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The investigation of trace element pollution is important for the environmental assessment and management of lacustrine ecosystems, especially when these represent critical freshwater resources in densely populated areas. In this context, this study determined the levels of 15 trace elements in muscles of shad, Alosa agone (Scopoli 1786), a commercialized zooplanktivourous fish, from three primary, but currently still poorly studied, Italian lakes, namely, Lake Como, Iseo, and Garda. Research findings show that shads present similar trace element accumulation patterns among lakes, except for arsenic, which occurs at lower levels in Lake Como. Results provide evidence also for mercury biomagnification in fish, whereas all the other selected trace elements undergo bio-dilution through the same trophic chain. Maximum allowable limits for foodstuff were exceeded for chromium and selenium in shads, whereas mercury levels exceeded the European Environmental Quality Standard biota. These results highlight the need for regular monitoring activities of trace elements in the biota of these lakes.

International audience; Fish concentrations of perfluorocarboxylic and perfluorosulfonic acids were reported for seven deep lakes in the European subalpine area, namely Lake Geneva, L. Lugano and L. Maggiore, L. Iseo, L. Como, L. Garda and L. Mergozzo, one shallow lowland (L. Varese) and two high-altitude alpine (> 2000 m asl) lakes. Fillets and, in selected cases, other body fractions (viscera, liver and residual carcass) from eight fish species were analysed. The possibility of harmonizing the monitoring protocols was tested: the results suggest that the sampling season is not critical for PFASs and the total protein content cannot be used for normalization of tissue concentrations because PFASs bind to specific proteins. Moreover, the polar lipid content could be used to reduce the variability of PFAS concentrations in phospholipid rich fractions of fish such as viscera and carcass. The data comparison and analysis demonstrate that the PFAS contamination in lake fish is generally correlated with the degree of the urbanization of the lake catchment, but it is sometimes difficult to compare absolute concentrations in lake fish, because the lake hydro-morphological characteristics have a substantial role in determining the chemical concentrations of persistent and mobile contaminants.

Zooplankton is a key node in many trophic webs, both for food that for persistent organic contaminants that can accumulate in biota. Zooplankton of different size was seasonally sampled for two years in three deep Italian subalpine lakes (Maggiore, Como, Iseo) with the aim of determining the concentrations of perfluoroalkyl substances (PFAS), DDT, and PCB, and assessing the seasonality impacts on contaminants concentrations. In general, Lake Maggiore showed the highest concentrations for each group of contaminants, with mean values of 7.6 ng g&minus, 1 ww for PFAS, 65.0 ng g&minus, 1 dw for DDT, and 65.5 ng g&minus, 1 dw for PCB. When considering the composition pattern, perfluorooctane sulfonate (PFOS) was detected in 96% of the samples and it was the predominant PFAS compound in all of the lakes. pp&rsquo, DDE was the most detected congener among DDTs and their metabolites, while for PCBs, the prevalent group was hexa-CB that constituted 35.4% of the total PCB contamination. A seasonal trend was highlighted for all contaminant groups with concentrations in colder months greater than in spring and summer, it was evident that the contaminant concentrations were more dependent from seasonality than from size, trophic levels, and taxa composition of zooplankton. Principal component analysis showed that one of the main driver for the accumulation of most of the studied contaminants is their lipophilicity, except for perfluorooctanoic acid (PFOA) and octachlorobiphenyl.

Zooplankton is crucial for the transfer of matter, energy, and pollutants through aquatic food webs. Primary and secondary consumers contribute to the abundance and standing stock biomass, which both vary seasonally. By means of taxa- and size-specific carbon and nitrogen stable isotope analysis, the path of pollutants through zooplankton is traced and seasonal changes are addressed, in an effort to understand pollutant dynamics in the pelagic food web. We analyzed zooplankton plurennial changes in concentration of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane and its relatives (DDTs) and in taxa-specific &delta, 15N signatures in two size fractions, &ge, 450 &micro, m and &ge, 850 &micro, m, representative of the major part of zooplankton standing stock biomass and of the fraction to which fish predation is mainly directed, respectively. Our work is aimed at verifying: (1) A link between nitrogen isotopic signatures and pollutant concentrations, (2) the predominance of size versus seasonality for concentration of pollutants, and (3) the contribution of secondary versus primary consumers to carbon and nitrogen isotopic signatures. We found a prevalence of seasonality versus size in pollutant concentrations and isotopic signatures. The taxa-specific &delta, 15N results correlated to pollutant concentrations, by means of taxa contribution to standing stock biomass and &delta, 15N isotopic signatures. This is a step forward to understanding the taxa-specific role in pollutant transfer to planktivores and of zooplankton enrichment in PCBs and DDTs.

