Assessing the risk of booster biocides for the marine environment: A case study at the Belgian part of the North Sea.

The biofouling of submerged surfaces such as ship hulls is often prevented by using anti-fouling components in combination with booster biocides. These booster biocides enter the water column and may affect non-target organisms. Although different negative effects have been associated with the use of booster biocides, their effects on non-target organisms are often unknown. So far, the environmental risks for booster biocides have barely been quantified in the North Sea. In this work, the concentration of five commonly used booster biocides as well as tributyltin has been monitored at five dredged spoil disposal sites in the Belgian part of the North Sea and the harbour and ports of Nieuwpoort, Oostende, and Zeebrugge. Hotspots were discovered where the concentration of one or more booster biocides exceeded the predicted no-effect concentration. Tributyltin has been banned since 2008, but concentrations of 237- to 546-fold of the predicted no-effect concentration were detected in the harbours and ports. Moreover, TBT has been detected in the same order of magnitude in other sea basins, emphasizing the need to monitor the trends and impact of booster biocides and TBT in environmental monitoring programs.

A recipe for plastic: Expert insights on plastic additives in the marine environment.

The production and consumption of plastic products had been steadily increasing over the years, leading to more plastic waste entering the environment. Plastic pollution is ubiquitous and comes in many types and forms. To enhance or modify their properties, chemical additives are added to plastic items during manufacturing. The presence and leakage of these additives, from managed and mismanaged plastic waste, into the environment are of growing concern. In this study, we gauged, via an online questionnaire, expert knowledge on the use, characteristics, monitoring and risks of plastic additives to the marine environment. We analysed the survey results against actual data to identify and prioritise risks and gaps. Participants also highlighted key factors for future consideration, including gaining a deeper understanding of the use and types of plastic additives, how they leach throughout the entire lifecycle, their toxicity, and the safety of alternative options. More extensive chemical regulation and an evaluation of the essentiality of their use should also be considered.

Emerging pharmaceutical therapies of Ascidian-derived natural products and derivatives.

In a growing multidrug-resistant environment, the identification of potential new drug candidates with an acceptable safety profile is a substantial crux in pharmaceutical discovery. This review discusses several aspects and properties of approved marine natural products derived from ascidian sources (phylum Chordata, subphylum Tunicata) and/or their deduced analogues including their biosynthetic origin, (bio)chemical preclinical assessments and known efficacy-safety profiles, clinical status in trials, but also translational developments, opportunities and final conclusions. The review also describes the preclinical assessments of a large number of other ascidian compounds that have not been involved in clinical trials yet. Finally, the emerging research on the connectivity of the ascidian hosts and their independent or obligate symbiotic guests is discussed. The review covers the latest information on the topic of ascidian-derived marine natural products over the last two decades including 2022, with the majority of publications published in the last decade.

Short- and long-term assessment of PAH, PCB, and metal contamination in the Belgian part of the North Sea.

Dredging activities can result in the relocation of contaminants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and metals from shipping channels, harbours, and ports into the marine environment where these components may exert a negative effect on the marine ecosystem. In this work, contamination associated with dredging is evaluated at and around dredged spoil disposal sites in the Belgian part of the North Sea, taking into account spatial as well as temporal variation. A homogeneous dispersion of the different contaminants was observed at the different sites. However, the contamination pattern was different for disposal sites that were linked with commercial ports, resulting in significantly higher PAH and PCB concentrations. When comparing concentrations with environmental assessment criteria, contamination of PAHs does not exceed these criteria in the Belgian Part of the North Sea, and for PCBs, only CB118 reveals a concerningly high concentration that exceeds the environmental assessment criteria. This is in contrast with metals where the contamination of As, Cr, Ni, and Zn exceeded the environmental limit values both at dredged spoil disposal sites and reference locations.

Microplastic detection and identification by Nile red staining: Towards a semi-automated, cost- and time-effective technique.

