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The great concern over the environmental impact of wastewaters has led to the designing of advanced treatment processes to upgrade conventional treatment plants and achieve a significant reduction of contaminants in receiving waters. In the present study we combined chemical and ecotoxicological analyses, aiming to evaluate the reduction of toxicity effects associated with the removal of micropollutants and to define the contribution of the detected compounds to the overall toxicity of the mixtures in a series of wastewater effluents collected from a secondary treatment (OUT 2) and from a tertiary activated carbon treatment (OUT 3) plant. The target compounds were selected after a screening procedure among pharmaceuticals, musk fragrances, and trace metals. The classical algal growth inhibition test was conducted on the original effluent samples and on different fractions obtained by solid-phase extraction (SPE) treatment. A good accordance was found between the removal of toxicity (30%-80%) and organic compounds (70%-80%) after the tertiary treatment, suggesting its high efficiency to improve the wastewater quality. The discrepancy between the contribution to the overall toxicity of the nonadsorbable compounds (i.e., inorganic or very polar organic compounds) as experimentally measured by the SPE bioassays (18%-76%) and calculated by the concentration addition approach (97%) could be mitigated by including the bioavailability correction in metal-toxicity modeling of wastewater mixtures. For the organic compounds, the toxic equivalency method enabled us to quantify the portion of toxicity explained by the detected chemicals in both OUT 2 (82%-104%) and OUT 3 (5%-57%), validating the selection of the target molecules. The applied integrating approach could be implemented by the inclusion of both additional target chemicals and toxicity endpoints. Environ Toxicol Chem 2022;41:2404-2419. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Dichlorodiphenyltrichloroethane (DDT) contamination in the Toce River in northern Italy was studied by collecting data from 2016 to 2021 upstream and downstream of a production factory which in the past had discharged technical DDT. Analysis of sediments and of bioaccumulation in different benthic invertebrate taxa (Gammaridae, Diptera, Ephemeroptera Baetidae and Heptageniidae) was carried out to assess the transfer of DDT from sediments to benthic invertebrates and the environmental risk of this legacy pollutant for the river ecosystem. DDT and its metabolites dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD), here called DDx, were analyzed by isotope dilution gas chromatography–mass spectrometry (GC-MS/MS). DDx values in sediments in upstream stations (1.14–2.25 ng g−1 1% Organic Carbon) were lower than downstream of the industrial site (5.60–7.60 ng g−1 1% Organic Carbon), often exceeding Sediment Quality Guidelines for total DDx. Peak levels derived from new inputs of parental DDT, as confirmed by fingerprint analysis. Bioaccumulation was higher at downstream sites (up to 5107 ng g−1 lipid weight), confirming the bioavailability of residual DDT as well as active metabolism, with the formation of DDD and DDE. The Biota-Sediment Accumulation Factor evidenced the highest values (over 4.2) for Diptera and Gammaridae, highlighting that invertebrates can transfer contamination from sediments to the trophic chain. Linear regression models were developed to estimate DDx concentrations in benthic invertebrates from DDx concentrations in sediments. However, determination coefficients R2 remained in the range of 0.36–0.51, highlighting the necessity of bioaccumulation analysis to fully estimate environmental risk. The results show that DDT contamination, even if residual, may still represent a risk due to its effective transfer to the trophic chain.

Lake tributaries collect contaminants from the watershed, which may accumulate in lake sediments over time and may be removed through the outlets. DDx, PCB, PAH, PBDE, and trace element (Hg, As, Cd, Ni, Cu, Pb) contamination was analyzed over 2001–2018 period in sediments of the 5 main tributaries and of the outlet of Lake Maggiore (Northern Italy). Sediment cores were collected in two points of the lake, covering 1995–2017 period. Concentrations were compared to Sediment Quality Guidelines (PECs), potential sources and drivers (land use, population numbers, industrial activities, hydrology) were analyzed, and temporal trends were calculated (Mann-Kendall test). PCB, PBDE, Pb, Cd, and Hg contamination derives mainly from heavy urbanization and industry. Cu and Pb show a temporal decreasing trend in the basin, likely as result of improved wastewater treatments and change in use. A recent PAH increase in the whole lake may derive from a single point source. A legacy DDx and Hg industrial pollution is still present, due to high persistence in sediments. Values of DDx, Hg, Pb, and Cu above the PECs in lake sediments and/or in the outlet show potential risk for aquatic organisms. Results highlight the key role of tributaries in driving contamination from the watershed to the lake through sediment transport.

We examined the temporal profiles of many organic micropollutants analysed in a sediment core sampled from a highly anthropized tributary of the Po River, the Lambro River. Analysed for extractable organic halogens (EOX), total petroleum hydrocarbons (C

The larvae of some species of the subgenus Orthocladius s. str. (Diptera, Chironomidae) are here described for the first time with corrections and additions to the descriptions of adult males and pupal exuviae. The identification of larvae is generally not possible without association with their pupal exuviae and/or adult males, so the descriptions here are based only on reared material or on pupae with the associated larval exuviae. Usually, Chironomidae larvae can be separated on the basis of morphometric characters, and the most discriminant characters ones are: 1- the ratio between the width of median tooth of mentum (Dm) and the width of the first lateral tooth (Dl) = mental ratio (DmDl), 2- the ratio between the length of the first antennal segment (A1) and the combined length of segments 2-5 (A(2-5)2-5) = antennal ratio (AR). The shape of mandible, maxilla, and other body parts are almost identical in all the species considered in this study. The larva of Orthocladius (Symposiocladius) lignicola is very characteristic and can be separated by the shape of mentum and the larvae of all the known species of Symposiocladius are characterized by the presence of large Lauterborn organs on antennae and of tufts of setae on abdominal segments. The larvae of Orthocladius (Orthocladius) oblidens and Orthocladius (Orthocladius) rhyacobius can be distinguished from other species basing on their large Dm and to each other by AR. A principal component analysis was carried out using 5 characters: 1- Dm, 2- Dl, 3- length of A1, 4- width of A1 (A1W), 5- combined length of segments 2-5 (A2-5). The most discriminant characters were Dm and A1, confirming that DmDl and AR can be used to separate species at larval stage, but the large superposition of morphometric characters in different species confirms that association with pupal exuviae is in any case needed to identify larvae. In future perspective, the development of reference DNA barcodes from specimens identified by specialists is recommended since possibly the best tool for larvae identification, but association of barcodes with morphotypes is in any case fundamental.

