Biomonitoring of organochlorine compounds and trace metals along the Eastern Adriatic coast (Croatia) using Mytilus galloprovincialis

Polychlorinated biphenyls in mussels, small pelagic fish, tuna, turtles, and dolphins from the Croatian Adriatic Sea waters: an overview of the last two decades of monitoring

This review summarises our two decades of polychlorinated biphenyl (PCB) monitoring in different marine organisms along the eastern Adriatic Sea. The aim was to gain an insight into the trends of PCB distribution in order to evaluate the effectiveness of past and current legislation and suggest further action. Here we mainly focus on PCB levels in wild and farmed Mediterranean mussels, wild and farmed bluefin tuna, loggerhead sea turtles, common bottlenose dolphins, and small pelagic fish. The use of artificial intelligence and advanced statistics enabled an insight into the influence of various variables on the uptake of PCBs in the investigated organisms as well as into their mutual dependence. Our findings suggest that PCBs in small pelagic fish and mussels reflect global pollution and that high levels in dolphins and wild tuna tissues raise particular concern, as they confirm their biomagnification up the food chain. Therefore, the ongoing PCB monitoring should focus on predatory species in particular to help us better understand PCB contamination in marine ecosystems in our efforts to protect the environment and human health.

Assessment of trace metal bioaccumulation in Mytilus galloprovincialis of the central Atlantic ocean after installation of treatment sewage facilities

Mussels (Mytilus galloprovincialis) are vital to Morocco's artisanal fishermen both nutritionally and economically. This study probed the bioaccumulation of trace metals zinc (Zn), cadmium (Cd), copper (Cu), and lead (Pb) in mussels from three sites north of Agadir: Anza, Aourir, and Imouran. Analyzed using atomic absorption techniques across different seasons, findings indicated variable metal concentrations, with Imouran notably presenting the highest, potentially due to influences from the new wastewater plants of Anza and Aourir. While lead was not detected, cadmium, albeit in lower concentrations, posed potential health concerns upon regular consumption. Individual Mean Bioaccumulation Index (IMBI) demonstrated fluctuations, majorly influenced by Zn, Cd, and Cu levels. These trends in IMBI between 2017 and 2018 for Aourir and Imouran hinted at similar environmental impacts or exposure levels. Despite site differences, Metal Pollution Index (MPI) values consistently pointing to analogous potential toxicity due to metal combinations. Intricate relationships between trace metals and their environmental parameters were evident, with multiple linear regression analysis (MLRA) showcasing differing correlations between variables. These results highlight the nuanced interactions between trace metals and bioaccumulation indices, such as MPI and IMBI. In conclusion, the findings accentuate the imperative of regular coastal water quality checks and effective management strategies to curtail pollutant discharges.

The Status of Marine Mussel Pollution Research in South Africa (2012-2022)

The growing human population requires more food each year, and seafood products can help meet this demand if clean water resources are available for their growth. Farmed and wild mussels are environmentally friendly seafood with many health benefits to human consumers, but they can also pose a health risk if they are harvested from areas where marine anthropogenic pollution is uncontrolled or unmonitored. While the coastline in South Africa has long been assumed to be pristine, a growing number of recent studies are raising contamination concerns. Baseline studies establish a wide range of anthropogenic pollutants to be present in the marine environment, specifically in urbanised or industrialised areas like major cities or harbours. This review summarises how mussels could pose health risks to human consumers and the current research that is being conducted by private researchers and institutions in South Africa. The review emphasises the need for more research in the field and for governmental pollution monitoring data to be released to the public.

Potential Toxic Elements and Their Carcinogenic and Non-Carcinogenic Risk Assessment in Some Commercially Important Fish Species from a Ramsar Site

Potentially toxic elements (PTEs) such as Hg, As, and Pb have become concentrated in the aquatic ecosystem as a result of increased human activities. However, these substances frequently have synergistic or antagonistic effects on the human body or other animals. As a result, there are concerns world-wide that commercially available food products, especially fish, may be contaminated with hazardous elements. In this study, samples of four selected fishes, Gutum (Lepidocephalichthys guntea), Baim (Macrognathus pancalus), Baila (Glossogobius giuris), Meni (Nandus nandus) were analyzed from one of the largest freshwater wetlands (designed as a Ramsar Site) in South Asia to evaluate PTEs contamination status and human health risk assessment. The result demonstrated that the degree of contamination for six PTEs decreased in the following sequences for fish: Fe > Zn > Cu > Pb > As > Hg. The edible part of G. giuris had the maximum value for Hg (0.42 μg/g dw), while N. nandus predominantly accumulated As (<0.41 μg/g dw). The estimated daily intake (EDI) values ranged from 0.003 to 1.75, which was much lower than the recommended values. The hazard index (HI), THQ, total target hazard quotient (TTHQ) scores through consuming fish followed the decreasing order of Fe > Hg > Cu > Zn > Pb. The values for each index were less than 1, indicating that there were no substantial health risks for the consumers. The carcinogenic risks (CR) derived from the intake of Pb ranged from 4.92 × 10-8 to 4.14 × 10-8 for males and 5.45 × 10-8 to 4.59 × 10-8 for females, which also did not exceed the standard limit (1.00 × 10-6). This study demonstrated that, under the existing consumption rate, there was no potential health harm to consumers from consuming the studied fishes. This study offers a chance to regularly check PTEs in this environment, reducing the contamination of heavy metals.

Seasonal Variations in the Trace Elements and Mineral Profiles of the Bivalve Species, Mytilus galloprovincialis, Chamelea gallina and Donax trunculus, and Human Health Risk Assessment

This study aimed to provide data on selected toxic (Cd, Pb and Ni), essential (Cr, Cu, Fe, Mn and Zn) and microelement (Na, K, Ca and Mg) concentrations in edible tissues of the Mediterranean mussel (Mytilus galloprovincialis), striped venus clam (Chamelea gallina) and the wedge clam (Donax trunculus). Samples were collected from the Black Sea (Bulgaria) four times over, a period of one year (2022). In comparison with the maximum permissible levels set by the EU and USFDA, all elemental concentration found in the bivalve species were lower than the prescribed limits. An estimation of the dietary metal intake through calculation of the target hazard quotients (THQ), hazard index (HI) and target risk (TR) was performed. The target hazard quotient (THQ) for individual metal and HI for combined metals were lower than 1, indicating no health risk for consumers due to the intake of either individual element or combined ones. The target risk value for toxic inorganic Pb and Cr was below 10^-6, indicating no carcinogenic risk. According to these results, the consumption of these bivalve species is completely safe for human health.

Using empirical negative cumulative extropy and image quality assessment to determine the accumulation of elements in marine organisms

In this study, the assessment of metals absorption capacity by macroalgae using image analysis was investigated for the first time and compared with fish bioaccumulatio. Empirical cumulative entropy (ECE), and also empirical negative cumulative extropy (ENCEX) were used as a newly introduced (information-based) indices. The regression equation was obtained between fish tissue-seawater in muscle of Sphyraena putnamiae (ENCEX=0.2001BAF; R²=0.96); In the case of muscle of Liza subviridis, the regression model was as (ENCEX=0.1950BAF; R²=0.93). The regression equation was obtained between algae-sediment (ENCEX_{H. hamulosa}=0.2695BAF; R²=0.97). The studied indices showed a high accumulation of Hypnea hamulosa compared to the other algae (ECE=0.2601; ENCEX=0.3995). IQA method showed the same result exhibiting that the algae can be evaluated as a bio-indicator of element accumulation using image analysis. Image analysis can help us find macro algae with high absorption capacity without laboratory examinations.

