Influence of an intensive agricultural drainage basin on the seasonal distribution of organic pollutants in seawater from a Mediterranean coastal lagoon (Mar Menor, SE Spain)

Comparative assessment of microplastics and microalgae as vectors of mercury and chlorpyrifos in the copepod Acartia tonsa

Microplastics (MPs) raise concerns not only as pollutants themselves, but also due to their ability to act as vectors of pollutants adsorbed from seawater, transferring them to marine organisms. However, the relevance of MPs as carriers of pollutants compared to microalgae needs further exploration. This study compared the role of MPs (2-10 μm non-oxidized and 10-15 μm oxidized high-density polyethylene) and natural organic particles (Rhodomonas lens microalgae, MA) as carriers of mercury (Hg, 2.3 μg Hg/L) and chlorpyrifos (CPF, 1.0 μg CPF/L) to adult Acartia tonsa copepods, after 24-48 h exposure. Dose-response experiments were first performed with adult female copepods exposed to oxidized MPs (0.25-4.0 mg/L), waterborne Hg (0.01-10.0 μg/L) and Ox MPs + Hg (0.25-4.0 mg oxidized MPs/L + 0.50-8.0 μg Hg/L) for 48 h, to complement previous studies that focused on the pesticide CPF. Effects were evaluated with four replicates for physiological and reproductive responses (6 females/replicate), biochemical techniques (40 individuals/replicate) and Hg/CPF bioaccumulation measurements (1000 individuals/replicate). Copepods accumulated Hg/CPF similarly from dissolved pollutants (6204 ± 2265 ng Hg/g and 1251 ± 646 ng CPF/g) and loaded MPs (3125 ± 1389 ng Hg/g and 1156 ± 266 ng CPF/g), but significantly less from loaded MA (21 ± 8 ng Hg/g and 173 ± 80 ng CPF/g). After 24-48 h, copepods exposed to MPs + Hg/CPF showed generally greater biological effects than those exposed to dissolved Hg/CPF or to MA + Hg/CPF, although differences were not statistically significant. MA + CPF had significantly lower AChE inhibition (1073.4 nmol min-1 mg-1) and MA + Hg lower GRx induction (48.8 nmol min-1 mg-1) compared to MPs + Hg/CPF and dissolved Hg/CPF (182.8-236.4 nmol min-1 mg-1 of AChE and 74.1-101.7 nmol min-1 mg-1 of GRx). Principal component analysis suggested different modes of action for Hg and CPF.

Temporal distribution and ecological risk assessment for pesticides in water from the north-central coastal zone of Sinaloa, Mexico

Water contamination with pesticides is one of the major pollution problems in northwestern Mexico, and this is due to the extensive use of pesticides in agriculture. In this research, water samples of ten sampling sites (fishing grounds, beaches, and both) were analyzed in the search for 28 pesticides (organochlorines, organophosphates, pyrethroids, carbamates, among other chemical classes), supplemented with a calculation of the resulting potential environmental risk. Pesticides were separated from the matrix by liquid-liquid extraction and quantified by gas chromatography coupled to electron micro-capture (organohalogenated) and pulsed flame photometric detectors (organophosphates). In addition, the ecotoxicological risk of pesticides in algae, invertebrates, and fish was assessed, based on seawater pesticide concentrations using the Risk Quotient (RQ) and Toxic Units (TU) approach. The results showed 18 pesticides identified in the analyzed samples, where cypermethrin and chlorpyrifos were identified with the maximum concentrations of 1.223 and 0.994 μg L-1, respectively. In addition, these two pesticides have been associated with acute toxic effects on algae, invertebrates, and fish. It is important to pay particular attention to the search for long-term alternatives to the use of chlorpyrifos and cypermethrin due to their high detection rates and the risks associated with their toxic properties. However, the adoption of alternative measures to synthetic pesticide control should be a priority, moving towards sustainable practices such as the use of biopesticides, crop rotation and polycultures.

Distribution of organophosphorus pesticides and its potential connection with probiotics in sediments of a shallow freshwater lake

Despite the serious health threats due to wide use of organophosphorus pesticides (OPPs) have been experimentally claimed to be remediated by probiotic microorganisms in various food and organism models, the interactions between OPPs and probiotics in the natural wetland ecosystem was rarely investigated. This study delves into the spatial and temporal distribution, contamination levels of OPPs in the Baiyangdian region, the diversity of probiotic communities in varying environmental contexts, and the potential connection with OPPs on these probiotics. In typical shallow lake wetland ecosystem-Baiyangdian lake in north China, eight OPPs were identified in the lake sediments, even though their detection rates were generally low. Malathion exhibited the highest average content among these pesticides (9.51 ng/g), followed by fenitrothion (6.70 ng/g). Conversely, chlorpyrifos had the lowest detection rate at only 2.14%. The region near Nanliu Zhuang (F10), significantly influenced by human activities, displayed the highest concentration of total OPPs (136.82 ng/g). A total of 145 probiotic species spanning 78 genera were identified in Baiyangdian sediments. Our analysis underscores the relations of environmental factors such as phosphatase activity, pH, and electrical conductivity (EC) with probiotic community. Notably, several high-abundance probiotics including Pseudomonas chlororaphis, Clostridium sp., Lactobacillus fermentum, and Pseudomonas putida, etc., which were reported to exhibit significant potential for the degradation of OPPs, showed strongly correlations with OPPs in the Baiyangdian lake sediments. The outcomes of this research offer valuable insights into the spatiotemporal dynamics of OPPs in natural large lake wetland and the probability of their in-situ residue bioremediation through the phosphatase pathway mediated by probiotic such as Lactic acid bacteria in soils/sediments contaminated with OPPs.

Floating plastics as integrative samplers of organic contaminants of legacy and emerging concern from Western Mediterranean coastal areas

This study investigates the role of floating plastics as integrative samplers of organic contaminants. To this end, plastics items were collected in two Western Mediterranean coastal areas: the Mar Menor lagoon, and the last transect of Ebro river. Floating plastics were identified and characterized by attenuated total reflection Fourier-transform infrared spectrometry. Then, organic contaminants were extracted from plastic items by ultrasonic extraction with methanol, and the concentrations of 168 regulated and emerging contaminants were analysed. These compounds were analysed by stir bar sorptive extraction coupled to gas chromatography-mass spectrometry (GC-MS), except for bisphenol analogues, which were analysed with a ultraperformance liquid chromatography pump coupled to a triple quadrupole mass spectrometer (UHPLC-MS/MS), and pharmaceutical compounds, determined by UPLC coupled to hybrid triple quadrupole-linear ion trap mass spectrometer (UPLC-MS/MS). All the contaminants groups considered were detected in the samples, being particularly relevant the contribution of plastic additives. The most frequently detected contaminants were UV-filters, PAHs, pharmaceuticals and synthetic musks. Apart from plasticizers, the individual contaminants octocrylene, homosalate, galaxolide, salycilic acid and ketoprofen were frequently detected in plastics items. The results pointed out to urban and touristic activities as the main sources of pollution in the coastal areas investigated. The utility of floating plastics as integrative samplers for the detection of organic contaminants in aquatic ecosystems has been demonstrated.

The impact of chemical pollution on the European eel (Anguilla anguilla) from a Mediterranean hypersaline coastal lagoon

The European eel (Anguilla anguilla) is a critically endangered species. The impact of environmental contamination on this species has been highlighted as contributing to the decline in recruitment. The Mar Menor hypersaline coastal lagoon (SE Spain) is one of the most productive fisheries of European eel in Europe, making it a critical habitat for species conservation. The present study aimed to provide an initial overview of the impact of organic chemical contaminants on the European eel and the potential sublethal effects of chemical pollution on pre-migrating eels in this hypersaline habitat. We investigated muscle bioaccumulation of main persistent and hazardous organic contaminants (including some current-use pesticides) and genotoxicity, neurotoxicity, and xenobiotic detoxification system responses. The findings show that lagoon eels were exposed to high levels of legacy organochlorine contaminants, recently banned pesticides (chlorpyrifos), and some emerging chemicals. Some individuals surpassed the maximum levels of CBs authorized by the European Commission for human consumption. In this species, residuals of chlorpyrifos, pendimethalin, and chlorthal dimethyl have been reported for the first time. This field study provides relevant data to stock management and human health consumption and provides the first biomarker responses in European eel under permanent hypersaline conditions. Furthermore, the high frequency of micronuclei in peripheral erythrocytes of lagoon eels indicates sublethal genotoxic effects on the organism. Overall, the European eels growing and maturing in the Mar Menor lagoon are exposed to toxic and carcinogenic chemicals. The lack of seafood safety regulations for human consumption for some legacy chemicals that were measured in high concentrations in our study requires special action. Further biomonitoring and research are recommended to protect the animal, public, and environmental health.

