Monitoring organic microcontaminants in the marine environment: principles, programmes and progress

Chlorinated Persistent Organic Pollutants (PCDD/Fs and PCBs) in Loggerhead Sea Turtles Stranded along the Central Adriatic Coast

Persistent organic pollutants are widespread in the marine environment. They can bioaccumulate and biomagnify in marine organisms through the food web with a potentially toxic effect on living organisms. The sea turtle Caretta caretta is a carnivorous animal with opportunistic feeding behavior. These turtles tend to bioaccumulate pollutants through food, and hence they can be considered an indicator of chemical pollutants in the marine ecosystem. In this study, 44 loggerhead sea turtles were considered, and liver and fat tissue were sampled from each of them to investigate the levels of dioxins (PCDD/Fs) and polychlorinated biphenyls (PCBs) in sea turtles and their potential correlation with sex and size in terms of curved carapace length (CCL). Results suggested that these contaminants were easily bioaccumulated, and PCBs were predominant compared to dioxins in both liver and fat tissue. The congener patterns were similar to those found in sea fish. Moreover, there were no differences in the contamination levels between females and males, nor was there a correlation with the size. There is a need to harmonize the methodological approaches to better evaluate the results and trends over time and to monitor the species and indirectly the health status of the marine environment.

Current Status, Challenges, and Policy Recommendations of China's Marine Monitoring Systems for Coastal Persistent Organic Pollution Based on Experts' Questionnaire Analysis

Persistent organic pollutants (POPs) monitoring and management in typical semi-enclosed bays is a major global environmental issue. This study concentrated on a questionnaire survey and analysis of marine environmental management and monitoring departments at all levels in China, and proposed suggestions on the construction and improvement of POPs monitoring and management system. Results show that POPs are initially involved in China's current marine environmental monitoring system, and the monitoring strength and capability still need to be continuously improved, mainly in the recognition, funding input, relevant standards, monitoring, and evaluation technical regulations of marine environmental POPs monitoring. Therefore, in order to gradually improve the monitoring and management system of China's offshore marine environment POPs, this study suggests starting from four directions: (1) Building POPs monitoring system of a marine ecological environment, and strengthening POPs monitoring in different environmental media; (2) strengthening land-based POPs emission and the related human activities' intensity survey, and establishing a POPs information sharing database; (3) optimizing POPs monitoring technology in the marine environment, and improving POPs supervision and management technical support system; and (4) participating in regional and international marine environment POPs monitoring and evaluation projects, and strengthening the construction of talent teams.

Spatial and temporal distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in sediments from Poyang Lake, China

Concentrations of polycyclic aromatic hydrocarbons (PAHs) were measured in 22 surface sediment samples and an approximately 100-year scale sediment core collected from Poyang Lake. This valuable sediments enable analysis of spatial and temporal distribution patterns of PAH sources, and determine the anthropogenic impacts on Poyang Lake. Total PAH concentrations in the surface sediments ranged from 73.2 to 367.2 ng/g dw, and higher residues were encountered in regions with high-density populations and intensive human activities. Total PAH concentrations in the sediment core ranged from 42.0 to 334.0 ng/g dw and were grouped in two clusters (pre-1990s and post-1990s to the present). PAH concentrations in sediments changed both temporally and spatially, suggesting a difference in PAH sources. Before the 1990s, major PAH sources in the sediment core were from coal, wood and grass combustion. This finding naturally agrees with open lake conditions on a spatial scale, which were related to agricultural activities. Petroleum combustion from industrialization and urbanization has become the predominant PAH source in the sediment core from the 1990s to the present and corresponds to sources observed in the southwestern lake near the relatively developed Nanchang City. In the northern lake leading to the Yangtze River, certain petroleum-related contaminants from shipping have become the main PAH sources. The different PAH sources observed in sediments generally reflect the degree of socio-economic development in the Poyang Lake valley, which is consistent with the local written records, indirectly validating the connection of sediment PAH records to the history of human activities in and around Poyang Lake.