Mediterranean fanworm, Sabella spallanzanii (Gmelin, 1791), as a potential biomonitor of trace metal pollution in the marine environment

Levels of trace metals (Cd, Cr, Cu, Fe, Ni, Pb, Mn, and Zn) were measured in soft tissues and external tubes of the Mediterranean fanworm, Sabella spallanzanii (Gmelin, 1791), to evaluate its suitability as a biomonitor of metal pollution. Study was conducted in the coastal area of the eastern Adriatic Sea. Polychaetes were collected from two locations, a site located in a local marina and an unpolluted control site. Results indicate that S. spallanzanii has the capacity to accumulate metals in soft tissues as well as in tubes. The levels of most metals were considerably higher in tubes compared to soft tissues, indicating long-term accumulation of metals in tubes. High levels of several metals (Cu, Zn, Cr, Pb and Fe), found in soft tissues and tubes sampled at the marina site, reflect the elevated contaminant levels in the marina, associated with the use of antifouling agents, paints, petrol additives, and ship maintenance activities. Metal concentrations in tissues and tubes generally decreased with size, indicating the influence of growth and metabolic rates on trace metal uptake. Trace metal levels found in S. spallanzanii tissues were comparable to the levels found in Mytilus galloprovincialis, a species commonly used in biomonitoring studies, in areas exposed to similar levels of anthropogenic stressors. According to the results of the present study, S. spallanzanii has been identified as a suitable biomonitor of metal pollution due to its sedentary nature, widespread distribution, abundance and the ability to accumulate high levels of metals within its tissues and tubes.

Organochlorines and Polycyclic Aromatic Hydrocarbons as fingerprint of exposure pathways from marine sediments to biota

To elucidate the dynamics of a suite of organochlorine contaminants (PCBs, HCB), PAHs and Hg and verify the potential of these pollutants as reliable fingerprints of sources, an ensemble of marine sediments and organisms (finfish, shellfish species and Mytilus galloprovincialis) were analysed from the contaminated Augusta Bay (Southern Italy). The Hg and HCB concentration in the sediments exceeded the EQS of the Directive 2000/60/EU. Similarly, ∑PCB and selected PAHs were above the threshold limit set by regulation. The marine organisms showed Hg concentrations above CE 1881/2006. Contaminants in transplanted mussel evidenced an increased accumulation overtime and different distribution patterns between sampling sites. Analysis of the homolog composition of PCB congeners revealed comparable patterns between sediments and marine organisms and offered the opportunity to define a robust fingerprint for tracing contaminants transfer from the abiotic to the biotic compartments. These results were confirmed by the Fluoranthene/Pyrene, Hg and HCB distribution modes.

Fatty acids, persistent organic pollutants, and trace elements in small pelagic fish from the eastern Mediterranean Sea

Fatty acids (FAs) composition, 24 persistent organic pollutants (POPs), and 16 trace elements were examined in small pelagic fish (sardine, anchovy, round sardinella, chub and horse mackerels) caught by a fishing fleet for more than three years in the eastern Mediterranean Sea. Five Unmix source profiles associated with both sources, such as overlapping diet, including low-niche marine organisms and inputs from the surrounding environmental compartments were resolved. Inorganic compounds were notably more abundant in fish tissue than organochlorine xenobiotics. Comparison with the values of toxicological parameters revealed that the examined fish species are safe for human consumption, while the content of FAs emphasized the studied species as a valuable source of nutrients. A significant linear correlation was not observed between the 18 FAs and lipophilic organochlorines. Based on the obtained database, future assessments of the quality of edible fish species and the aquatic environment of the eastern Mediterranean Sea, which is known as an important fishing ground, could be significantly improved.

Total mercury content in the California ribbed sea mussel Mytilus californianus from the west coast of Baja California, México: Levels of contamination and human health risk

We analyzed spatial and temporal variations in total mercury concentration (THg) in Mytilus californianus from the west coast of Baja California, México, and assessed the potential risk for human health. The sites from the northern zone showed the highest levels of THg over the entire three years of study, however, no significant differences among years were found. The highest level of THg (0.110 μg/g d.w.) was recorded in 2010 at Bajamar (SS2), and the lowest (0.011 μg/g d.w.) in 2007 and 2008 at Eréndira (SS4) and Los Ojitos (SS7), respectively. The estimated daily intake (EDI) values for adults through mussel consumption were lower than the oral reference dose (RfDo) and the acceptable daily intake (ADI) values established by the USEPA and the FAO/WHO, respectively. The target hazard quotient (THQ) values were <1.0, indicating that mercury concentrations in M. californianus are not likely to pose a risk for human health.

The influence of natural vs anthropogenic factors on trace metal(loid) levels in the Mussel Watch programme: Two decades of monitoring in the Spanish Mediterranean sea

The spatial distribution and temporal trends of trace metals (i.e. Cd, Cu, Hg, Pb and Zn) and a metalloid (i.e. As) along the Spanish Mediterranean coast from 1993 to 2013 are presented with a new estimation of their background levels monitored using wild mussels. Over a 20 years period, yearly mussel monitoring was undertaken with a rigorous field sampling protocol using 3 pooled samples strategy (3 x n = 80, with 8 mussels in the 3.0 to 3.9 size categories at each site), obtained in the pre-spawning period (May-June) to minimize biological factors and seasonal variability, which is a fundamental element of the international programme. Spatial distribution was characterized every 5 years and temporal trends were determined in 11 locations. The main aims of the present long term study are to evaluate the environmental status of different coastal locations regarding trace metal levels and follow the evolution of these levels over time after the implementation of regulatory measures. Regarding spatial distribution, the highest values for Cd, Cu, Hg and Pb were found close to known highly anthopogenic cities or shipyard areas. However, As and Zn did not strictly follow this pattern, showing natural increased concentrations in the Levantine Balearic and Strait of Gibraltar-Alboran Sea demarcations respectively. These distributions are associated with the conjunction of two geological formation inputs (Massif Central in France and Iberian Pyritic Belt in Spain) and the oceanographic conditions in the adjacent coastal area. In the case of temporal trends, metal concentrations decreased significantly over time in most stations, confirming the effectiveness of the regulatory measures and prohibitions established under European legislation. Concentrations of Pb were above the established thresholds for human consumption in only 12-14% of the sampling areas. With the information obtained for this study, we estimate background concentrations and propose new Background Assesment Criteria (BAC) for the Spanish Mediterranean coast as a threshold criterion: 1.62 mg/kg d.w. for Cd, 8.75 mg/kg d.w. for Cu, 0.202 mg/kg d.w. for Hg and 2.83 mg/kg d.w. for Pb. Exceptions should exist for As and Zn, for which there should be different levels in each demarcation, due to the geological, hydrological and oceanographic peculiarities of the Spanish coast. For the Levantine-Balearic demarcation, the proposed background concentrations are 117 mg/kg d.w. for As and 200 mg/kg d.w. for Zn., whereas in the Strait of Gibraltar-Alboran Sea demarcation, they are 27.5 mg/kg d.w. for As, and 471 mg/kg d.w. for Zn. This work demonstrates the vital importance of defining the background levels of metal(loid)s at a regional or subregional level because, for areas not affected by anthropogenic causes which have high values as the result of natural processes, this would avoid the risk of constantly surpassing the levels proposed in directives.

Seasonal accumulation of trace elements in native Mediterranean mussels (Mytilus galloprovincialis Lamarck, 1819) collected in the Calich Lagoon (Sardinia, Italy)

The occurrence of 21 trace elements in native Mediterranean mussel (Mytilus galloprovincialis) from the Calich Lagoon, a typical brackish area of the northwest of Sardinia (Italy), was investigated. The seasonal variation of metals in bivalves was considered, and the highest values were found in spring and summer; in particular, a high significant (P < 0.001) temporal variation was reported for silver (Ag) and mercury (Hg). The highest and similar concentrations were registered for aluminium (Al, mean 32 mg kg^-1wet weight), iron (Fe, mean 32 mg kg^-1 w. w.), and zinc (Zn, mean 25 mg kg^-1 w. w.). The maximum limits set by European Regulations for cadmium (Cd), mercury (Hg), and lead (Pb) were never exceeded. Speciation analysis revealed negligible risk related to inorganic arsenic (iAs). Therefore, M. galloprovincialis confirmed its role as suitable bioindicator to monitor the contamination of coastal environments. Although the recommended tolerable weekly intake (TWI) was not exceeded, the levels of aluminium should be carefully evaluated in monitoring plans in the studied lagoon. Graphical abstract.