Occurrence and distribution of contaminants of legacy and emerging concern in surface waters of two Western Mediterranean coastal areas: Mar Menor Lagoon and Ebro Delta

The occurrence and distribution of UV filters, plastic additives, synthetic musks, other personal care products (Other PCPs), triazines, polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), organophosphorus pesticides (OPPs), polychlorinated biphenyls (PCBs) and other current-use pesticides (Other CUPs) were characterised during summer 2018 and winter 2019 in surface waters of two sensitive areas of the Spanish coast located on the Mediterranean Sea (Mar Menor lagoon and Ebro Delta). Sixty-three organic contaminants out of a total of 100 compounds were detected, thus confirming the presence of all groups of pollutants studied in surface water at concentrations of ng/L. Both areas are affected by agricultural, urban and recreational activities, PCPs (mainly UV filters) being the predominant compounds found in both seasons which showed significant increases in concentrations in summer. The contaminants found at the highest concentrations were octocrylene, homosalate and ethylhexyl salicylate, which showed risk quotients higher than 1, indicating a potential risk to aquatic organisms, particularly in summer.

Adsorption of pesticides and personal care products on pristine and weathered microplastics in the marine environment. Comparison between bio-based and conventional plastics

The hydrophobicity of persistent organic pollutants (POPs) makes them adsorb on microplastics in the marine environment, affecting their distribution, persistence, or their transfer to the trophic chain. Fragrances and non-polar pesticides can be adsorbed by microplastics in the marine environment because of their physico-chemical characteristics. In this work, the adsorption of two pesticides (α-endosulfan and chlorpyrifos) and 6 musk fragrances (musk xylene, musk ketone, musk moskene, galaxolide, tonalide, and celestolide) on polyamide (PA6) (a petroleum based polymer) and on polyhydroxybutyrate (PHB) (biopolymer) in seawater was studied, considering also the effect of water temperature and plastic weathering. Results show higher adsorption of the selected pollutants for PHB than PA, being PA more affected by the water temperature and the plastic weathering. The highest percentage of adsorption was achieved in most cases at 24 h. In addition, this process was irreversible, as it showed the leaching assays. Besides, this work revealed that plastics mitigate the degradation of α-endosulfan in aquatic media (hydrolysis), showing that plastics can act as inhibitors of degradation of POPs, increasing its persistence in the environment.

Assessing the colonization by Daphnia magna of pesticide-disturbed habitats (chlorpyrifos, terbuthylazine and their mixtures) and the behavioral and neurotoxic effects

The spread of pesticides in water bodies integrated into agricultural landscapes may prevent some areas from being colonized. In this study, the effects on the colonization responses of D. magna exerted by gradients of realistic environmental concentrations of the pesticides chlorpyrifos, terbuthylazine and their mixtures were tested in a novel multicompartment non-forced exposure system. Furthermore, the effects of both pesticides and their mixtures on the swimming behavior and the neurotransmission activity of D. magna were analyzed using a traditional forced exposure system. The synthesis and concentration of the main environmental metabolites of terbuthylazine were also analyzed. Results confirmed that D. magna exposed to mixture gradients were able to detect the pollutants and their colonization dynamics were drastically inhibited. The swimming behavior increased in D. magna exposed to the highest concentration of the mixture treatment. AChE activity was only significantly inhibited in the D. magna exposed to the highest concentration of chlorpyrifos. Changes in swimming behavior could not be directly related to the effects on AChE. Furthermore, the synthesis of the metabolite terbuthylazine 2-hydroxy during the course of the experiments was confirmed. These results demonstrate the importance of integrating pesticide mixtures in both non-forced and forced exposure systems during ecotoxicological assays.

Non-targeted analysis by DLLME-GC-MS for the monitoring of pollutants in the Mar Menor lagoon

Non-targeted analysis for the monitoring of organic pollutants resulting from agricultural and industrial practices, plastics and pharmaceutical products of seawater from the Mar Menor lagoon (SE Spain) is proposed using dispersive liquid-liquid microextraction (DLLME) and gas chromatography-mass spectrometry (GC-MS). Initially, a home-made MS database including 118 environmental organic pollutants, whose presence in different ecosystems has already been reported, was created. The analytical method was applied for the analysis of 42 samples and a total of 18 pollutants were detected and identified. Samples were obtained from different sites around the Mar Menor in three sampling campaigns, enabling the assessment of impact of rain on the input of the detected chemicals and their distribution. In addition, this methodology was validated using a standard mixture containing 54 of the environmental pollutants included in the database, allowing the quantification of the 9 of the identified compounds (dibutyl phthalate, diisobutyl phthalate, diethyl phthalate, bis(2-ethylhexyl) phthalate, anthracene, 2-methylnaphthalene, hexachlorocyclopentadiene, bis(2-ethylhexyl) adipate and oleamide) with concentration between 3 and 271 μg L^-1.

Combined polystyrene microplastics and chlorpyrifos decrease levels of nutritional parameters in muscle of rainbow trout (Oncorhynchus mykiss)

Microplastic (MP) is a major contaminant in the aquatic environment. In addition to the physical threats posed by microplastic ingestion, their potential as a vector for the transport of hydrophobic pollutants is required to be adequately addressed. This study examined the effects of polystyrene microplastics individually or combined with chlorpyrifos insecticide on nutritional parameters in muscle of rainbow trout (Onchorhynchus mykiss). Fish were exposed to individual polystyrene microplastic concentrations (30 or 300 μg/L), or individual chlorpyrifos concentrations (2 or 6 μg/L), and their combination at similar concentrations of chlorpyrifos and microplastics. Results showed individual polystyrene microplastics had minimal effects on amino acid and fatty acid composition and no effect on protein contents of fish muscle. However, significant alterations in amino acid and fatty acid composition, and protein contents, were observed in combined polystyrene microplastics and chlorpyrifos groups. These findings suggested that polystyrene microplastics cause toxicity and increase the adverse effects of chlorpyrifos on the muscle of fish. This investigation provided evidence toward low nutritional value of farmed or wild fish muscle that grows in areas with high concentrations of microplastics and pesticides.

Assessment of anthropogenic pollution by monitoring occurrence and distribution of chemicals in the river Liffey in Dublin

This paper evaluates for the first time the spatial distribution of a wide group of organic (phthalates, nitro, aliphatic, halogen, aromatic, phenol and amino compounds) and inorganic pollutants along the Liffey river in Dublin city. The work takes into account the effect of short-term weather conditions on the occurrence of these contaminants. The results showed that rainfall conditions affect the levels of pollutants along the river in the days following a rainfall event. In addition, the tributaries entering the river Liffey were not found to impact its water quality. In relation to organic pollutants, 2,4,6-trichlorophenol, 2-nitrophenol and phthalate compounds were found in many water samples between concentrations of 0.21 and 2.17 μg L-1. On the other hand, dimethyl phthalate was present in certain samples at levels around 100 μg L-1. The levels of these contaminants in the river were lower than the toxicity values reported in the literature. Regarding inorganic pollutants, nitrates were detected from 0.59 to 6.81 mg L-1 increasing from upstream to downstream. Based on the chemical nature and applications of detected pollutants, the river contamination can be mainly related to agricultural, industrial activities as well as diffuse urban contributions. These vary with location within a short distance and have the potential to impact aquatic biodiversity as the chemical composition changes with rainfall events.

Seasonal variations in atrazine degradation in a typical semienclosed bay of the northwest Pacific ocean

Pesticides are widely used to alleviate pest pressure in agricultural systems, and atrazine is a typical diffuse pollutant and serves a sensitivity index for environmental characteristics. Based on the physicochemical properties of parent substances, degradation products of pesticides may pose a greater threat to aquatic ecosystems than pesticides. Atrazine and three primary degradation products (deethylatrazine (DEA), deisopropylatrazine (DIA) and didealkylatrazine (DDA)) were investigated in a semienclosed bay of the western Pacific Ocean. Seasonal surface water and suspended particulate sediment (SPS) samples were collected from the estuary and bay in January, April, and August 2019. The level of pesticide contamination was lower in the bay than in the estuary, and the pesticide concentration in the dissolved phase was higher than that in the adsorbed phase. The average concentrations of atrazine and the three degradation products in the three seasons ranged from 2.42 to 328.46 ng/L in water and from 0.07 to 12.75 ng/L in SPS. The proportion of atrazine among the four detected pollutants decreased from 0.7 to 0.1 in surface water and from 0.3 to 0.1 in SPS over the seasons. As the main degradation products, the concentration proportions of DDA and DEA reached as high as 0.6 in August. The ratio of DEA to atrazine (DEA/ATR) increased from January to August, which indicated the progressive degradation process in the bay. Single-factor analysis of variance and principal component analysis indicated that atrazine degradation was sensitive to temperature, dissolved oxygen, and salinity. These three factors accounted for almost 70% of the seasonal variance in atrazine without a quantification assessment of photolysis or bacteria. The spatial distributions of DEA in the three seasons demonstrated that wind and currents also played important roles in pollutant redistribution. The seasonal temporal and spatial correlations between water and SPS demonstrated the degradation patterns of atrazine in marine conditions, supporting the need for future detailed toxicity studies.

