption and that the percentage of heroin users seeking treatment in Split is probably rather low. The prevalence of smoking calculated in this study (30.6 %) was consistent with national survey data for 2015 (27.5-31.5 %), while the average alcohol consumption per capita >15 years (5.2 L) was lower than sales statistics suggest (8.9 L).

Multiclass determination of drug residues in water and fish for bioaccumulation potential assessment

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 physicochemical characteristics. In order to obtain a reliable and robust analytical protocol, different combinations of extraction and cleanup techniques were systematically examined. Aqueous samples were extracted using a simple Oasis HLB SPE enrichment protocol with pH-optimized sample percolation (pH 3). The extraction of cryo-homogenized biota samples was performed using double extraction with MeOH basified with 0.5% NH₃, which allowed high extraction recoveries for all target analytes. The problem of the coextracted lipid matrix, which is known to be the key obstacle for reliable biota analysis, was systematically examined in a series of model cleanup experiments. A combination of cryo-precipitation, filtration, and HLB SPE cleanup was proposed as a protocol, which allowed reliable and robust analysis of all target compounds at low ng/g levels. At the final conditions, the method which was validated at three concentration levels showed high extraction recoveries (68-97%), acceptable matrix effects (12 to -32%), accuracies (81-129%), and reproducibilities (3-32%) for all analytes. The developed method was used to determine drug concentrations in river water and in feral freshwater fish, including whole fish and muscle tissue, from the Sava River (Croatia), in order to estimate their corresponding bioaccumulation potential. With respect to bioaccumulation potential in whole fish and fish muscle, the most relevant drugs were lisinopril, sertraline, terbinafine, torsemide, diazepam, desloratadine, and loratadine with estimated bioaccumulation factors ranging from 20 to 838 and from 1 to 431, respectively.

Analysis and occurrence of macrolide residues in stream sediments and underlying alluvial aquifer downstream from a pharmaceutical plant

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 products, is still missing. In this work, a novel method, based on pressurized liquid extraction and liquid chromatography-tandem mass spectrometry, was developed and validated for the determination of such an extended range of macrolide residues in sediment and soil samples at low ng/g levels. The method was applied to determine distribution of 13 macrolides in surface and alluvial aquifer sediments collected in a small stream with a history of chronic exposure to wastewater discharges from AZI production. The total concentrations of the target macrolide compounds in surface sediments were up to 29 μg/g and the most prominent individual macrolides were parent AZI, its synthesis intermediate N-demethyl AZI and transformation products decladinosyl AZI and N'-demethyl AZI. Some ERY-related compounds, originating from AZI synthesis, were also frequently detected, though at lower concentration levels (up to 0.31 ng/g in total). The distribution of macrolide residues in surface sediments indicated their active longitudinal transport by resuspension and redeposition of the contaminated sediment particles. The vertical concentration profiles in stream sediments and the underlying alluvial aquifer revealed that macrolide residues reached deeper alluvial sediments (up to 5 m). Moreover, significant levels of macrolides were found in groundwater samples below the streambed, with the total concentrations reaching up to 1.7 μg/L. This study highlights the importance of comprehensive chemical characterization of the macrolide residues, which were shown to persist in surface and alluvial aquifer sediment more than ten years after their discharge into the aquatic environment.

Gestational diabetes mellitus: Prevention, diagnosis and treatment. A fresh look to a busy corner

BACKGROUND

Gestational diabetes mellitus (GDM) is a common pregnancy complication characterized by hyperglycaemia with onset or first recognition during pregnancy. Risk factors include family history of diabetes, previous GDM, genetic predisposition for GDM/type 2 diabetes, insulin resistance conditions such as overweight, obesity and ethnicity. Women with GDM are at high risk for fetal macrosomia, small for gestational age, neonatal hypoglycaemia, operative delivery and caesarean delivery. The aim of this narrative review is to summarize the most recent findings of diagnosis and treatment of GDM in order to underline the importance to promote adequate prevention of this disease, especially through lifestyle interventions such as diet and physical activity.

