Climate projections over the next century include disproportionately warmer nighttime temperatures (“asymmetrical warming”). Cool nighttime temperatures lower metabolic rates of aquatic ectotherms. In contaminated waters, areas with cool nights may provide thermal refugia from high rates of daytime contaminant uptake. We exposed Cope's gray tree frogs (Hyla chrysoscelis), southern leopard frogs (Lithobates sphenocephalus), and spotted salamanders (Ambystoma maculatum) to five concentrations of a mixture of cadmium, copper, and lead under three to four temperature regimes, representing asymmetrical warming. At concentrations with intermediate toxicosis at test termination (96 h), temperature effects on acute toxicity or escape distance were evident in all study species. Asymmetrical warming (day:night, 22:20 °C; 22:22 °C) doubled or tripled mortality relative to overall cooler temperatures (20:20 °C) or cool nights (22:18 °C). Escape distances were 40–70% shorter under asymmetrical warming. Results suggest potentially grave ecological impacts from unexpected toxicosis under climate change.

Bioinvasions are a major cause of biodiversity and ecosystem changes. The rapid range expansion of the invasive quagga mussel (Dreissena rostriformis bugensis) causing a dominance shift from zebra mussels (Dreissena polymorpha) to quagga mussels, may alter the risk of secondary poisoning to predators. Mussel samples were collected from various water bodies in the Netherlands, divided into size classes, and analysed for metal concentrations. Concentrations of nickel and copper in quagga mussels were significantly lower than in zebra mussels overall. In lakes, quagga mussels contained significantly higher concentrations of aluminium, iron and lead yet significantly lower concentrations of zinc66, cadmium111, copper, nickel, cobalt and molybdenum than zebra mussels. In the river water type quagga mussel soft tissues contained significantly lower concentrations of zinc66. Our results suggest that a dominance shift from zebra to quagga mussels may reduce metal exposure of predator species.

Lead contamination remains a persistent global environmental problem, the hazards of which are often difficult to identify without specific and targeted research. This study examines environmental contamination arising from the widespread use of lead solder in the joints of large gravity water supply pipelines. Contamination of adjacent grazing lands and subsequent poisoning of domestic livestock are evaluated. In particular, the study demonstrates that replacement of lead joints along an above ground 70 km water supply pipeline in central New South Wales (NSW), Australia, has caused soil lead contamination of up to 20,600 mg/kg. Contamination either side of the pipeline corridor extends to ∼10 m before surface soil lead values correspond more closely to natural background concentrations of 26 mg/kg. The estimated total volume of contaminated soil requiring remediation is 21,000 m³. Contamination is linked to toxicity and mortality in several farm animals and to elevated contamination of grass fodder (up to 50 mg/kg of lead) close to the pipeline. Other similar large-scale above ground reticulation systems in the Sydney (NSW) Metropolitan region and adjacent to the 560 km long Kalgoorlie (Western Australia) Golden Pipeline are shown to present similar environmental hazards. The use of lead solder joints in other international large scale reticulation networks are also identified, demonstrating that this specific anthropogenic hazard is likely to be a more global problem, which has not has been detailed in the research literature to any significant extent.

In the present study, changes in erythrocyte rheology in association with mercury toxicity and the role of propolis were analyzed in rats. Forty male Wistar Albino rats that were 4–5 months old were used in the study. The control group was administered normal saline intraperitoneal (ip) injections; the mercury chloride group was administered HgCl₂ (4 mg/kg, ip); the propolis group was administered propolis (200 mg/kg, by gavage); and the HgCl₂+ propolis group was administered HgCl₂ (4 mg/kg, ip) + propolis (200 mg/kg, by gavage) for 3 days. The following parameters were analyzed: hematological parameters, plasma potassium (K) levels, methemoglobin, 2,3-DPG, erythrocyte deformability, and hemolysis as a percentage. The results revealed that leukocyte count significantly increased, and a significant decline occurred in the platelet count (p < 0.01). Serum K⁺, MetHb, 2, 3-DPG, and hemolysis percentage significantly increased in the rats exposed to mercury (p < 0.01). However, the values of rats administered only with propolis were close to the values of the control group and the changes were avoided by the administration of propolis as protection in the rats exposed to mercury chloride.