Simple Summary The biodiversity study and conservation are primary objectives in preventing loss of species consequent to global climatic change. The present contribution adds information to a key taxon, a holometabolous insect belonging to Order Diptera, family Chironomidae, whose larvae are members of freshwater macroinvertebrate fauna and are considered good indicators of water quality. Abstract The larvae of some species of the subgenus Orthocladius s. str. (Diptera, Chironomidae) are here described for the first time with corrections and additions to the descriptions of adult males and pupal exuviae. The identification of larvae is generally not possible without association with pupal exuviae and/or adult males, so the descriptions here are based only on reared material or on pupae with the associated larval exuviae. Usually, Chironomidae larvae can be separated on the basis of morphometric characters, the most discriminant ones are: (1) the ratio between the width of median tooth of mentum (Dm) and the width of the first lateral tooth (Dl) = mental ratio (DmDl), (2) the ratio between the length of the first antennal segment (A1) and the combined length of segments 2–5 (A2–5) = antennal ratio (AR). The shape of mandible, maxilla, and other body parts are almost identical in all the species considered in this study. The larva of Orthocladius (Symposiocladius) lignicola is very characteristic and can be separated by the shape of mentum and the larvae of all the known species of Symposiocladius are characterized by the presence of large Lauterborn organs on antennae and of tufts of setae on abdominal segments. The larvae of Orthocladius (Orthocladius) oblidens and Orthocladius (Orthocladius) rhyacobius can be distinguished from other species basing on their large Dm and to each other by AR. A principal component analysis was carried out using 5 characters: (1) Dm, (2) Dl, (3) length of A1, (4) width of A1 (A1W), (5) combined length of segments 2–5 (A2–5). The most discriminant characters were Dm and A1, confirming that DmDl and AR can be used to separate species at larval stage, but the large superposition of morphometric characters in different species confirms that association with pupal exuviae is in any case needed to identify larvae. In future perspective, the development of reference DNA barcodes from specimens identified by specialists is recommended since possibly the best tool for larvae identification, but association of barcodes with morphotypes is in any case fundamental.

Green roofs (GRs) are considered sustainable solutions for the adaptation of urban water management to climate change. The use of GRs is particularly promising in urban environments like the Metropolitan Area of Milan, the most urbanized area in Italy. In this work, we evaluated the subsurface runoff coefficient at the event-time scale, for more than one year of observations, of 68 small-scale test beds comprising different configurations of green roofs (e.g., different vegetations, types and depths of growing media, and different slopes) installed in the Metropolitan Area of Milan. The objectives of this study are three-fold. Firstly, the controlling factors of the hydraulic have been assessed for efficiency. We calculated a mean drainage flow rate of 51%, finding that growing media play a significant role in determining the drainage flow during the spring, at the beginning of the vegetative period. During this season, water retention in fertilized beds increases significantly. At the beginning of the summer, the vegetation cover is able to significantly reduce the drainage flow, playing an even more crucial role with respect to the growing medium material. However, we found that the vegetation type (grass field and Sedum) does not play a significant role in the retention processes. Secondly, the delay of the peak flow rate was determined. We found a precipitation peak delay from 1 to 2 h, which would be sufficient to guarantee environmental benefits for urban drainage. Finally, the factors controlling the hydraulic efficiency of GRs for individual precipitation events were assessed. We found that soil moisture and cumulated precipitation are both significant factors determining the drainage flow rate. In conclusion, we point out that soil moisture is one of the main parameters characterizing GR drainage and should be further considered in future research efforts devoted to the analysis of GR performance.

We developed and compared two analytical methods for determination of MeHg in freshwater biota and sediments, by: I) simplified static headspace GC-MS using internal standard (IS) isotope dilution quantification, after microwave acid digestion and aqueous phase NaBEt4 ethylation; II) Automated Mercury Analyzer, after double toluene extraction followed by back-extraction with L-cystein. The performance was evaluated by analysis of certified reference materials. For biota, mean recovery was 100 ± 2% and relative standard deviation (RSD) ≤ 6.8% for method I, and mean recovery was 98 ± 7% and RSD ≤13% for method II. For sediments, recovery of 94.5% and RSD of 8.8% were obtained with method I, and recovery of 90.3% and RSD of 9.4% with method II. Limits of detection (LOD) were 0.7 µg kg−1 and 6 µg kg−1, respectively. Both techniques were tested for MeHg analysis in freshwater invertebrates, fish and sediments, covering a large range of MeHg values (1.9–670 µg kg−1 d.w.). • Both protocols proved to be suitable for MeHg analysis in complex environmental matrices, even if, for method II, interferences in the extraction phase and limited sensitivity may hinder sediment analysis. • Passing-Bablock regression revealed a slight disproportion between methods, with line slope = 1.058 (95% CI ranging from 1.001 to 1.090)., Graphical abstract Image, graphical abstract

We present the first assessment of atmospheric pollution by mercury (Hg) in an industrialized area located in the Ossola Valley (Italian Central Alps), in close proximity to the Toce River. The study area suffers from a level of Hg contamination due to a Hg cell chlor-alkali plant operating from 1915 to the end of 2017. We measured gaseous elemental Hg (GEM) levels by means of a portable Hg analyzer during car surveys between autumn 2018 and summer 2020. Moreover, we assessed the long-term dispersion pattern of atmospheric Hg by analyzing the total Hg concentration in samples of lichens collected in the Ossola Valley. High values of GEM concentrations (1112 ng m−3) up to three orders of magnitude higher than the typical terrestrial background concentration in the northern hemisphere were measured in the proximity of the chlor-alkali plant. Hg concentrations in lichens ranged from 142 ng g−1 at sampling sites located north of the chlor-alkali plant to 624 ng g−1 in lichens collected south of the chlor-alkali plant. A north-south gradient of Hg accumulation in lichens along the Ossola Valley channel was observed, highlighting that the area located south of the chlor-alkali plant is more exposed to the dispersion of Hg emitted into the atmosphere from the industrial site. Long-term studies on Hg emission and dispersion in the Ossola Valley are needed to better assess potential impact on ecosystems and human health.

