Biological effects of polycyclic aromatic hydrocarbons (PAH) and their first metabolic products in in vivo exposed Atlantic cod (Gadus morhua).

The monitoring of the presence of polycyclic aromatic hydrocarbons (PAH) in the aquatic environment is a worldwide activity since some of these compounds are well-established carcinogens and mutagens. Contaminants in this class are in fact regarded as priority hazardous substances for environmental pollution (Water Framework Directive 2000/60/EC). In this study, Atlantic cod (Gadus morhua) was selected to assess in vivo effects of two PAH and their first metabolic products, namely, the corresponding trans-dihydrodiols, using biological markers. Fish were exposed for 1 wk to a single PAH (naphthalene or chrysene) and its synthetic metabolites ((1R,2R)-1,2-dihydronaphthalene-1,2-diol and (1R,2R)-1,2-dihydrochrysene-1,2-diol) by intraperitoneal injection in a continuous seawater flow system. After exposure, PAH metabolism including PAH metabolites in bile and ethoxyresorufin O-deethylase (EROD) activity, oxidative stress glutathione S-transferases (GST) and catalase (CAT) activities, and genotoxicity such as DNA adducts were evaluated, as well as general health conditions including condition index (CI), hepatosomatic index (HSI), and gonadosomatic index (GSI). PAH metabolite values were low and not significantly different when measured with the fixed-wavelength fluorescence screening method, while the gas chromatography-mass spectroscopy (GC-MS) method showed an apparent dose response in fish exposed to naphthalene. DNA adduct levels ≥0.16 × 10(-8) relative adduct level (RAL) were detected. It should be noted that 0.16 × 10(-8) RAL is considered the maximal acceptable background level for this species. The other biomarkers activities of catalase, GST, and EROD did not display a particular compound- or dose-related response. The GSI values were significantly lower in some chrysene- and in both naphthalene- and naphthalene diol-exposed groups compared to control.

An evaluation of coral lophelia pertusa mucus as an analytical matrix for environmental monitoring: A preliminary proteomic study.

For the environmental monitoring of coral, mucus appears to be an appropriate biological matrix due to its array of functions in coral biology and the non-intrusive manner in which it can be collected. The aim of the present study was to evaluate the feasibility of using mucus of the stony coral Lophelia pertusa (L. pertusa) as an analytical matrix for discovery of biomarkers used for environmental monitoring. More specifically, to assess whether a mass-spectrometry-based proteomic approach can be applied to characterize the protein composition of coral mucus and changes related to petroleum discharges at the seafloor. Surface-enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF MS) screening analyses of orange and white L. pertusa showed that the mucosal protein composition varies significantly with color phenotype, a pattern not reported prior to this study. Hence, to reduce variability from phenotype difference, L. pertusa white individuals only were selected to characterize in more detail the basal protein composition in mucus using liquid chromatography, mass spectrometry, mass spectrometry (LC-MS/MS). In total, 297 proteins were identified in L. pertusa mucus of unexposed coral individuals. Individuals exposed to drill cuttings in the range 2 to 12 mg/L showed modifications in coral mucus protein composition compared to unexposed corals. Although the results were somewhat inconsistent between individuals and require further validation in both the lab and the field, this study demonstrated preliminary encouraging results for discovery of protein markers in coral mucus that might provide more comprehensive insight into potential consequences attributed to anthropogenic stressors and may be used in future monitoring of coral health.

A rapid method for preparation of the cerebrospinal fluid proteome.

The cerebrospinal fluid (CSF) proteome is of great interest for investigation of diseases and conditions involving the CNS. However, the presence of high-abundance proteins (HAPs) can interfere with the detection of low-abundance proteins, potentially hindering the discovery of new biomarkers. Therefore, an assessment of the CSF subproteome composition requires depletion strategies. Existing methods are time consuming, often involving multistep protocols. Here, we present a rapid, accurate, and reproducible method for preparing the CSF proteome, which allows the identification of a high number of proteins. This method involves acetonitrile (ACN) precipitation for depleting HAPs, followed by immediate trypsination. As an example, we demonstrate that this method allows discrimination between multiple sclerosis patients and healthy subjects.

Application of GCMS-pyrolysis to estimate the levels of microplastics in a drinking water supply system.

Communities value water and aquatic environments for a many diverse reasons. Ensuring safe drinking water is prioritized on the political agenda with a dedicated focus on safe and affordable drinking water under the 6th of the UN sustainable development goals. The occurrence of micron sized plastic fragments has been confirmed even in very remote areas. In the present study we analysed drinking water of a medium-sized Norwegian urban area for the presence of microplastics ≥ 1 µm. A modular filtering sampling devices was developed allowing a sequential in-situ enzymatic and mild oxidizing driven sample preparation prior to pyrolysis gas chromatography-mass spectrometry sample's analysis (pyr-GCMS). Samples were taken at different stages of the drinking water supply chain. The total amount of polymers per sites ranged from 6.1 to 93.1 µg/m3. Higher levels were detected in the raw water, but significant reduction rates ranging from 43% to 100% depending on the polymer type were scored after the water treatment processes. Polyethylene, polyamide, and polyester were the most frequently detected polymer types. Overall, the levels of MPs in the raw water influence the occurrence and polymer type occurrence and distribution is the drinking water supply net. This study contributes to the emerging field of plastics pollution in drinking water supply systems by providing effective methods helping with future routine monitoring of this source of human plastic uptake.

First occurrence and composition assessment of microplastics in native mussels collected from coastal and offshore areas of the northern and central Adriatic Sea.