DNA damage in marine rock oyster (Saccostrea Cucullata) exposed to environmentally available PAHs and heavy metals along the Arabian Sea coast

Molecular biomarkers are used world wide for quick assessment of the immediate effect of environmental pollution on marine ecosystems. Recently, we evaluated oxidative stress responses of marine rock oyster, Saccostrea cucullata impacted due to polycyclic aromatic hydrocarbons (PAHs) accumulated in their tissues at a few sampling sites along the coast of Goa around the region of the Arabian sea coast, India (Sarkar et al., 2017). Using a combination of partial alkaline unwinding and comet assays, we now report a comprehensive study on the impairment of DNA integrity (DI) in S. cucullata due to exposure to environmentally available PAHs and also heavy metals (Pb, Cd, Cu, Fe and Mn) along the Arabian Sea coast, Goa, India exclusively around the entire coast of Goa. First, we determined significant correlation between DI in S. cucullata and the extent of exposure to and bioaccumulation of different PAH compounds including 2-3 aromatic ring PAHs (R², 0.95), 4-6 aromatic ring PAHs (R², 0.85), oxygenated-PAHs (oxy-PAHs, R², 0.84) and total PAHs (t-PAHs, R², 0.98). Second, we observed dose-dependent decrease in DI in S. cucullata with increasing concentrations of different PAH components in oyster tissues. We substantiated our field observations with appropriate laboratory controls using benzo[a]pyrene (BaP). Third, we performed stepwise multiple regression analyses of different water quality parameters including pH, salinity, temperature, dissolved oxygen (DO), biochemical oxygen demand (BOD), nitrite (NO₂), nitrate (NO₃), phosphate (PO₄), turbidity and also t-PAH-biota, t-PAH-water with DI as the dependent variable. Among all these parameters, only four parameters such as t-PAH-biota in combination with DO, BOD and NO₂ showed significant correlation (R¯² = 0.95) with loss in DI in S. cucullata. Based on these results, we created a map indicating the percentage of DNA damage in S. cucullata exposed to PAHs and heavy metals at each sampling location along the west coast of India around Goa, India.

Evaluation of the impact of bioaccumulation of PAH from the marine environment on DNA integrity and oxidative stress in marine rock oyster (Saccostrea cucullata) along the Arabian sea coast

Marine pollution due to oil spills is of great concern globally for their impact on the health of marine ecosystems. We assessed the genotoxic effects and oxidative stress due to genotoxic pollutants accumulated from the ambient marine environment in the tissues of marine rock oyster, Saccostrea cucullata along the Arabian Sea coast around Goa, India. The extent of DNA damage in S. cucullata was determined by comet assay as variation of comet parameter: mean % tail DNA along the coast with respect to that at the reference site (Tiracol, Goa, India). In addition, the oxidative stress responses of rock oysters exposed to marine pollutants such as polycyclic aromatic hydrocarbons (PAHs) were assessed as a function of variation in antioxidant enzyme activities such as glutathione-s-transferase (GST), catalase (CAT) and superoxide dismutase (SOD) along the coast. Spearman correlation analysis showed significant correlation between different components of PAHs (viz., 2-3-PAH, 4-6-PAH and oxy-PAH) in the tissues of the rock oysters and the antioxidant enzyme activities. The antioxidant enzyme activities in S. cucullata increased with increasing concentrations of PAHs in tissues in the following order of sampling sites: Tiracol < Arambol < Betul < Velsao. Among the PAHs, oxy-PAH was found to be most predominant in causing DNA damage in S. cucullata. These results provide an insight into environmental genotoxicity and oxidative stress induced by PAHs along the Arabian Sea coast, India.

Origin and distribution of hydrocarbons and organic matter in the surficial sediments of the Sfax-Kerkennah channel (Tunisia, Southern Mediterranean Sea)

We investigated the origin and distribution of aliphatic and polycyclic aromatic hydrocarbons (AHs and PAHs) and organic matter (OM) in surficial sediments of the Sfax-Kerkennah channel in the Gulf of Gabès (Tunisia, Southern Mediterranean Sea). TOC, AH and PAH concentrations ranged 2.3-11.7%, 8-174μgg^-1sed.dw and 175-10,769ngg^-1sed.dw, respectively. The lowest concentrations were recorded in the channel (medium sand sediment) and the highest ones in the Sfax harbor (very fine sand sediment). AHs, PAHs and TOC were not correlated for most of the stations. TOC/N and δ¹³C values revealed a mixed origin of OM with both marine and terrestrial sources. Hydrocarbon molecular composition highlighted the dominance of petrogenic AHs and the presence of both petrogenic and pyrogenic PAHs, associated with petroleum products and combustion processes. This work underscores the complex distribution patterns and the multiple sources of OM and hydrocarbons in this highly anthropogenized coastal environment.