Appraisal of water matrix on the removal of fungicide residues by heterogeneous photocatalytic treatment using UV-LED lamp as light source

In this study, the photocatalytic degradation of four fungicides, myclobutanil, penconazole and difenoconazole (triazole compounds) and boscalid (carboxamide), has been examined in different aqueous matrices (tap water, irrigation water and two WWPT effluents). Experiments were conducted at laboratory scale with different reagents-zinc oxide (ZnO), titanium dioxide (TiO₂), sodium persulphate (Na₂S₂O₈) and the combined systems ZnO/Na₂S₂O₈ and TiO₂/Na₂S₂O₈-in water exposed to UV-LED irradiation. Previously, the effect of catalyst and oxidant loading on the disappearance kinetics of the different fungicides was assessed to know maximum degradation efficiency. The influence of water matrices and pesticide loading in removal effectiveness has been evaluated. It was observed a greater efficiency in processes conducted using the tandems ZnO/Na₂S₂O₈ and TiO₂/Na₂S₂O₈ in irrigation and tap waters. Results showed that UV-LED are a suitable alternative for tackling the removal of organic pollutants in water.

Multiple metals and agricultural use affects oxidative stress biomarkers in freshwater Aegla crabs

Metals and agrochemicals are among the main aquatic contaminants, being able to trigger oxidative stress in exposed organisms. The objective of this work was to evaluate the correlation between the level of oxidative stress biomarkers in Aegla crabs (Crustacea, Anomura) with (i) the set of metals present in the streams sediment and (ii) with land uses of three hydrographic basins. The study was carried out in streams (≤ 2nd order) of hydrographic basins in southern Brazil (Basins of Rio Suzana, Rio Ligeirinho-Leãozinho and Rio Dourado). In these streams were quantified the land uses and Cu, Cr, Cd, Fe, Mn and Zn concentrations in the sediment. The enzymes Catalase (CAT) and Glutathione Reductase (GR), as well as the level of membrane lipid peroxidation (TBARS), were analyzed in adult females. The PCA analysis showed that the distribution of metals was different between the basins. Cd, Cr and Fe were correlated positively with CAT and negatively with TBARS and GR. The Dourado basin had the lowest concentrations of these three metals and the highest levels of TBARS. However, in Dourado basin there is predominance of agriculture land use, and TBARS was positively correlated with agricultural land use. Besides in Dourado basin, GR activity was higher than in the others basins, indicating a compensatory response in relation to CAT inhibition. The basins of Suzana and Ligeirinho-Leãozinho rivers had lower TBARS values, which may be due to the induction of CAT in response to metals accumulated in sediment. In summary, this work indicates that in the basins with a higher concentration of toxic metals there is an adaptive response of CAT induction, which reduces TBARS in Aegla. On the other hand, in the basin with lower metallic contamination, TBARS occurrence was primarily influenced by agricultural land use.

Extended suspect screening to identify contaminants of emerging concern in riverine and coastal ecosystems and assessment of environmental risks

A suspect screening methodology was developed for the fast and reliable identification of 360 contaminants of emerging concern (CECs) of anthropogenic origin in the vulnerable area of the Ebro Delta (Catalonia, Spain) and to track for potential contamination sources. The suspect screening methodology was combined with a risk assessment approach to prioritize the most ecologically relevant CECs. Out of the 360 suspects, 37 compounds were tentatively identified, 22 of which were fully confirmed using isotopically labelled standards. The detected suspect compounds included pesticides, pharmaceuticals, personal care products, stimulants and their metabolites. Pesticides were more ubiquitous in irrigation and drainage channels, while pharmaceuticals, stimulants, and personal care products were the most common in effluent wastewaters, in the receiving freshwater systems as well as in the marine environment. Ten compounds were found to be of high ecological concern, including the pharmaceuticals telmisartan, venlafaxine, and carbamazepine, the herbicides terbuthylazine, desethylterbuthylazine, and terbutryn, the fungicides azoxystrobin, tebuconazole and prochloraz and the insecticide tebufenozide. These compounds could be used as markers of anthropogenic contamination in riverine and coastal ecosystems.

Identification of contaminants of emerging concern with potential environmental risk in Spanish continental shelf sediments

The distribution of per- and polyfluoroalkyl substances (PFAS), alkylphenols, organotin compounds, phthalates, alkylated polycyclic aromatic hydrocarbons, current-use pesticides (CUPs) and personal care products (PCPs) was characterized in 29 surface sediments from two Spanish Iberian continental shelf areas (14 on the Atlantic and 15 on the Mediterranean coasts). Concretely, 115 organic contaminants were determined and a specific methodology was used for each contaminant group, including contaminants of emerging concern (CECs) and traditional ones, such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorinated pesticides (OCPs). PAHs, alkylated PAHs, alkylphenols and phthalates were found in all samples, showing mean concentrations per group higher than 20 ng/g (16-4974 ng/g d.w.) in the subregions under consideration (Galician, Cantabrian, Levantine-Balearic and Strait-Alboran). CUPs and PCPs were found in the majority of samples at very low concentrations of ng/g (1.4-46.8 ng/g d.w.), whereas organotins and PFAS were found principally in sediments from the Mediterranean subregions (2.5-3.9 ng/g d.w.). Different distribution patterns were observed for the contaminant groups and subregions under consideration as a consequence of the diverse predominant sources (industrial, urban, transport and agricultural activities) and environmental behavior (mainly hydrophobicity and persistence). Risk assessment confirmed the impact of phthalates, alkylphenols, PAHs and PCBs on Atlantic ecosystems and of alkylphenols, chlorpyrifos, phthalates, TBT, PAHs, OCPs and PCBs on the Mediterranean ones. Furthermore, the presence of CUPs, PCPs and PFAS in sediments from the Spanish continental shelf located between 2 and 31 km from the coast suggested that those contaminants may also provoke adverse effects on coastal marine ecosystems between their sources and their depositional areas. CAPSULE: Alkylphenols, phthalates and organotins may provoke adverse effects on Spanish coastal marine ecosystems from their sources to the sediment depositional areas.

Morpho-Functional Alterations in the Gills of a Seawater Teleost, the Ornate Wrasse (Thalassoma pavo L.), after Short-Term Exposure to Chlorpyrifos

Chlorpyrifos (CPF) is an organophosphorus insecticide commonly used for domestic and agricultural purposes. The risk posed by environmental contamination from CPF is well acknowledged, and it has been detected worldwide in aquatic habitats and coastal areas. In addition, due to its slower degradation in seawater compared to freshwater, CPF is of particular concern for marine environments. Here, we investigated for the first time the morpho-functional alterations induced by CPF on the gills of Thalassoma pavo, a widespread species in the Mediterranean Sea. We tested the effects of two sublethal concentrations (4 and 8 µg/L) after 48 and 96 h. Our study demonstrates that the alterations induced by CPF are dose and time-dependent and highlight the harmful properties of this insecticide. After exposure to the low tested concentration, the more frequent alteration is an intense proliferation of the primary epithelium, whereas after exposure to the high concentration, the primary epithelium proliferation is less extensive, and the most evident effects are the thinning of secondary lamellae and the ectopia of chloride and goblet cells. CPF also modulated the expression of Na⁺/K⁺-ATPase. Dilation of lamellar apical tips, pillar cell degeneration, and appearance of aneurysms are often observed.

