A total of 1345 specimens belonging to 58 different species of wild fish and seafood from the western Mediterranean Sea were analyzed to assess total mercury levels and to estimate which species meet the EU recommendations for human consumption (0.5 μg g⁻¹ ww) in all cases. All fish species were caught off the Mediterranean coasts and intended for human consumption. All specimens were collected from local markets located in Spain, Italy and France that sell fish caught by local fishermen (Eivissa, Menorca, Mallorca, Alacant, L'Ampolla, Ametlla de Mar, Marseille, Genoa, Civitavecchia, Alghero) at different time periods. Mercury concentrations were measured by thermal decomposition-gold amalgamator-atomic absorption spectrometry. Only thirteen species were found that did not exceed 0.5 μg g⁻¹ ww in any specimen analyzed. These safe species were sardines (Sardina pilchardus), anchovies (Engraulis encrasicolus), blue whiting (Micromesistius poutassou), picarel (Spicara smaris), blackspot seabream (Pagellus bogaraveo), gilthead seabream (Sparus aurata), pearly razorfish (Xyrichtys novacula), surmullet (Mullus surmuletus), painted comber (Serranus scriba), brown meagre (Sciaena umbra), salema (Sarpa salpa), common dolphinfish (Coryphaena hippurus) and squid (Loligo vulgaris). These species occupy different trophic levels, have different lengths and average weights, but show a low mercury concentration than others living in the same environments. Potential human consumption of these species as sole source of fish would imply estimated weekly intakes representing between 49% and 70% of the recommended provisional tolerable weekly intake of methylmercury in the worst case. Health authorities should pay specific attention to species that do not meet EU thresholds and make appropriate precautionary health recommendations, especially for pregnant women and children.

Noise pollution is a pervasive factor that increasingly threatens natural resources and human health worldwide. In particular, large-scale changes in road networks have driven shifts in the acoustic environment of rural landscapes during the past few decades. Using sampling plots from the Spanish Landscape Monitoring System (SISPARES), 16 km² each, we modelled the spatio-temporal changes in road traffic noise pollution in Ecoregion 1 of Spain (approximately 66,000 km²). We selected a study period that was characterised by significant changes in the size of the road network and the vehicle fleet (i.e. between 1995 and 2014) and used standard and validated acoustic computation methods for environmental noise modelling (i.e. European Directive, 2002/49/EC) within sampling plots. We then applied a multiple linear regression to expand noise modelling throughout the whole of Ecoregion 1. Our results showed that the noise level increased by 1.7 dB(A) in average per decade in approximately 65% of the territory, decreased by 1.3 dB(A) per decade in about 33%, and remained unchanged in 2%. This suggests that road traffic noise pollution levels may not grow homogeneously in large geographical areas, maybe due to the concentration of large fast traffic flows on modern motorways connecting towns. Our research exemplifies how landscape monitoring systems such as cost-effective approaches may play an important role when assessing spatio-temporal patterns and the impact of anthropogenic noise pollution at large geographical scales, and even more so in a global context of constricted resources and limited availability of historical data on traffic and environmental noise monitoring.

Cadmium (Cd) is a toxic metal found in tobacco, air and food. Recent cross-sectional studies have suggested that Cd negatively impacts physical performance, but the prospective association is uncertain.We used data from 2548 older adults from the Seniors-ENRICA II cohort in Madrid, Spain. Whole blood Cd levels were measured at baseline using inductively coupled plasma-mass spectrometry. At baseline (2017) and follow-up (2019), overall physical function was evaluated using the physical component summary (PCS) of the SF 12-Item Health questionnaire, lower-extremity performance with the Short Physical Performance Battery (SPPB), muscle weakness with a hand dynamometer, and frailty with a Deficit Accumulation index. Mobility limitations and disability in instrumental activities of daily living (IADL) were ascertained with standardized questionnaires. Analyses were adjusted for relevant confounders, including tobacco smoke, number of cigarettes smoked per day and time since cessation in former smokers.In cross-sectional analyses, odds ratios (95% confidence interval) per two-fold increase in blood Cd were 1.16 (1.03; 1.31) for low PCS scores, 1.08 (0.97; 1.20) for impaired lower-extremity performance, 1.10 (0.98; 1.23) for low grip strength, 1.11 (1.02; 1.20) for mobility limitations, 1.16 (1.02; 1.31) for frailty, and 1.26 (1.08; 1.47) for IADL disability. In longitudinal analyses, corresponding hazard ratios were 1.25 (1.03; 1.51) for low PCS scores, 1.14 (1.03; 1.27) for impaired lower-extremity performance, 1.02 (0.92; 1.13) for low grip strength, 1.03 (0.91; 1.16) for mobility limitations, and 1.16 (1.00; 1.35) for frailty. All the associations where consistent when current smokers were excluded from the analyses.Our results support the role of Cd as a risk factor for physical function impairments in older adults.

