The intensive use of benzotriazoles as corrosion inhibitors for various applications and their application in dishwasher detergents result in an almost omnipresence of benzotriazole (BTri), 4-methyl- and 5-methyl-benzotriazole (4-TTri and 5-TTri, respectively) in aquatic systems. This study aims on the evaluation of the biodegradation potential of activated sludge communities (ASCs) toward the three benzotriazoles regarding aerobic, anoxic, and anaerobic conditions and different nutrients. ASCs were taken from three wastewater treatment plants with different technologies, namely, a membrane bioreactor (MBR-MH), a conventional activated sludge plant CAS-E (intermittent nitrification/denitrification), and CAS-M (two-stage activated sludge treatment) and used for inoculation of biodegradation setups. All ASCs eliminated up to 30 mg L⁻¹5-TTri and BTri under aerobic conditions within 2–7 and 21–49 days, respectively, but not under anoxic or anaerobic conditions. 4-TTri was refractory at all conditions tested. Significant differences were observed for BTri biodegradation with non-acclimated ASCs from MBR-MH with 21 days, CAS-E with 41 days, and CAS-M with 49 days. Acclimated ASCs removed BTri within 7 days. Furthermore, different carbon and nitrogen concentrations revealed that nitrogen was implicitly required for biodegradation while carbon showed no such effect. The fastest biodegradation occurred for 5-TTri with no need for acclimatization, followed by BTri. BTri showed sludge-specific biodegradation patterns, but, after sludge acclimation, was removed with the same pattern, regardless of the sludge used. Under anaerobic conditions in the presence of different electron acceptors, none of the three compounds showed biological removal. Thus, presumably, aerobic biodegradation is the major removal mechanism in aquatic systems.

An approach to establish a soil environmental assessment model was proposed to evaluate the soil environmental quality level. The kriging technique and a self-organizing map (SOM) were integrated to investigate the soil environmental quality in a geographic information system (GIS). In this study, SOM was applied to categorize the data set of nine heavy metals in topsoil. A total of 261 topsoil samples were collected to determine the concentrations of Cu, Pb, Zn, Cd, Ni, Cr, Hg, As, and Mn. The samples were clustered into three classes by SOM and visualized by GIS. The results show that different environmental quality categories are significantly different and that the soil environmental quality assessment model is effective.

The present work describes the application of an analytical procedure, utilizing ultra performance liquid chromatography (UPLC) coupled with mass spectrometry instrumentation, for the determination of 253 multiclass pesticides, classified in six different groups. Solid phase extraction was applied for the isolation and pre-concentration of target compounds in water samples. Surface waters of the lakes located in Northern Greece (Volvi, Doirani, and Kerkini), were collected in two time periods (fall/winter 2010 and spring/summer 2011) and analyzed, applying the developed analytical methods. Spatial distribution of detected pesticides was visualized using interpolation methods and geographical information systems (GIS). Pesticides with maximum concentrations were amitrole, propoxur, simazine, chlorpyrifos, carbendazim, triazophos, disulfoton-sulfone, pyridaben, sebuthylazine, terbuthylazine, atrazine, atrazine-desethyl, bensulfuron-methyl, metobromuron, metribuzin, rotenone, pyriproxyfen, and rimsulfuron. In Lake Kerkini, mainly carbamates and triazines were determined at elevated concentrations, near the coastal point of the NW side of the lake. Seasonal variations were strong among the applied pesticide classes and determined concentrations, indicating the contribution of pesticide application patterns and rainfall. Lake Doirani exhibited organophosphate pesticides at higher concentrations mainly at coastal points, while triazines emerged as the main pollutant during spring sampling. Lake Volvi exhibited the highest pesticide concentrations, mostly triazines and ureas at the central part of the lake. The occurrence of extreme values and nonconstant seasonal variations indicated that the concentrations were increased disproportionately during the second sampling, as a result of the varying contribution of pollution sources right after the application period. In all cases, the total concentration of pesticides increased during the second sampling period.