Presence and risk assessment of herbicides in the marine environment of Camps Bay (Cape Town, South Africa)

The present study was conducted during a time of drought to assess the concentration of herbicides and their potential for accumulation in marine biota found in the near shore marine environment of an urban setting (Camps Bay, Cape Town, South Africa). The purpose was to establish whether raw sewage containing selected persistent chemicals that are released through a local marine outfall would be sufficiently diluted by the ocean to prevent impact on the near-shore marine environment of the suburb Camps Bay. Samples of seawater, sediment, seaweed, and selected marine organisms present in the near shore environment, such as limpets (Cymbula granatina), mussels (Mytilus galloprovincialis), and sea urchins (Parechinus angulosus), were analysed for five indicator herbicides, namely atrazine, alachlor, simazine, metolachlor, and butachlor, with gas chromatography coupled with a mass spectrometer. The concentration of the compounds detected ranged from below the limit of detection (<LOD) to 4.2 ng/L in seawater, <LOD to 45.3 ng/g dry weight (dw) in sediments, <LOD to 157.8 ng/g dw in marine organisms, and between 12.3 and 87.0 ng/g dw in seaweed. Results of ecological risk assessment for acute and chronic risk, calculated following the US Environmental Protection Agency method, showed a possible threat to the near shore environment from sewage released by the marine outfall, as the herbicide contamination in the biota posed a low to high ecotoxicological risk for marine organisms. The hazard quotients and carcinogenic risk caused by herbicide pollution in Camps Bay seawater were above the acceptable level indicating that these chemicals pose adverse health effects, should an average sized human (70 kg) consume any of the marine species analysed herein on a daily basis (daily consumption of 54 g), over a lifetime period (life expectancy of 70 years). The study also indicated the extensive use of these herbicides for cosmetic and ornamental purposes in gardening, or for weed control in an urban setting, thus, it is apparent that consumers and municipalities need to be educated about their inadvertent use and safe disposal of these compounds. The use of these herbicides to control weeds within the area and discharge of sewage to Camps Bay must be checked through adequate control of the trade, handling of herbicides, and enforcement of appropriate sanctions and development of suitable regulations.

Polyethylene microplastics increase the toxicity of chlorpyrifos to the marine copepod Acartia tonsa

Ingestion of microplastics by marine organisms has been well documented, but their interaction with chemical pollutants has not been sufficiently addressed. The aim of this study was to determine the individual and combined effects of chlorpyrifos (CPF) and polyethylene microplastics (MP) on the survival, fecundity, feeding and egg viability of Acartia tonsa, a calanoid copepod widely distributed in planktonic communities. The median lethal concentration obtained for CPF was higher (LC₅₀ = 1.34 μg/L) than for the combination with MP (LC₅₀ = 0.37 μg/L), or CPF-loaded MP (LC₅₀ = 0.26 μg/L). Significant effects were also observed for feeding and egg production (EC₅₀ = 0.77 and 1.07 μg/L for CPF, 0.03 and 0.05 μg/L for CPF combined with MP, 0.18 and 0.20 μg/L for CPF-loaded MP). No significant effects were observed in the exposure to 'virgin' MP. This study confirms the role of MP as vectors of pollutants to marine organisms and supports the increased availability of certain toxicants carried out by MP. The effects observed in fitness-related responses suggest potential damage to A. tonsa populations. The comparison of the results obtained here with environmental concentrations indicates that the combined exposure to CPF and MP could constitute a risk to A. tonsa in the natural environment.

Development, validation, comparison, and implementation of a highly efficient and effective method using magnetic solid-phase extraction with hydrophilic-lipophilic-balanced materials for LC-MS/MS analysis of pesticides in seawater

To achieve multi-pesticides residue analysis in seawater, hydrophilic-lipophilic-balanced magnetic particles were designed and fabricated by swelling polymerization of divinyl benzene (DVB) and N-vinyl pyrrolidone (NVP) on the surface of Fe₃O₄@SiO₂ magnetic particles. The ratio of DVB to NVP was adjusted to achieve a proper balance in hydrophilicity and lipophilicity. The obtained magnetic particles were systematically characterized by TEM, SEM, FT-IR and vibrating sample magnetization. Based on the optimized magnetic nanoparticles, a sensitive magnetic solid-phase extraction method was developed for the simultaneous pre-concentration and determination of 96-pesticide residues from large-volume seawater samples prior to being detected by liquid chromatography-tandem mass spectrometry. Recoveries of pesticides in spiked seawater samples (0.001, 0.01, 0.1, 1.0 μg L^-1) ranged from 62% to 112% with RSDs less than 21%. The method limits of detection of 96 pesticides ranged from 0.13 to 0.42 ng L^-1, the method limits of quantification of 96 pesticides ranged from 1.0 to 10 ng L^-1. The method was successfully applied to pesticide residue analysis in water samples from Jiulong River Estuary of China, demonstrating the prospects of this technique as a potential method for the rapid determination of trace levels of multi-pesticide residues in seawater.

Impacts of Seasonal Variation on Organochlorine Pesticides in the East China Sea and Northern South China Sea

To investigate the characteristics of historic-use organochlorine pesticides (OCPs) in the marginal seawater of China, we examined the seasonal and spatial distributions of hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), and dichlorodiphenyltrichloroethane (DDTs) in the northern South China Sea (NSCS, 18-23° N) and East China Sea (ECS, 26-32° N). Seasonally, in the NSCS, the significantly higher concentrations (p < 0.05) of HCB, HCHs, and DDTs were found in summer, autumn, and summer through autumn, respectively. In the ECS, the higher concentrations were found in summer through winter, autumn, and summer. Spatially, HCB concentrations were significantly higher in the NSCS than in the ECS during all seasons except winter. During all four seasons, concentrations of HCHs were significantly higher in the NSCS than in the ECS. In summer and autumn, concentrations of DDTs were significantly higher in the NSCS than in the ECS, while no significant differences were found in spring and winter. Generally, regional usage, river-influenced coastal plumes, phytoplankton abundances, and ocean currents played crucial roles in the input, transport, degradation, and dilution of OCPs. These dynamic factors along with the seasonally alternating monsoon directly influenced the seasonal and spatial characteristics of OCPs. Furthermore, the profiles and diagnostic ratios of HCHs and DDTs revealed highly weathered OCP residues, attributed to eroded soils carried by surface runoff and long-range oceanic and atmospheric transport.

Abundance, morphology and chemical composition of microplastics in sand and sediments from a protected coastal area: The Mar Menor lagoon (SE Spain)

This paper presents the abundance and ubiquitous presence of microplastics in a protected coastal zone located in the southeast of Spain: The Mar Menor lagoon, an important tourist destination in this region. Seventeen sampling sites, corresponding to both intertidal and backshore points, were collected during winter 2017 and 2018, being situated in different protected areas according to international, European and Spanish environmental policies. The main objectives of the study were to examine microplastics in both protected and non-protected areas, and to test the importance of local activities on their presence. Northwest samples reported higher average microplastic concentrations than samples collected in the southeastern part of the coastal lagoon, likely due to the extensive use of sludge from wastewater treatment plants besides the fragmentation of low density polyethylene from plastic greenhouses, being microplastic films also higher for northwest than for southeast samples. Moreover, large inter-site differences observed in microplastic concentrations also demonstrated that local activities, mainly tourism and fishery, may play an important role as microplastic sources. The extensive amount of 17 different polymer types identified in this paper, much higher than most reported in similar studies, together with the variety of colors of microplastics most of them in a fragmented form (59.4%) and mainly detected in urban beaches, should be related to the geographical situation of this coastal lagoon, together with enormous environmental passives accumulated over the past 50 years. Only polyvinyl ester resins proved to be statistically higher in non-protected than in protected zones, probably related to their use in manufacturing boat hulls, although sources and pathways for microplastics are always difficult to assess. Measures to avoid microplastic pollution should be taken through educational programs, with also a clear commitment from plastic producers and transformers.

Ecological risk and estimates of organophosphate pesticides loads into the Central Mediterranean Sea from Volturno River, the river of the "Land of Fires" area, southern Italy

The organophosphate pesticides pollution in the Volturno River and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea) were estimated. Eight selected organophosphate pesticides (diazinon, dimethoate, malathion, chlorpyrifos, pirimiphos-methyl, fenitrothion, methidathion and tolclofos-methyl) were determined in the water dissolved phase, suspended particulate matter and sediment samples collected from 10 sites in different seasons. Total organophosphate pesticides concentrations ranged from 0.12 to 65.09 ng L^-1 in water (as the sum of the water dissolved phase and suspended particulate matter) and from 1.19 to 23.17 ng g^-1 in sediment samples. It has been calculated that the discharge of pollutants from the Volturno river into the Tyrrhenian Sea was about 71.815, 31 g year^-1; for this reason the river is to be considered one of the main mouths of organophosphate pesticides in the Tyrrhenian Sea. In relation to environmental risk assessment, the concentrations of most OPPs in water and sediments from the Volturno River and its estuary were lower than guideline values, but the mean concentration of chlorpyrifos (5.41 ng L^-1) in the Volturno River and Estuary has been shown that the ecological integrity of the river watercourse is possibly at risk.