River sediments generally act as a sink for trace elements but, when resuspended, they contribute to long-term downstream transport of contamination, which may finally reach the marine environment. This study analyzed these processes in a complex aquatic system that includes a contaminated tributary, the Lambro River (Northern Italy) and its recipient and main Italian watercourse, the Po River, with the prodelta in the Adriatic Sea. The study was conducted from a historical perspective which, covering the last 50 years, examined the main driving events such as the inputs of contaminants, the construction of WWTPs and the evolution of environmental legislation. The time trend of trace element contamination was analyzed in a sediment core collected in the Lambro River and dated 1962–2011. The highest enrichments were found for Hg, Zn, Cu, Pb and Cd, which showed similar trends, with EF maxima in the '60s–'90s (172, 56, 40, 28 and 21, respectively), following industrial and urban development, and a general decreasing pattern after the late ‘90s. Only in the 2000s the ecological risk associated with metal contamination showed mean PEC Quotients stably below 1. The results of a literature survey on sedimentary trace elements in the Po River and the prodelta for the last 50 years were then compared to the Lambro sediment core. A significant contribution to Cu, Zn, Pb, Hg and Cd contamination was proved to derive from Lambro sediment transport. In the prodelta, increasing Ni and Cr concentrations were also evidenced, likely as a result of enhanced soil erosion in the Po basin. This study highlights the key role of WWTPs, of lower-impact industrial processes and of environmental legislation in reducing contaminant inputs. It also emphasizes the active contribution of riverine sediment-bound contamination to long-distance marine sediment quality.

Mercury bioavailability was assessed by exposing the dipteran Chironomus riparius for the whole life cycle to legacy-contaminated fluvial sediments (0.038–0.285 mg Hg kg−1 d.w.) and analyzing tissue concentrations in larvae at different exposure times (7, 11, and 16 days) and in adults. In the same experiment, diffusive gradients in thin-film passive samplers (DGTs), both piston- and probe-shaped, were co-deployed in the same sediments and retrieved at the same times as the organisms. To compare the two approaches, results showed a good agreement between accumulation kinetics of C. riparius and DGTs, both approximating an apparent steady-state. A strong correlation was found between values in tissues and in both types of DGTs (r between 0.74 and 0.99). Concentrations in mature larvae (19–140 µg kg−1 w.w.), which may represent a basal level of the aquatic food web, exceeded the European Environmental Quality Standard for biota (20 µg kg−1 w.w.), which aims at protecting the top predators from secondary poisoning. Body burdens in larvae and in adults were similar, showing negligible decontamination during metamorphosis and proving an efficient mercury transfer from sediments to terrestrial food webs.

Lake tributaries collect contaminants from the watershed, which may accumulate in lake sediments over time and may be removed through the outlets. DDx, PCB, PAH, PBDE, and trace element (Hg, As, Cd, Ni, Cu, Pb) contamination was analyzed over 2001-2018 period in sediments of the 5 main tributaries and of the outlet of Lake Maggiore (Northern Italy). Sediment cores were collected in two points of the lake, covering 1995-2017 period. Concentrations were compared to Sediment Quality Guidelines (PECs), potential sources and drivers (land use, population numbers, industrial activities, hydrology) were analyzed, and temporal trends were calculated (Mann-Kendall test). PCB, PBDE, Pb, Cd, and Hg contamination derives mainly from heavy urbanization and industry. Cu and Pb show a temporal decreasing trend in the basin, likely as result of improved wastewater treatments and change in use. A recent PAH increase in the whole lake may derive from a single point source. A legacy DDx and Hg industrial pollution is still present, due to high persistence in sediments. Values of DDx, Hg, Pb, and Cu above the PECs in lake sediments and/or in the outlet show potential risk for aquatic organisms. Results highlight the key role of tributaries in driving contamination from the watershed to the lake through sediment transport.

Negli ecosistemi d'acqua dolce il mercurio è adsorbito principalmente nei sedimenti, dove può essere parzialmente convertito in metilmercurio (MeHg), un composto del mercurio più tossico e bioaccumulabile rispetto alle forme inorganiche. La sua analisi può fornire quindi utili informazioni per valutare il rischio ambientale legato alla contaminazione da mercurio. La determinazione del MeHg nelle matrici ambientali risulta spesso difficile per le basse concentrazioni e per la presenza di diversi interferenti. Scopo di questo lavoro è sviluppare e confrontare due protocolli per l'analisi del MeHg in campioni di organismi e di sedimenti d'acqua dolce, mediante Analizzatore Automatico di Mercurio (AMA 254) e mediante GC-MS. La valutazione dei metodi è stata effettuata tramite analisi di materiali di riferimento certificati e di campioni di invertebrati bentonici di fiume, pesci e sedimenti lacustri. La metodica in AMA 254 prevede una doppia estrazione liquido-liquido con toluene e L-cisteina. Il protocollo in GC-MS utilizza la tecnica dello spazio di testa statico, usando il metodo di quantificazione della diluizione isotopica con standard interno. Entrambe le metodiche hanno mostrano una buona performance, con recuperi dell'86-102 % rispetto ai valori certificati e coefficienti di variazione (CV) del 2,5-13,2 %. Per i campioni naturali, la ripetibilità è risultata buona, con CV inferiori al 20 %. Il limite di quantificazione calcolato per il metodo in AMA 254 (21 µg MeHg kg-1) può risultare non adeguato per l'analisi di sedimenti naturali, mentre il metodo in GC-MS risulta più sensibile (LOQ = 1,4 µg MeHg kg-1). Una comparazione preliminare tra i due metodi sembrerebbe indicare equivalenza, nonostante la metodica in GC-MS dia recuperi tendenzialmente più alti rispetto a quella in AMA 254.