Microplastic pollution is an issue of concern due to the accumulation rates in the marine environment combined with the limited knowledge about their abundance, distribution and associated environmental impacts. However, surveying and monitoring microplastics in the environment can be time consuming and costly. The development of cost- and time-effective methods is imperative to overcome some of the current critical bottlenecks in microplastic detection and identification, and to advance microplastics research. Here, an innovative approach for microplastic analysis is presented that combines the advantages of high-throughput screening with those of automation. The proposed approach used Red Green Blue (RGB) data extracted from photos of Nile red-fluorescently stained microplastics (50-1200 µm) to train and validate a 'Plastic Detection Model' (PDM) and a 'Polymer Identification Model' (PIM). These two supervised machine learning models predicted with high accuracy the plastic or natural origin of particles (95.8%), and the polymer types of the microplastics (88.1%). The applicability of the PDM and the PIM was demonstrated by successfully using the models to detect (92.7%) and identify (80%) plastic particles in spiked environmental samples that underwent laboratorial processing. The classification models represent a semi-automated, high-throughput and reproducible method to characterize microplastics in a straightforward, cost- and time-effective yet reliable way.

Oxygenated polycyclic aromatic hydrocarbons in mussels: analytical method development and occurrence in the Belgian coastal zone.

An analytical method was developed for the trace quantification of oxygenated polycyclic aromatic hydrocarbons (oxyPAHs) in mussels. Compounds included were naphthalene-1-ol, 9H-fluoren-9-one, anthracene-9,10-dione, 7H-benz[de]anthracene-7-one, naphtacene-5,12-dione, and benzo[a]anthracene-7,12-dione. Pyrene-1-carboxaldehyde was applied as an internal standard. Sample extraction by pressurized liquid extraction was followed by cleanup on silica, separation by high performance liquid chromatography, and quantitative measurement by mass spectrometry with atmospheric pressure chemical ionization. The method was validated by the analysis of spiked mussel samples, resulting in trueness values of 90-124% and measurement uncertainties of 6-49%, except for naphthalene-1-ol. Quantification limits varied from 0.25 ng·g-1 to 10.7 ng·g-1. The developed analytical oxyPAH method was applied on mussel samples from groynes and quaysides along the Belgian coastline and oxyPAH data were compared to PAH concentration data. The sum of 14 US EPA priority PAHs reached maxima at the eastern side of the Belgian coastal zone, with on average 202 ng·g-1 wet weight for quayside Zeebrugge and 38.4 ng·g-1 wet weight for groyne Knokke mussels. Anthracene-9,10-dione concentrations reached maxima of 19.1 ng·g-1 wet weight at the most industrialized quayside of Zeebrugge. For other oxyPAHs, no clear relationship could be made with direct PAH emissions. Concentrations of anthracene-9,10-dione and 9H-fluoren-9-one were found to exceed corresponding parent PAH concentrations.

The effect of crude protein reduction on performance and nitrogen metabolism in piglets (four to nine weeks of age) fed two dietary lysine levels1.

Lowering the CP level in piglet diets reduces the risk of postweaning diarrhea and N excretion to the environment. The question remains at what point CP becomes limiting. An experiment was designed with 2 standardized ileal digestible (SID) Lys levels (10 and 11 g) and 6 CP levels (140, 150, 160, 170, 180, 190 g/kg) in a 2 × 6 factorial design (with 6 pens of 6 animals each per treatment). Linear and quadratic (QP) mixed models of performance in function of CP were fitted to study the effect of SID Lys and CP and their interaction. To determine optima, QP models and broken line models with linear (BLL) or quadratic (BLQ) ascending portions were fitted through the data. It was hypothesized 1) that the response to a decreasing digestible CP level could be described with broken line models and 2) that the break point of these models is dependent on the dietary SID Lys level. Decreasing the CP level decreased ADG (P < 0.001). For G:F, the effect of decreasing CP level depended on the SID Lys level (P of the interaction = 0.028 in the linear model and P = 0.002 in the QP model). According to the BLL model, with 11 g SID Lys in the diet, G:F started to decline with CP levels < 176 g CP [SID Lys:CP = 0.062, SID Lys:apparent total tract digestible (ATTD) CP = 0.077], and with 10 g SID Lys, CP levels < 165 g/kg (SID Lys:CP = 0.061, SID Lys:ATTD CP = 0.075) depressed performance. Serum creatinine levels showed a linear decrease with increasing SID Lys:CP levels (P < 0.001). Across both SID Lys levels, when fitting a BLL model, minimal serum urea levels were reached at an SID Lys:CP ratio of 0.064. This seems to be the point where CP and not Lys limits muscle deposition. The small difference in break point between serum urea level and performance suggests that the composition of nonessential AA may also be at stake. The effect of decreasing CP level depends on SID Lys, and using a maximal SID Lys:CP ratio may be useful for optimizing the AA profile of dietary CP. When the SID Lys:CP ratio exceeds 0.064 (SID Lys:ATTD CP > 0.079), protein and not individual AA limits growth in most piglets between 4 and 9 wk of age.