Determination of Polycyclic Aromatic Hydrocarbons in the Presence of Humic Acid in water

The presence of humic acid (HA) makes it extremely difficult to determine and quantify accurately polycyclic aromatic hydrocarbons (PAHs) in aquatic environment because of their complex and strong interaction. To solve this problem, a new method was developed in this work through the combination of PARAFAC and fluorescence spectroscopy, which mainly includes: (1) the fluorescence quantum yield acquisition of PAHs with and without HA by PARAFAC; (2) the  concentration score correction of PAHs in validation and test sets using the fluorescence quantum yields; and (3) the prediction of PAHs concentration in the validation and test sets in the presence of HA by corrected concentration. Using this method, the PAHs concentration on the level of µg L(-1) in the test samples with HA of 2.5 mg/L and 5.0 mg/L can be successfully predicted with the root mean square error below 0.15 µg L(-1), relative error of prediction below 4% for validation samples, recoveries of each PAH between 82.5% and 102.6% for test samples.

Maritime pollutants in shipping and commercial European ports based on relevant physical and biogeochemical environmental parameters (IUPAC Technical Report)

Ports are closed or semi-closed coastal systems with limited water circulation, poor flushing and weak tidal exchange. They are characterized as pollution hotspots or areas of stagnation with a variety of maritime pollutants. Nowadays, shipping and port managers aim to address environmental risk in their operations, striving to achieve suitable environmental management systems and environmental policies. In that way, environmental impacts are thoroughly considered, actions to minimize and prevent these effects are identified while human activities for prevention, reduction and mitigation of harmful consequences are managed. The current project provides details of quality and performance indicators, based on physical and biogeochemical environmental parameters required to monitor and audit the effectiveness of environmental management system and environmental policy applied in ports. These indicators will be used as powerful tools strengthening sound decisions when developing, shaping and evaluating national and local environmental management systems and policies. The selected indicators are described and their monitoring processes are presented and discussed. Examples of selected best environmental practice from various port authorities are included.

Environmental risk assessment of water quality in harbor areas: a new methodology applied to European ports

This work presents a standard and unified procedure for assessment of environmental risks at the contaminant source level in port aquatic systems. Using this method, port managers and local authorities will be able to hierarchically classify environmental hazards and proceed with the most suitable management actions. This procedure combines rigorously selected parameters and indicators to estimate the environmental risk of each contaminant source based on its probability, consequences and vulnerability. The spatio-temporal variability of multiple stressors (agents) and receptors (endpoints) is taken into account to provide accurate estimations for application of precisely defined measures. The developed methodology is tested on a wide range of different scenarios via application in six European ports. The validation process confirms its usefulness, versatility and adaptability as a management tool for port water quality in Europe and worldwide.

Identification and quantification of known polycyclic aromatic hydrocarbons and pesticides in complex mixtures using fluorescence excitation-emission matrices and parallel factor analysis

Polycyclic aromatic hydrocarbons (PAHs) and pesticides are among the most widespread organic contaminants in aquatic environments. Because of their aromatic structure, PAHs and pesticides have intrinsic fluorescence properties in the ultraviolet/blue spectral range. In this study, excitation-emission matrix (EEM) fluorescence spectroscopy and parallel factor (PARAFAC) analysis were used to characterise and discriminate fluorescence signatures of nine PAHs and three pesticides at the μg L(-1) level in the presence of humic substances (0.1-10 mgCL(-1)). These contaminants displayed a diversity of fluorescence signatures regarding spectral position (λEx: 220-335 nm, λEm: 310-414 nm), Stokes shift (39-169 nm) and number of peaks (1-8), with detection limits ranging from 0.02 to 1.29μgL(-1). The EEM/PARAFAC method applied to mixtures of PAHs with humic substances validated a seven-component model that included one humic-like fluorophore and six PAH-like fluorophores. The EEM/PARAFAC method applied to mixtures of pesticides with humic substances validated a six-component model that included one humic-like fluorophore and three pesticide-like fluorophores. The EEM/PARAFAC method adequately quantified most of the contaminants for humic substance concentrations not exceeding 2.5 mg CL(-1). The application of this method to natural (marine) samples was demonstrated through (1) the match between the Ex and Em spectra of PARAFAC components and the Ex and Em spectra of standard PAHs, and (2) the good linear correlations between the fluorescence intensities of PARAFAC components and the PAH concentrations determined by GC-MS.

