Long-term persistence of sedimentary copper contamination in Lake Orta: potential environmental risks 20 years after liming

Lake Orta, northern Italy, has suffered from severe copper pollution and human-induced acidification between the 1920s and the 1990s because of discharges from a rayon factory and electroplating industries located in its water basin. Following liming operations in the late 1990s, the chemical quality of the water column has been restored and signs of, still ongoing, biological recovery observed. Examination of two sediment cores collected close to the main historical Cu discharge and in the central part of the Lake shows that Cu concentrations in the uppermost layers of bottom sediments remain 10 to 40-fold higher than background levels. Past studies demonstrated the toxic potential of Lake Orta sediments to a variety of organisms at Cu concentrations comparable to present ones. Comparison with published results suggests that current level of Cu contamination may still pose a risk to sediment-ingesting organisms and slow down further ecological recovery of Lake Orta. Particular attention should be given to understand the effects of dietary ingestion of Cu from sediments which, unlike in previous ecotoxicological studies, may now represent the main route of Cu exposure for sediment-ingesting benthic organisms

Inhibition of Larval Development of Marine Copepods Acartia tonsa by Neonocotinoids

Neonicotinoids (NEOs) are neurotoxic pesticides widely used in agriculture due to their high effectiveness against pest insects. Despite their widespread use, very little is known about their toxicity towards marine organisms, including sensitive and ecologically relevant taxa such as copepods. Thus, we investigated the toxicity of five widely used NEOs, including acetamiprid (ACE), clothianidin (CLO), imidacloprid (IMI), thiacloprid (THI), and thiamethoxam (TMX), to assess their ability to inhibit the larval development of the copepod Acartia tonsa. The more toxic NEOs were ACE (EC50 = 0.73 μg L−1), TMX (EC50 = 1.71 μg L−1) and CLO (EC50 = 1.90 μg L−1), while the less toxic compound was IMI (EC50 = 8.84 μg L−1). Early life-stage mortality was unaffected by NEOs at all of the tested concentrations. The calculated toxicity data indicated that significant effects due to ACE (EC20 = 0.12 μg L−1), THI (EC20 = 0.88 μg L−1) and TMX (EC20 = 0.18 μg L−1) are observed at concentrations lower than established chronic aquatic life benchmarks reported by USEPA for freshwater invertebrates. Nevertheless, since environmental concentrations of NEOs are generally lower than the threshold concentrations we calculated for A. tonsa, the effects may be currently of concern only in estuaries receiving wastewater discharges or experiencing intense runoff from agricultur

Ecological effects of multiple stressors on a deep lake (Lago Maggiore, Italy) integrating neo and palaeolimnological approaches

To understand interactions of lake physical characteristics, trophic dynamics and climate in Lago Maggiore, we compare longterm limnological and meteorological monitoring data and results from sediment cores. We include analyses of nutrients, pigments, diatoms and cladoceran microfossils. Over the past decades, caloric content increased. Eutrophication from the 1960s to early 1980s was followed by oligotrophication. DDTs, PCBs and Hg showed high contamination in the \u2760s, compared to point source inputs in the \u2790s. Algal biomass was predicted by total pigments and some algal specific carotenoids. Following nutrient enrichment, Chydorus sphaericus, and total abundance of cladocerans changed inversely with trophic status. Fewer large Daphnia since the late \u2780s matched an increase in with subfossil Eubosmina mucro lengths. Both were explained by the 10-fold increase in Bythotrephes longimanus from 1987 to 1993, when an increase of its mean annual population density occurred during warmer winter and springs. Bythotrephes remained abundant and further increased during the following 10 years as water temperature increased. We conclude that warmer water affects food chains indirectly by changing habitat use and predator-prey interactions. Relative abundances of Daphnia and its peak population density in the warm year of the oligotrophic period (2003) were close to the record from the mesotrophic period in 1982, supporting the hypothesis that warming can produce a eutrophication-like signal. The study illustrates the complexity of biological responses to synchronous changes in multiple drivers (e.g., eutrophication, fish introduction, ban of fish harvesting, chemical pollution, and climate) and, despite this complexity, how Lago Maggiore responded to multiple stressors

1079-102 Correlation between norepinephrine and epinephrine myocardial spillover and tumor necrosis factor-alpha in conventional versus off-pump coronary artery bypass surgery

Background: Complete revascularization obtained by coronary artery bypass surgery does not prevent long term left ventricular remodeling and heart failure development. Periprocedural events linked to different surgical techniques, such as cardiopulmonary bypass with cardioplegic arrest (CABG) versus off-pump procedures may trigger an irreversible microvascular dysfunction or myocytes necrosis and apoptosis. Methods: To test this hypothesis we measured norepinephrine and epinephrine coronary sinus and aortic spillover before and after surgery, simultaneously with Tumor Necrosis Factor-alpha (TNF-alpha) measurements in 30 patients randomized to CABG (n=15), or off-pump (n=15) coronary surgery. Plasma catecholamines were assessed by high performance liquid chromatography and TNF-alpha by ELISA. Results: Norepinephrine and epinephrine spillover was similar in the two groups before surgery, being 1.38\ub10.62 and 1.08\ub10.45, respectively. After surgery norepinephrine spillover was 1.43\ub10.56, 0.72\ub10.49 in CABG and off-pump, respectively (P<0.05 CABG versus off-pump, means \ub1SD ). Epinephrine spillover was 1.27\ub10.16 and 0.65\ub10.15 respectively (P<0.05, CABG versus off-pump). TNF-alpha significantly increased only in CABG patients being 22.17\ub16.79 and 35.4\ub15.98, pg/mL, before and after surgery (P<0.05), respectively. After surgery norepinephrine spillover correlated with TNF-alpha levels (P=0.01, R=0.553). Conclusions: Patients undergoing off-pump interventions showed significantly lower catecholamines spillover as compared to CABG, suggesting that the off-pump technique may result less invasive, not only for a lower local and whole body inflammatory response but also for a lower sympathetic drive. For the first time in humans we have detected an increase in epinephrine-spillover after cardiac surgery. Further studies are necessary to evaluate if the short-term advantages observed after off-pump coronary surgery translate into a long-term attenuation of left ventricular remodeling and in the prevention of heart failure progression

Impacts of exhaust gas cleaning systems (EGCS) discharge waters on planktonic biological indicators

Exhaust Gas Cleaning Systems (EGCS), operating in open-loop mode, continuously release acidic effluents (scrubber waters) to marine waters. Furthermore, scrubber waters contain high concentrations of metals, polycyclic aromatic hydrocarbons (PAHs), and alkylated PAHs, potentially affecting the plankton in the receiving waters. Toxicity tests evidenced significant impairments in planktonic indicators after acute, early-life stage, and long-term exposures to scrubber water produced by a vessel operating with high sulphur fuel. Acute effects on bacterial bioluminescence (Aliivibrio fischeri), algal growth (Phaeodactylum tricornutum, Dunaliella tertiolecta), and copepod survival (Acartia tonsa) were evident at 10 % and 20 % scrubber water, while larval development in mussels (Mytilus galloprovincialis) showed a 50 % reduction at ∼5 % scrubber water. Conversely, larval development and reproductive success of A. tonsa were severely affected at scrubber water concentrations ≤1.1 %, indicating the risk of severe impacts on copepod populations which in turn may result in impairment of the whole food web