Sampling Site Specific Biomarker Responses in Mediterranean Mussels from the Adriatic Sea

This study aims to explore the spatial and temporal patterns in biomarker responses during early spring and late summer in Mytilus galloprovincialis using samples from two Adriatic Sea ecosystems between 2009 and 2012. The condition index was higher in September at all sampling sites and suggests that mussels can store energy during summer for wintertime spawning and survival through the winter. Over the entire study period, higher values of metallothioneins indicated sites with higher levels of heavy metals (Boka Kotorska Bay), while acetylcholine esterase activity was inhibited at the Gulf of Trieste. Genotoxicity was similar among sampling sites. We summarized biomarker responses in a stress index, IBRv2, and found that sampling sites in the Gulf of Trieste had lower stress levels while the highest stress levels were detected in the Boka Kotorska Bay.

Microplastics and their associated organic pollutants from the coastal waters of the central Adriatic Sea (Italy): Investigation of adipogenic effects in vitro

Even though microplastic (MP) pollution in aquatic environment is nowadays widely studied, a huge gap of knowledge exists on their actual biological effects. In this study we first reported environmental baseline data on the occurrence and characterization of floating MPs in Italian coastal waters of the Central Adriatic Sea by using a standardized monitoring protocol. Further, we analyzed the concentrations of MP-associated chemicals and evaluated their potential adipogenic effects using 3T3-L1 preadipocytes. MPs were found in each sampling stations showing the highest abundance (1.88 ± 1.78 items/m³) in the sites more distant from the coast with fragments as the most common shape category. All targeted organic pollutants (i.e. polychlorinated biphenyls - PCBs, polycyclic aromatic hydrocarbons -PAHs, organophosphorus - OP, and organochlorine - OC pesticides) have been detected on the surface of the collected MPs. The highest concentrations of PAHs were found on MPs from inshore (i.e. <1.5 NM) surface waters with low-ring PAHs as dominant components. Similarly, MPs from inshore waters had higher ΣPCB concentrations (64.72 ng/g plastic) than those found in offshore (i.e. >6 NM) waters (10.37 ng/g plastic). Among pesticides, all measured OPs were detected in each sample analyzed with pirimiphos-methyl as the most representative compound. For OCs, the sum of all concentrations of congeners was higher in coastal with respect to offshore waters. Moreover, in vitro 3T3-L1 screening of MP extracts indicated potential metabolic effects resulting in both adipogenesis and lipid uptake/storage.

Heavy metal concentrations and associated health risks in edible tissues of marine nekton from the outer Pearl River Estuary, South China Sea

Seven heavy metals including Hg, Cu, Pb, Cd, Zn, Cr, and As were examined in seventeen marine nekton species from the outer Pearl River Estuary (PRE), South China Sea. On the wet weight basis, the metal concentration ranges were 0.016-0.157 μg/g for Hg, 0.18-14.3 μg/g for Cu, 0.26-1.48 μg/g for Pb, 0.021-0.873 μg/g for Cd, 1.35-57.15 μg/g for Zn, 0.15-0.53 μg/g for Cr, and 0.42-7.83 μg/g for As, respectively. The levels of tested metals except for Pb in crustaceans were found to be higher than those in fish and cephalopods, suggesting that the diet and habitat played important roles on heavy metal accumulation ability of marine organism. Except for Cd in Champsodon capensis, Calappa lophos, and Portunus argentatus, all the left metal concentrations of investigated nekton species were below their permissible upper limits, indicating that consumption of examined marine nekton should be considered as safe for human health. The values of single target hazard quotient (THQ) and total THQ were all less than 1 and also suggested that there was no health risk for consumption. Even so, the local people should control their daily intake of crustacean foods from the outer PRE, since there might be potential As and Cd cumulative risks.

Simultaneous determination of PCBs, OCPs and PAHs in mussel by ultrasound-assisted cloudy extraction and gas chromatography-tandem mass spectrometry

A method for the simultaneous determination in mussel of 8 polychlorinated biphenyls (PCBs), 23 organochlorine pesticides (OCPs), and 35 polycyclic aromatic hydrocarbons (PAHs), including alkyl-PAHs, was optimised using ultrasound-assisted cloudy extraction and gas chromatography-tandem mass spectrometry (GC-MS/MS). Optimal selection of the extraction solvent and the dispersing solvent contributed to a high extraction yield and a clean extract. The ranges of the lower limits of detection of PCBs, OCPs and PAHs were 0.012-0.058, 0.01-0.29 and 0.01-0.5 μg kg^-1, respectively. The feasibility of the proposed method was validated by analysing standard reference materials of mussel with satisfactory results. The precision achieved by this method was in the range of 0.677-2.69% (PCBs), 1.14-6.60% (OCPs) and 0.694-7.46% (PAHs), and its accuracy was in the range of 101-104% (PCBs), 99.6-106% (OCPs) and 101-110% (PAHs). The advantages of the method include the simultaneous measurement of 66 analytes and the simplicity, low cost and high sensitivity of the procedure. When the proposed method was used to analyse the target compounds in 11 mussel samples, the analytical results displayed a concentration range of 0.41-0.45 µg kg^-1 for PCBs, 0.26-6.49 µg kg^-1 for OCPs, and 3.48-30.69 µg kg^-1 for PAHs.

Biomarker response of Mediterranean mussels Mytilus galloprovincialis regarding environmental conditions, pollution impact and seasonal effects

The complexity of seasonally and spatially variable environments, coupled with complex biological interactions, makes it difficult to pinpoint biological responses to specific environmental stressors, including chemical pollution. To disentangle causative factors and reveal biomarker responses, we applied biomarker-based multivariate approaches to 15 native populations of Mediterranean mussel Mytilus galloprovincialis in spring and autumn. In addition, we used a subset of these populations in transplant experiments between clean and polluted environments in nature and in lab mesocosms. The extent of biomarker responses in native populations is affected by season, and significantly lower variability across seasons was observed among mussels from clean than from polluted sites. Results of paired block designed transplant experiment demonstrated both regional and pollution effect, with mussels uniformly exhibiting higher responses on more impacted sites in each of the Adriatic regions. Biomarker status of mussels varied among Adriatic regions in dependence on the set of environmental variables, and between clean and polluted sites in dependence on measured concentrations of metals in mussels' tissue. Results of the mesocosm experiment revealed distinctive biomarker responses of two populations of different origin when exposed to common conditions. Multivariate description of biomarker activity and application of specific experiments allowed us to link environmental condition, exposure to pollution and seasonality to mussels' biomarker responses.

Risk-based prediction of metal toxicity in sediment and impact on human health due to consumption of seafood (Saccostrea cucullata) found in two highly industrialised coastal estuarine regions of Eastern India: a food safety issue

Estuarine ecosystems of the Bay of Bengal, India, are considered as the most productive environment, which have been persistently threatened by substantial anthropogenic activity. This study aims to investigate the metal contamination in the sediment of two estuaries and possible biomagnifications in the indigenous edible oyster Saccostrea cucullata and related health hazards due to its consumption. The accumulative ecological risks indicated that the sediment is moderate to strongly contaminated with cadmium and lead. The sediment pollution index and pollution load index suggested that the sediment possesses a little ecological stress on the exposed flora and fauna. The statistical interpretation highlights the most metals which have a similar source of origin and are bound to the finer fractions of the sediment, except nickel. Bioaccumulation of sediment-associated Cu and Zn in oyster reflects their potential biomagnifications through aquatic food chain. HPI range was below the critical limit of safe human consumption. The non-carcinogenic (THQ) and carcinogenic (CR) health hazards were estimated from the PTDI provided by USEPA. Except Cr, Hg and Zn, the THQ of all other metals was > 1 suggesting detrimental non-carcinogenic health effects on humans. The TCR of Cr and Cd above safety limit indicates the exposed population might be under severe carcinogenic threat due to those metals.