METHODS

The research was conducted using the following electronic databases, MEDLINE, EMBASE, Web of Science, Scopus, ClinicalTrial.gov, OVID and Cochrane Library, including all published randomized and non-randomized studies as well as narrative and systematic reviews.

RESULTS

The lack of universally accepted criteria makes the definition of diagnosis and prognosis of this condition difficult. Early diagnosis and glucose blood level control may improve maternal and fetal short and long-term outcomes. Treatment strategies include nutritional interventions and exercise. Medical treatment can be necessary if these strategies are not effective. Moreover, novel non-pharmacologic agents such as myo-inositol seem to be effective and safe both in the prevention and the treatment of GDM.

CONCLUSIONS

It is important to promote adequate prevention of GDM. Further studies are needed in order to better define the most appropriate strategies for the clinical management of women affected by GDM.

Spatio-temporal assessment of illicit drug use at large scale: evidence from 7 years of international wastewater monitoring

BACKGROUND AND AIMS

Wastewater-based epidemiology is an additional indicator of drug use that is gaining reliability to complement the current established panel of indicators. The aims of this study were to: (i) assess spatial and temporal trends of population-normalized mass loads of benzoylecgonine, amphetamine, methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA) in raw wastewater over 7 years (2011-17); (ii) address overall drug use by estimating the average number of combined doses consumed per day in each city; and (iii) compare these with existing prevalence and seizure data.

DESIGN

Analysis of daily raw wastewater composite samples collected over 1 week per year from 2011 to 2017.

SETTING AND PARTICIPANTS

Catchment areas of 143 wastewater treatment plants in 120 cities in 37 countries.

MEASUREMENTS

Parent substances (amphetamine, methamphetamine and MDMA) and the metabolites of cocaine (benzoylecgonine) and of Δ⁹ -tetrahydrocannabinol (11-nor-9-carboxy-Δ⁹ -tetrahydrocannabinol) were measured in wastewater using liquid chromatography-tandem mass spectrometry. Daily mass loads (mg/day) were normalized to catchment population (mg/1000 people/day) and converted to the number of combined doses consumed per day. Spatial differences were assessed world-wide, and temporal trends were discerned at European level by comparing 2011-13 drug loads versus 2014-17 loads.

FINDINGS

Benzoylecgonine was the stimulant metabolite detected at higher loads in southern and western Europe, and amphetamine, MDMA and methamphetamine in East and North-Central Europe. In other continents, methamphetamine showed the highest levels in the United States and Australia and benzoylecgonine in South America. During the reporting period, benzoylecgonine loads increased in general across Europe, amphetamine and methamphetamine levels fluctuated and MDMA underwent an intermittent upsurge.

CONCLUSIONS

The analysis of wastewater to quantify drug loads provides near real-time drug use estimates that globally correspond to prevalence and seizure data.

Aerobic biodegradation of tramadol by pre-adapted activated sludge culture: Cometabolic transformations and bacterial community changes during enrichment

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 (20 mg/L). TRAM and its transformation products (TPs) were determined by applying ultrahigh-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UHPLC-QTOF-MS), the sludge culture was characterized using a 16S rRNA gene amplicon sequencing, whereas ecotoxicological evaluation was performed based on determination of toxicity to freshwater algae. Tramadol removal was much faster (t_1/2 = 1.3 days) and more efficient in glucose-containing mineral medium (cometabolic conditions) than in a medium without glucose. The elimination of the parent compound resulted in the formation of five TPs, two of which (TP 249 and TP 235) were identified as N-desmethyltramadol (N-DM TRAM) and N,N-didesmethyltramadol (N,N-diDM TRAM). The remaining 3 TPs (TP 277a-c) were isomeric compounds with an elemental composition of protonated molecules C₁₆H₂₄NO₃ and a putative structure which involved oxidative modification of the dimethylamino group. Pronounced changes in the taxonomic composition of the activated sludge were observed during the enrichment, especially regarding an enhanced percentage of 8 genera (Bacillus, Mycobacterium, Enterobacter, Methylobacillus, Pedobacter, Xanthobacter, Leadbetterella and Kaistia), which might be related to the observed transformations. The removal of TRAM resulted in proportional reduction of algal toxicity, implying a positive result of the accomplished transformation processes.