Perfluorinated compounds in blood of Caretta caretta from the Mediterranean Sea

Perfluorinated compounds (PFCs), widely used for their hydro-oil repellent properties, are almost non-degradable in the environment; there is scientific evidence that indicate bioaccumulation. They represent a threat to many organisms, because they are toxic and are endocrine disruptors. Scientific studies have demonstrated the presence of PFCs in blood and liver samples of fish, turtles, birds and mammals of marine ecosystems in different geographical areas. The aim of this study was to determine the distribution of PFOS and PFOA in blood samples of the marine turtle Caretta caretta, using a minimally invasive sampling procedure. 49 blood samples of marine turtle, taken from several Italian marine turtle rescue centers, were analyzed. While PFOA was never detected, measurable concentrations of PFOS were found in 15 blood samples; the values show a range from 1.14 ng/g to 28.51 ng/g (wet wt.). No differences between groups of samples taken from different areas were found.

The occurrence of chemical elements and POPs in loggerhead turtles (Caretta caretta): an overview

Chemical elements and persistent organic pollutants (POPs) are globally present in aquatic systems and their potential transfer to loggerhead marine turtles (Caretta caretta) has become a serious threat for their health status. The environmental fate of these xenobiotics may be traced by the analysis of turtles' tissues and blood. Generally, loggerhead turtles exhibited a higher metal load than other turtle species, this could be explained by differences in diet habits being food the main source of exposure. Literature shows that muscle, liver and kidney are most considered for the quantification of chemical elements, while, organic compounds are typically investigated in liver and fat. This paper is an overview of the international studies carried out on the quantification of chemical elements, polychlorinated biphenyls (PCBs), organochlorines (OCs) and perfluorinated compounds (PFCs), in tissues, organs and fluids of C. caretta from the Mediterranean Sea, the Atlantic and the Pacific Oceans.

An integrated approach for bioaccumulation assessment in mussels: towards the development of Environmental Quality Standards for biota

The possible use of chemical concentrations measured in mussels (Mytillus galloprovincialis) for compliance checking against Environmental Quality Standards (EQS) established for biota is analyzed with the help of an integrated model. The model consists of a 3D planktonic module that provides biomasses in the different compartments, i.e., phytoplankton, zooplankton and bacteria; a 3D fate module that provides the concentrations of contaminants in the water column and in the sediments; and a 3D bioaccumulation module that calculates internal concentrations in relevant biotic compartments. These modules feed a 0D growth and bioaccumulation module for mussels, based on the Dynamic Energy Budget (DEB) approach. The integrated model has been applied to study the bioaccumulation of persistent organic pollutants (POPs) in the Thau lagoon (France). The model correctly predicts the concentrations of polychlorinated biphenyls (PCBs) and polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs) in mussels as a function of the concentrations in the water column and in phytoplankton. It also sheds light on the origin of the complexity associated with the use of EQS for biota and their conversion to water column concentrations. The integrated model is potentially useful for regulatory purposes, for example in the context of the European Water Framework (WFD) and Marine Strategy Framework Directives (MSFD).

Behavioural ecotoxicology, an "early warning" signal to assess environmental quality

BACKGROUND

In this review, the position of behavioural ecotoxicology within the available means to assess the status of marine environments is described as filling the gap for the needed "early warning" signals. A few examples of studies performed since the 1960s are discussed to highlight the sensitivity of these approaches in investigating the effects of chemicals, including priority pollutants and emerging contaminants, relative to conventional toxicity tests measuring survival.

DISCUSSION

The advantage of the behavioural response is due to the integration of biochemical and physiological processes that reflect changes at higher levels of organisation with ecological relevance. Avoidance often represents a behavioural symptom easily detected in many animals exposed to contaminants and would be a useful test to explore more widely. This rapid response would reflect a defence mechanism protective against further exposure and the potential development of more pronounced deleterious effects, whilst in some cases, escape could lead to the relocation of a species with negative consequences. An investigation of the avoidance behaviour of mud shrimp, Corophium volutator, along with the chemical analyses of sediments and amphipods to assess the quality of harbour sediments is summarised. The body burden of the amphipods was 1,000 times lower than the one associated with narcosis, emphasizing the sensitivity of this endpoint. The application of this acute toxicity test is briefly compared to additional work that involved intertidal mussels collected in the field.

CONCLUSIONS

Recent research undertaken with mud snails, Ilyanassa obsoleta, and harbour sediments confirmed the usefulness of the escape behaviour as an assessment tool. However, the limits of the state of knowledge regarding the fate of contaminants in species with the ability to metabolise contaminants is further discussed along with directions to be pursued to address questions arising from the reviewed literature.