In recent years, the occurrence of microplastics in the aquatic environment has gathered increasing scientific interest. Several studies have shown that the ingestion of microplastics may negatively influence the physiology of marine organisms having different feeding strategies, particularly in those species which cannot discriminate between food sources. Recent studies highlighted the potential for such particles to accumulate in the food web, posing risks to human health via the consumption of seafood. Furthermore, early findings also indicated the role of microplastics as vectors of chemical pollutants either used as additives during synthesis of the plastics or adsorbed directly from seawater, i.e., PAHs, PCB, and surfactants. Despite the importance of microplastics in adsorption and transport of hydrophobic pollutants, little is known about their distribution and accumulation in marine food webs, or their direct and indirect harmful effects. The Adriatic Sea represents a semi-enclosed basin with a low water recirculation rate and high anthropogenic pressures associated with unsustainable fishing and inputs of contaminants. The body burden, accumulation rates, polymer composition, and recurring morphotypes of microplastics in native blue mussels (M. galloprovincialis) were examined. Organisms collected offshore were compared to those collected in coastal areas. Microplastics were recovered from the soft tissues of all analyzed mussels. Coastal organisms showed a load of 1.06-1.33 fragments g-1 (wet weight) and 0.62-0.63 fibers g-1 (wet weight) while offshore organisms showed an accumulation of 0.65-0.66 fragments g-1 (wet weight) and 0.24-0.35 fibers g-1 (wet weight). The size class distribution revealed a marked prevalence of smaller particles (20 µm to 40 µm range) and the most recurring polymer type in analyzed organisms was PE followed by PP, PET, and equal amounts of PS, PLY, and PVC. A significant site-, time-, and oceanographic-related distribution trend was observed. Based on the findings presented here, there is a clear need to implement a seafood safety monitoring program to better understand actual human health-related risks.

First record of characterization, concentration and distribution of microplastics in coastal sediments of an urban fjord in south west Norway using a thermal degradation method.

Plastic waste is of increasing concern in the aquatic environment. A large proportion of plastic waste is generated onshore from where it eventually reaches the marine environment, which is considered the main sink of plastic debris To date there is a substantial lack of knowledge on the composition of these accumulated polymers, their environmental levels and distribution in marine and coastal areas. Current efforts are underway to develop standardized methods to characterize and quantify the occurrence of microplastic in different environmental matrices using microscopy-oriented methods using Fourier Transformed Infra-Red (FTIR) or Raman techniques. However, time-consuming sample preparation, processing and interpretation of complex data limits their use within monitoring programs. As an alternative, a thermal degradation method based on a gas chromatographic mass spectrometer coupled with pyrolysis represents a validated method for qualitative and quantitative polymer analyses. A technique has been developed that combines sample preparation and thermo-analysis for identifying microplastics in samples of marine sediment. Quantification and polymeric composition of plastic particles found in sediment samples taken from ten sites located in Boknafjorden subjected to diverse sources of pollution and anthropogenic pressure were investigated. Plastic microparticles were extracted from 8 kg of wet sediments per site, purified, size-fractionated thorough a set of stainless-steel certified sieves covering the range of 10-250 µm mesh size, pre-concentrated on fiberglass filters and whole filters analyzed by thermal desorption pyrolysis gas chromatography/mass spectrometry. Most of the detected polymers were identified as polypropylene, polyethylene, polyethylene terephthalate, polyvinylchloride, polystyrene or polyamide. In most of the sites, the largest fraction of the extracted micro debris fell in the size range 10-40 µm. Some shifts in size distribution were also observed in some sites and were likely related to the marine sea bottom currents and the influence of specific anthropogenic activities. The adopted thermal degradation method showed good sensitivity, reliability and rapidity and therefore represents a promising technique for microplastic analysis within monitoring activities.

Study of the bile proteome of Atlantic cod (Gadus morhua): Multi-biological markers of exposure to polycyclic aromatic hydrocarbons.

PAH metabolites present in bile are well-known biological markers of exposure in fish, and their investigation is recommended by the ICES (International Council for the Exploration of the Sea) and the OSPAR convention (Convention for the Protection of the Marine Environment of the North-East Atlantic) for monitoring purposes. Development of analytical strategies for fish bile is encouraged by the need for more sensitive and informative markers (e.g., capable of tracking the PAH composition of contamination sources) and strengthened by recent results in both fish genomics and proteomics. Herein, the study of the Atlantic cod bile proteome is presented. Preliminary testing for discovering new sensitive markers in the form of expressed proteins affected by PAH exposure (i.e., PAH-protein adducts) is reported. Protein markers were identified using LC-MS/MS analysis, as single biological indicators. Through multivariate analyses, the overall proteome was revealed to be a sensitive multi-biological marker of exposure to PAHs.

Ecotoxicology goes MudPIT?

Exposure to natural and anthropogenic compounds can potentially alter the proteome in body fluids and tissues of living organisms, and by applying proteomics it is possible to discover, identify and understand such alterations. This study show results from a proteomic approach where one- or multidimensional separation (MudPIT) combined with high-accuracy tandem mass spectrometry (i.e. LTQ Orbitrap) were used to identify proteins from a non-model organism (Salmo salar). An optimized two-dimensional method resulted in more than 680 proteins identified with high significance compared to 197 proteins identified using a one-dimensional separation. Thus, MudPIT proteomics greatly increase the number of successful protein identification studies in ecotoxicology, and could potentially provide more insight into chemical modes of actions.