Occurrence and Behavior of Macrolide Antibiotics in Municipal Wastewater Treatment: Possible Importance of Metabolites, Synthesis Byproducts, and Transformation Products

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 azithromycin-, clarithromycin-, and erythromycin-related compounds reaching up to 25, 12, and 0.25 μg/L, respectively. The most prominent individual constituents were the parent macrolides azithromycin and clarithromycin. However, a substantial contribution of their derivatives, formed by deglycolysation and microbial phosphorylation, was also detected. In addition, widespread presence of several linearized nontarget TPs was confirmed for the first time in real wastewater samples by suspect screening analysis. Complex characterization of macrolide-derived compounds enabled decoupling of industrial and therapeutic sources from the in situ transformations. Due to the high inputs and incomplete removal and/or formation of several TPs during the conventional wastewater treatment, the average mass load of azithromycin-related compounds in secondary effluents exceeded 3.0 g/day/1000 inhabitants. This is the first study to reveal the importance of metabolites, byproducts, and TPs for the overall mass balance of macrolide antibiotics in urban wastewater systems.

Long-term monitoring of drug consumption patterns in a large-sized European city using wastewater-based epidemiology: Comparison of two sampling schemes for the assessment of multiannual trends

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 addressed the impact of different sampling schemes on the assessment of temporal drug consumption patterns, in particular multiannual consumption trends and documented the possible errors associated with the one-week sampling scheme. The highest drug consumption prevalence was determined for cannabis (from 59 ± 18 to 156 ± 37 doses/day/1000 inhabitants 15-64 years), followed by heroin (from 11 ± 10 to 71 ± 19 doses/day/1000 inhabitants 15-64 years), cocaine (from 8.3 ± 0.9 to 23 ± 4.0 doses/day/1000 inhabitants 15-64 years) and amphetamine (from 1.3 ± 0.9 to 21 ± 6.1 doses/day/1000 inhabitants 15-64 years) whereas the consumption of MDMA was comparatively lower (from 0.18 ± 0.08 to 2.7 doses ±0.7 doses/day/1000 inhabitants 15-64 years). The drug consumption patterns were characterized by clearly enhanced weekend and Christmas season consumption of stimulating drugs (cocaine, MDMA and amphetamine) and somewhat lower summer consumption of almost all drugs. Pronounced multiannual consumption trends were determined for most of the illicit drugs. The investigated 8-year period was characterized by a marked increase of the consumption of pure cocaine (1.6-fold), THC (2.7-fold), amphetamine (16-fold) and MDMA (15-fold) and a concomitant decrease (2.3-fold) of the consumption of pure heroin. The heroin consumption decrease was associated with an increase of methadone consumption (1.4-fold), which can be linked to its use in the heroin substitution therapy. The estimated number of average methadone doses consumed in the city of Zagreb was in a good agreement with the prescription data on treated opioid addicts in Croatia.

Biodegradation study of methadone by adapted activated sludge: Elimination kinetics, transformation products and ecotoxicological evaluation