Spirulina platensis (SP) is one of the most commonly used dietary supplements in human and many animal species, including fish. Recently, it has gained more attention in fish not only for its growth-promoting and immunomodulatory effects but also for its antioxidant potential. The present study was conducted to investigate the protective role of two different dietary levels of SP on freshwater Nile tilapia; Oreochromis niloticus exposed to subacute deltamethrin (DLM) intoxication. Spirulina was supplemented at levels of 0.5 and 1 % in the diet along with DLM at a concentration of 1.46 μg/l for 28 days. Serum biochemical parameters, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total protein, albumin, cholesterol, urea, uric acid and creatinine, were estimated. In addition, the level of malondialdehyde (MDA) was analysed as a lipid peroxidation marker. Reduced glutathione (GSH) content and glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) activities were analysed as antioxidant biomarkers in liver, kidney and gills. The results revealed that DLM intoxication increased serum AST, ALT, ALP, cholesterol, urea, uric acid, creatinine and tissue MDA, while decreased serum total protein and albumin as well as tissue GSH level and GSH-Px, SOD and CAT activities. SP supplementation at the two tested levels enhanced all altered serum biochemical parameters as well as tissue lipid peroxidation and antioxidant biomarkers. Therefore, it could be concluded that SP administration could minimize DLM-induced toxic effects by its free radical scavenging and potent antioxidant activity.

The neurological damages resulted by endosulfan poisoning is not completely elucidated, especially in cellular organelles such as mitochondria. In the present study, the pro-oxidant effect of endosulfan on brain mitochondria was first investigated. Gavages of endosulfan into rats at the dose of 2 mg/kg induced oxidative stress in this organelle since it provokes a significant reduction of catalase (CAT), superoxide dismutase (SOD), and glutathione (GSH) level. In addition, a significant increase in mitochondria swelling and malondialdehyde (MDA) levels were observed in neuronal mitochondria, indicating clearly an intense peroxidation within mitochondria. Second, the protective effect of quercetin (QE) (10 mg/kg) against endosulfan-induced oxidative stress in mitochondria was also assessed. Indeed, the pretreatment of rats with QE protects brain mitochondria from oxidative stress, lipid peroxidation, and mitochondria swelling induced by endosulfan. The activities of antioxidant enzymes and the mitochondrial content of GSH and MDA were returned to control values. Thus, although endosulfan can have neurotoxic effects in brain rats, this toxicity can be prevented by quercetin.

Arsenic poisoning due to contaminated subsoil water is one of the most alarming environment hazards in West Bengal, India. Cattle are also affected by arsenic due to ingestion of arsenic contaminated water, paddy straw, crops and vegetables. Thirty milch cattle having arsenic content in the range of 3.5 to 4.5 mg/kg in hair were chosen for this experiment from cattle of five respective villages in Nadia District, West Bengal, India. The cattle were divided into three groups containing 10 animals each. Group I cattle were treated with turmeric powder (Curcuma longa) 20 g/day orally for 60 days. Group II cattle were treated with turmeric powder (10 g/day) and Amaranthus spinosus powder (10 g/day) orally for 60 days. Group III cattle were treated with turmeric powder (10 g/day) and Eclipta alba powder (10 g/day) orally for 60 days. Ten apparently healthy milch cows with no history of exposure to arsenic were selected and kept as control group (group IV). Arsenic content in hair, faeces, urine and milk; different biochemical and haematological parameters and DNA fragmentation percentage assay were carried out before commencement of the treatment, after 30 days and after 60 days of treatment. The test drugs were found significantly (p < 0.05) effective to eliminate arsenic from the body and lead to significant improvement in different biochemistry, pathology and DNA fragmentation assay. These drugs also give protection from possible damage caused by arsenic exposure.