Distribution and sources of organic contaminants in surface sediments of Hooghly river estuary and Sundarban mangrove, eastern coast of India

This study investigated polycyclic aromatic hydrocarbons (PAHs) and organochlorine compounds such as polychlorinated biphenyls (PCBs) and DDT-related pesticides in surface sediments of Hooghly estuary and the Sundarban mangrove wetlands. Concentrations of ∑₁₇PAH, ∑₁₈₂PCB and ∑₆DDT ranged from 15.4 to 1731, not detected (nd) to 13.5 and nd to 8.97 ng g^-1 dry weight, respectively. Low levels of PCBs and low to moderate concentrations of DDTs and PAHs reflected recent development in West Bengal, which was dominated by agriculture and multifarious industries in the past. Diagnostic ratios suggested that major sources of PAHs are combustion processes, DDTs are input by agriculture, antifouling paints and public health campaigns, and organochlorines are predominantly from industrial origin. Heavier PCB congeners suggest local sources and short-range transport of such chemicals. Decision makers may use these findings for managing the Hooghly River watershed in order to promote a sustainable development on the eastern coast of India.

Legacy and emerging pollutants in marine bivalves from the Galician coast (NW Spain)

The presence of pollutants in estuary and oceanic systems is a global problem and a serious concern to human and environmental health. Usually, environmental monitoring studies consider classical persistent organic pollutants (POPs). However, the lists of POPs keep continuously growing and new POPs and other emerging pollutants should be considered in new monitoring programs. So, this study aimed to investigate the distribution and profile of classical POPs (polychlorinated biphenyl (PCBs), organochlorine pesticides (OCPs), and polycyclic aromatic hydrocarbons (PAHs)), new POPs and emerging pollutants (polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFCs), novel halogenated flame retardants (NFRs) and UV filters) in bivalve mollusc samples (both raft-cultivated and wild mussel, Mytilus galloprovincialis; cockle, Cerestoderma edule; and clam, Ruditapes descussatus) collected in nine Galician Rias during the period February 2012 to February 2013. A predominance of PAHs (6.8-317 ng/g dry weight (dw)) followed by PCBs (0.47-261 ng/g dw), UV filters (1.4-157 ng/g dw), PFCs (0.53-62 ng/g dw), OCPs (0.07-29 ng/g dw), PBDEs (0.31-6.6 ng/g dw) and NFRs (0.07-3.2 ng/g dw) was found in the studied bivalves, being the UV filter octocrylene the compound found at the highest concentration (141 ng/g dw in a cockle sample), while the PAHs chrysene and benzo(b)fluoranthene were the compounds with the highest average concentration (20 and 14 ng/g dw, respectively). Inter-species, temporal and geographical variations on pollutants concentration were assessed by multifactorial analysis of variance. Statistically significant differences among the type of mollusc were observed for levels of organochlorinated and organobrominated pollutants considered (PCBs, OCPs and PBDEs), which were detected at higher concentrations in wild mussel. On the other hand, the main PFCs and UV filters showed a higher detection frequency in cockle samples. Location played significant role for PAHs, PCBs and the main PBDEs, being the most polluted rias those more industrialized and populated, i.e. A Coruña, Ferrol and/or Vigo. Finally, sampling timepoint was also a significant factor for most of the families considered but with different profiles. Thus, PAHs and PCBs showed higher concentrations in both February 2012 and 2013 and lower in August 2012, while the main PBDEs were measured at higher concentrations in November 2012 and lower in February 2012; and the main NFRs, PFCs and UV filters were present at lower levels in February 2013.

Assessing chemical contamination in the coastal waters of the Adriatic Sea using active mussel biomonitoring with Mytilus galloprovincialis

The MYTIAD project focused on the assessment of chemical contamination (metals, PAHs, PCBs and organochlorine pesticides) in the Adriatic coastal waters by active mussel watching. Its purpose was harmonising and standardising strategies and methodologies used to assess the contamination status of the Adriatic Sea, in the framework of the WFD, the MSFD and UNEP/MAP Integrated Monitoring and Assessment Programme. Data on metals pointed out some hotspots along the eastern and western Adriatic Sea coasts, with the highest values of total PAH concentration detected in Split, Trieste, and Taranto (Ionian Sea). PCB and endrin contamination was higher in the Adriatic Sea than in the western Mediterranean Sea. This is the first comprehensive overview of contamination in the Adriatic Sea with critical comparisons of related studies over the Mediterranean Sea. It provides a useful harmonised dataset to support a coordinated definition of baselines, targets and thresholds, and further management of chemical contamination.

Monitoring of trace metal accumulation in two South African farmed mussel species, Mytilus galloprovincialis and Choromytilus meridionalis

Mussels pose health risks to consumers through accumulation of trace metals from the ocean. Saldanha Bay, South Africa, has heavy industry and international shipping, creating concerns over pollution levels for aquaculture facilities. Samples of C. meridionalis and M. galloprovincialis were collected from mussel rafts over two-years and analysed for trace metal content using Inductively Coupled Plasma Mass Spectrometry. Aluminium, Cr, Fe, Zn, Cd and Pb were higher in M. galloprovincialis, while C. meridionalis accumulated more Cu and Mn. Temporal fluctuations occurred for Fe and As concentrations in C. meridionalis, and Fe, As, Hg and Pb in M. galloprovincialis. Arsenic exceeded South African regulatory limits (3 mg/kg) once in each species (max = 3.4 mg/kg w.w.). Lead concentrations in M. galloprovincialis were within EU regulatory limits for bivalves (1.5 mg/kg) but exceeded SA regulatory limits for fish (0.5 mg/kg) four times. Overall, farmed mussels from Saldanha Bay were determined to be safe for human consumption.

Linking organochlorine contaminants with demographic parameters in free-ranging common bottlenose dolphins from the northern Adriatic Sea

Marine top predators, including marine mammals, are known to bio-accumulate persistent pollutants such as polychlorinated biphenyls (PCBs), a serious conservation concern for these species. Although PCBs declined in European seas since the 1970s-1980s ban, considerable levels still persist in European and Mediterranean waters. In cetaceans, stranded animals are a valuable source of samples for pollutant studies, but may introduce both known and unknown biases. Biopsy samples from live, free-ranging cetaceans offer a better alternative for evaluating toxicological burdens of populations, especially when linked to known histories of identified individuals. We evaluated PCB and other organochlorine contaminants in free-ranging common bottlenose dolphins (Tursiops truncatus) from the Gulf of Trieste (northern Adriatic Sea), one of the most human-impacted areas in the Mediterranean Sea. Biopsies were collected from 32 male and female dolphins during 2011-2017. All animals were photo-identified and are part of a well-known population of about 150 individuals monitored since 2002. We tested for the effects of sex, parity and social group membership on contaminant concentrations. Males had significantly higher organochlorine concentrations than females, suggesting offloading from reproducing females to their offspring via gestation and/or lactation. Furthermore, nulliparous females had substantially higher concentrations than parous ones, providing further support for maternal offloading of contaminants. Overall, 87.5% of dolphins had PCB concentrations above the toxicity threshold for physiological effects in experimental marine mammal studies (9 mg/kg lw), while 65.6% had concentrations above the highest threshold published for marine mammals based on reproductive impairment in ringed seals (41 mg/kg lw). The potential population-level effects of such high contaminant levels are of concern particularly in combination with other known or suspected threats to this population. We demonstrate the utility of combining contaminant data with demographic parameters such as sex, reproductive output, etc., resulting from long-term studies.

