Coastal areas, such as bays, estuaries, and harbors, are heavily polluted since these areas are the settlements to which toxic chemicals from industrial and domestic wastes are discharged. The genetic damage was evaluated using bioindicator mussel Mytilus galloprovincialis caused by toxic chemicals (metals and polycyclic aromatic hydrocarbons) in İzmir and Çandarlı Bays (the Eastern Aegean Sea) through comet assay. Three sampling sites from the two bays were selected and the study was conducted during the spring and autumn periods. The highest levels of DNA damage expressed as %Tail-DNA were observed in İzmir Bay (34.60 % Tail-DNA) in the spring. Analysis of the correlation between PAHs and metals in mussels and %T-DNA in the hemolymph and gill cells showed a statistically significant positive correlation between %T-DNA and ∑PAH, chromium (p < 0.05). This study determined the pollution level of the İzmir and Çandarlı Bays by using the DNA damage to the mussel, which can identify the effects of environmental pollutants at the cellular levels. These results confirm that comet assay can be used to determine the temporal and spatial differences of DNA damage, and as a suitable tool for the measurement of genotoxicity in regions with low pollutant concentrations.

A culture supernatant from Micrococcus luteus containing resuscitation-promoting factor (SRpf) was used to enhance the biological nutrient removal of potentially functional bacteria. The obtained results suggest that SRpf accelerated the start-up process and significantly enhanced the biological nutrient removal in sequencing batch reactor (SBR). PO₄ ³⁻-P removal efficiency increased by over 12 % and total nitrogen removal efficiency increased by over 8 % in treatment reactor acclimated by SRpf compared with those without SRpf addition. The Illumina high-throughput sequencing analysis showed that SRpf played an essential role in shifts in the composition and diversity of bacterial community. The phyla of Proteobacteria and Actinobacteria, which were closely related to biological nutrient removal, were greatly abundant after SRpf addition. This study demonstrates that SRpf acclimation or addition might hold great potential as an efficient and cost-effective alternative for wastewater treatment plants (WWTPs) to meet more stringent operation conditions and legislations.

For humans, fish consumption is the major source of mercury (Hg) exposure. The aim of this study was to assess the effect of Hg in the peacock blenny Salaria pavo, a species of the family of blennies that was used as indicator of water pollution. We performed a sublethal contamination of fish to 66 μg HgCl₂ L⁻¹ during 1, 4, 10 and 15 days but Hg concentration measured in the experimental water was much lower than the nominal concentration. Hg was also measured in both gill and liver tissues and displays a significant increase of its concentration in gills after 1 day of exposure followed by a decrease throughout the experiment. In the liver, Hg burden reaches its maximum at day 4 followed also by a decrease. Partial-length cDNA of mt1, mt2, gpx, cat, mnsod and cuznsod was characterized. Results from mRNA expression levels displayed an up-regulation of mt1, gpx and mnsod while a downregulation of cat was observed. Several biomarker activities were determined in gills and liver and exposure to Hg affected all antioxidant enzymes in gills. EROD, GST and GPx significantly decreased, while CAT levels increased from 4 days of Hg exposure. No lipid peroxidation (LPO) induction was observed in gills of exposed fish. Regarding the liver, the activity of all enzymes increased significantly from the beginning of the experiment. LPO induction was, however, induced after 4 days only. The histological analysis also performed indicated that fish exhibited several damages in gills and liver, mainly in relation to circulatory disturbances in the gills and regressive changes in the liver. All biomarkers assessed showed that peacock blennies are able to detoxify Hg from gill and liver tissues by developing various defense mechanisms.

This work studies the efficiency of an electroflotation process for the separation of the solids produced during the electrocoagulation treatment of three different types of wastewater: kaolin suspension, coloured organic solution and oil-in-water emulsion. Additionally, a combined electrocoagulation-electroflotation reactor is designed and optimized taking into account the effect of current density, residence time, pollutant concentration and the ratio floated/settled solids. To do this, an experimental design with response surface methodology (RSM) has been used. Results show that electroflotation is a good alternative to the removal of oil microdrops and dyes, but it is not recommended for the separation of solids formed during electrocoagulation of colloid suspensions due to its high density. It has been found that the use of aluminium leads to better results than the use of iron in the treatment of oil-in-water emulsions and coloured solutions. In these cases, the use of a combined electrocoagulation-electroflotation reactor is recommended and the effect of the main inputs has been studied.