Microplastics (MPs) are becoming an environmental growing concern, being the sewage sludge applied to agriculture fields one of the most important inputs to the environment. To date, there is no standardized protocol for their extraction and changes in vegetative growth and fruit maturation on cultivated plants induced by sludge containing MPs have not been studied yet. Sewage sludge from three different wastewater treatment plants located in Murcia, Spain, were studied. First, the microplastic concentration was estimated and, then, the effects of the sewage sludge in the development of tomato plants and fruit production was analyzed. The measured parameters in tomato plants were both, biomass and length, for shoot and root part, as well as, stem diameter and tomato production. The present work has developed and validated a protocol for the extraction and quantification of MPs comprising several shapes, materials and sizes from samples of sewage sludges, which offers a good compromise for the extraction of different types of microplastic. The protocol used for MPs extraction had a recovery efficiency of 80 ± 3% (mean ± SE) and used bicarbonate, to maximize MPs extraction. The mean abundance of MPs in the studied sewage sludge samples was 30,940 ± 8589 particles kg⁻¹ dry weight. Soils with sludge containing MPs fostered the growth of tomato plants, while delaying and diminished fruit production. However, other factors or their interactions with MPs could have influenced the outcomes. Further studies are necessary to corroborate these findings and explain the mechanisms of possible effects of MPs on plants.

Surfactants, after use, enter the environment through diffuse and point sources such as irrigation with treated and non-treated waste water and urban and industrial wastewater discharges. For the group of non-ionic synthetic surfactant alcohol ethoxylates (AEOs), most of the available information is restricted to the levels and fate in aquatic systems, whereas current knowledge of their behavior in soils is very limited. Here we characterize the behavior of different homologs (C12–C18) and ethoxymers (EO3, EO6, and EO8) of the AEOs through batch experiments and under unsaturated flow conditions during infiltration experiments. Experiments used two different agricultural soils from a region irrigated with reclaimed water (Guadalete River basin, SW Spain). In parallel, water flow and chemical transport were modelled using the HYDRUS-1D software package, calibrated using the infiltration experimental data. Estimates of water flow and reactive transport of all surfactants were in good agreement between infiltration experiments and simulations. The sorption process followed a Freundlich isotherm for most of the target compounds. A systematic comparison between sorption data obtained from batch and infiltration experiments revealed that the sorption coefficient (Kd) was generally lower in infiltration experiments, performed under environmental flow conditions, than in batch experiments in the absence of flow, whereas the exponent (β) did not show significant differences. For the low clay and organic carbon content of the soils used, no clear dependence of Kd on them was observed. Our work thus highlights the need to use reactive transport parameterization inferred under realistic conditions to assess the risk associated with alcohol ethoxylates in subsurface environments.

Gymnodimine A has been found in mollusks obtained along the whole northern coast of Spain from April 2017 to December 2019. This is the first time that this toxin is detected in mollusks from the Atlantic coast of Europe. The prevalence of the toxin was, in general, low, being detected on average in approximately 6% of the obtained samples (122 out of 1900). The concentrations recorded were also, in general, low, with a median of 1.3 μg kg⁻¹, and a maximum value of 23.93 μg kg⁻¹. The maxima of prevalence and concentration were not geographically coincident, taking place the first at the easternmost part of the sampled area and the second at the westernmost part. In most cases (>94%), gymnodimine A and 13-desmethyl spirolide C were concurrently detected, suggesting that Alexandrium ostenfeldii could be the responsible producer species. The existence of cases in which gymnodimine A was detected alone suggests also that a Karenia species could also be involved. The geographical heterogeneity of the distribution suggests that blooms of the producer species are mostly local. Not all bivalves are equally affected, clams being less affected than mussels, oysters, and razor clams. Due to their relatively low toxicity, and their low prevalence and concentration, it seems that these toxins do not pose an important risk for the mollusk consumers in the area.

Two different methodologies were combined to evaluate the risks that antibiotics can pose in the environment; i) an effect-based methodology based on microbial growth inhibition and ii) an analytical method based on liquid-chromatography coupled to mass spectrometry (LC-MS). The first approach was adapted and validated for the screening of four antibiotic families, specifically macrolides/β-lactams, quinolones, sulfonamides and tetracyclines. The LC-MS method was applied for the identification and quantification of target antibiotics; then, the obtained results were combined with ecotoxicological data from literature to determine the environmental risk. The two methodologies were used for the analysis of antibiotics in water samples (wastewater, river water and seawater) and biofluids (fish plasma and mollusk hemolymph) in two monitoring campaigns undertaken in the Ebro Delta and Mar Menor Lagoon (both in the Mediterranean coast of Spain). Both approaches highlighted macrolides (azithromycin) and quinolones (ciprofloxacin and ofloxacin) as the main antibiotics in wastewater treatment plant (WWTP) effluents with potential risk for the environment. However, no risk for the aquatic life was identified in the river, lagoon and seawater as antibiotic levels were much lower than those in WWTP effluents. Fish from Ebro River were the organisms presenting the highest antibiotic concentration when compared with bivalves (mussels) from the Mediterranean Sea and gastropods (marine snails) from the Mar Menor Lagoon. The effect-based methodology successfully determined antibiotic risk in wastewater, but its applicability was less clear in environmental waters such as seawater, due to its high detection limits. Improving sample preconcentration could increase the method sensibility. Overall, combination of both methodologies provides comprehensive insights in antibiotic occurrence and risk associated in areas under study.