Seasonal variations of heavy metals content in mussels (Mytilus galloprovincialis) from Cala Iris offshore (Northern Morocco)

Heavy metal concentrations of Cd, Cr, Cu, Fe, Ni, Zn, Co, and Pb were investigated in soft tissues of Mytilus galloprovincialis coming from an aquaculture farm in Cala Iris sea of AlHoceima. Mytilus galloprovincialis were collected monthly during the period January to December 2016. The seasonal variations were affected significantly the concentrations of metals (Cd, Fe and Cr) in M. galloprovincialis. The highest heavy metal concentrations were recorded in winter (0.89 mg/kg, 673.2 and 3.330 mg/kg; for Cd, Fe and Cr, respectively) and the lowest values were founded in summer for Cd (0.646 mg/kg), and in autumn for Fe (340.1 mg/kg) and Cr (1.959 mg/kg). A significant effect of seasons on metal concentrations can be attributed to a number of biological and environmental inter-related factors. Data from this study may provide information on the use of M. galloprovincialis as a bioindicator for heavy metals pollution in the Cala Iris Sea.

Determination of trace metals in Mytilus galloprovincialis along the Boka Kotorska Bay, Montenegrin coast

The concentrations of six trace metals, cadmium (Cd), copper (Cu), chromium (Cr), lead (Pb), zinc (Zn) and mercury (Hg) were determined in the soft tissues of the mussel Mytilus galloprovincialis and bottom sediments collected from the coastal area of Boka Kotorska Bay (Montenegrin coast). The mussels and sediment samples were collected at three sites along the Boka Kotorska Bay from the autumn of 2014 to the winter of 2016. The concentrations (mg/kg dw) of these metals in the mussel samples ranged from 1.01 to 2.87 for Cd, 6.08 to 13.2 for Cu, 1.37 to 3.55 for Pb, 85.6 to 241 for Zn, 0.72 to 4.05 for Cr and 0.098 to 0.269 for Hg. The concentrations (mg/kg dw) of these metals in the sediment samples ranged from 0.16 to 0.39 for Cd, 4.32 to 48.2 for Cu, 7.02 to 49.8 for Pb, 22.0 to 158 for Zn, 93.1 to 317 for Cr and 0.035 to 0.497 for Hg. The metal content in the mussel samples and the metal content in the sediment collected from three locations over four different seasons were analyzed using the Pearson correlation coefficient (r) and cluster analysis (CA). A correlation between the metal levels found in the mussel soft tissues with those found in the sediments, for both 2014 and 2015, were established. The metal pollution indexes (MPI) for the sediment and mussels were compared, indicating that the most polluted sediment was at the location Institute of Marine Biology Kotor (IBMK) and the most polluted mussels were sampled from the Zanjice location.

Assessment of multiple anthropogenic contaminants and their potential genotoxicity in the aquatic environment of Plitvice Lakes National Park, Croatia

In this study, the influence of anthropogenic pollution on the aquatic environment of Plitvice Lakes National Park (PLNP) was investigated during 2011-2012 using a combination of chemical and cytogenetic analyses. Four groups of major contaminants [(volatile organic compounds: benzene, toluene, ethylbenzene, and xylenes (BTEX); persistent organochlorine pollutants: organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs); major and trace elements; anthropogenic radionuclides (⁹⁰Sr, ¹³⁴Cs, and ¹³⁷Cs)] were determined in three aquatic compartments (water, sediment, fish). Mass fractions of inorganic constituents in different compartments reflected the geological background of the area, indicating their origin from predominantly natural sources. Levels of volatile and persistent organic compounds in water and fish, respectively, were very low, at levels typical for remote pristine areas. Analysis of anthropogenic radionuclides in water and sediment revealed elevated activity concentrations of ¹³⁷Cs in water, and measurable ¹³⁴Cs in the upper sediment layers from April 2011, possibly as a consequence of the Fukushima nuclear accident in March 2011. The potential genotoxicity of river and lake water and lake sediment was assessed under laboratory conditions using the alkaline comet assay on human peripheral blood lymphocytes, and measured levels of primary DNA damage were within acceptable boundaries. The results showed that despite the protected status of the park, anthropogenic impact exists in both its terrestrial and aquatic components. Although contaminant levels were low, further monitoring is recommended to make sure that they will not rise and cause potentially hazardous anthropogenic impacts.

Assessing the environmental quality of sediments from Split coastal area (Croatia) with a battery of cell-based bioassays

A battery of cell-based bioassays, including PLHC-1 cells, zebrafish-Pxr-transfected COS-7 cells and estrogen receptor-recombinant yeast assay (ER-RYA), were applied to detect the presence of bioactive pollutants in sediments collected from Kaštela Bay and Brač Channel (Croatia). Exposure of PLHC-1 cells to the sediment extracts evidenced significant cytotoxicity and presence of CYP1A inducers in sediments collected in Kaštela Bay, near the industrial zone and cargo port of Split. Sediments from this area, which is highly contaminated with PCBs, HCB, DDTs and γ-HCH, also activated the zebrafish Pxr (zfPxr) reporter system. No evidence of estrogenicity was detected for any of the sediments extracts in the ER-RYA assay. Importantly, the battery of in vitro assays identified Kaštela Bay as the area with the higher anthropogenic impact, where sediment-bound pollutants could pose a risk to aquatic organisms. In contrast, sediments from the Brač Channel showed rather low response in the different bioassays.

Heavy metal concentrations in some gastropods and bivalves collected from the fishing zone of South India

The present study investigates heavy metal concentrations in gastropods and bivalves collected from major fishing centers in South India. Three gastropods, Bursa spinosa, Tibia curta, and Murex trapa, and two bivalves, Perna viridis and Villoritta cyprinoids, were collected for the analysis of heavy metals. The metals in the present study followed the order Mg>Ca>Zn>Fe>Cu>Mn>Cr>Pb>Ni>Co>Cd. Trace metal concentrations in the soft tissue of the molluscs varied as follows: for Cd: 0.04-5.33, Co: 0.09-0.87, Cr: 2.18-7.59, Cu: 9.54-37.02, Mn: 1.30-8.50, Ni: 0.94-3.21, Pb: 1.16-2.64 and Zn: 68.16-113.64mgkg^-1. Metal concentrations in all the species were below the limits proposed by the World Health Organization, except for Pb and Cd. This baseline study suggests that the levels of toxic metals in M. trapa, T. curta, and B. spinosa should be continuously monitored to assess the fate and effects of these metals in this fragile ecosystem.

Spatial distribution and biological effects of trace metals (Cu, Zn, Pb, Cd) and organic micropollutants (PCBs, PAHs) in mussels Mytilus galloprovincialis along the Algerian west coast

Native mussels Mytilus galloprovincialis are used as bioindicator organisms to assess the concentration levels and toxic effects of persistent chemicals, polychlorobiphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and heavy metals using biomarker responses, such as catalase (CAT), glutathione s-transferase (GST), and condition indices, for the Algerian coast. The results show that mussels of Oran Harbour are extremely polluted by PCBs and PAHs, i.e., 97.6 and 2892.1μg/kg d.w., respectively. Other sites present low levels of pollution. Furthermore, high concentrations of zinc, lead and cadmium are found in mussels from fishing, agricultural and estuarine sites, respectively, while low concentrations of copper are found in all of the sites studied. CAT activity is negatively correlated with Cd and Cu, and Zn is positively correlated with GST and CAT. Site classification tools reveal the potential toxicity of coastal areas exposed to anthropogenic pressure and a gradient of toxicity along the Algerian west coast.