Rock-glacier sediment transfer and ice melting can impact surface waters located downstream. However, there is a lack of knowledge on the influence of rock-glacier dynamics on the geochemical, hydrochemical, and ecological characteristics of adjacent impounded surface waters. In the Col d'Olen area (Long-Term Ecological Research site, NW Italian Alps), an intact rock glacier terminates into a pond and solute-enriched waters originating from the rock glacier flow into the pond through a subsurface hydrological window. In this study, we performed geophysical and ground surface temperature measurements. Moreover, we sampled soils and sediments in different compartments of the investigated rock-glacier - pond system and we further sampled benthic invertebrates in the pond. Cold ground thermal regime, ground-ice presence, and coarse debris cover on the rock glacier together with its lithology (serpentinites) influence the rock-glacier geochemistry and ecology with respect to surrounding areas. Pond geochemistry is affected by transfer of trace-metal-enriched fine-grained debris and meltwaters from the rock glacier. Enhanced bioavailability of serpentinite-associated trace metals was proved, with concentrations of Ni and Cr in benthic invertebrates up to 384 and 110 mg kg−1 d.w., respectively, potentially exerting toxic effects on pond biota. The advancing movement of the rock glacier not only has delivered sediments to the pond, but it has progressively filled the valley depression where the pond is located, creating a dam that could have modified the level of impounded water. This process likely constituted a sediment trap in which serpentinitic rock-glacier sediments could be deposited at the pond bottom, with related geochemical and ecological implications. This study illustrates the importance of rock glaciers in influencing the characteristics of downstream freshwater bodies and highlights the need to improve our knowledge about climate-change-related impacts of rock-glacier dynamics on alpine headwaters.

Many hydrobiological studies have dealt with the autecology of species within the family Chironomidae and discussed factors affecting species distribution. The aim of the present research is to consider the most important factors affecting chironomid species distribution. Habitat type (lentic, lotic, krenal, rhithral, etc.), water temperature, conductivity, and trophic status are confirmed key factors controlling their assemblage structure. Here, we introduce the term “morphotaxon” as the taxonomic level, intermediate between genus and species, more suitable to describe the ecological responses of Chironomidae. The present uncertainty related to species identification is at the base of the proposal, with the assumption that species belonging to the same morphotaxon have similar ecological needs. In this study, this hypothesis was found to be valid, with few exceptions represented by species-rich genera (e.g., Tanytarsus, Paratanytarsus). The morphotaxon can be viewed as an interim measure waiting for the implementation of new complementary approaches, such as species identification with molecular methods.

Total mercury (THg) and methylmercury (MeHg) concentrations were analyzed in zooplankton (≥450 and ≥850 µm size fractions) collected seasonally over 6 years in Lake Maggiore (Northern Italy), characterized by a legacy mercury contamination. Analysis of δ 15N and δ13C stable isotopes was carried out to trace how taxa with different trophic levels and carbon sources contributed to mercury concentrations and trends. THg ranged between 44–213 µg kg−1 d.w. and MeHg 15–93 µg kg−1 d.w., representing 24–61% of THg. Values showed strong seasonal variations, with peaks in winter, due to the high biomass of predator taxa (Bythotrephes longimanus, Leptodora kindtii) and of Daphnia longispina-galeata gr. A positive correlation between THg and MeHg and δ15N signature was observed. D. longispina-galeata gr. prevailed in both size fractions, substantially contributing to THg and MeHg concentrations. Δ13C signature was strictly bound to lake thermal circulation dynamics. Mercury stock in the zooplankton compartment ranged between 19–140 ng THg m−2 and 6–44 ng MeHg m−2 for the ≥450 µm size fraction and between 2–66 ng THg m−2 and 1–7 ng MeHg m−2 for the ≥850 µm fraction, with the highest values in spring when zooplanktivorous fish actively prey in the pelagic zone. The results highlighted the crucial role of zooplankton as a repository of mercury, easily available to higher trophic levels.

The larvae of some species of the subgenus Orthocladius s. str. (Diptera, Chironomidae) are here described for the first time with corrections and additions to the descriptions of adult males and pupal exuviae. The identification of larvae is generally not possible without association with pupal exuviae and/or adult males, so the descriptions here are based only on reared material or on pupae with the associated larval exuviae. Usually, Chironomidae larvae can be separated on the basis of morphometric characters, the most discriminant ones are: (1) the ratio between the width of median tooth of mentum (Dm) and the width of the first lateral tooth (Dl) = mental ratio (DmDl), (2) the ratio between the length of the first antennal segment (A1) and the combined length of segments 2–5 (A2–5) = antennal ratio (AR). The shape of mandible, maxilla, and other body parts are almost identical in all the species considered in this study. The larva of Orthocladius (Symposiocladius) lignicola is very characteristic and can be separated by the shape of mentum and the larvae of all the known species of Symposiocladius are characterized by the presence of large Lauterborn organs on antennae and of tufts of setae on abdominal segments. The larvae of Orthocladius (Orthocladius) oblidens and Orthocladius (Orthocladius) rhyacobius can be distinguished from other species basing on their large Dm and to each other by AR. A principal component analysis was carried out using 5 characters: (1) Dm, (2) Dl, (3) length of A1, (4) width of A1 (A1W), (5) combined length of segments 2–5 (A2–5). The most discriminant characters were Dm and A1, confirming that DmDl and AR can be used to separate species at larval stage, but the large superposition of morphometric characters in different species confirms that association with pupal exuviae is in any case needed to identify larvae. In future perspective, the development of reference DNA barcodes from specimens identified by specialists is recommended since possibly the best tool for larvae identification, but association of barcodes with morphotypes is in any case fundamental.

