Arsenic toxicity becomes one of the major public health issues in several countries. Chronic and acute exposure to arsenic has been reported to be toxic to various systems of the human body and also observed in controlled experimental studies. The study was conducted to evaluate the neurotoxic effect of arsenic in Swiss albino mice and its amelioration by Vitamin E, Coenzyme Q10 and their combination. Swiss albino mice were treated with arsenic of 136 ppm for 15 days. The daily dose is 1/3 of LD 50 (acute) reported dose of arsenic. Thereafter, the animals were maintained either on drinking water or treated with Vitamin E (50 mg/kg bwt), Coenzyme Q10 (10 mg/kg bwt), and their combination by i.p.daily for 15 days. After the treatment, animals were sacrificed. The weight of the brain was marginally lower (ns), in arsenic-treated group as compared to control and antioxidant-protected groups. The LPO (lipid peroxidation) level was higher in arsenic-treated group, and this elevation was checked to some extent by the selected antioxidants which were statistically significant in combination of antioxidant-protected group. A significant reduction was found in GSH (reduced glutathione) level in the brain of arsenic-treated mice whereas GSH level was considerably higher in antioxidant-protected groups. Further, total thiol and total protein level were lower in arsenic-treated group. However, total thiol was significantly higher in antioxidant-protected groups. CAT (catalase) activity was significantly lower while SOD (superoxide dismutase) activity was marginally lowered in arsenic-treated group, and it was slightly higher in antioxidant-protected groups. Further, reduction in AChE (acetylcholinesterase) and BChE (butyrylcholinesterase) and motor coordination activity were also observed in arsenic-treated groups. Whereas, a higher AChE, BChE, and motor coordination activity was observed in antioxidant-protected group. These data indicate a positive role of selected antioxidant against the toxicity of arsenic in the brain of mice.

In dairy farming, recirculation and continuous use of nutrients are necessary for sustainable nutrient management in both the short- and long-term. When managed effectively, nutrient recycling can improve soil fertility. On the other hand, if applied nutrients are in excess of the soil’s nutrient holding capacity, nutrients can enter surface and ground water bodies resulting in eutrophication. Phosphorus (P) characterisation in manure, pond sludge and crust, in terms of plant availability, is the first step to sustainably manage nutrients within dairy farms. In this study, pond sludge and crust were characterised for P using a sequential fractionation method. Pond sludge and crust contained significant amounts of labile P. Water extractable P (H₂O-P) in primary anaerobic pond and secondary facultative pond sludges was found to be about 8 to 13 times higher than the amount found in the surface soil (0–10 cm) of a grazing paddock. Similarly, sodium bicarbonate extractable P (NaHCO₃-P) in the two types of sludges was found to be about 6 times higher than in the soil. The relatively higher labile P (H₂O-P and NaHCO₃-P) in sludge compared to soil indicates that the sludge can be utilised as a P fertilizer on grazing pasture. In contrast, lower H₂O-P compared to that of raw manure indicates that the use of sludge and crust instead of raw manure can reduce the possibility of P loss by surface runoff and leaching. Hence, it is preferable to use pond sludge and crust as fertiliser instead of raw manure.

Nontuberculous mycobacteria (NTM) are widely distributed in the environment. On one hand, they are opportunistic pathogens for humans and animals, and on the other hand, they are effective in biodegradation of some persistent pollutants. Following the recently recorded large abundance of NTM in extreme geothermal environments, the aim of the study was to ascertain the occurrence of NTM in the extreme environment of the water zone of the Hranice Abyss (HA). The HA mineral water is acidic, with large concentrations of free CO₂, and bacterial slimes creating characteristic mucilaginous formations. Both culture and molecular methods were used to compare the mycobacterial diversity across the linked but distinct ecosystems of HA and the adjacent Zbrašov Aragonite Caves (ZAC) with consideration of their pathogenic relevance. Six slowly growing NTM species (M. arupense, M. avium, M. florentinum, M. gordonae, M. intracellulare) and two rapidly growing NTM species (M. mucogenicum, M. sediminis) were identified in the water and in the dry zones at both sites. Proteobacteria were dominant in all the samples from both the HA and the ZAC. The bacterial microbiomes of the HA mineral water and HA slime were similar, but both differed from the microbiome in the ZAC mineral water. Actinobacteria, a phylum containing mycobacteria, was identified in all the samples at low proportional abundance. The majority of the detected NTM species belong among environmental opportunistic pathogens.

Copper accumulation in the gill, liver, kidney, spleen, and muscle tissues of Oreochromis niloticus was determined after exposing the fish to 10, 50, and 100 μg Cu/L applied as copper sulphate (CuSO₄) and copper oxide nanoparticles (CuO NPs) after 1, 7, and 15 days. Changes in the liver SOD, CAT, and GPx activities influenced by this accumulation were also studied. No mortality was observed during the experiments. Copper levels increased in the gill, liver, kidney, and spleen tissues of O. niloticus compared to control when exposed to both CuSO₄ and CuO NPs, whereas no accumulation was detected in muscle tissue at the end of the exposure period. Highest accumulation of copper was observed in the order of the liver, kidney, spleen, and gill tissues, respectively. SOD, CAT, and GPx activities increased in the liver tissue at the end of the exposure period. Overall, CuO NPs are more effective than CuSO₄ in terms of tissue accumulation and liver enzyme activities.