Assessment of PCB and chlorinated pesticide accumulation in mussels at Kaštela Bay (Eastern Adriatic)

The biological response of mussels Mytilus galloprovincialis, resident and transplanted to cages, to contamination with anthropogenic pollutants from Kaštela Bay, located in the central part of the eastern Adriatic coast, was investigated. The main purpose of this paper is to trace the accumulation of PCBs and chlorinated pesticides (HCB, lindane, heptachlor, aldrin, p,p'-DDTs) as a direct measure of potential contaminant availability to organisms, in a period from 2000 to 2011. In order to do so, cultured mussels (Mytilus galloprovincialis) of the same size and age were transplanted from the unpolluted Mali Ston Bay to the Kaštela Bay. Sampling was performed bimonthly, and the level of target contaminants in whole soft tissue was determined. After two months of exposure, the concentration of PCBs in transplanted mussels increased on average 6.5-times, and of DDTs 2-times, while the intensity of changes for HCB, lindane, heptachlor and aldrin was negligible. Seasonal variation of pesticide content was similar without a significant change throughout the experimental period, while that of PCBs was somewhat different showing increased accumulation in summer. Seasonal and spatial variation of organochlorines in the Kaštela Bay was likely the result of prevailing environmental rather than biological parameters. In accordance with prevailing hydrodynamic cycling, contaminant concentration decreased in acyclonic direction towards the exit of the Bay. Measurement of target contaminants in resident mussels sampled from the most contaminated area of the Bay exhibited decreasing concentrations of lindane, aldrin and p,p'-DDTs. However, PCBs exhibited statistically significant increasing concentrations in relation to the slightly increasing concentrations of HCB. With regard to human health, organochlorine (OC) levels in the mussel tissue were below prescribed limits for human consumption.

Presence of trace metals in aquaculture marine ecosystems of the northwestern Mediterranean Sea (Italy)

Information regarding chemical pollutant levels in farmed fish and shellfish, along with the risks associated with their consumption is still scarce. This study was designed to assess levels of exposure to 21 trace elements in fish (Dicentrarchus labrax), mussels (Mytilus galloprovincialis) and oysters (Crassostrea gigas) collected from aquaculture marine ecosystems of the northwestern Mediterranean Sea. Metal concentrations showed great variability in the three species; the highest values of the nonessential elements As and Cd were found in oysters while the highest levels of Al, Pb and V were found in mussels. The essential elements Cu, Mn and Zn were highest in oysters, but Fe, Cr, Ni, Se, Co and Mo levels were highest in mussels. Fish had the lowest concentrations for all trace elements, which were at least one order of magnitude lower than in bivalves. The rare earth elements cerium and lanthanum were found at higher levels in mussels than in oysters, but undetectable in fish. The maximum values set by European regulations for Hg, Cd and Pb were never exceeded in the examined samples. However, comparing the estimated human daily intakes (EHDIs) with the suggested tolerable copper and zinc intakes suggested a potential risk for frequent consumers of oysters. Similarly, people who consume high quantities of mussels could be exposed to concentrations of Al that exceed the proposed TWI (tolerable weekly intake).

Organochlorine pesticides and PCBs (including dl-PCBs) in human milk samples collected from multiparae from Croatia and comparison with primiparae

This study investigated the levels of 20 congeners of polychlorinated biphenyls (PCBs), including toxic dioxin-like PCBs and 7 organochlorine pesticides (OCPs) in 33 human milk samples collected in 2011 from multiparae living in Zadar, Croatia. Concentrations of ∑PCBs, ∑DDTs, ∑HCHs and HCB in samples ranged from 11.7 to 146.3, 8.7 to 89.2, 0.9 to 28.4, and <LOD to 8.0ngg(-1) milk fat, respectively. PCB congeners -153, -138, -180 and -170 dominated in the PCB profiles, while p,ṕ-DDE was the most abundant OCP. PCB-126 was the most abundant non-ortho PCB, while among mono-ortho PCBs, the congeners -118, -105 and -156 equally contributed to the mono-ortho PCB fraction. TEQs for dl-PCBs ranged between 0 and 13.3pgg(-1) milk fat. The calculated estimated daily intakes for all compound groups were below the tolerable daily intake indicating no risk for breastfed infants. A comparison of our results with our previous study on primiparae revealed that the concentrations of the main contaminant groups are lower in the milk of multiparae, with the exception of toxic mono-ortho PCBs whose concentrations and TEQ remained similar among the groups, and HCB whose concentrations were found to be higher in multiparae. Concentrations of PCBs and OCPs found in the samples from this study did not exceed those from other parts of the world. This study revealed that there are differences in contaminant concentrations depending on the mothers' parity and that this fact should be taken into account when risk assessment studies are conducted.

Metals and PCB levels in some edible marine organisms from the Ionian Sea: dietary intake evaluation and risk for consumers

Concentrations of some metals (Cd, Cu, As, Hg, Pb) and polychlorinated biphenyls (PCBs) were investigated in edible marine organisms from different trophic levels and feeding behaviour like bivalve molluscs (Mytilus galloprovincialis and Chlamys glabra), gastropod molluscs (Hexaplex trunculus) and some commercial species of fish (Trachurus trachurus, Boops boops, Sarpa salpa and Gobius niger). These species were collected in the first inlet of the Mar Piccolo of Taranto (Ionian Sea, Southern Italy), classified as 'Site of National Interest' established by National Law 426 (1998) and included in the 'National Environmental Remediation and Restoration Projects'. The aim of this work was to investigate contamination levels and public health risks, associated with consuming seafood harvested from these areas. Moreover, in this study, was also estimated the weekly intake in children and adults, both for metals and PCBs. In comparison with the permissible limits set by EC Regulations, Cd and Pb levels were over the limit in the H. trunculus (in all sampling stations) and in the fish T. trachurus respectively. PCBs were over the legal limit in all sampled species with the exception of M. galloprovincialis (station 1), C. glabra and the herbivorous fish S. salpa. In the fish T. trachurus, for example, the concentration of six target PCBs was about five times higher than the EC limit. The estimated intakes of those trace elements included in this study through seafood consumption by the population exceed the provisional tolerable weekly intake recommended by the Joint FAO/WHO Expert Committee on Food Additives for Cd and Hg in the H. trunculus and T. trachurus, especially in children. Moreover, hazard quotience (HQ) for Hg and Cd was >1 in the children for T. trachurus and H. trunculus consumption. As regard non-dioxin-like PCB (NDL-PCB), the estimated intake were always above the 'provisional guidance value' (70 ng/kg body weight) Arnich et al. (Regul Toxicol Pharm 54: 287-2, 2009) for all sampled organism. Thus, health risks due to the dietary Hg, Cd and PCBs intake, especially for children, cannot be excluded. Therefore, an extended remediation programme is necessary to safeguard marine ecosystem, human health and, not less important, the economic activities, in the Taranto marine area.

Polychlorinated biphenyls, organochlorine pesticides and trace metals in cultured and harvested bivalves from the eastern Adriatic coast (Croatia)

Polychlorinated biphenyls, organochlorine pesticides and trace metals were determined in tissues of bivalve molluscs (Mytilus galloprovincialis, Ostrea edulis, Venus verrucosa, Arca noae and Callista chione), collected from 11 harvesting and 2 cultured locations along the eastern Adriatic coast, in May and November 2012. Concentrations (ng g(-1) dry weight) of organochlorines ranged from 1.53 to 21.1 for PCBs and 0.68 to 5.21 for p,p'-DDTs. HCB, lindane, heptachlor and aldrin-like compounds were found in lower levels or were not detected. Metal concentrations (mg kg(-1) dry weight) ranged from 0.23 to 4.03 for Cd, 0.87-3.43 for Cr, 3.69-202.3 for Cu, 0.06-0.26 for HgT, 0.62-9.42 for Ni, 0.95-4.64 for Pb, and 55.76-4010.3 for Zn. Established organochlorine and trace metal levels were lower than the maximum allowable levels in seafood set by the European Commission.