Effects of steaming on contaminants of emerging concern levels in seafood.

Seafood consumption is a major route for human exposure to environmental contaminants of emerging concern (CeCs). However, toxicological information about the presence of CeCs in seafood is still insufficient, especially considering the effect of cooking procedures on contaminant levels. This study is one among a few who evaluated the effect of steaming on the levels of different CeCs (toxic elements, PFCs, PAHs, musk fragrances and UV-filters) in commercially relevant seafood in Europe, and estimate the potential risks associated with its consumption for consumers. In most cases, an increase in contaminant levels was observed after steaming, though varying according to contaminant and seafood species (e.g. iAs, perfluorobutanoate, dibenzo(ah)anthracene in Mytilus edulis, HHCB-Lactone in Solea sp., 2-Ethylhexyl salicylate in Lophius piscatorius). Furthermore, the increase in some CeCs, like Pb, MeHg, iAs, Cd and carcinogenic PAHs, in seafood after steaming reveals that adverse health effects can never be excluded, regardless contaminants concentration. However, the risk of adverse effects can vary. The drastic changes induced by steaming suggest that the effect of cooking should be integrated in food risk assessment, as well as accounted in CeCs regulations and recommendations issued by food safety authorities, in order to avoid over/underestimation of risks for consumer health.

Bioaccumulation of PCBs from microplastics in Norway lobster (Nephrops norvegicus): An experimental study.

Plastic debris acts as a sorbent phase for hydrophobic organic compounds like polychlorinated biphenyls (PCBs). Chemical partitioning models predict that the ingestion of microplastics with adsorbed chemicals in the field will tend not to result in significant net desorption of the chemical to the organism's tissues. This is expected due to the often limited differences in fugacity of the chemical between the indigestible plastic materials and the tissues, which are typically already exposed in the same environment to the same chemicals as the plastic. However laboratory trials validating these model predictions are scarce. In this study, PCB-loaded microplastics were offered to field-collected Norway lobsters (Nephrops norvegicus) during in vivo feeding laboratory experiments. Each ingestion experiment was repeated with and without loading a mixture of ten PCB congeners onto plastic microspheres (MS) made of polyethylene (PE) and polystyrene (PS) with diameters of either 500-600 µm or 6 µm. We observed that the presence of chemicals adsorbed to ingested microplastics did not lead to significant bioaccumulation of the chemicals in the exposed organisms. There was a limited uptake of PCBs in Nephrops tail tissue after ingestion of PCB-loaded PE MS, while almost no PCBs were detected in animals exposed to PS MS. In general, our results demonstrated that after 3 weeks of exposure the ingestion of plastic MS themselves did not affect the nutritional state of wild Nephrops.

Chemical analyses of dredged spoil disposal sites at the Belgian part of the North Sea.

The chemical status of five dredged spoil disposal sites in the Belgian Part of the North Sea is evaluated. A linear mixed-effect model was applied to PCB, PAH and heavy metal data from 2005 to 2014. No decrease in PCB concentrations was found, with even an increase at two disposal sites. Hg/AL ratios increased with 62% at one disposal site (BR&WS2) from 2005 to 2006 to 2013-2014. Cu and Zn concentrations increased at two disposal sites. Additional harbour sampling suggests that the latter is possibly linked to antifouling paints. Based on OSPAR environmental assessment criteria, the current chemical status of the sites suggests no chronic effect of dredged spoil disposal. However, increasing time trend data for PCB, Hg, Cu and Zn demonstrate the importance of monitoring to identify adverse trends.

A qualitative screening and quantitative measurement of organic contaminants on different types of marine plastic debris.

Chemical compounds present on plastic were characterised on different types of plastic litter and beached pellets, using a general GC-MS screening method. A variety of plastic related compounds, such as building blocks, antioxidants, additives and degradation products, were identified next to diverse environmental pollutants and biofilm compounds. A validated method for the analysis of PAHs and PCBs on beached pellets at the Belgian Coast, showed concentrations of ∑ 16 EPA-PAHs of 1076-3007 ng g(-1) plastic, while the concentrations of ∑ 7 OSPAR-PCBs ranged from 31 to 236 ng g(-1) plastic. The wide variety of plastic compounds retrieved in the general screening showed the importance of plastic as a potential source of contaminants and their degradation products.