PAHs, pesticides, personal care products and plastic additives in plastic debris from Spanish Mediterranean beaches

In this study the role of plastic debris as a pollution vector has been evaluated by determining the concentrations of hydrophobic organic contaminants in polymers from three Western Mediterranean coastal areas as well as their potential transfer to seawater. Plastic debris was sampled at three Iberian Peninsula Southeastern beaches, each affected by different predominant anthropogenic activities (tourism, agriculture, urban activities, transport and industry). Plastic debris was characterized by attenuated total reflection Fourier-transform infrared spectrometry. The organic contaminants were extracted from plastics by ultrasonic extraction with methanol and quantified by stir bar sorptive extraction coupled to gas chromatography-mass spectrometry (GC-MS). In two areas, the desorption of these contaminants from plastic debris to seawater during 24 h was also evaluated. The contaminant groups considered in this study (polycyclic aromatic hydrocarbons (PAHs), personal care products (PCPs), current use pesticides (CUPs), organochlorinated compounds (OCPs, including polychlorinated biphenyls and organochlorinated pesticides) and plastic additives were found in polymers from the three areas. The most abundant contaminants were plastic additives and PCPs, underlining the relevance of the leaching of plastic components, and urban and tourism activities as typical pollution sources in the coastal areas. In general, large piece-to-piece variability was found for all polymers and areas mainly as a consequence of their different origin, exposition time, use and surface-to-volume ratio. This fact difficulted the visualization of significant differences between polymers or areas, but for CUPs, whose concentrations were significantly higher in Cape Cope than in the other areas due to the influence of close agricultural activities. PCPs and CUPs were desorbed partially in seawater for 24 h, particularly the most hydrophilic compounds such as triazines and other CUPs. However, a significant fraction of other contaminants (mainly PAHs) was retained, which suggests they can be transported far away from their origin.

Occurrence of selected endocrine disrupting compounds in Iberian coastal areas and assessment of the environmental risk

The spatial and temporal distribution of selected endocrine disrupting compounds (4-tert-octylphenol, 4-n-octylphenol, 4-n-nonylphenol, nonylphenol, and bisphenol A) in two coastal areas of the Iberian Peninsula (Ria de Vigo and Mar Menor lagoon) were evaluated for the first time. Seawater and sediment samples collected during spring and autumn of 2015 were analysed using greener extraction techniques and liquid chromatography-tandem mass spectrometry. The presence of branched isomers (4-tert-octylphenol and nonylphenol) and bisphenol A in almost all seawater and sediment samples demonstrated their importance as pollutants in the frame of water policy, while no concentrations of linear isomers (4-n-octylphenol and 4-n-nonylphenol) were found. Higher seawater levels were observed in Mar Menor lagoon, especially in spring, associated with wastewater treatment plant effluents and nautical, agricultural and industrial activities. Similar sediment concentrations were measured in both studied areas, being nonylphenol levels five times higher than those measured for the other EDCs. Experimental sediment-water partition coefficients showed a moderate sorption of target compounds to sediments. Risk quotients for water compartment evidenced a moderate risk posed by nonylphenol, considering the worst-case scenario. For sediments, moderate risk related to 4-tert-octylphenol and high risk to nonylphenol were estimated.

Effect of microplastics on the toxicity of chlorpyrifos to the microalgae Isochrysis galbana, clone t-ISO

It is highly likely that phytoplanktonic organisms will interact with MPs in the ocean, and consequently with the pollutants sorbed onto their surfaces. Microalgae play an essential role in maintaining the balance of the marine ecosystem due to the fact that they are a primary producer and the base of marine trophic chains. Therefore, their fitness represents an important index in the assessment of water quality. The objectives of this study were i) to assess the toxicity of MPs and the pesticide chlorpyrifos (CPF) to the microalgae, Isochrysis galbana, clone t-ISO and ii) to ascertain whether the presence of MPs affects the toxicity of CPF. Microalgae growth rate was selected as the endpoint and a commercial virgin PE micronized powder was chosen as a micro-plastic model, with mean size ranging from 2 to 6 µm, assayed until 25 mg L^-1. CPF was tested at concentrations ranging from 0 to 4 mg L^-1. A constant concentration of MPs (5 mg L^-1) was loaded with increasing doses of CPF (0-3 mg L^-1) with a 2 h incubation period. Bioassays were performed at 20 °C, in glass tubes of 50 ml, with air and constant light and an exposure time of 72 h. Cell counts were performed using a Coulter Counter Multisizer III and HPLC was used to quantify the partition of this pollutant among MPs and water. Although microalgae growth was not impacted by MPs, growth was clearly affected by exposure to CPF from 2 mg L^-1 and above, with a total growth inhibition at concentrations over 3 mg L^-1. Subsequent to incubation, 80% of CPF was sorbed onto MP surfaces. Two different dose-response curves resulted from CPF bioassays depending on the presence of MP, with lower percentages of inhibition when CPF was presented through MP. Thus, the adsorption of CPF onto MP surfaces modulates the toxicity of CPF on I. galbana growth through a reduction in its toxicity, as CPF is adsorbed onto MP surfaces which are less bio-available to the algal cells.

Long-Term GIS Analysis of Seaside Impacts Associated to Infrastructures and Urbanization and Spatial Correlation with Coastal Vulnerability in a Mediterranean Area

The relationship between the impacts of coastal perimeter transformations derived from human activity and coastal vulnerability is not easy to assess. The impacts associated with coastal dynamics are phenomena that usually develop very extensively over a considerable time. These are transformations that cause significant environmental damage in vulnerable coastal areas, but whose results are very often not really visible until 10, 20, or even 40 years have elapsed. In addition, the analysis and quantification of the current context in complex territories is particularly difficult, since the spatial feedback of various issues and its consequences can generate an uncertain scenario with many interrelated variables. In this field, the use of GIS tools can be of great help to objectively analyze the relationship between coastal anthropization and its impact on its vulnerability in order to correct wrong inertias in vulnerable coastal areas. To this end, a long-term GIS analysis has been carried out of the impacts from urbanization and seaside infrastructures suffered by a complex Mediterranean coastal area in Spain. This territory, with singular elements such as dune ridges, beaches located in protected areas, and a coastal lagoon, will be evaluated using GIS spatio-temporal indicators over the last 90 years and geostatistical correlation methods. This approach will allow us to better understand the relationship between territorial transformations on the coast and the current coastal vulnerability of this area.

Occurrence and ecotoxicological assessment of pharmaceuticals: Is there a risk for the Mediterranean aquatic environment?

Due to their pseudo-persistence and their biological activity, pharmaceuticals are emerging contaminants of major concern for the environment. The aim of this review is to provide an updated inventory of the contamination of aquatic environments by 43 drugs representing different classes of pharmaceuticals, such as antibiotics, anti-inflammatory drugs, anti-depressants, sex hormones, lipid regulators and beta-blockers. The data collected is focused on contamination levels reported in marine coastal waters and in waste and river waters flowing into the Mediterranean Sea. The most widely produced/prescribed classes of medicines are compared with the substances most widely searched for in the environment. Ranges of pollution levels according to the type of water body are also presented, to examine the fate in sewage treatment plants and the persistence in the environment of the targeted molecules. Levels of pharmaceuticals ranged from 100 to 10,000 or even 100,000 ng·L^-1 in sewage waters, dropping to 1 to 10,000 ng·L^-1 in rivers and to not detected to 3000 ng·L^-1 in sea water. However, this paper evidences a lack of data for seawater and also for several countries along the southern coast of the Mediterranean Sea. In order to assess the risk for aquatic ecosystems associated with pharmaceuticals, experimental ecotoxicological values obtained using normalized acute and/or chronic bioassays carried out with different trophic levels were collected for each drug. Targeted biological species and associated bioassays are classified on the basis of their sensitivity to each class of compounds. Occurrence and ecotoxicology are then linked by using the Hazard Quotient (HQ) to assess the environmental risk caused by pharmaceuticals in the Mediterranean Basin. Correlations between HQ and frequency of detection of pharmaceuticals highlighted thirteen compounds that are cause for concern in Mediterranean fresh and sea waters, such as 17α-ethinylestradiol, metoprolol, 8 antibiotics and 3 analgesics/anti-inflammatories.