Organochlorine pesticides and polychlorinated biphenyl congeners in wild terrestrial mammals from Croatia: Interspecies comparison of residue levels and compositions

In this pilot study, we investigated levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in the adipose tissues of two free-ranging terrestrial carnivores from Croatia sampled in 2010 and 2011: the brown bear (Ursus arctos; N=32) and the grey wolf (Canis lupus; N=29). Concentrations of ∑OCPs and ΣPCBs ranged from 0.45 to 4.09 ng g(-1) lipid mass (lm) and from 0.93 to 8.52 ng g(-1) lm in brown bear, and from 1.18 to 5.67 ng g(-1) lm and 2.68 to 48.9 ng g(-1) lm in grey wolf adipose tissues, respectively. PCBs were dominant accounting for over 72% of total analyzed persistent organic pollutants (POPs). The sum of six indicator non-dioxin-like PCBs (Σ6IndNDL PCBs) made up 60-93% and 58-85% of the total congener concentrations in brown bears and wolves, respectively. Although the levels of the measured parameters were significantly higher in grey wolves than in bears, the contaminant profiles of the two species were similar, with γ-HCH, HCB, β-HCH and DDE as major OCP contaminants, and PCB-153>PCB-180≈PCB-170>PCB-138 as the dominant congeners. The sum of hexachlorocyclohexanes (ΣHCHs) and 8 toxicologically relevant dioxin-like PCBs (Σ8ToxDL PCBs) was higher in the males than in the females of the brown bear. Concentrations of ΣDDTs, HCB, ΣOCP, ΣPCBs, Σ6IndNDL PCBs, and toxicologically relevant non-dioxin-like PCBs (ΣToxNDL PCBs) were significantly positively correlated with lipid content in the grey wolf. Concentrations of OCPs and PCBs in brown bears and wolves from Croatia were low and normal for large terrestrial mammals.

Concentrations of Contaminants with Regulatory Limits in Samples of Clam (Chamelea gallina) Collected along the Abruzzi Region Coast in Central Italy

Concentrations of pollutants with regulatory limits were determined in specimens of Chamelea gallina, a species of clam collected along the Abruzzi coastal region of the central Adriatic Sea. Nine sampling sites were selected to evaluate the distribution of contaminants in the environment and the health risk for consumers. The concentrations of all the examined compounds were lower than the maximums set by European legislation. Polycyclic aromatic hydrocarbons and total mercury were below the detection limit (0.18 μg/kg for benzo[a]anthracene, 0.30 μg/kg for chrysene, 0.12 μg/kg for benzo[b]fluoranthene, 0.08 μg/kg for benzo[a]pyrene, and 0.0050 mg/kg for total mercury) in all the analyzed samples. Mean concentrations of lead and cadmium were 0.104 and 0.110 mg/kg, respectively. Of the non-dioxin-like polychlorinated biphenyls, PCB-153, PCB-180, and PCB-138 were the most abundant at all sampling sites (1a to 9a) at 0.25 mi (ca. 0.4 km) and at some sampling sites (1b, 2b, 3b, 5b and 7b) at 0.35 mi (ca. 0.56 km). Principal component analysis revealed that the concentrations of dioxin-like polychlorinated biphenyls were similar at the majority of sampling sites, and O8CDD and 2,3,7,8-T4CDF were the predominant dioxin congeners.

Concentration distribution and potential health risk of heavy metals in Mactra veneriformis from Bohai Bay, China

To investigate the pollution level and evaluate the potential health risks of heavy metals, the concentrations of chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), molybdenum (Mo), cadmium (Cd), antimony (Sb), and lead (Pb) were determined by inductively coupled plasma-mass spectrometry (ICP-MS) in 198 clams (Mactra veneriformis) collected from 11 sites of the Bohai Bay. The results showed that heavy metal concentrations in the clams were different at different sites (p<0.05). Mn was dominant with a percentage of 22.08-77.03% in heavy metals, followed by Zn with 12.66-57.11%, and the concentration of Pb was the lowest with 0.45-1.04%. The potential health risk to consumers was evaluated by the target hazard quotient (THQ) and the maximum daily consumption rate (CRmax). The results indicated that the THQs of Co were the highest with the values of 1.125, 1.665, and 1.144 at three sections; the values of other individual metals were <1, which indicated that consumption of clams from the study areas caused health risks due to Co. Moreover, the CRmax values also indicated the potential health risk caused by Co in clams consumed in this area. Pearson correlation analysis and principal component analysis (PCA) indicated that there were significantly positive or negative correlations between the heavy metals (p<0.05), and the studied metals were divided into four groups. The results indicated that the concentrations of heavy metals in clams were affected not only by pollution sources but also by the characteristics of clams that could absorb selectively and accumulate special metals. This study offers important information on the pollution levels of heavy metals in clams and warns consumers of the health risks associated with the consumption of clams in the area.

Distribution of persistent organic pollutants (POPs) in cultured mussels from the Croatian coast of the Adriatic Sea

In this study we investigated the distribution of 7 organochlorine pesticides (OCPs) and 17 polychlorinated biphenyl (PCBs) congeners in the edible tissue of the blue mussels (Mytilusgalloprovincialis) collected at 15 shellfish breeding farms and 1 harvesting area along the Croatian Adriatic coast. All analyzed OCPs were found in all samples (0.011-1.47 ng g(-)(1) w.wt.). Concentrations of PCB congeners in positive samples ranged between 0.007 and 7.66 ng g(-)(1) w.wt. The most abundant compounds were γ-HCH, PCB-138 and PCB-153. Overall levels of PCBs and OCPs were in the lower end of the concentration ranges reported in literature. Significant differences of all contaminants were recorded between seasons, with higher values in the warmer part of the year. Results of the evaluation of the risks to human health associated with consumption of the mussels containing organic contaminants suggest that the levels of these compounds in mussels do not pose any threat for consumers of cultivated mussels.

Distribution and bioaccumulation of polychlorinated biphenyls and organochlorine pesticides residues in sediments and Manila clams (Ruditapes philippinarum) from along the Mid-Western coast of Korea

The distribution and bioaccumulation features of PCBs, DDTs, and HCHs were investigated in the sediments and Manila clams collected from along the Mid-Western coast of Korea. The measured concentrations of ΣPCBs, ΣDDTs and ΣHCHs were 1.08-3.5, 0.12-0.35 and 0.090-0.30 ng g(-1) dw in sediment, and 33-390, 7.4-46 and 6.3-27 ng g(-1) lipid in Manila clam, respectively. Their levels were found to be relatively lower than those of other contaminated areas and the consumption of Manila clam from these areas seems to be safe for human health according to calculated lifetime cancer risk and hazard indices. The ΣPCBs and ΣDDTs concentrations in sediments showed a significant relationship to those in clams. The significant correlation was observed between BSAF in clams and Kow for each PCB congeners and DDT metabolites. These findings support that the PCBs and DDTs levels, which are highly hydrophobic chemicals, in clam reflect the sediment pollution through bioaccumulation.

Does the clam Ensis siliqua provide useful information about contamination by polychlorinated biphenyls and organochlorine pesticides beyond that of mussel Mytilus galloprovincialis?

Several polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) investigated in soft tissues of the frequently monitored Mytilus galloprovincialis were compared to those of Ensis siliqua, a highly dispersed and economically important bivalve species, though rarely investigated. Overall PCBs had higher concentrations than OCPs in both species with a prevalence of tri- tetra-and penta-chlorinated biphenyls in E. siliqua and a prevalence of hexa- hepta and octa-chlorinated biphenyls in M. galloprovincialis. E. siliqua emerges as a suitable complement to mussels for monitoring PCBs and OCPs pollution.

Human exposure to trace metals and possible public health risks via consumption of mussels Mytilus galloprovincialis from the Adriatic coastal area

Considering the growing concern due to different levels of anthropogenic loadings, the main purpose of this study was to identify the levels of trace metals (Fe, Mn, Cu, Zn, Co, Ni, Cd, Pb and Hg) in the mussels Mytilus galloprovincialis sampled along the marine coast of Boka Kotorska Bay, Montenegro. In comparison with the permissible limits set by the EU and the US FDA, all trace metal concentrations found in the mussels from the coastal area of Boka Kotorska Bay were lower than the prescribed limits. Generally, the trace metal concentrations found in Montenegrin mussels are within the range of trace metal concentrations determined in low to moderately polluted Adriatic areas. Based on these and other available literature data published by other authors for Adriatic region, the public health risks associated with the consumption of mussels in relation to reported trace metal concentrations were evaluated. In terms of the obtained trace metals concentrations in mussels and the provisional tolerable weekly intake prescribed by the JECFA and oral reference doses by the US EPA, the Pb and Cd concentrations and the Co and Cd concentrations were recognized as the limiting factor for the consumption of mussels from some Adriatic areas, respectively.