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 products (TPs) and assessment of ecotoxicological effects of biotransformation processes. The chemical analyses were performed by ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry, whereas the ecotoxicological assessment was made based on determinations of toxicity to freshwater algae. Changes of the adapted sludge culture during the experiment were followed using the 16S rRNA gene amplicon sequencing. Depending on the experimental conditions, the elimination efficiency of methadone (10 mg/L) varied from 9% to 93% with the corresponding half-lives from 11.4 days to 1.5 days. A significantly faster elimination (t_1/2 from 1.5 days to 5.8 days) was achieved at cometabolic conditions, using glucose-containing media, as compared to the experiments with MTHD as a single organic carbon source (t_1/2 = 11.4 days). Moreover, increased biotransformation rate following the additional supplementation of ammonia, revealed a possible importance of nitrogen availability for the transformation at cometabolic conditions. The elimination of parent compound was associated with the formation of 3 different TPs, two of which were identical to main human metabolites of MTHD, 2-Ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 2-ethyl-5-methyl-3,3-diphenyl-1-pyrroline (EMDP). EDDP represented over 90% of the total TP concentration at the end of experiment. The biodegradation of MTHD was associated with a pronounced drop in algal toxicity, confirming a rather positive ecotoxicological outcome of the achieved biotransformation processes.

Biotransformation of macrolide antibiotics using enriched activated sludge culture: Kinetics, transformation routes and ecotoxicological evaluation

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 biotransformation products (TPs) and assessment of ecotoxicological effects of biotransformation. The chemical analyses were performed by ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry, which enabled a tentative identification of TPs formed during the experiments. The ecotoxicological evaluation included two end-points, residual antibiotic activity and toxicity to freshwater algae. The enriched activated sludge culture was capable of degrading all studied macrolide compounds with high removal efficiencies (>99%) of the parent compounds at elevated concentrations (10 mg/L). The elimination of all three macrolide antibiotics was associated with the formation of different TPs, including several novel compounds previously unreported in the literature. Some of the TPs were rather abundant and contributed significantly to the overall mass balance at the end of the biodegradation experiments. Biodegradation of all investigated macrolides was associated with a pronounced reduction of the residual antibiotic activity and algal toxicity, indicating a rather positive ecotoxicological outcome of the biotransformation processes achieved by the enriched sludge culture.

Wastewater-based assessment of regional and temporal consumption patterns of illicit drugs and therapeutic opioids in Croatia

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, Karlovac, Zadar and Zagreb) varied widely in the population size (27,000-688,000 inhabitants) as well as in the number of registered drug consumers included in compulsory and voluntary medical treatment and rehabilitation programs (30-513 persons/100,000 inhabitants of age 15-64). The most consumed illicit drugs were cannabis (10-70doses/day/1000 inhabitants), heroin (<0.2-10doses/day/1000 inhabitants) and cocaine (0.2-8.7doses/day/1000 inhabitants), while the consumption of amphetamine-type drugs was much lower (<0.01-4.4doses/day/1000 inhabitants). Enhanced consumption of illegal drugs was generally associated with larger urban centers (Zagreb and Zadar) however comparatively high consumption rate of cocaine, MDMA and methadone was determined in some smaller cities as well. The overall average dose number of 3 major illegal stimulants (cocaine, MDMA, amphetamine) was rather similar to the number of corresponding heroin doses, which is in disagreement with a comparatively much higher proportion of heroin users in the total number of registered drug users in Croatia. Furthermore, the illicit drug consumption pattern in the large continental city (Zagreb) was characterized by a significant enhancement of the consumption of all stimulants during the weekend, which could not be confirmed neither for the coastal city of Zadar nor for the remaining small continental cities. On the other hand, the city of Zadar exhibited a significant increase of stimulant drug usage during summer vacation period, as a result of pronounced seasonal changes of the population composition and lifestyle in coastal tourist centers. The obtained results represent a valuable complementary data source for the optimisation and implementation of strategies to combat drug abuse in Croatia.

Spatial differences and temporal changes in illicit drug use in Europe quantified by wastewater analysis

AIMS

To perform wastewater analyses to assess spatial differences and temporal changes of illicit drug use in a large European population.

DESIGN

Analyses of raw wastewater over a 1-week period in 2012 and 2013.

SETTING AND PARTICIPANTS

Catchment areas of wastewater treatment plants (WWTPs) across Europe, as follows: 2012: 25 WWTPs in 11 countries (23 cities, total population 11.50 million); 2013: 47 WWTPs in 21 countries (42 cities, total population 24.74 million).