Potential transfer of organic pollutants from littoral plastics debris to the marine environment

Plastic polymers act as passive samplers in air system and concentrate hydrophobic organic contaminants by sorption or specific interactions, which can be transported to other systems such as the marine environment. In this study plastic debris was sampled in the surrounding area of a Mediterranean lagoon in order to determine the concentration of persistent and emerging organic contaminants. More specifically, desorption of 91 regulated and emerging organic contaminants (polycyclic aromatic hydrocarbons, polychlorinated biphenyls, organochlorinated pesticides, current-use pesticides, personal care products, other pesticides and plastic additives) was characterized for the first 24 h from different polymers to seawater and the remaining content of these contaminants was also extracted by ultrasonic extraction with methanol. All samples were analyzed by Stir Bar Sorptive Extraction coupled to GC/MS. A significant fraction of sorbed contaminants in polymers was desorbed in the first 24 h, particularly for triazines and organophosphorus pesticides due to their lower hydrophobicity than other considered analytes. The remaining contaminants contained in plastics can be also transferred to seawater, sediments or biota. Considering 24 h desorbed fraction plus the remaining methanol extracted fraction, the highest transfer levels corresponded to personal care products, plastic additives, current-use pesticides and PAHs. This is the first study to show the relevance of the transport of organic contaminants on plastic debris from littoral areas to the marine environment.

Ecotoxicological evaluation of the risk posed by bisphenol A, triclosan, and 4-nonylphenol in coastal waters using early life stages of marine organisms (Isochrysis galbana, Mytilus galloprovincialis, Paracentrotus lividus, and Acartia clausi)

This study assessed the environmental risk on coastal ecosystems posed by three phenolic compounds of special environmental and human health concern used in plastics and household products: bisphenol A (BPA), triclosan (TCS) and 4-nonylphenol (4-NP). These three chemicals are among the organic contaminants most frequently detected in wastewater. The most toxic compound tested was 4-NP, with 10% effective concentration at 11.1 μg L^-1 for Isochrysis galbana, 110.5 μg L^-1 for Mytilus galloprovincialis, 53.8 μg L^-1 for Paracentrotus lividus, and 29.0 μg L^-1 for Acartia clausi, followed by TCS (14.6 μg L^-1 for I. galbana, 149.8 μg L^-1 for M. galloprovincialis, 129.9 μg L^-1 for P. lividus, and 64.8 μg L^-1 for A. clausi). For all species tested, BPA was the less toxic chemical, with toxicity thresholds ranging between 400 and 1200 μg L^-1 except for A. clausi nauplii (186 μg L^-1). The relatively narrow range of variation in toxicity considering the broad physiological differences among the biological models used point at non-selective mechanisms of toxicity for these aromatic organics. Microalgae, the main primary producers in pelagic ecosystems, showed particularly high susceptibility to the chemicals tested. When the toxicity thresholds experimentally obtained were compared to the maximum environmental concentrations reported in coastal waters, the risk quotients obtained correspond to very low or low risk for BPA and TCS, and from low to high for 4-NP.

Seasonal distribution of herbicide and insecticide residues in the water resources of the vineyard region of La Rioja (Spain)

Pesticides are needed to maintain high production in the vineyard area of La Rioja (Spain), and monitoring their spatial distribution is a priority for preserving the quality of natural resources. Accordingly, the purpose of this work was to conduct a study to evaluate the presence and seasonal distribution of herbicide and insecticide residues in ground and surface waters in this region. The monitoring network comprised 12 surface waters and 78 groundwaters, covering the three subareas (63,593ha) into which the vineyard region is divided. The quality of natural waters was examined through the analysis of twenty-two herbicides, eight of their main degradation products, and eight insecticides. Pesticides were extracted by solid-phase extraction, and analysed by gas chromatography-mass spectrometry or by liquid-chromatography-mass spectrometry. The results reveal the presence of most of the herbicides and insecticides included in the study in one or more of the samples collected during the four campaigns. The herbicide terbuthylazine and its metabolite desethylterbuthylazine were the compounds more frequently detected (present in >65% of the samples across all the campaigns). Other compounds detected in >50% of the samples in one sampling campaign were the herbicides fluometuron, metolachlor, alachlor and ethofumesate. Insecticides were present in a small number of samples, with only pirimicarb being detected in >25% of the samples in March and June campaigns. The results reveal that the sum of compounds detected (mainly herbicides) was higher than 0.5μgL^-1 in >50% of the samples, especially in the campaigns with the highest application of these compounds. A possible recovery of the quality of the waters was detected outside the periods of crop cultivation, although more monitoring programmes are needed to confirm this trend with a view to preventing and/or maintaining the sustainability of natural resources.

Toxicological effects of fungicide mixtures on the amphipod Austrochiltonia subtenuis

Approaches to assess the toxicity of mixtures often use predictive models with acute mortality as an endpoint at relatively high concentrations. However, these approaches do not reflect realistic situations where organisms could be exposed to chemical mixtures over long periods at low concentrations at which no significant mortalities occur. The present study investigated chronic effects of 2 common fungicides, Filan® (active ingredient [a.i]) boscalid) and Systhane™ (a.i. myclobutanil), on the amphipod Austrochiltonia subtenuis at environmentally relevant concentrations under laboratory conditions. Sexually mature amphipods were exposed singly and in combination to Filan (1, 10, and 40 μg a.i./L) and Systhane (3 μg a.i./L) over 28 d. Survival, growth, a wide range of reproduction endpoints, and glutathione-S-transferase (GST) activity were measured at the end of the experiment. Both fungicides had significant independent effects on male growth, sex ratio, and juvenile size. Filan mainly affected female growth and the number of embryos per gravid female, whereas Systhane mainly affected the time for females to become gravid. The combined effects of these fungicides on numbers of gravid females and juveniles were antagonistic, causing a 61% reduction in the number of gravid females and a 77% reduction in the number of juveniles produced at the highest concentrations (40 μg a.i./L of boscalid and 3 μg a.i./L of myclobutanil) compared with the controls. There were no significant effects on survival or GST activity. The present study demonstrated that the effects of mixtures were endpoint dependent and that using a variety of endpoints should be considered for a comprehensive understanding of mixture effects. Also, chronic studies are more informative than acute studies for environmentally relevant fungicide concentrations. Environ Toxicol Chem 2017;36:2651-2659. © 2017 SETAC.

Seasonal antioxidant responses in the sea urchin Paracentrotus lividus (Lamarck 1816) used as a bioindicator of the environmental contamination in the South-East Mediterranean

In this study, sea urchin Paracentrotus lividus were sampled seasonally at three stations during 2012 in the coastal areas of the Gulf of Annaba (southeast Mediterranean). For all sea urchins, the gonad index was calculated to determine sea urchin reproductive status. Moreover, a set of biochemical parameters, including biomarkers and oxidative stress parameters, was measured in gonads. The pesticides and physiochemical parameters were measured and dosed in sea water. The results obtained highlighted that the levels of pesticide were generally low and below those commonly applied by environmental quality standards (EQS), indicating that no alarm state is currently present in the Gulf of Annaba. In addition to pollution, seasonal change is an important factor influencing biomarker activity, and the significant increases in biomarker levels in spring are a major observed trend. This activity may also be related to reproductive status. Seasonal variability was confirmed by the significant results of the Kruskal-Wallis test and by the high degree of divergence between seasons in PCA, with a total of 83.83% of variance explained. These results indicate that environmental factors that vary seasonally may affect the antioxidant status of the sea urchin Paracentrotus lividus.

Phosphorus retention and fractionation in an eutrophic wetland: A one-year mesocosms experiment under fluctuating flooding conditions

This study aimed to evaluate the response of salt marshes to pulses of PO₄^3--enriched water, with and without the presence of Phragmites australis. A one-year mesocosms experiment was performed in simulated soil profiles (fine-textured surface layers and sandy subsurface layers) from a coastal salt marsh of the Mar Menor lagoon under alternating flooding-drying conditions with eutrophic water, under low (1.95 mg L^-1 P-PO₄^3-) and high (19.5 mg L^-1 P-PO₄^3-) P load, and with the presence/absence of Phragmites. The PO₄^3- concentrations in soil porewater and drainage water were regularly measured, and P accumulated in soils (including a fractionation procedure) and plants (roots, rhizomes, stems and leaves) were analyzed. The experimental mesocosms were highly effective in the removal of P from the eutrophic flooding water (>90% reduction of the P added to the system both in the soil pore water and drainage water), regardless of the nutrient load, the season of the year and the presence/absence of Phragmites. The soil was the main sink of the P added to the system, while Phragmites had a minor role in P removal. The biomass of Phragmites accumulated ∼27% of the P added with the flooding water in the treatment with water of low P load while ∼12% of P in that of high P load; the rhizomes were the organs that contributed the most (∼67-72% of the total P retained by the plants). Ca/Mg compounds were the main contributors to the retention of P in the soil compartment, especially in the fine-textured surface soil layers (∼34-53% of the total P in the soil was present in this fraction). Phragmites favored the retention of P onto metal oxides (∼12% increase of the P retained in the metal oxides fraction in the treatment with water of high P load). Hence, the use of constructed wetlands to ameliorate the negative impacts of P-enriched waters in the Mar Menor lagoon and similar areas is recommended. We propose the incorporation of fine-textured carbonated materials, with high content of Ca/Mg compounds, and the use of Phragmites to favor the retention of P by these systems.