The paper reports results of four intensive campaigns carried out on the Seveso River (Milan metropolitan area, Italy) between 2014 and 2016, during intense precipitation events. Laboratory analyses were coupled with on-site, continuous measurements to assess the impact of pollutants on water quality based on both conventional and surrogate parameters. Laboratory data included total suspended solids, caffeine, total phosphorus and nitrogen, and their dissolved forms. Screening of trace metals (Cr, Cu, Pb, Ni, Cd) and PBDEs (polybromodiphenylethers) was carried out. Continuous measurements included water level, physico-chemical variables and turbidity. Nutrient concentrations were generally high (e.g. average total phosphorus > 1,000 μg/L) indicating strong sewage contributions. Among monitored pollutants Cr, Cu, Pb, and Cd concentrations were well correlated to TSS, turbidity and discharge, being bound mostly to suspended particulate matter. A different behavior was found for Ni, that showed an early peak occurring before the flow peak, as a result of first flush events. PBDEs correlated well to nutrient concentrations, showing the highest peaks soon after activation of the combined sewer overflows, likely because of its accumulation in sewers. In addition to showing the existing correlations between quality parameters, the paper highlights the importance of surrogate parameters as indicators of anthropic pollution inputs.

Selected type and non-type material belonging to the genus Orthocladius van der Wulp, 1874 (Diptera: Chironomidae) sensu GOETGHEBUER (1940-1950), deposited in the Royal Belgian Institute of Natural Sciences (RBINS), originally comprising specimens dry pinned or stored in isinglass, were mounted on microscope slides and re-examined. Other chironomids present in the RBINS collection belonging to other genera were also examined. Fifty slides were prepared and identified to species, or to generic level when the condition of the specimens did not allow species identification. The following types, representing taxa formerly considered as nomina dubia, were examined and the concerned species are stated here as valid: Georthocladius collarti (Goetghebuer, 1941) comb. nov., Georthocladius scaturiginis (Goetghebuer, 1940) comb. nov., Lapposmittia succinea (Goetghebuer, 1942) comb. nov., Orthocladius (Euorthocladius) tolleti Goetghebuer, 1944 (new subgenus placement), Orthocladius (Orthocladius) timoni Goetghebuer & Timon-David, 1939, Pseudorthocladius hockaiensis (Goetghebuer, 1933). Orthocladius (Orthocladius) mitisi Goetghebuer, 1938, previously stated as junior synonym of Orthocladius (Orthocladius) glabripennis (Goetghebuer, 1921), is reinstated as valid species. The following new synonyms are proposed: Georthocladius (Georthocladius) collarti = Parachaetocladius retezati Albu, 1972: 19, syn. nov.; Cricotopus (Paratrichocladius) rufiventris (Meigen, 1830) = Orthocladius franzi Goetghebuer, 1949, syn. nov.; Cricotopus (Paratrichocladius) skirwithensis Edwards, 1929 = Orthocladius nigritus Goetghebuer, 1938, syn. nov. = Paratrichocladius spiesi Ashe & O’Connor, 2012; Hydrobaenus distylus (Potthast, 1914) = Orthocladius antennalis Goetghebuer, 1944, syn. nov. Lectotypes of Orthocladius collarti Goetghebuer, 1941, Orthocladius antennalis Goetghebuer, 1944, Orthocladius timoni Goetghebuer & Timon-David, 1939, and Orthocladius hockaiensis Goetghebuer, 1933 are designated. Non-type material assigned to Orthocladius was also mounted on slides and identified. Although a list of the non-Orthocladius taxa is also provided, no taxonomic changes are proposed for the latter.

Author(s): Rossaro, Bruno; Pirola, Niccolo; Marziali, Laura; Magoga, Giulia; Boggero, Angela; Montagna, Matteo | Abstract: In a first list of chironomid species from Italy from 1988, 359 species were recognized. The subfamilies represented were Tanypodinae, Diamesinae, Prodiamesinae, Orthocladiinae and Chironominae. Most of the species were cited as widely distributed in the Palearctic region with few Mediterranean (6), Afrotropical (19) or Panpaleotropical (3) species. The list also included five species previously considered Nearctic. An updated list was thereafter prepared and the number of species raised to 391. Species new to science were added in the following years further raising the number of known species. The list of species known to occur in Italy is now updated to 580, and supported by voucher specimens. Most species have a Palearctic distribution, but many species are distributed in other biogeographical regions; 366 species are in common with the East Palaearctic region, 281 with the Near East, 248 with North Africa, 213 with the Nearctic, 104 with the Oriental, 23 species with the Neotropical, 23 with the Afrotropical, 16 with the Australian region, and 46 species at present are known to occur only in Italy. On the basis of new findings in Italy and in nearby areas it is stated that the knowledge of chironomid fauna is still incomplete.