An on-line TFC (Turbulent Flow Chromatography) clean up procedures coupled with UHPLC–MS/MS (Ultra High Performance Liquid Chromatography Mass Spectrometry) multi-residue method was developed for the simultaneous determination of 8 perfluroalkyl carboxylic acids (PFCA, from 5 to 12 carbon atoms) and 3 perfluoroalkyl sulfonic acids (PFSA, from 4 to 8 carbon atoms) in environmental solid matrices. Fast sample preparation procedure was based on a sonication-assisted extraction with acetonitrile. Phospholipids in biological samples were fully removed by an off-line SPE purification before injection, using HybridSPE® Phospholipid Ultra cartridges. The development of the on-line TFC clean-up procedure regarded the choice of the stationary phase, the optimization of the mobile phase composition, flow rate and injected volume. The validation of the optimized method included the evaluation of matrix effects, accuracy and reproducibility. Signal suppression in the analysis of fortified extracts ranged from 1 to 60%, and this problem was overcome by using isotopic dilution. Since no certified reference materials were available for PFAS in these matrices, accuracy was evaluated by recoveries on spiked clam samples which were 98–133% for PFCAs and 40–60% for PFSAs. MLDs and MLQs ranged from 0.03 to 0.3 ng g−1 wet weight and from 0.1 to 0.9 ng g−1 wet weight respectively. Repeatability (intra-day precision) and reproducibility (inter-day precision) showed RSD from 3 to 13% and from 4 to 27% respectively. Validated on-line TFC/UHPLC–MS/MS method has been applied for the determination of perfluoroalkyl acids in different solid matrices (sediment, fish, bivalves and bird yolk).

The biomagnification of mercury, polychlorobiphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs) and perfluoroalkyl acids substances (PFASs) was evaluated in the trophic web of Lake Mergozzo, a small and deep Italian subalpine lake, which has been chosen because it is a protected environment, and discharges into the lake are mostly avoided. Carbon source and relative trophic levels were calculated by using 13C and 15N stable isotopes, respectively, and trophic magnification factors (TMFs) were derived. Zooplankton and thirteen species of fish were collected and analyzed, and the results showed the elevated level of biota contamination from both legacy and emerging pollutants, even if direct discharges were avoided. Concentrations in biota, expressed as sums of compounds, ranged from 0.4 to 60 &micro, g kg&minus, 1 wet weight (ww) for PFASs, from 16 to 1.3 104 &micro, 1 lipid content (lw) for DDTs, from 17 to 1.5 104 &micro, 1 lw for PCBs and from 20.0 to 501 &micro, 1 ww for mercury (Hg). TMFs of this deep, cold lake, with a prevalent pelagic trophic chain, were high and clearly indicated fish biomagnification, except for PFAS. The biomagnification capability of PFAS in a fish-only food web was discussed by using the biomagnification of Hg as a benchmark for assessing their bioaccumulation potential.

DDx, PCBs, PBDEs, Hg, and As contamination in sediments and aquatic organisms of different trophic levels (zooplankton, mussel, fish) were analyzed in Lake Maggiore and Lake Lugano, two large deep perialpine lakes. In the period 2001–2015, we analyzed the spatial and temporal trends of the considered pollutants to detect potential contamination sources and to compare concentrations with Sediment Quality Guidelines (SQGs) or existing Quality Standards (QSs). DDx and Hg contamination deriving from past industrial activities in the Pallanza Basin still exceeded SQGs in sediments and QSs in fish, with potential risks for the ecosystem. Banned in Europe in 1985, PCBs showed low residual values, while recent PBDE peaks resulted in the exceedance of the QSs for biota in both lakes, probably due to current industrial activities. Arsenic mainly derives from geochemical origin. The analysis of the biomagnification of toxicants in a pelagic food chain in Lake Maggiore (zooplankton–fish) according to a stable isotope approach is also presented, according to both the Trophic Magnification Factor and the Trophic Level-adjusted BioMagnification Factor: the importance of seasonality and a Hg > DDx ≈ PBDEs biomagnification capacity were observed. Low PCB bioaccumulation was detected in biota, probably because equilibrium was not reached yet in young fish.