Presence and distribution of current-use pesticides in surface marine sediments from a Mediterranean coastal lagoon (SE Spain)

The spatial and seasonal distributions of current-use pesticides (CUPs), including triazines, organophosphorus pesticides, and tributylphosphate, were characterized in surface sediments from the Mar Menor lagoon during 2009 and 2010. The impact of two flash flood events on the input of CUPs and their distribution in the lagoon were also assessed. The total (dissolved + sorbed phase) input of CUPs in the two flash floods through the El Albujón watercourse into the lagoon was estimated at 38.9 kg, of which 9.9 kg corresponded to organophosphorus pesticides and 5.5 kg to triazines. CUP distribution onto sediments was not homogeneous in the lagoon due to the different contaminant sources, sediment types, and the physicochemical and hydrodynamic conditions of the Mar Menor lagoon. Thirteen CUPs were detected in 2009 and 19 in 2010, including mainly herbicides, insecticides, and the additive tributylphosphate. Mean CUP concentrations in the lagoon were generally below 20 ng g^-1, except for chlorpyrifos and tributylphosphate in 2010. The highest concentrations were detected in depositional areas of the lagoon, in the area of influence of the El Albujón watercourse and other wadis with groundwater contributions such as El Mirador (north) and Los Alcázares (east) and that of marine water from El Estacio channel. In fact, the maximum concentration was detected close to El Albujón watercourse (chlorpyrifos, 102.8 ng g^-1 dry weight). Four herbicides, two insecticides, two fungicides, and tributylphosphate showed a risk quotient higher than 1, with that for chlorpyrifos ranging from 96 to 35,200 after flash flood events.

Impact of flash flood events on the distribution of organic pollutants in surface sediments from a Mediterranean coastal lagoon (Mar Menor, SE Spain)

The influence of flash flood events on the input and distribution of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorinated pesticides (OCPs) in surface sediments from the Mar Menor lagoon were characterized in this study. These contaminants were analyzed in surface water samples collected during two flash flood events in the main surface watercourse which flow into the Mar Menor lagoon. Surface sediments were sampled semiannually before and after flash flood events. The total input of PAHs, OCPs, and PCBs (sorbed + dissolved) during two flash flood events was estimated at 0.98, 1.32, and 0.34 kg, respectively, the main input corresponding to p,p'-DDE (1.00 kg). The distribution of organic contaminants in surface sediments was not homogeneous as a consequence of the presence of many simultaneous sources and different meteorological, hydrodynamic, and physicochemical conditions. As a consequence of flash flood events, p,p'-DDE concentrations in surface sediments increased significantly in the central and south zones of the lagoon. However, in the case of PCBs, a dilution effect was observed in the south zone after such events, reducing the environmental risk. These changes in the pollutant distribution persisted at least 1 year later (autumn 2010), showing that the impact of flood events in the distribution of persistent organic contaminants in Mediterranean coastal lagoons is of relevance according to the ecological risk assessment carried out. The impact of these events should be also considered in other coastal systems, especially in semiarid and semiconfined areas.

Occurrence and seasonal distribution of polycyclic aromatic hydrocarbons and legacy and current-use pesticides in air from a Mediterranean coastal lagoon (Mar Menor, SE Spain)

The occurrence and seasonal distribution of polycyclic aromatic hydrocarbons (PAHs) and legacy and current-use pesticides (CUPs) in air were characterized around the Mar Menor lagoon using both active and passive sampling devices. The seasonal distribution of these pollutants was determined at 6 points using passive samplers. Passive sampler sampling rates were estimated for all detected analytes using an active sampler, considering preferentially winter data, due to probable losses in active sampling during summer (high temperatures and solar irradiation). The presence of 28 compounds (14 CUPs, 11 PAHs and 3 organochlorinated pesticides) were detected in air by polyurethane passive sampling. The most commonly detected contaminants (>95% of samples) in air were chlorpyrifos, chlorpyrifos-methyl and phenanthrene. The maximum concentrations corresponded to phenanthrene (6000 pg m^-3) and chlorpyrifos (4900 pg m^-3). The distribution of contaminants was spatially and seasonally heterogeneous. The highest concentrations of PAHs were found close to the airport, while the highest concentrations of pesticides were found in the influence area of agricultural fields (western stations). PAH and herbicide concentrations were higher in winter than in the other seasons, although some insecticides such as chlorpyrifos were more abundant in autumn. The presence of PAHs and legacy and current-use pesticides in air confirmed their transference potential to marine coastal areas such as the Mar Menor lagoon.

Polychlorinated biphenyls and organochlorine pesticides in Tiber River and Estuary: Occurrence, distribution and ecological risk

The polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) pollution in the Tiber River and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea) were estimated. 32 PCBs and 17 OCPs (aldrin, α-BHC, β-BHC, δ-BHC, lindane, p,p'-DDD, p,p'-DDE, p,p'-DDT, dieldrin, endosulfan I, endosulfan II, endosulfan sulfate, endrin, endrin aldehyde, heptachlor, heptachlor epoxide, methoxychlor) were determined in the water dissolved phase (DP), suspended particulate matter (SPM) and sediment samples. Total concentrations of PCBs ranged from 0.54 to 74.75ngL(-1) in water (sum of DP and SPM) and from 3.73 to 79.30ngg(-1) dry weigh in sediment samples; while the concentrations of total OCPs collected in water (sum of DP and SPM) ranged from 0.07 to 7.04ngL(-1) and from 0.66 to 10.02ngg(-1) dry weigh in sediment samples. Contaminant discharges into the sea were calculated in about 227.08kgyear(-1) for PCBs and 24.91kgyear(-1) for OCPs, showing that this river should account as one of the main contribution sources of PCBs and OCPs to the Tyrrhenian Sea. The ∑TEQPCB from the sediment samples ranged from 0.0006 to 0.37ngg(-1) with an average level of 0.13ngg(-1). Based on Sediments Quality Guidelines, biological adverse effects on aquatic ecosystem were rare to occasional for PCB and OCP levels in Tiber water system.

Intra-annual trends of fungicide residues in waters from vineyard areas in La Rioja region of northern Spain

The temporal trends of fungicides in surface and ground water in 90 samples, including both surface waters (12) and ground waters (78) from an extensive vineyard area located in La Rioja (Spain), were examined between September 2010 and September 2011. Fungicides are used in increasing amounts on vines in many countries, and they may reach the water resources. However, few data have been published on fungicides in waters, with herbicides being the most frequently monitored compounds. The presence, distribution and year-long evolution of 17 fungicides widely used in the region and a degradation product were evaluated in waters during four sampling campaigns. All the fungicides included in the study were detected at one or more of the points sampled during the four campaigns. Metalaxyl, its metabolite CGA-92370, penconazole and tebuconazole were the fungicides detected in the greatest number of samples, although myclobutanil, CGA-92370 and triadimenol were detected at the highest concentrations. The highest levels of individual fungicides were found in Rioja Alavesa, with concentrations of up to 25.52 μg L^-1, and more than 40 % of the samples recorded a total concentration of >0.5 μg L^-1. More than six fungicides were positively identified in a third of the ground and surface waters in all the sampling campaigns. There were no significant differences between the results obtained in the four sampling campaigns and corroborated a pattern of diffuse contamination from the use of fungicides. The results confirm that natural waters in the study area are extremely vulnerable to contamination by fungicides and highlight the need to implement strategies to prevent and control water contamination by these compounds.

Patterns of trace element bioaccumulation in jellyfish Rhizostoma pulmo (Cnidaria, Scyphozoa) in a Mediterranean coastal lagoon from SE Spain

The effects of an abandoned mining area, exploited for centuries in the mining district of Cartagena-La Union, result in a continuous supply of heavy metals into the Mar Menor coastal lagoon after rain episodes. As a consequence, concentration of trace elements in water column and sediments of this ecosystem is usually higher than in other areas. For monitoring ecosystem health, this study assessed the ability of Rhizostoma pulmo to bioaccumulate trace elements. A total of 57 individuals were sampled at eight different sampling stations during the summer of 2012. Although the concentrations of different analyzed elements (Al, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Sn, and Pb) were moderate, bioconcentration levels in relation to seawater metal concentration were extremely high. In any case, the use or disposal of these organisms should consider their metal content, because of their potential environmental and health implications.