MEASUREMENTS

Excretion products of five illicit drugs (cocaine, amphetamine, ecstasy, methamphetamine, cannabis) were quantified in wastewater samples using methods based on liquid chromatography coupled to mass spectrometry.

FINDINGS

Spatial differences were assessed and confirmed to vary greatly across European metropolitan areas. In general, results were in agreement with traditional surveillance data, where available. While temporal changes were substantial in individual cities and years (P ranging from insignificant to <10(-3) ), overall means were relatively stable. The overall mean of methamphetamine was an exception (apparent decline in 2012), as it was influenced mainly by four cities.

CONCLUSIONS

Wastewater analysis performed across Europe provides complementary evidence on illicit drug consumption and generally concurs with traditional surveillance data. Wastewater analysis can measure total illicit drug use more quickly and regularly than is the current norm for national surveys, and creates estimates where such data does not exist.

Assessment of stability of drug biomarkers in municipal wastewater as a factor influencing the estimation of drug consumption using sewage epidemiology

Stability of the selected urinary biomarkers of six illicit drugs and two therapeutic opioids in municipal wastewater was studied in order to determine errors associated with their possible transformation in the sewer. The stability was assessed in experiments conducted at 10°C and 20°C in order to simulate typical winter and summer temperature conditions in the sewer system. Among fourteen substances tested, the most unstable compounds were morphine-3-β-D glucuronide (MG), 6-acetyl morphine (6-AM), cocaine (COC) and 6-acetyl codeine (6-AC), while all other investigated compounds appeared to be relatively stable over a period of 72 h. The transformation of all degradable compounds followed pseudo-first order kinetics with significantly longer half-times (t1/2) at winter conditions. At 20°C, t1/2 of MG, 6-AM, COC and 6-AC was 7h, 87 h, 35 h and 58 h, respectively, while the corresponding t1/2 values at 10°C were 18 h, 139 h, 173 h and 87 h. The main transformation mechanism of MG, 6-AM and 6-AC was most probably their enzymatic hydrolysis to morphine (MOR) and codeine (COD), while COC transformation to benzoylecgonine (BE) was primarily governed by chemical hydrolysis. The results indicate that the effect of the observed transformation of urinary biomarkers of COC and 6-AM on the estimates of COC and heroin consumption are relatively small (<10%) if the in-sewer hydraulic retention time is lower than 12h. Acidification of the wastewater samples proved to be the good way to stabilise the wastewater samples for the analysis of all selected compounds, except for 11-nor-9-carboxy-∆9-tetrahydrocannabinol (THC-COOH). This finding should be taken into account when selecting the preservation technique for multiresidual analyses of different groups of illicit drugs.

Occurrence and fate of dissolved and particulate antimicrobials in municipal wastewater treatment

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 occurrence of human-use antimicrobials in raw wastewater samples with the total concentrations ranging from 2 to 20 μg/L, while veterinary antimicrobials were typically present in much lower concentrations (<100 ng/L). The percentage of the particulate fraction in raw wastewater varied significantly depending on the type of the antimicrobial and the load of suspended solids. A detailed study of the mass flows of dissolved and particulate antimicrobials, performed in the wastewater treatment plant of the city of Zagreb, allowed an improved assessment of the biological and physico-chemical removal mechanisms of investigated compounds during the conventional activated sludge treatment. The overall removal efficiencies of antimicrobials from the water phase were rather variable, ranging from 0% for trimethoprim to 85% for norfloxacin. A significant percentage of fluoroquinolones (norfloxacin and ciprofloxacin) and macrolides (azithromycin and clarithromycin) was associated with the primary and excess secondary sludge, explaining 14-77% of the total removal. The removal, which could be attributed to biological transformation, was relatively poor for all antimicrobials, exceeding 30% only for SMX (32%) and clarithromycin (55%).