The degradation of two sulfonylurea herbicides, nicosulfuron and thifensulfuron methyl in water by chlorine dioxide, was studied for the first time in this paper. In order to examine the optimal parameters for degradation of both herbicides, degradation was investigated under light or dark conditions with different amount of chlorine dioxide, different degradation periods, and at different pH values. Degradation efficiency of herbicides was monitored using high-performance liquid chromatography with photodiode array detection (HPLC-DAD). The degradation products were analyzed by gas chromatography with triple quadrupole mass detector (GC–QQQ). Three products were identified after degradation of nicosulfuron and two products after degradation of thifensulfuron methyl. Total organic analysis (TOC) gave insight into some differences in degradation mechanisms and degrees of mineralization after degradation of the herbicides using chlorine dioxide. A simple mechanism of herbicide degradation was proposed. Acute toxicity tests were performed on the products produced after degradation with chlorine dioxide, and the results showed that the degradation products were less toxic than the parent compounds. The findings of the present study are very useful for the treatment of wastewaters contaminated with herbicides.

Diatom analysis was undertaken on a 200-year sediment record in an alpine lake (Popradské pleso, Tatra Mountains, Central Europe). Due to its remote character and well-documented human influence since the mid-nineteenth century, it allows a study of the relationship between anthropogenic pressures and diatom assemblages. Altogether, 122 diatom taxa of 40 genera were identified, and two major taxonomic shifts were revealed in the stratigraphic record. The timing of the first significant shift in ~ 1850 precludes the possibility of being caused by direct human activities, since according to historic documents there was neither continuous human presence nor grazing in the valley before that time. In addition, the direct effect of organic pollution early in the 1960s connected with the operation of a tourist hotel was not clearly reflected in the diatom signal. The diatom-inferred total phosphorus (DI-TP) reconstruction indicated the highest TP content well before the most direct wastewater pollution from a newly built hotel. There was a considerable effect of climate to diatom assemblage structure as well as diatom life forms. Our results suggest that direct organic pollution influenced the diatom communities less than expected, and the main driver of change was climate warming. We hypothesize that it is because of the short residence time of the lake, since it has both strong inlet and outlet, and it has been showed that the inlet had significant effect on benthic communities in the past. At the same time, fish manipulation could have been the reason for some fluctuation in DI-TP unrelated to climate and organic pollution.

Benzene-tolerant phyllosphere microorganisms isolated from Dracaena sanderiana were identified as Pantoea sp. B11 and Staphylococcus sp. B12. Inoculating D. sanderiana with these microorganisms growing under 70 and 348 mg/m³ of airborne benzene showed a higher benzene removal efficiency than D. sanderiana without inoculation. Under 348 mg/m³ of benzene, inoculating D. sanderiana with Staphylococcus sp. B12 can remove benzene higher than inoculating D. sanderiana with Pantoea sp. B11 and co-culture between Staphylococcus sp. B12 and Pantoea sp. B11. In addition, individual Staphylococcus sp. B12 had higher ability to bio-remediate benzene than individual Pantoea sp. B11 and co-culture. Staphylococcus sp. B12 can also produce high indole-3-acetic acid (IAA) and harbor 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, which can protect plant from the stress. Photosystem II activity and chlorophyll content of D. sanderiana were decreased clearly under exposure with a 348 mg/m³ of benzene. Inoculating D. sanderiana with Staphylococcus sp. B12 had significantly higher photosystem II activity and chlorophyll content than inoculating D. sanderiana with Pantoea sp. B11 and co-cultures. In co-culture inoculation, Pantoea sp. B11 inhibited growth of Staphylococcus sp. B12, which can probably decrease benzene removal efficiency. Application of Staphylococcus sp. B12 can enhance benzene phytoremediation efficiency in D. sanderiana and protect plant from benzene stress.

This study investigated the water pollution impact of mine drainage from an underground colliery that had stopped mining 3 years earlier. After more than a century of operation, the mining stopped, pumping ceased and groundwater accumulated, causing the flooding of the deepest sections (c. 15%) of the mine workings. The mine then began free-draining to the adjacent Wingecarribee River. The closure and flooding triggered acid mine drainage that has resulted in mildly acidic pH and higher concentrations of several metals. Of greatest environmental concern were ecologically hazardous concentrations of three metals: nickel (418 μg/L), zinc (1161 μg/L) and manganese (11,909 μg/L) in the mine drainage. Such concentrations are some of the highest concentrations reported for these metals in drainage from an Australian coal mine and are 2.5 to seven times higher than when the mine was operating. The concentration of nickel and manganese were stable, but zinc gradually declined throughout the 13-month study. The inflow of the drainage increased the concentration of the three metals in the river, causing exceedance of water quality guidelines for protection of aquatic species. The ecological impact of the mine drainage was substantial, causing a 63% reduction in family richness and a 90% reduction in proportion of invertebrates from the known pollution-sensitive orders (Ephemeroptera, Plecoptera and Trichoptera). Literature suggests the pollution could continue for decades. Of additional concern is that the mine drainage is currently untreated and pollutes a river in the water catchment of Australia’s largest domestic water supply reservoir.

Effluents containing phosphorous as phosphate ions are frequently discharged in freshwater resources contributing to the eutrophication and directly interfering in the biological equilibrium. Clam shell residues and sewage sludge were combined for preparing efficient adsorbents for phosphate removal from aqueous medium. The adsorbents were characterized before and after adsorption testing, and the adsorption equilibrium and kinetics were investigated. Phosphate removal of 89 ± 1% was attained for samples prepared with 0.1 < X < 1.0, where X corresponds to sewage sludge/clam shell mass ratio. The analyses of the experimental errors indicated that the phosphorous removal followed the Elovich kinetic model, which describes adsorption in very heterogeneous surfaces. On the other hand, the best modelling was achieved using the Koble–Corrigan isotherm model, which incorporate different aspects of both Langmuir and Freundlich isotherms to represent the equilibrium data. The observed adsorption capacity (21.4 mgP g⁻¹) are comparable or greater to that observed for other adsorbents described in the literature.