Estimates of Tiber River organophosphate pesticide loads to the Tyrrhenian Sea and ecological risk

The organophosphate pesticides pollution in the Tiber River and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea) were estimated. Eight selected organophosphate pesticides (diazinon, dimethoate, malathion, chlorpyrifos, pirimiphos-methyl, fenitrothion, methidathion, tolclofos-methyl) were determined in the water dissolved phase, suspended particulate matter and sediment samples collected from 21 sites in different seasons. Total organophosphate pesticides concentrations ranged from 0.40 to 224.48ngL(-1) in water (as the sum of the water dissolved phase and suspended particulate matter) and from 1.42 to 68.46ngg(-1) in sediment samples. Contaminant discharges of organophosphate pesticides into the sea were calculated in about 545.36kgyear(-1) showing that this river should be consider as one of the main contribution sources of organophosphate pesticides to the Tyrrhenian Sea. In relation to the eco-toxicological assessment, the concentrations of most OPPs in the water and sediments from the Tiber River and its estuary were lower than guideline values.

Do pharmaceuticals bioaccumulate in marine molluscs and fish from a coastal lagoon?

The bioaccumulation of 20 pharmaceuticals in cockle (Cerastodema glaucum), noble pen shell (Pinna nobilis), sea snail (Murex trunculus), golden grey mullet (Liza aurata) and black goby (Gobius niger) was evaluated, considering their distribution throughout the Mar Menor lagoon and their variations in spring and autumn 2010. The analytical procedure was adapted for the different matrices as being sensitive and reproducible. Eighteen out of the 20 compounds analysed were found at low ngg(-1) in these species throughout the lagoon. Hydrochlorothiazide and carbamazepine were detected in all species considered. The bioaccumulation of pharmaceuticals was heterogeneous in the lagoon, with a higher number of pharmaceuticals being detected in fish (18) than in wild molluscs (8), particularly in golden grey mullet muscle (16). В-blockers and psychiatric drugs were preferentially bioccumulated in fish and hydrochlorothiazide was also confirmed in caged clams. The higher detection frequency and concentrations found in golden grey mullet suggested that mugilids could be used as an indicator of contamination by pharmaceuticals in coastal areas. To the best of our knowledge, this is the first study that shows data about hydrochlorothiazide, levamisole and codeine in wild marine biota.

Environmental risk assessments and spatial variations of polycyclic aromatic hydrocarbons in surface sediments in Yangtze River Estuary, China

In this study, based on sampling data from 30 sites in August 2010, the environmental risks associated with 16 priority PAHs were estimated in surface sediments from the Yangtze River Estuary (YRE). The results indicated that the toxic equivalent quantities of the benzo[a]pyrene (TEQBap) from 30 sites were in the range of 1.93-75.88ngg(-1), and the low-molecular-weight PAHs were the dominated species with higher potential toxicity. The results of the Incremental Lifetime Cancer Risk (ILCR) model indicated that the ILCR values of dermal contact were higher than 10(-6) in the northeast region, suggesting that there were significant potential carcinogenic health risks for fishermen exposure to sedimentary PAHs via dermal contact in these areas. RQ values of PAHs indicated the various distributions of ecological risk levels in the study area. These variations might be caused by the natural and anthropogenic inputs and currents in the YRE.

Metabolomic responses in caged clams, Ruditapes decussatus, exposed to agricultural and urban inputs in a Mediterranean coastal lagoon (Mar Menor, SE Spain)

The Mar Menor is a coastal lagoon affected by the growth of intensive agriculture and urban development in the surrounding area. Large amounts of chemical pollutants from these areas are discharged into El Albujón, a permanent water-course flowing into the lagoon. Biomarkers such as the activity of acetylcholinesterase or antioxidant enzymes have been previously tested in this lagoon demonstrating the presence of neurotoxicity and oxidative stress in clams transplanted in sites affected by the dispersion of the effluent from El Albujón. To complete this traditional toxicology work, a metabolomic profiling of these transplanted organisms has been carried out for the detection of metabolic biomarkers induced by agricultural/urban pollutants. More than 70 metabolites have been quantified using a targeting metabolomics platform based on HPLC-MS. The intracellular metabolic pattern was analyzed by PCA from the digestive gland of clams after 7 and 22 days of transplantation. Results showed a different profile of metabolite between organisms collected from control and exposed sites. At the shorter exposure time, there was an increase in several metabolites in the latter when compared with those from control sites, whereas metabolic profiling at 22 days showed that those metabolites were drastically diminished, with even lower levels than at control sites. These metabolites included: (i) 12 amino acids from the 21 proteogenic and HomoSer, (ii) osmotic protectants such as γ-butyrobetaine and taurine and (iii) nucleotides such as ITP. Regarding sulfur-containing molecules, taurine could be highlighted as a potential biomarker since its concentration was reduced by more than 30 times after 22 days of exposure, whereas the antioxidant glutathione remained constant in the organisms from both control and exposed sites. Although targeted metabolomics has been shown as an early technique of pollutant effect detection, the two-phase pattern could highlight a more complicated metabolite response to pollutants than classical biomarkers.

Spatial distribution and partitioning of organophosphates pesticide in water and sediment from Sarno River and Estuary, Southern Italy

The organophosphates pesticide (OPP) pollution in the Sarno River and its environmental impact on the Gulf of Naples (Tyrrhenian Sea, Central Mediterranean Sea) were estimated. Nine selected OPPs (diazinon, dimethoate, malathion, chlorpyrifos, dichlorvos, fenitrothion, methidathion, tolclofos-methyl, azinphos-methyl) were determined in the water dissolved phase (DP), suspended particulate matter (SPM) and sediment samples. Total OPP concentrations ranged from 5.58 to 39.25 ng L(-1) in water (as the sum of the DP and SPM) and from 0.19 to 3.98 ng g(-1) in sediment samples. Contaminant discharges of OPPs into the sea were calculated in about 48,064.08 g year(-1), showing that this river should account as one of the main contribution sources of OPPs to the Tyrrhenian Sea.

Distribution of polycyclic aromatic hydrocarbons in surface sediments of lower reaches of the Don River (Russia) and their ecotoxicologic assessment by bacterial lux-biosensors

The lower Don River in the south of the European part of Russia was studied to determine the concentration, spatial distribution, and sources of 19 polycyclic aromatic hydrocarbons (PAHs) in surface sediments. Total PAH concentrations ranged from 14.2 to 529 ng/g-dw. Sedimentary PAH concentrations were higher in the delta of the Don River and in the estuaries of rivers Sal and Aksai compared to the main channel of the Don. Analysis of the PAHs sources showed that PAHs came mostly from pyrogenic sources as a result of incomplete combustion of coal. Bioluminescent bacterial sensors were used for ecotoxicological assessment of surface sediments. The surface sediments of all the investigated stations of lower reaches of the Don River were toxic and genotoxic. The maximum concentration of PAHs and the high genotoxicity effect caused by the presence of genotoxicants were found in the surface sediments of the same stations. Significant correlations between the concentrations of individual PAHs in sediments and the genotoxic effect were found. Correlation between genotoxicity of surface sediments and concentration of phenanthrene and benz(k)fluoranthene was the most significant both with and without application of metabolic activation.

Seasonal distribution of pharmaceuticals in marine water and sediment from a Mediterranean coastal lagoon (SE Spain)

The seasonal variations in the occurrence and distribution of pharmaceuticals were evaluated in seawater and sediment of Mar Menor lagoon from spring 2010 to winter 2011. A total of 20 pharmaceuticals in seawater and 14 in sediments were found at concentrations from low ngL(-)(1) up to 168ngL(-)(1) (azithromycin) in seawater and from low ngg(-1) up to 50.3ngg(-1) (xylazine) in sediments. Azithromycin, xylazine and metoprolol were the most ubiquitous compounds in seawater since they were found in all seawater samples collected. Seven compounds were quantified in both matrices: clarithromycin, erythromycin, hydrochlorothiazide, irbesartan, losartan, salicylic acid and valsartan. Seasonal distribution profiles revealed different sources of pollutants associated to both, El Albujón watercourse (which receives the input of a WWTP) and other non-controlled discharges, into the lagoon. In summer the highest concentrations in seawater for most of the pharmaceuticals were detected close to main touristic nuclei, probably as consequence of sources such as the excretion from bathers and/or other non-controlled discharges, these being significantly higher than in autumn and winter for antibiotics. On the contrary, the mean concentration of lorazepam was significantly higher in colder seasons than in warmer ones. Sulfamethoxazole, erythromycin and especially clarithromycin showed hazard quotients higher than 1 in seawater at some areas of this lagoon indicating a potential risk to aquatic organisms in such specific areas.