Copper export and mobility in acid mine drainage are difficult to understand with conventional approaches. Within this context, Cu isotopes could be a powerful tool and here we have examined the relative abundance of dissolved (<0.22 μm) Cu isotopes (δ⁶⁵Cu) in the Meca River which is an outlet of the Tharsis mine, one of the largest abandoned mines of the Iberian Pyrite Belt, Spain. We followed the chemical and isotopic composition of the upstream and downstream points of the catchment during a 24-h diel cycle. Additional δ⁶⁵Cu values were obtained from the tributary stream, suspended matter (>0.22 μm) and bed sediments samples. Our goals were to 1) assess Cu sources variability at the upstream point under contrasted hydrological conditions and 2) investigate the conservative vs. non conservative Cu behavior along a stream. Average δ⁶⁵Cu values varied from −0.47 to −0.08‰ (n = 9) upstream and from −0.63 to −0.31‰ downstream (n = 7) demonstrating that Cu isotopes are heterogeneous over the diel cycle and along the Meca River. During dry conditions, at the upstream point of the Meca River the Cu isotopic composition was heavier which is in agreement with the preferential release of heavy isotopes during the oxidative dissolution of primary sulfides. The more negative values obtained during high water flow are explained by the contribution of soil and waste deposit weathering. Finally, a comparison of upstream vs. downstream Cu isotope composition is consistent with a conservative behavior of Cu, and isotope mass balance calculations estimate that 87% of dissolved Cu detected downstream originate from the Tharsis mine outlet. These interpretations were supported by thermodynamic modelling and sediment characterization data (X-ray diffraction, Raman Spectroscopy). Overall, based on contrasted hydrological conditions (dry vs flooded), and taking the advantage of isotope insensitivity to dilution, the present work demonstrates the efficiency of using the Cu isotopes approach for tracing sources and processes in the AMD regions.

Water pollution by pesticides used in agriculture is currently a major concern both in Spain and in Europe as a whole, prompting the need to evaluate water quality and ecological risk in areas of intensive agriculture. This study involved monitoring pesticide residues and certain degradation products in surface and ground waters of the Denomination of Origin (DO) Jumilla vineyard area in Spain. Sixty-nine pesticides were selected and evaluated at twenty-one sampling points using a multi-residue analytical method, based on solid-phase extraction (SPE) and analysis by liquid chromatography coupled with mass spectrometry (LC-MS), providing reliable results. Twenty-six compounds from those selected were detected in the samples analyzed (eleven insecticides including one degradation product, nine herbicides, and six fungicides) and fifteen of them were found in concentrations over 0.1 μg L⁻¹ (upper threshold established by the EU for pesticides detected in waters for human consumption). Indoxacarb was present in more than 70% of the samples, being the most frequently detected compound in water samples. Some pesticides were ubiquitous in all the water samples. Ecotoxicological risk indicators, toxic units (TUs) and risk quotients (RQs), for algae, Daphnia magna and fish were calculated to estimate the environmental risk of the presence of pesticides in waters. The compounds with the highest risk were the herbicides pendimethalin, with RQ values > 1 for the three aquatic organisms, and diflufenican, posing a high risk for algae and fish, and the insecticide chlorpyrifos, with a high risk for Daphnia magna and fish. The ∑TUi determined for water at each sampling point posed only a high risk for the three aquatic organisms in a sample. These results are important for considering the selection of pesticides with less environmental risk in intensive agricultural areas.

The Tharsis mine is presently abandoned, but the past intense exploitation has left large dumps and other sulphide-rich mining wastes in the area generating acid mine drainages (AMD). The main goal of this work is to study the effect of hydrogeochemical processes, hydrological regime and the waste typology on the physicochemical parameters and dissolved concentrations of pollutants in a deeply AMD-affected zone. Extreme leachates are produced in the area, reaching even negative pH and concentrations of up to 2.2 g/L of As and 194 g/L of Fe. The results of the comparison of ore grades of sulphide deposits with dissolved concentrations in waters shows that Pb is the least mobile element in dissolution probably due to the precipitation of Pb secondary minerals and/or its coprecipitation on Fe oxyhydroxysulphates. Arsenic, Cr, and V are also coprecipitated with Fe minerals. Seasonal patterns in metal contents were identified: elements coming from the host rocks, such as Al, Mn and Ni, show their maximum values in the dry period, when dilution with freshwater is lower and the interaction of water-rock processes and evaporation is higher. On the other hand, As, Cr, Fe, Pb and V show minimum concentrations in the dry period due to intense Fe oxyhydroxysulphate precipitation. In this sense, large sulphide rich waste heaps would be a temporal sink of these elements (i.e. Pb, As, Cr and V) in the dry period, and a significant source upon intense rainfalls.