Comparing illicit drug use in 19 European cities through sewage analysis

The analysis of sewage for urinary biomarkers of illicit drugs is a promising and complementary approach for estimating the use of these substances in the general population. For the first time, this approach was simultaneously applied in 19 European cities, making it possible to directly compare illicit drug loads in Europe over a 1-week period. An inter-laboratory comparison study was performed to evaluate the analytical performance of the participating laboratories. Raw 24-hour composite sewage samples were collected from 19 European cities during a single week in March 2011 and analyzed for the urinary biomarkers of cocaine, amphetamine, ecstasy, methamphetamine and cannabis using in-house optimized and validated analytical methods. The load of each substance used in each city was back-calculated from the measured concentrations. The data show distinct temporal and spatial patterns in drug use across Europe. Cocaine use was higher in Western and Central Europe and lower in Northern and Eastern Europe. The extrapolated total daily use of cocaine in Europe during the study period was equivalent to 356 kg/day. High per capita ecstasy loads were observed in Dutch cities, as well as in Antwerp and London. In general, cocaine and ecstasy loads were significantly elevated during the weekend compared to weekdays. Per-capita loads of methamphetamine were highest in Helsinki and Turku, Oslo and Budweis, while the per capita loads of cannabis were similar throughout Europe. This study shows that a standardized analysis for illicit drug urinary biomarkers in sewage can be applied to estimate and compare the use of these substances at local and international scales. This approach has the potential to deliver important information on drug markets (supply indicator).

Removal of antimicrobials using advanced wastewater treatment

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, released from pharmaceutical industries, which can contain rather high concentrations of antimicrobials. The aim of this work was to evaluate membrane bioreactors (MBRs), nanofiltration, reverse osmosis and ozonation, as well as their combinations, for the removal of antimicrobials from a synthetic wastewater which simulated highly contaminated industrial effluents. The study was performed using a mixture of four important classes of antimicrobials, including sulfonamides (SA), fluoroquinolones (FQ), macrolides (MAC) and trimethoprim (TMP). Performance of two different types of MBRs, Kubota and Zenon, was evaluated under different regimes regarding hydraulic retention time, total organic load and total nitrogen load. It was shown that elimination of SA in MBR treatment was very efficient, while the elimination of MAC, FQ, and TMP was incomplete. A mass balance of these contaminants in MBR suggested that microbial transformation represented the main mechanism, while only a small percentage was eliminated from the aqueous phase by adsorption onto sludge particles. Nanofiltration and reverse osmosis achieved high elimination rates however produced highly contaminated concentrate. High removal was achieved using ozonation, but further research is needed to characterize formed ozonation products.

Assessment of toxicological profiles of the municipal wastewater effluents using chemical analyses and bioassays

The hazardous chemical contamination of untreated wastewater and secondary effluent from the wastewater treatment plant (WWTP) of the city of Zagreb, Croatia was comprehensively characterized using large-volume solid-phase extraction (SPE) and silica gel fractionation, followed by a detailed analysis of the resulting extracts by a combination of chemical and bioassay methods. Over 100 individual contaminants or closely related-contaminant groups were identified by high-resolution gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/quadrupole time-of-flight mass spectrometry (LC-QTOF). Ecotoxicity profiling of the investigated samples, including cytotoxicity, chronic toxicity and EROD activity; inhibition of the multixenobiotic resistance (MXR), genotoxicity and estrogenic potential, revealed the most significant contribution of toxic compounds to be present in polar fractions. Wastewater treatment using conventional activated sludge process reduced the initial toxicity of raw wastewater to various extents, ranging from 28% for algal toxicity to 73.2% for an estrogenic activity. The most efficient toxicity removal was observed for the polar compounds.