Ciprofloxacin ozonation in hospital wastewater treatment plant effluent: effect of pH and H2O2.

The ozonation of ciprofloxacin was studied in hospital wastewater treatment plant effluent with focus on parent compound degradation, degradation product identification and residual antibacterial activity. Before ozonation, ciprofloxacin sorption on suspended solids was tested as a function of temperature (10.0-27.5 degrees C) and pH (3, 7 and 10). Temperature did not significantly affect ciprofloxacin sorption while sorption was highest at pH 7 (logK(d)=4.7) compared to pH 3 (logK(d)=4.3) and 10 (logK(d)=3.9) (n=3). Ozonation was slowest at pH 7 with ciprofloxacin half life times of 29 min, compared to 19 and 27 min at pH 10 and 3, respectively. Addition of 10-1000 microM H(2)O(2) increased ciprofloxacin half life times up to 38 min, probably influenced by competition with H(2)O(2) for ozone as well as radical species. Ciprofloxacin ozonation products were identical as previously detected during ciprofloxacin ozonation in deionized water and revealed strong pH dependence. Residual antibacterial activity was measured by agar diffusion tests. For Pseudomonas fluorescens and Escherichia coli, reduction of antibacterial activity was related to the parent compound degradation, while degradation products indicated to be the main compounds with respect to the antibacterial activity against Bacillus coagulans.

Ozonation and advanced oxidation by the peroxone process of ciprofloxacin in water.

A bubble reactor was used for ozonation of the antibiotic ciprofloxacin. Effects of process parameters ozone inlet concentration, ciprofloxacin concentration, temperature, pH and H(2)O(2) concentration were tested. Desethylene ciprofloxacin was identified, based on HPLC-MS analysis, as one of the degradation products. Formation of desethylene ciprofloxacin was highly dependent on pH, with the highest concentration measured at pH 10. Radical scavengers t-butanol and parachlorobenzoic acid were added in order to gain mechanistic understanding. Radical species other than hydroxyl radicals were suggested to occur at acidic pH which can explain fast ciprofloxacin ozonation at pH 3.

Sample preparation for the analysis of volatile organic compounds in air and water matrices.

This review summarizes literature data from the past 5 years on new developments and/or applications of sample preparation methods for analysis of volatile organic compounds (VOC), mainly in air and water matrices. Novel trends in the optimization and application of well-established airborne VOC enrichment techniques are discussed, like the implementation of advanced cooling systems in cryogenic trapping and miniaturization in adsorptive enrichment techniques. Next, focus is put on current tendencies in integrated sampling-extraction-sample introduction methods such as solid phase microextraction (SPME) and novel in-needle trapping devices. Particular attention is paid to emerging membrane extraction techniques such as membrane inlet mass spectrometry (MIMS) and membrane extraction with a sorbent interface (MESI). For VOC enrichment out of water, recent evolutions in direct aqueous injection (DAI) and liquid-liquid extraction (LLE) are highlighted, with main focus on miniaturized solvent extraction methods such as single drop microextraction (SDME) and liquid phase microextraction (LPME). Next, solvent-free sorptive enrichment receives major attention, with particular interest for innovative techniques such as stir bar sorptive extraction (SBSE) and solid phase dynamic extraction (SPDE). Finally, recent trends in membrane extraction are reviewed. Applications in both immersion and headspace mode are discussed.

Critical points in the analysis of ciprofloxacin by high-performance liquid chromatography.

Chromatographic analysis of the antibiotic compound ciprofloxacin on a C18 column proved to show some critical points. On a C18 column, ciprofloxacin analysis resulted in two peaks in the chromatogram. Effects of stock solution composition, mobile phase composition and type of stationary phase were investigated to understand the occurrence of both peaks. Esterification of the carboxylic group of ciprofloxacin was shown when methanol was used as stock solution solvent in acidic conditions. Secondly, a ciprofloxacin pK(a) value of 3.64 in water at position N-1 was found which could not fully explain the observation of the two peaks: mobile phase composition and type of stationary phase were also found to be important parameters with respect to the peak area ratio of both peaks.