We reported previously that okadaic acid (OA) and dinophysistoxin-1 (DTX1) were responsible for diarrhetic shellfish poisoning (DSP) incidents due to consuming cultivated mussels (Mytilus galloprovincialis) in coastal cities near the East China Sea in May 2011. Pectenotoxin-2 (PTX2) and its seco acids were also present in these mussels. Causative species of microalgae were not identified because detailed information on the location of the contaminated shellfish was not recorded. In order to explore potential causes for these poisoning events, the lipophilic toxin profiles in picked cells of Dinophysis and in shellfish samples collected from two mariculture zones in the East China Sea were analyzed in the present study. Single-cell isolates (100 cells total for each location) of Dinophysis were collected from the aquaculture zones of Gouqi Island (Ningbo City, Zhejiang Province) and Qingchuan Bay (Ningde City, Fujian Province) in July and September 2013, respectively, for lipophilic toxin profiling. Shellfish samples collected over the course of a year from the Gouqi Island aquaculture zone and mussels (M. galloprovincialis) collected four times from the Qingchuan Bay aquaculture zone were tested for lipophilic toxins by LC-MS/MS. The Dinophysis cells isolated from both sampling sites were identified under the light microscope as Dinophysis caudata. Average quota of PTX2, the predominant toxin in D. caudata isolated from the coastal waters of Gouqi Island and Qingchuan Bay, was 0.58 and 2.8 pg/cell, respectively. Only trace amounts of OA and DTX1 were detected in D. caudata. PTX2, PTX2sa, 7-epi-PTX2sa, OA, and/or DTX1 were found in samples of mussels (M. galloprovincialis and Mytilus coruscus) collected in the Gouqi Island aquaculture zone from the end of May to the beginning of July 2013. PTX2, PTX2sa, and 7-epi-PTX2sa were also detected in oyster (Crassostrea gigas) during that period, but almost no OA and DTX1 were present. Gymnodimine (GYM) was detected in almost all mussel (M. coruscus) samples, with the highest levels occurring in winter. Trace amounts of pectenotoxins (PTXs) and OAs were also found in mussels (M. galloprovincialis) collected from Qingchuan Bay. D. caudata is suggested as an important source of PTXs in shellfish cultivated in the East China Sea. This is the first report of toxin profiles for single-cell isolates of Dinophysis in the East China Sea.

The aim of this study was to evaluate the concentrations of Pb, Cu, Zn, Rb, Cs, Sr and Ba in the muscles of red deer that were hunted in two regions of Poland (south-western and north-eastern). The data obtained were evaluated with regards to benefits and potential risk to consumers’ health. Samples for the investigations were collected in 2008 and 2009 from 50 female red deer, and the metal concentrations were determined by using the inductively coupled plasma–mass spectrometric (ICP-MS) method. The mean concentrations of Pb did not differ statistically between regions and were equal to that permitted for farm animals. The results of this study support the conclusion that the meat of the analysed animals does not pose a risk of lead intoxication. Statistically higher mean concentrations of Cu and Zn were found in the muscles of red deer from the south-western region (namely, 2.99 and 25.78 mg kg⁻¹) than those in animals from north-eastern Poland (namely, 2.61 and 23.39 mg kg⁻¹ wet weight). In terms of human nutritional needs, the meat of red deer can be considered as a good source of Cu and Zn. Furthermore, Rb, Cs, Sr and Ba concentrations did not differ statistically between regions. Their mean concentrations were 4.50, 0.09, 0.16 and 0.31 mg kg⁻¹ wet weight, respectively. Although high Cs, Sr and Ba concentrations were found, the meat of red deer does not pose a risk for adult consumers. Only high Ba content may potentially result in negative health effects for children.