Despite DDT and PCB having been banned for about 40 years, they are still detectable in the environment. In the present research we specifically investigated the trophic transfer of these organochlorine contaminants (OC) through a pelagic food web of a deep lake in Northern Italy (Lake Como) over time. Zooplankton and fish were sampled each season of a year and OC concentrations and the carbon and nitrogen isotopic ratios were measured. By using stable isotopes, the direct trophic relationship between pelagic zooplankton and zooplanktivorous fish was confirmed for Alosa agone only in summer. Based on this result, the biomagnification factor normalized on the trophic level (BMFTL) for organic contaminants was calculated. BMFTL values were within the range 0.9-1.9 for DDT isomers and 1.6-4.9 for some PCB congeners (PCB 95, PCB 101, PCB 149, PCB 153, PCB 138 - present both in zooplankton and in fish and representing >60% of the PCB contamination), confirming the biomagnification of these compounds in one of the two zooplanktivorous fish species of the lake. (C) 2018 Elsevier B.V. All rights reserved.

The evidence that in Northern Italy significant sources of perfluoroalkylacids (PFAA) are present induced the Italian government to establish a Working Group on Environmental Quality Standard (EQS) for PFAA in order to include some of them in the list of national specific pollutants for surface water monitoring according to the Water Framework Directive (2000/60/EC). The list of substances included perfluorooctanoate (PFOA) and related short chain PFAA such as perfluorobutanoate (PFBA), perfluoropentanoate (PFPeA), perfluorohexanoate (PFHxA) and perfluorobutanesulfonate (PFBS), which is a substitute of perfluorooctanesulfonate. For each of them a dossier collects available data on regulation, physico-chemical properties, emission and sources, occurrence, acute and chronic toxicity on aquatic species and mammals, including humans. Quality standards (QS) were derived for the different protection objectives (pelagic and benthic communities, predators by secondary poisoning, human health via consumption of fishery products and water) according to the European guideline. The lowest QS is finally chosen as the relevant EQS. For PFOA a QS for biota was derived for protection from secondary poisoning and the corresponding QS for water was back-calculated, obtaining a freshwater EQS of 0.1μgL-1. For PFBA, PFPeA, PFHxA and PFBS threshold limits proposed for drinking waters were adopted as EQS.

Perfluooctane sulfonate (PFOS) is considered an emerging pollutant because of its wide distribution in both aquatic and terrestrial ecosystems, as well as its potential toxicity to living organisms. Although PFOS environmental levels and the adverse effects on classical model organisms in toxicological studies are well known, including developmental alterations and alteration of oxidative status, its toxicity to free-living species has been seldom investigated. The aim of this study was to assess the potential toxicity of environmental levels of PFOS to yellow-legged gull (Larus michahellis) embryos under field experimental conditions. In a within-clutch experimental design, we injected two PFOS concentrations (100 ng PFOS/g egg weight and 200 ng PFOS/g egg weight) in ovo soon after laying. Eggs were collected when they reached the cracking stage. We investigated the effects of PFOS treatment, laying order and sex on both morphological and biochemical endpoints of embryos. Specifically, we assessed changes in embryo body mass and tarsus length, as well as in liver and brain mass. Moreover, the imbalance of oxidative status was evaluated in both liver and brain from embryos by measuring total antioxidant capacity (TAC) and total oxidant status (TOS), while the levels of protein carbonyl content (PCO) and DNA fragmentation were measured as oxidative and genetic damage endpoints, respectively. The concentrations of PFOS we tested did not significantly alter the morphological endpoints, independently of laying order and sex. Similarly, embryo oxidative status and oxidative and genetic damage were not significantly affected by PFOS in ovo exposure. These findings suggest that current environmental PFOS levels do not affect early development of yellow-legged gull embryos.