Distribution and trend of organochlorine pesticides in Galicia coast using mussels as bioindicator organisms. Possible relationship to biological parameters

Contamination of organochlorine pesticides (OCPs) such as DDT and its metabolites (ΣDDs), γ-HCH (hexachlorocyclohexane), HCB (hexachlorobenzene), aldrin, endrin, isodrin and trans-nonachlor were investigated in wild mussels (Mytilus galloprovincialis) collected from Galician Rías (Rías of Ferrol, A Coruña, Muros, Arousa, Pontevedra and Vigo) during the period 1998-2012. Biological parameters, lipid content, shell length and condition index, were also studied. The OCPs levels in the wild mussel were in the order ΣDDs>γ-HCH>HCB. The other pesticides, aldrin, endrin, isodrin and trans-nonachlor, were not detected or were below the analytical detection limit. All concentrations found in these samples were below the allowable limits for human consumption (Regulation (EC) no. 396/2005). Univariate analysis confirmed that levels of some compounds presented significant relation with biological parameters. Multivariate analysis of the OCPs levels revealed significantly differences between studied Rías, samples from Ría of Ferrol had the highest levels of these compounds (values of ΣDDs ranged from 3.9 to 4.2 ng g(-1) ww) and samples from Ría of Arousa, the lowest levels (values of ΣDDs from 1.3 to 2.4 ng g(-1) ww). Temporal trends showed a decrease of OCPs levels along the studied period 1998-2012 in the Galician Rías.

Biomonitoring of trace metal pollution using the bivalve molluscs, Villorita cyprinoides, from the Cochin backwaters

Trace metal concentrations in the muscle of the bivalve Villorita cyprinoides from the Cochin backwaters (southwest coast of India) were investigated during the monsoon, post-monsoon and pre-monsoon periods. The seasonal average ranges of metals (μg g(-1), dry weight) in the bivalve were as follows: Fe (18,532.44-28,267.05), Co (23.25-37.58), Ni (10.56-19.28), Cu (3.58-11.35), Zn (48.45-139.15), Cd (1.06-1.50) and Pb (3.05-4.35). The marginally elevated metal concentrations in bivalve muscles are probably related to high influx of metals as a result of pollution from the industries and agricultural fields with consequent increased bioavailability of metals to the bivalve. Evaluation of the risks to human health associated with consumption of the bivalves suggested that there is no health risk for moderate shellfish consumers. A regular and continuous biomonitoring program is recommended to establish V. cyprinoides as a bioindicator for assessing the effects of trace metal pollution and to identify future changes to conserve the "health" of this fragile ecosystem.

Interspecific comparison of polycyclic aromatic hydrocarbons and persistent organochlorines bioaccumulation in bivalves from a Mediterranean coastal lagoon

The bioaccumulation of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) was characterized in cockle, oyster and noble pen shell from nine areas in the Mar Menor lagoon with different hydrodynamic and pollutant sources. Biota, sediment and water samples were simultaneously collected in the spring and autumn of 2010. Considering all bivalve samples, PAH concentrations ranged from 8.98 to 370 μg·kg(-1) d.w., those of PCBs from 0.15 to 42.36 μg·kg(-1) d.w. and those of DDXs from below detection limit to 240.6 μg·kg(-1) d.w., where p,p'-DDE was the main fraction. The bioaccumulation of PAHs was similar for cockle, oyster and noble pen shell, being higher close to ports and wastewater effluents. However, DDX and PCB bioaccumulations in oyster and noble pen shell were significantly higher than in cockle in spring (p=0.02). The first organic pollutant bioaccumulation data for noble pen shell were obtained in this study, showing a preferential accumulation of pyrene. The increase of PAH bioaccumulation in autumn, as compared to spring, was low, due to high water temperatures during the summer, which favoured PAH dissipation processes. No significant seasonal variations were detected for OCPs and PCBs, except in some specific areas. The PAH, PCB and OCP levels detected in these bivalves were lower than OSPAR/MED POL environmental assessment criteria, except for p,p'-DDE in bivalves sited close to El Albujón watercourse mouth.

Spatial and seasonal distribution of trace metal concentrations in mussel (Mytilus galloprovincialis) and sediment of Bosphorus and Golden Horn

The Golden Horn Estuary and Bosphorus Strait are two major marine environments of metropolitan Istanbul which have been exposed to intensive industrial discharges for more than 50 years. In the present study, concentrations of cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb) and zinc (Zn) were measured in mussel tissue and sediment samples by using inductively coupled plasma-atomic emission spectroscopy to assess the current status of metal pollution in the Golden Horn and Bosphorus Strait. Ranges of Cd, Cr, Cu, Pb and Zn concentrations in soft parts of the mussels were BDL-2.59; BDL-7.35; 3.96-20.90; BDL-10.0; and 124.8-293.2 μg g(-1) dry weight (dw), respectively, while the ranges of Cd, Cr, Cu, Pb and Zn in <63 μm sediment fractions were BDL, 19.5-300.3, 16.9-724.7, 10.5-260.9, and 39.3-793.1 μg g(-1) dw, respectively. Ranges of Cd, Cr, Cu, Pb and Zn in >63 μm sediment fractions were BDL, 4.73-52.81, 3.45-481.87, 3.13-174.67 and 10.7-241.2 μg g(-1) dw, respectively. Trace metal concentrations found in sediment of the Golden Horn were 5-10 times higher than average literature values obtained in Mediterranean marine environment, whereas those of the Bosphorus Strait were consistent with or slightly higher than average literature values.

As, Cd, Hg and Pb in four edible shellfish species from breeding and harvesting areas along the eastern Adriatic Coast, Croatia

Four species of shellfish (Mytilus galloprovincialis, Ostrea edulis, Chlamis varia and Venus verrucosa) were collected during the autumn 2011 and spring 2012 along the eastern Adriatic coast from six shellfish harvesting areas (all species) and 13 breeding sampling areas (mussels) to assess As, Cd, Hg and Pb levels and the human risks of shellfish consumption. The mean metal concentrations (wet weight) in the examined species ranged from 1.420 to 9.575mg/kg for As, 0.034 to 1.270 for Cd, 0.005 to 0.680 for Hg and 0.140 to 2.072 for Pb. Examination of the spatial distribution of As, Cd, Hg and Pb revealed statistically significant differences among the studied areas. Since the concentrations were below the maximum prescribed by the laws of the EU and Croatia (the concentrations slightly exceeded the upper limits for three samples; Pb, Cd and Hg) and the hazard index, (HI) for Cd, Hg and Pb were below 1 and the target cancer risk (TR) for As was lower than 1×10(-6), there is no human health risk of consumption of shellfish from Croatian waters.

Gene flow vs. pollution pressure: genetic diversity of Mytilus galloprovincialis in eastern Adriatic

Environmental pollution may modify all the evolutionary processes involved in shaping the genetic patterns of exposed populations. In order to evaluate the pollution impact on the genetic diversity of Mediterranean mussel Mytilus galloprovincialis ten populations inhabiting differently polluted sites along the eastern Adriatic coast, from pristine bays to heavily trafficked harbours, were studied. Pollution pressure was assessed through an integrated study of biological effects and responses across different levels of biological organization. Eight microsatellite markers were analysed to assess genetic diversity of investigated populations. Both the principal component analysis (PCA) of the biomarker data set as well as the biomarker response index (BRI) confirmed substantial pollution pressure at the highly polluted sites, and very low pollution exposure at the three reference sites. Very shallow genetic differentiation was found in respect to maritime distances or pollution status, and this was attributed to a high gene flow among the populations. However, populations inhabiting polluted sites exhibited higher levels of genetic diversity and evolutionary mechanisms underlying this phenomenon are discussed.