A multigenerational test with Chironomus riparius was performed to assess long-term effects on life-traits of exposure to selected perfluoroalkyl compounds: perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and perfluorobutane sulfonate (PFBS). These persistent contaminants are widespread in aquatic ecosystems at low concentrations, possibly exerting long-term toxicity. Larvae of C. riparius of a native population were exposed for 10 generations to 10 μg/L nominal concentrations of PFOS, PFOA, and PFBS, comparable with the maximum values found in European rivers. All treatments showed reduced growth at most/several generations. No effects on survival, development, and reproduction were found. A final tolerance-induction test was performed exposing the pre-exposed experimental cohorts to 100 µg/L PFOS and 150 µg/L PFOA for a whole life cycle. Factorial analysis of variance revealed no difference between treatments (i.e., PFOS vs PFOA), indicating no induced tolerance. Instead, organisms pre-exposed to PFBS were the most stressed, followed by those pre-exposed to PFOA and PFOS, with earlier emergence and reduced adult weight. The results may be related to general stress and genetic erosion induced by long-term laboratory culture, but also to long-term toxicant exposure. However, no effects at the population level (population growth rate) were proved, and thus a toxicity risk in real ecosystems at the tested concentrations seems unlikely. Environ Toxicol Chem 2019;00:1-12. © 2019 SETAC.

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.

The determination of sediment toxicity is challenging due to site-specific factors affecting pollutants distribution and bioavailability, especially when contamination levels are close to expected non-effect concentrations. Different lines of evidence and sensitive tools are necessary for a proper toxicity risk assessment. We examined the case study of the Toce River (Northern Italy), where past industrial activities determined Hg, DDT and As enrichment in sediments. A triad approach comprising chemical, ecotoxicological and ecological analyses (benthic invertebrates) was carried out for risk assessment of residual contamination in river sediments. A “blank” site upstream from the industrial site was selected to compare the other sites downstream. Sediment, water and benthic invertebrate samplings were carried out following standard protocols. Results emphasized that despite the emissions of the industrial site ceased about 20 years ago, sediments in the downstream section of the river remain contaminated by Hg, DDT and As with concentrations exceeding Threshold Effect Concentrations. A chronic whole-sediment test with Chironomus riparius showed decreased development rate and a lower number of eggs per mass in the contaminated sediments. Benthic community was analyzed with the calculation of integrated (STAR_ICMi) and stressor-specific metrics (SPEAR pesticide and mean sensitivity to Hg), but no significant differences were found between upstream and downstream sites. On the other hand, multivariate analysis (partial Redundancy Analysis and variation partitioning) emphasized a slight impact on invertebrate community, accounting for 5% variation in taxa composition. Results show that legacy contaminants in sediments, even at low concentrations, may be bioavailable and possibly toxic for benthic invertebrates. At low concentration levels, sensitive and site-specific tools need to be developed for a proper risk analysis.

Actual standard for evaluation of sediment and water quality in different European Countries are mainly conservative, ensuring the widest possible protection of living organisms in aquatic environments. However this approach led authorities to considerer as contaminated all the sites in which sediment, water or biota quality standards are overcome for defined pollutants. Very high costs are expected to restore these contaminated sites without any indication of the real bioavailability of contaminants in the different sites. An alternative approach is provided by environmental risk assessment (ERA) evaluation conducted at specific sites, in order to rank different areas within each site: areas not at risk, areas potentially at risk and areas at risk. ERA evaluation allows the prioritization of contaminated sites, pointing out the areas with the highest specific risk for aquatic ecosystems. Methods: ERA evaluation was developed considering different lines of evidence (chemical analyses, toxicity test and ecological analyses), applying an approach called Sediment Quality Triad (SQT) integrated with specific assessments on bioaccumulation and secondary poisoning for persistent and bioavailable pollutants; the SQT approach is supported for the evaluation of sediment quality in water bodies by the US Environmental Protection Agency (USEPA), the National Oceanic and Atmospheric Administration (NOAA), and is used also in the European Union (ECHA, 2013, European Commission 2010). The SQT approach mainly starts defining the Conceptual Site model (CSM) with relevant exposure routes and the receptors (Fig. 1). The CSM may also include some human receptors, potentially exposed to pollutants, for example through dietary consumption of fish. The SQT procedure followed a three step Tiered approach starting from the overcoming of water, sediment and biota quality standards (Tier 1). Subsequently, a comparison was carried out between pollutant concentrations in different matrices (sediments, water, macroinvertebrates, fishes and birds) in the considered site and the toxicological chronic effects with a sensitivity specific evaluation for the considered pollutants (Tier 2); at the end (Tier 3), results allowed to define a risk management approach that consists of the definition of three different risk thresholds: a screening threshold, that indicates no risk, an attention risk threshold and a Results and discussion: The SQT model was applied to a large river-lake ecosystem in Northern Italy, industrially contaminated by DDTs and Hg and officially defined as a contaminated Site of National Interest (SIN). The Italian Ministry of Environment established in January 2014 a Technical Board to define the application of SQT approach to the case study, including experts of environmental authorities and public health agencies (ARPA Piemonte, ISS, Ispra), public research institutes (CNR-IRSA) and the private involved companies (Ramboll Environ and Syndial). The results of the SQT evaluation allowed to define site-specific attention risk and probable risk thresholds for all the considered pollutants (HCB, DDT and Hg) in different environmental matrices (sediment, water and biota). The present approach overcomes the simple evaluation based on chemical analyses and is protective for biota at all trophic levels. Results showed the exceedance of the attention thresholds for sediment (for DDx and mercury) and benthic invertebrates (only for DDx) in the lake and in the river and in some cases the exceedance of the probable threshold for Hg in the lake. Based on these results, it was suggested for the future to carry out a monitoring plan that takes into account these environmental matrices and possibly other lines of evidence supporting the specific environmental risk assessment. Exceedance of the attention value may in fact cause a low / moderate adverse effects on specific components of the ecosystem under investigation.