The decrease of ice cover in polar areas is expected to lead to an increase in ship traffic. In this context, the risk associated with exposure of the aquatic environment to oil-related chemicals from spills and/or accidental fuel discharges from ships will increase in the near future, potentially causing negative impacts on sensitive Arctic species. This study investigated for the first time the biomarker responses of the Icelandic scallops (Chlamys islandica) to marine diesel exposure. Antioxidant response, neurotoxic effect, gonad maturation, and lipid content were assessed in male and female scallops, Chlamys islandica after a 7-day exposure to marine diesel. At the end of exposure, results showed an inhibition of acetylcholinesterase activity in Icelandic scallops exposed to high concentration of diesel. At the end of exposure, results showed an increase in naphthalene residues in hemolymph, together with an inhibition of AChE activity in Icelandic scallops exposed to high concentration of diesel. In addition, alteration of the escape capacity was observed suggesting effects on behavior responses. Overall, this study contributes to the better knowledge of physiological effects of marine diesel in Arctic marine organisms.

Vancomycin (VCM) is an antibiotic, known medically as the deadline for defending against bacteria. In this study, the removal and fate of VCM were investigated in each treatment unit at two pharmaceutical wastewater treatment plants (PWWTPs) in eastern China. VCM was present in all wastewater and sludge samples of both PWWTPs. After the treatment procedure (the moving bed biofilm reactor technology for PWWTP1 and the modified anaerobic–anoxic–oxic technology for PWWTP2), total removal efficiencies were up to 99 %, corresponding to a reduction of two orders of magnitude of the influent concentrations in both PWWTPs. The aerobic tank dominated VCM removal. Mass balance flow analyses indicated that biodegradation (99.15 % for PWWTP1 and 99.51 % for PWWTP2) was the principle mechanism for removing VCM, while the contribution of sorption by sludge for both PWWTPs was negligible. However, the results of the environmental risk assessment of VCM in the effluents showed that the maximum trigger quotient values were much higher than 1 in both PWWTPs, indicating the non-negligible environmental and health risks. This is the first report of the fate and risks of VCM in pharmaceutical wastewater, and underscores the importance of PWWTPs as antibiotic pollution sources, even though wastewater management appeared efficient.

Human beings working or living near an industrial site where toxic chemicals such as As, Hg, Cd, Cu, Mn, Pb, Zn and or their compounds are used or indiscriminately discharged into the environment, are constantly exposed to such chemicals via ingestion (drinking or eating), dermal contact or inhalation (breathing). However, in developing countries such as Ghana, limited data on levels of the aforementioned chemicals in whole blood and serum of human beings as a result of exposure to the aforementioned chemicals from mining communities and non-mining communities is preventing effective policy formulation to protect human health. Hence, this study was undertaken to measure the levels of the aforementioned toxic chemicals in whole blood and serum of 300 resident adults from mining (Tarkwa Nsuaem Municipality Assembly (TNMA) and Prestea Huni Valley District (PHVD)) and non-mining (Cape Coast Metropolis) communities in Ghana, using neutron activation analysis (NAA). Blood samples were taken from 200 resident adults (105 males and 95 females) from mining and 100 resident adults (60 males and 40 males) from non-mining communities in the study area following the completion of an informed consent and the issuance of ethical clearance by the Ghana Health Service Ethical Committee. The mean concentrations for As, Hg, Cd, Cu, Mn, Pb and Zn in whole blood of residents from mining communities were as follows: 38 ± 320 μg/L, 63 ± 0.23 μg/L, 303 ± 117 μg/L, 3300 ± 953, 195 ± 90 μg/L, 28 ± 14 μg/L and 1405 ± 458 μg/L, respectively; while the levels of measured toxic chemicals in the serum of resident adults from mining communities were as follows: 65 ± 14 μg/L, 358 ± 22 μg/l, 134 ± 12 μg/L, 3590 ± 254 μg/L, 401 ± 113 μg/L, 58 ± 5.8 μg/L and 49 ± 31 μg/L, respectively, for As, Hg, Cd, Cu, Mn, Pb and Zn and were found to have exceeded the permissible WHO guideline values.