Utilization of a submersible UV fluorometer for monitoring anthropogenic inputs in the Mediterranean coastal waters

We evaluated the performances of a submersible ultraviolet fluorometer (EnviroFlu-HC, TriOS Optical Sensors) dedicated to the real time measurement of polycyclic aromatic hydrocarbons (PAHs) in the aquatic media. We conducted calibration experiments and in situ measurements in the coastal Mediterranean Sea. We found that the EnviroFlu-HC was not strictly specific to PAHs, even though it exhibited the highest sensitivity for phenanthrene, but could response to tryptophan-like material as well, and in a much less extent, to humic substances. The sensor signal showed great spatial and temporal variations in clean and polluted sites, with likely a high contribution of PAHs in the harbors, and a high contribution of tryptophan-like and humic-like materials in the sewage effluent. We conclude that the EnviroFlu-HC is a good tool for monitoring anthropogenic inputs in the coastal waters, although its utilization should be combined to other fluorescence measurements to improve the information about the nature of the aromatic compounds detected.

Distribution and bioaccumulation of PAHs in the UNESCO protected natural reserve of Urdaibai, Bay of Biscay

Along 10 campaigns, from June 2002 to September 2004, the concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were measured in sediments and oysters (Crassostrea sp.) taken from four sites in the Unesco protected natural reserve of Urdaibai (Basque Country, Bay of Biscay). Total PAH concentration ranged from 0.7 to 140 microg kg(-1) (dw) in the case of sediments, and from 300 to 1400 microg kg(-1) (dw) in the case of oysters. During this study, the coast of the Bay of Biscay was severely affected by the Prestige oil spill (November 2002). Presumably, as a consequence of this accident, both spatial and temporal variations of the PAHs, as well as the sources of the PAHs were affected by the oil spill, and this effect was observed in the total concentrations and, especially, in several diagnostic ratios and in multivariate data analysis. Finally, both BAF (bioaccumulation factor) and BSAF (biota-sediment accumulation factor) parameters were calculated to conclude that particulate matter seems to be the most favourable uptake pathway of PAHs in oysters from this estuary.

Analysis of polycyclic aromatic hydrocarbons (PAHs) in environmental samples: a critical review of gas chromatographic (GC) methods

Polycyclic aromatic hydrocarbons (PAHs) are frequently measured in the atmosphere for air quality assessment, in biological tissues for health-effects monitoring, in sediments and mollusks for environmental monitoring, and in foodstuffs for safety reasons. In contemporary analysis of these complex matrices, gas chromatography (GC), rather than liquid chromatography (LC), is often the preferred approach for separation, identification, and quantification of PAHs, largely because GC generally affords greater selectivity, resolution, and sensitivity than LC. This article reviews modern-day GC and state-of-the-art GC techniques used for the determination of PAHs in environmental samples. Standard test methods are discussed. GC separations of PAHs on a variety of capillary columns are examined, and the properties and uses of selected mass spectrometric (MS) techniques are presented. PAH literature on GC with MS techniques, including chemical ionization, ion-trap MS, time-of-flight MS (TOF-MS), and isotope-ratio mass spectrometry (IRMS), is reviewed. Enhancements to GC, for example large-volume injection, thermal desorption, fast GC, and coupling of GC to LC, are also discussed with regard to the determination of PAHs in an effort to demonstrate the vigor and robustness GC continues to achieve in the analytical sciences.

Certified reference materials for inorganic and organic contaminants in environmental matrices

Chemical measurements often constitute the basis for informed decision-making at different levels in society; sound decision-making is possible only if the quality of the data used is uncompromised. To guarantee the reliability and comparability of analytical data an intricate system of quality-assurance measures has to be put into effect in a laboratory. Reference materials and, in particular, certified reference materials (CRMs) are essential for achieving traceability and comparability of measurement results between laboratories and over time. As in any other domain of analytical chemistry, techniques used to monitor the levels and fate of contaminants in the environment must be calibrated using appropriate calibration materials, and the methods must be properly validated using fit-for-purpose matrix-matched CRMs, to ensure confidence in the data produced. A sufficiently large number of matrix CRMs are available for analysis of most elements, and the group of chemicals known as persistent organic pollutants, in environmental compartments and biota. The wide variety of analyte/level/matrix/matrix property combinations available from several suppliers enables analysts to select CRMs which sufficiently match the properties of the samples they analyse routinely. Materials value-assigned for the so-called emerging pollutants are scarce at the moment, though an objective of current development programmes of CRM suppliers is to overcome this problem.