Reservoirs are often characterized by high siltation rates which impair the storage capacity. Accumulated sediments are frequently removed by flushing, causing physical-mechanical impacts on aquatic organisms in the downstream rivers. In some cases, however, chemical compounds (organics and trace metals) adsorbed on sediments may induce toxic effects, mainly in a long-term perspective. Some researches emphasized that flushing operations may determine contaminant release from sediments, altering their bioavailability. Based on real case studies from Northern Italy, the "Analytical protocol for ecotoxicological and physical-chemical characterization of sediments in reservoirs" (PrATo) was developed in order to define proper methods for reservoir sediment characterization in the Lombardy Region, with the final purpose of a sustainable management of operations involving the release of sediments into downstream riverine ecosystems, i.e. the protection of aquatic communities. The protocol was developed by considering 30 reservoirs of Lombardy Region (Northern Italy), characterized by different degrees of silting and anthropogenic pressures. PrATo includes standard protocols for sampling, chemical analysis and ecotoxicological characterization of sediments of the reservoirs and of the downstream river stretches. It also includes criteria for risk assessment using an approach similar to TRIAD, which takes into account: 1) the comparison between micropollutant concentrations in sediments and quality thresholds selected from existing national legislation or from literature (e.g. cb-TEC and cb-PEC; MacDonalds et al., 2000); 2) the assessment of toxicity of sediments using ecotoxicological test batteries (for example, the chronic test with Heterocypris incongruens is considered as screening test); 3) the chemical and ecotoxicological assessment of sediments of the downstream river stretch before flushing as basis for planning proper operations, and after flushing as criteria to evaluate the results of these operations by comparison with the previous conditions. The final aim of the characterization is to provide practical information for a sustainable management of flushing operations. For example, a proper sediment: water dilution factor to be applied during flushing to prevent overcoming toxicity thresholds can be calculated. Preliminary trials of the protocol were carried out on 20 reservoirs. Results show that the definition of proper quality thresholds is rather difficult, since they are generally not representative of site-specific bioavailability. Therefore, the ecotoxicological characterization is necessary to assess sediment toxicity. PrATo provides a practical and efficient tool for a sustainable management of the flushing activities and will be adopted in Lombardy as technical guidance for the Reservoir Management Plans.

a b s t r a c t A multigeneration toxicity test on Chironomus riparius was performed with the aim of investigating the evolutionary consequences of exposure to perfluoralkyl substances (perfluorooctane sulfonic acid, PFOS; perfluorooctanoic acid, PFOA; perfluorobutane sulfonate, PFBS). Six-hundred larvae were bred per treatment and per generation until emergence and egg deposition under a nominal concentration of 10 g/L of contaminants. Newborn larvae were used to start the next generation. Evolution of genetic variability was evaluated along a total of 10 consecutive generations based on 5 microsatellite loci. Analysis of life-history traits (survival, sex ratio and reproduction) was also carried out. Rapid genetic variability reduction was observed in all treatments, including controls, across generations due to the test conditions. Nevertheless, an increased mutation rate determined a stronger conservation of genetic variability in PFOS and, at minor extent, in PFBS exposed populations compared to controls. No significant effects were induced by exposure to PFOA. Direct mutagenicity or induced stress conditions may be at the base of increased mutation rate, indicating the potential risk of mutational load caused by exposure to PFOS and PFBS. The test provided the opportunity to evaluate the use of approximate Bayesian computation (ABC) and coalescent approaches in evolutionary ecotoxicology. A weak performance was evidenced for ABC, either in terms of bias or dispersion of effective population sizes and of estimates of mutation rate. On the contrary, coalescent simulations proved the sensitivity of traditional genetic endpoints (i.e. heterozygosity and number of alleles) to the alteration of mutation rate, but not to erosion of genetic effective size. © 2014 Elsevier B.V. All rights reserved.

The benthic macro-invertebrate community response to tricyclazole treatments in an experimental rice paddy field was analyzed using univariate and multivariate statistical analysis. The observed community presented low species diversity, dominated by the gastropods Gyraulus albus and Physa fontinalis, the oligochaetes Branchyura sowerbyi, and the hirudinea Alboglossiphonia heteroclita. No significant effect was detected following tricyclazole treatments, while a moderate shift in community composition was observed during the sampling period, with gastropods prevailing at the end of the experiment. Multivariate classification tree analysis emphasized the importance of sampling date over tricyclazole treatments. The limited period of submersion of the rice paddy field, the low oxygen content and the high water temperatures are supposed to be the reasons of the low community diversity observed.

DDT and mercury (Hg) contamination in the Toce River (Northern Italy) was caused by a factory producing technical DDT and using a mercury-cell chlor-alkali plant. In this study, DDT and Hg contamination and bioavailability were assessed by using different approaches: (1) direct evaluation of sediment contamination, (2) assessment of bioaccumulation in native benthic invertebrates belonging to different taxonomic/functional groups, and (3) evaluation of the in situ bioavailability of DDT and Hg using passive samplers. Sampling sites were selected upstream and downstream the industrial plant along the river axis. Benthic invertebrates (Gammaridae, Heptageniidae, and Diptera) and sediments were collected in three seasons and analyzed for DDT and Hg content and the results were used to calculate the biota sediment accumulation factor (BSAF). Polyethylene passive samplers (PEs) for DDT and diffusive gradients in thin films (DGTs) for Hg were deployed in sediments to estimate the concentration of the toxicants in pore water. Analysis for (DDx) were performed using GC-MS. Accuracy was within +/- 30 % of the certified values and precision was > 20 % relative standard deviation (RSD). Total mercury concentrations were determined using an automated Hg mercury analyzer. Precision was > 5 % and accuracy was within +/- 10 % of certified values. The results of all the approaches (analysis of sediment, biota, and passive samplers) showed an increasing contamination from upstream to downstream sites. BSAF values revealed the bioavailability of both contaminants in the study sites, with values up to 49 for DDx and up to 3.1 for Hg. No correlation was found between values in sediments and the organisms. Concentrations calculated using passive samplers were correlated with values in benthic invertebrates, while no correlation was found with concentrations in sediments. Thus, direct analysis of toxicant in sediments does not provide a measurement of bioavailability. On the contrary, analysis of bioaccumulation in benthic organisms provides the most realistic picture of the site-specific bioavailability of DDx and Hg, but this approach is time-consuming and not always feasible. On the other hand, the in situ deployment of passive samplers proved to be a powerful tool, providing a good surrogate measure of bioaccumulation.