The relative potencies of non-ortho-substituted coplanar polychlorinated biphenyl (PCB) congeners to activate the aryl hydrocarbon receptor (AhR) and to cause the AhR-dependent toxic events are essential for their risk assessment. Since some studies suggested that abundant non-dioxin-like PCB congeners (NDL-PCBs) may alter the AhR activation by PCB mixtures and possibly cause non-additive effects, we evaluated potential suppressive effects of NDL-PCBs on AhR activation, using a series of 24 highly purified NDL-PCBs. We investigated their impact on the model AhR agonist-induced luciferase reporter gene expression in rat hepatoma cells and on induction of CYP1A1/1B1 mRNAs and deregulation of AhR-dependent cell proliferation in rat liver epithelial cells. PCBs 128, 138, and 170 significantly suppressed AhR activation (with IC₅₀ values from 1.4 to 5.6 μM), followed by PCBs 28, 47, 52, and 180; additionally, PCBs 122, 153, and 168 showed low but still significant potency to reduce luciferase activity. Detection of CYP1A1 mRNA levels in liver epithelial cells largely confirmed these results for the most abundant NDL-PCBs, whereas the other AhR-dependent events (CYP1B1 mRNA expression, induction of cell proliferation in confluent cells) were less sensitive to NDL-PCBs, thus indicating a more complex regulation of these endpoints. The present data suggest that some NDL-PCBs could modulate overall dioxin-like effects in complex mixtures.

Biochar as soil amendment can increase soil carbon (C) sequestration and mineral nutrients; however, some of its soluble elements may also be unintentionally released during the application. In this work, eight types of biochars were derived from herbaceous, woody, and waste (tailing, manure, sludge) biomass feedstocks through slow pyrolysis at 600 °C in N₂. The elemental composition, specific surface area, morphology, crystalline phases, thermal stability, surface functional groups, and pH of the point of zero charge of the biochars were determined using various methods. These properties varied significantly among the tested biochars, suggesting that feedstock type played an important role in controlling their properties. Laboratory release and toxicity characteristic leaching procedure extraction experiments were conducted to evaluate the potential release of nutritious and toxic element from biochars. Results showed that all the biochars released nutritious elements and thus, may be beneficial to plants when amended in soils. In general, biochars produced from herbaceous and woody biomass feedstocks showed low risks of releasing toxic elements. Biochar derived from sludge, however, might present ecotoxicological challenges for its environmental applications due to the release of toxic elements, such as heavy metals.

The gas-phase ammonia (NH₃) and fine particle PM₂.₅ ammonium (pNH₄ ⁺) (collectively, NHx) were monitored between July 2013 and August 2014 in a busy traffic area of Nanjing, China. Results showed that PM₂.₅ concentration was 66.7 μg m⁻³, and NH₃ concentration was 6.66 μg m⁻³. In the PM₂.₅, the concentration of pNH₄ ⁺ was 3.04 μg m⁻³, SO₄ ²⁻ (pSO₄ ²⁻) was 10.16 μg m⁻³, and NO₃ ⁻ (pNO₃ ⁻) was 1.60 μg m⁻³. The significant correlation curves from the tests of PM₂.₅ revealed that molar ratio of pNH₄ ⁺ and pSO₄ ²⁻ was approximately 2, which could be (NH₄)₂SO₄. Particulate NH₄ ⁺ primarily associated with pSO₄ ²⁻, which accounted for 4.54 % of total PM₂.₅ mass. The PM₂.₅ observed acidic and the NH₃ in the atmosphere neutralized acidic species, mainly in a sulfate form. The traffic intensity in the region was partially related to the formation of PM₂.₅ and NH₃, suggesting that traffic pollution may be an important source of PM₂.₅. The reaction between NHx and acidic species was assumed to the secondary PM₂.₅. The neutralization and photochemical property of NHx were discussed.