The potential influence of autochthonous microorganisms on virus fate in soil is usually determined through extreme conditions of sterilization vs. nonsterilization; however, the relative importance of microbial cells and their exudates remains unclear. In this study, bacterial cells (cell) were harvested, and their exuded extracellular polymeric substances (EPS) were extracted from three strains of bacteria, namely, Gram-negative bacteria Pseudomonas putida and Pseudomonas aeruginosa as well as Gram-positive bacterium Bacillus subtilis. This study aimed to evaluate virus removal in solutions in the presence of cell, EPS, and their combination (cell/EPS), as well as to investigate how their presence affects virus removal efficiencies by four red soils based on batch experiments. Results showed that virus removal percentage in solutions ranged from 11 to 23 in the presence of cells only and from 12 to 15 in the presence of EPS only. The removal percentage in the combined cell/EPS treatment can be estimated by summing the results achieved by the cell and EPS treatments, separately. Meanwhile, cell presence had a negligible effect on virus removal by red soils. EPS and combined cell/EPS significantly reduced virus removal by 20 to 69 % and 16 to 50 %, respectively, which indicated that EPS served a dominant function in reducing virus removal. This study clearly demonstrated that the prediction of virus removal by red soils must consider the effect of bacteria, especially those producing large quantities of EPS, which can be responsible for the underestimation of viral load in certain studies.

In the present work, we investigated the use of nano-metallic calcium (Ca) and calcium oxide (CaO) dispersion mixture for the simultaneous remediation of contaminated soils with both heavy metals (As, Cd, Cr, and Pb) and polychlorinated biphenyls (PCBs). Regardless of soil moisture content, nano-metallic Ca/CaO dispersion mixture achieved about 95–99 % of heavy metal immobilization by a simple grinding process. During the same treatment, reasonable PCB hydrodechlorination efficiencies were obtained (up to 97 %), though higher hydrodechlorination efficiency by preliminary drying of soil was observed.

This in vitro study investigates the impact of silica-coated magnetite particles (Fe₃O₄@SiO₂/SiDTC, hereafter called IONP; 2.5 mg L⁻¹) and its interference with co-exposure to persistent contaminant (mercury, Hg; 50 μg L⁻¹) during 0, 2, 4, 8, 16, 24, 48, and 72 h on European eel (Anguilla anguilla) brain and evaluates the significance of the glutathione (GSH) redox system in this context. The extent of damage (membrane lipid peroxidation, measured as thiobarbituric acid reactive substances, TBARS; protein oxidation, measured as reactive carbonyls, RCs) decreased with increasing period of exposure to IONP or IONP + Hg which was accompanied with differential responses of glutathione redox system major components (glutathione reductase, GR; glutathione peroxidase, GPX; total GSH, TGSH). The occurrence of antagonism between IONP and Hg impacts was evident at late hour (72 h), where significantly decreased TBARS and RC levels and GR and glutathione sulfo-transferase (GST) activity imply the positive effect of IONP + Hg concomitant exposure against Hg-accrued negative impacts [vs. early (2 h) hour of exposure]. A period of exposure-dependent IONP alone and IONP + Hg joint exposure-accrued impact was perceptible. Additionally, increased susceptibility of the GSH redox system to increased period of exposure to Hg was depicted, where insufficiency of elevated GR for the maintenance of TGSH required for membrane lipid and cellular protein protection was displayed. Overall, a fine-tuning among brain glutathione redox system components was revealed controlling IONP + Hg interactive impacts successfully.

In the present study, cadmium and lead concentrations were compared in barnacles, ghost shrimps, polychaetes, bivalves, and sediment from ten different locations along the intertidal zone of the Persian Gulf and the Gulf of Oman. The results revealed significant differences in the heavy metal concentrations between the organisms with barnacles showing, by far, the highest metal concentrations. The bioaccumulation factor of Cd in different animals follows this pattern with barnacles > bivalves > polychaetes > ghost shrimps, while the pattern for Pb was barnacles > polychaetes > bivalves > ghost shrimps. In most of the stations, sediments showed the lowest lead and cadmium concentrations. Therefore, it is concluded that barnacles with Pb concentrations between 0.17 and 2,016.1 μg/g and Cd concentrations ranging from 0.4 to 147.1 μg/g are the best organisms to be employed in monitoring programs designed to assess pollution with bioavailable metals in the Persian Gulf and the Gulf of Oman.