This paper reviews the scientific knowledge on the use of a lanthanum modified bentonite (LMB) to manage eutrophication in surface water. The LMB has been applied in around 200 environments worldwide and it has undergone extensive testing at laboratory, mesocosm, and whole lake scales. The available data underline a high efficiency for phosphorus binding. This efficiency can be limited by the presence of humic substances and competing oxyanions. Lanthanum concentrations detected during a LMB application are generally below acute toxicological threshold of different organisms, except in low alkalinity waters. To date there are no indications for long-term negative effects on LMB treated ecosystems, but issues related to La accumulation, increase of suspended solids and drastic resources depletion still need to be explored, in particular for sediment dwelling organisms. Application of LMB in saline waters need a careful risk evaluation due to potential lanthanum release.

Il primo contributo di questo numero è introduttivo alle tematiche di INHABIT quali: habitat, interazione tra variabilità naturale e antropica e riqualificazione, con particolare riferimento all'ambito fluviale. Uno dei principali risultati del progetto INHABIT conferma il ruolo determinante che le condizioni idrauliche (proporzione tra aree lentiche e lotiche in un fiume) rivestono nell'influenzare le comunità degli inverte-brati bentonici e, di conseguenza, la valutazione dello stato ecologico. Soprattutto in area mediterranea - ma non esclusivamente - risulta rilevante individuare i fattori di variabilità che naturalmente influenza-no la comunità biologica, differenziandoli da quelli legati allo stress antropico, al fine di poter pianifica-re adeguati interventi di misura e mitigazione. A questo proposito il presente contributo fornisce una sintesi dei principali aspetti di habitat che il progetto INHABIT ha considerato e posto in relazione alle biocenosi, distinguendoli in aspetti naturali e legati alle attività antropiche. È inoltre presentato un qua-dro di sintesi delle variabili di stato, evidenziando le connessioni tra le possibili azioni di riqualificazione e ripristino della qualità degli habitat fluviali e gli aspetti considerati nel progetto INHABIT .

Benthic macroinvertebrates samples were taken from Italian lakes with different geological, morphological and chemical characteristics. Thirty-two lowland small and large lakes sampled using a grab in soft substrate were selected to develop biotic indices. Diversity indices based on species numbers - abundances and indices using species sensitivity values were compared. The lakes selected were all situated in the Alpine Ecoregion below 800 m a.s.l. and had similar chemical composition but different levels of anthropogenic pressure. Lakes with data available in different years were included as separate lakes in the analysis; littoralsublittoral samples of large lakes were also separated from profundal samples yielding a total of 41 sites for analysis. Seven different biotic indices were compared: (1) Shannon diversity index (H), (2) weighted Shannon diversity index (Hw) including in the calculation a sensitivity value assigned to each species, (3) a benthic quality index based on means of three different environmental variables, measuring trophic status, weighted by species abundances (BQITS), (4) an index based on weighted means using a larger set of environmental variables (BQIENV), (5) a modified BQITS, which included both species numbers and total abundance of individuals (BQIES), (6) an index calculated according to a rarefaction method (ES), (7) an index considering indicator species based on experts judgment (BQIEJ). The indices were compared with a trophic status index (TSI) constructed by joining three environmental variables: O2% saturation in the hypolimnion during summer stratification, total phosphorous and transparency during full circulation. Comparisons were also made with another environmental stress index (ENI) constructed on a larger number of variables. All the biotic indices had significant correlations with both TSI and ENI. BQIES, WFD compliant and well correlated with TSI and ENI, was selected to tentatively assign the investigated lakes into 5 quality classes: high (H), good (G), moderate (M), poor (P) and bad (B). The statistical power of the classification was estimated. Assuming tentatively equal intervals for each of the five quality classes, 2 lakes were classified at high status, 7 lakes were classified as good, 13 were classified as moderate, 13 were classified as poor and 4 were classified as bad. Fifteen lakes were classified with a power less than 80%. Some of the lakes resampled in different periods displayed a shift of class in the different years. Future work should focus on extending the database to test the indices in other lake types subjected to different pressures.

(2010). The chironomids (Diptera: Chironomidae) from 108 Italian Alpine springs. SIL Proceedings, 1922-2010: Vol. 30, No. 9, pp. 1467-1470.

Chironomid larvae and pupae were studied in selected Mediterranean rivers with the aim of identifying pool and riffle taxa assemblages and of analyzing their response to ecological quality gradients. Macroinvertebrate samples were collected in 6 Italian rivers along a pool-riffle sequence in 3 seasons following a multihabitat sampling technique. Chironomids were identified as genus/species, other macroinvertebrates as family/genus. The main physico-chemical, hydromorphological and geographical data were collected. Samples were ascribed to 5 quality classes according to the STAR_ICM index. Based on Chironomid taxa, PCA axis 1 represented an organic pollution gradient, axis 2 represented seasonality. Pool and riffle samples were significantly different according to taxa assemblages. Similar results were obtained with PCA based on the whole macrobenthic community. Indicator Value analysis facilitated the detection of the Chironomid indicators of high/good quality pools (e.g. C. pallidula, R. ornata, E. ephemerae) and riffles (T. calvescens, E. gracei). The Berger-Parker dominance index based on Chironomid assemblages in pools was correlated to PCA axis 1 and performed well in discriminating between quality classes. In riffles no correlations to PCA axes were detected and a wide overlap between quality classes was present. Thus, assessment in the analyzed river type may focus on pool mesohabitat as this seems to represent best the ecological gradient of sites.

(2008). Paleolimnological techniques applied to springs habitats: Challenges and limits as highlighted by the CRENODAT project (southeastern Alps, Italy) SIL Proceedings, 1922-2010: Vol. 30, No. 3, pp. 329-332.