Nontarget analysis of polar contaminants in freshwater sediments influenced by pharmaceutical industry using ultra-high-pressure liquid chromatography-quadrupole time-of-flight mass spectrometry

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 that was highly impacted by wastewater discharges from the pharmaceutical industry. A number of different contaminants were successfully identified owing to the high mass accuracy of the QTOFMS system, used in combination with high chromatographic resolution of UHPLC. The major compounds, identified in investigated sediment, included a series of polypropylene glycols (n=3-16), alkylbenzene sulfonate and benzalkonium surfactants as well as a number of various pharmaceuticals (chlorthalidone, warfarin, terbinafine, torsemide, zolpidem and macrolide antibiotics). The particular advantage of the applied technique is its capability to detect less known pharmaceutical intermediates and/or transformation products, which have not been previously reported in freshwater sediments.

Illicit drugs in wastewater of the city of Zagreb (Croatia)--estimation of drug abuse in a transition country

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 and ecstasy, was made on the basis of their representative excretion rates, which were determined over a period of 8 months. Marijuana (1000 kg/year), heroin (75 kg/year) and cocaine (47 kg/year) were found to be the most frequently consumed illicit drugs, while the consumption of amphetamine-type drugs was much lower (1-3 kg/year). A comparison with other reports indicated that drug abuse profiles in transition countries might be different from those reported for Western Europe, in particular with respect to the comparatively increased consumption of heroin. Enhanced consumption of stimulating drugs (cocaine and ectasy) was systematically detected during weekends.

Spatial and temporal variability of carbohydrates in the northern Adriatic--a possible link to mucilage events

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 distribution of particulate (PTCHO) and dissolved carbohydrates (DTCHO) in the period from June 1999 to July 2002, with a special emphasis on the summer mucilage events. A particular attention was paid to the relationship between the phytoplankton crop as reflected by photosynthetic pigments and carbohydrate levels in different seasons. The concentration of PTCHO varied in a very wide range (1-72 micromol C/l). Their seasonal distribution revealed that enhanced levels of PTCHO occurred only in the surface layer (0-5 m) and were associated with major phytoplankton blooms. However, the main pool of CHO was in the dissolved fraction, comprising on average 84+/-10% of the total CHO. In contrast to PTCHO, there was no seasonal coincidence between the enhanced phytoplankton biomass and concentrations of DTCHO. In fact, the concentration of DTCHO showed regularly a marked increase during summer, when the phytoplankton biomass remained relatively low. Nevertheless, the concentration of DTCHO in the productive surface layer, influenced by the Po River discharges, was significantly higher than that in the deeper layers. The detailed vertical distribution of carbohydrates indicated that phytoplankton populations in the bottom layer possessed a rather modest potential as a source of CHO. The spatial distribution in the surface layer along the transect Rovinj-Po River mouth revealed only a moderate increase of the total CHO concentration in the more eutrophic western part of the basin. Analysis of pluriannual variability of the total CHO levels showed that probability of a mucilage event in a given year depended on the accumulation of CHO during spring, but, even more, on the prevailing circulation pattern in the basin during the stratification period.

Elimination of aromatic surfactants from municipal wastewaters: comparison of conventional activated sludge treatment and membrane biological reactor

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 chromatography (HPLC) equipped with spectrofluorimetric detection. Liquid chromatography/tandem mass spectrometry (LC/MS/MS) was used for identification and quantification of stable metabolites, including nonylphenol (NP), nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO) and nonylphenoxy carboxylic acids (NPnEC). The study showed that aromatic surfactants belong to the most prominent constituents in the examined municipal wastewaters with typical LAS and NPnEO concentrations of 2-10 mg/L and 0.1-0.5 mg/L, respectively. The removal of aromatic surfactants in conventional STP showed well-known features reported in the literature, including an efficient microbial transformation of the parent molecules and formation of stable metabolic products. The elimination efficiency of aromatic surfactants using the MBR unit was higher than that in the conventional STP, while the composition of recalcitrant nonylphenolic residues in the effluent seems to be ecotoxicologically more favourable due to the lower contributions of the lipophilic metabolites.