Concentrations and chemical composition of the coarse particle fraction (PMc) were investigated at two urban sites in the city of Thessaloniki, Greece, through concurrent sampling of PM₁₀ and PM₂.₅ during the warm and the cold months of the year. PMc levels at the urban-traffic site (UT) were among the highest found in literature worldwide exhibiting higher values in the cold period. PMc levels at the urban-background site (UB) were significantly lower exhibiting a reverse seasonal trend. Concentration levels of minerals and most trace metals were also higher at the UT site suggesting a stronger impact from traffic-related sources (road dust resuspension, brake and tire abrasion, road wear). According to the chemical mass closure obtained, minerals (oxides of Si, Al, Ca, Mg, Fe, Ti, and K) dominated the PMc profile, regardless of the site and the period, with organic matter and secondary inorganic aerosols (mainly nitrate) also contributing considerably to the PMc mass, particularly in the warm period. The influence of wind speed to dilution and/or resuspension of coarse particles was investigated. The source of origin of coarse particles was also investigated using surface wind data and atmospheric back-trajectory modeling. Finally, the contribution of resuspension to PMc levels was estimated for air quality management perspectives.

In recent years, attention has been directed to chemicals with possible endocrine-disrupting properties. Polychlorinated biphenyls (PCBs) and their metabolites belong to one group of environmental contaminants that have been shown to interact with the endocrine system in mammals, including humans. Although recent developments have been made in terms of determination of PCB metabolites in blood samples, still limited number of studies have been able to elucidate their profiles and toxicological and health effects in humans. This review aims to evaluate and compare the levels of hydroxylated PCBs (OH-PCBs) and methyl sulfone PCBs (MeSO₂-PCBs) in blood and their relationship to parent compounds and also address the potential risks and adverse health effects in humans. Levels of OH-PCBs varied between 0.0002 and 1.6 ng g⁻¹ w/w in human serum/plasma from the selected literature, correlating well with ∑PCBs. In contrast, ∑OH-PCB/∑PCB ratio in animals did not show a significant correlation, which might suggest that the bioaccumulation plays an even more important role in the concentration of OH-PCBs compared to PCB metabolism. Highest levels of MeSO₂-PCBs were reported in marine mammals with high selectivity retention in the liver. Health effects of PCB metabolites included carcinogenicity, reproductive impairment, and developmental neurotoxicity, being more efficiently transferred to the brain and across the placenta from mother to fetus in comparison to the parent PCBs. Based on the lack of knowledge on the occurrence and distribution of lower chlorinated OH-PCBs in humans, further studies to identify and assess the risks associated to human exposure are essential.

Seafood consumption provides a significant amount of arsenic, although in its organic, nontoxic forms. Mediterranean populations may incorporate high levels of this metalloid as a consequence of seafood consumption. In the present study, the significance of this input among pregnant women from a Mediterranean city (Sabadell, Catalonia, Spain) is assessed. Total urinary arsenic was analyzed in 489 pairs of urine samples, corresponding to the 12th and 32th weeks of pregnancy. Association of arsenic content with seafood and other dietary items were studied. Geometric mean concentrations were 34 and 37 μg/g creatinine during the first and third trimesters, respectively. The observed concentrations were similar to those reported in studies from other Mediterranean countries. The differences between both periods were not statistically significant. The only dietary factor significantly and positively associated with total urinary arsenic in both series of samples was seafood, particularly lean fish. Moreover, lean fish consumption during both periods was found to be the main determinant for differences in levels of arsenic between the first and third trimesters, which confirms the association between high levels of total urinary arsenic and seafood consumption.