The main objective of the current study was to estimate the potential environmental risks associated with human consumption of antimicrobials in Greece. Consumption data was collected for the 24 most often used antimicrobials for the years 2008–2010, and their predicted environmental concentrations (PECs) in raw and treated wastewater were calculated using mass balances and literature data on human excretion and elimination efficiency during wastewater treatment. The ecotoxicological risk was estimated by calculating the ratio of PEC to predicted no-effect concentration (PNEC) for three categories of aquatic organisms (algae, daphnids, and fish). PNEC values were calculated based on experimental ecotoxicity data and data originated from the Ecological Structure Activity Relationship (ECOSAR). PEC values in raw sewage ranged between 0.02 μg L⁻¹(erythromycin) and 27 μg L⁻¹(amoxicillin), while in treated wastewater, the highest concentration was predicted for cefuroxime axetil (6.6 μg L⁻¹). Based on acute toxicity data for algae, risk quotient (RQ) values higher than 1 were obtained for 7 out of the 24 target antimicrobials in raw and treated wastewater, while no significant risk was estimated for daphnids and fish. Regarding the possible risk due to the chronic toxicity of antimicrobials, RQ values higher than 80 were obtained for amoxicillin and clarithromycin in algae. The use of baseline toxicity data from ECOSAR showed that the environmental risk from exposure to mixtures of antimicrobials was low for all three aquatic species. However, further studies on toxicity of mixtures should be performed as calculation of toxicity ratio (TR) values showed that 90 % of the target antimicrobials seem to exhibit a specific mode of toxic action when present in mixtures rather than baseline toxicity. As a result, an underestimation of toxicity based on the ECOSAR model is possible for the mixture of target antimicrobials. For Greek rivers where low (dilution factor, D < 10) and medium (D = 10–100) dilution of wastewater occurs, moderate to high risk is expected due to the existence of individual antimicrobials such as amoxicillin, clarithromycin, ciprofloxacin, azithromycin, erythromycin, and levofloxacin in discharged treated wastewater.

We investigated the bioaccumulation of selected trace elements in samples of the lichen Evernia prunastri (L.) Ach. transplanted across two seasons in the urban area of Genoa (NW Italy), which is heavily affected by traffic and industrial pollution. Total concentration of most elements did not exhibit differences between seasons, exceptions being Al and Na, higher in summer, and As, Cd, and Ti, higher in winter. Differences emerged in the initial concentrations of some elements in control samples, and this was accounted for by the use of exposed-to-control (EC) ratios, which allowed interpretation of changes in element concentrations. The study area resulted highly polluted, likely by particulate matter, as suggested also by the higher concentrations of airborne PM₁₀during winter months. Bioaccumulation of particulate matter seems to be affected by differences in rainfall regimes across seasons, since element solubilization and leaching due to precipitation may vary considerably.

Water is an essential factor for maintaining the vital functions of living beings. Nickel is the 24th most abundant element on Earth; it is a heavy metal that is genotoxic and mutagenic in its chloride form. Due to industrial use, its concentration in surface sediments increased considerably. Fish develop characteristics that make them excellent experimental models for studying aquatic toxicology. They are particularly useful because they can alert of the potential danger of chemical substances or environmental pollution. Due to water quality impairment and because there are few published studies that relate nickel to tissue alteration, this study aimed to examine the consequences of nickel in an aquatic environment. For this analysis, individuals of Oreochromis niloticus were exposed for 96 h to three different concentrations of nickel dissolved in water according to the standard established by Brazilian law and compared them to a control group. After exposure, the gills were analyzed using X-ray microanalysis, ultramorphology, and histological and histochemical analysis. The results demonstrated that all the concentrations used in the experiment altered the histophysiology of the individuals exposed. In conclusion, the nickel presents a toxic potential to fish, even at the lowest concentration tested, which is equivalent to half of the concentration allowed by law. The CONAMA resolution should be revised for this parameter because of the interference of this metal in the histophysiology of the tested organism.

An efficient pretreatment and analytical method was developed to investigate the occurrence and fate of four free estrogens (estrone (E1), 17β-estradiol (17β-E2), estriol (E3), and 17α-ethinylestradiol (EE2)), four conjugated estrogens (estrone-3-sulfate sodium salt (E1-3S), 17β-estradiol-3-sulfate sodium salt (E2-3S), estrone-3-glucuronide sodium salt (E1-3G), and 17β-estradiol-3-glucuronide sodium salt (E2-3G)), and bisphenol A (BPA) in three livestock farms raising beef cattle, cows, sheep, swine, and chickens in Qi County, which is located in North China. The results demonstrated that one cow and one beef cattle excreted 956.25–1,270.41 and 244.38–319.99 μg/day of total (free and conjugated) estrogen, respectively, primarily through feces (greater than 91 %), while swine excreted 260.09–289.99 μg/day of estrogens, primarily through urine (98–99 %). The total estrogen excreted in sheep and broiler chicken feces was calculated to be 21.64–28.67 and 4.62–5.40 μg/day, respectively. It was determined that conjugated estrogens contributed to 21.1–21.9 % of the total estrogen excreted in cow feces and more than 98 % of the total estrogen excreted in swine urine. After composting, the concentration of total estrogen decreased by 18.7–59.6 %; however, increased levels of BPA were measured. In treated compost samples, estrogens were detected at concentrations up to 74.0 ng/g, which indicates a potential risk of estrogens entering the surrounding environment.

In this work, protein phosphatase inhibition assays (PPIAs) have been used to evaluate the performance of recombinant PP1 and recombinant and wild-type PP2As. The enzymes have been compared using microcystins-LR (MC-LR) as a model cyanotoxin. Whereas PP2ARₑcprovides a limit of detection (LOD) of 3.1 μg/L, PP1Rₑcand PP2AWᵢₗdprovide LODs of 0.6 and 0.5 μg/L, respectively, lower than the guideline value proposed by the World Health Organization (1 μg/L). The inhibitory potencies of seven MC variants (-LR, -RR, -dmLR, -YR, -LY, -LW and -LF) have been evaluated, resulting on 50 % inhibition coefficient (IC₅₀) values ranging from 1.4 to 359.3 μg/L depending on the MC variant and the PP. The PPIAs have been applied to the determination of MC equivalent contents in a natural cyanobacterial bloom and an artificially contaminated sample, with multi-MC profiles. The inhibition equivalency factors (IEFs) have been applied to the individual MC quantifications determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, and the estimated MC-LR equivalent content has been compared to PPIA results. PPIAs have demonstrated to be applicable as MC screening tools for environmental applications and to protect human and animal health.

Organic pollutants present in the soil of a microcosm containing pulp and paper mill black liquor were extracted with hexane/acetone (1:1 v/v) to study the biodegradation and detoxification potential of a Bacillus sp. gas chromatography-mass spectroscopic (GC-MS) analysis performed after biodegradation showed formation of simpler compounds like p-hydroxyhydrocinnamic acid (retention time [RT] 19.3 min), homovanillic acid methyl ester (RT 21.6 min) and 3,5-dimethoxy-p-coumaric alcohol (RT 24.7 min). The methyltetrazolium (MTT) assay for cytotoxicity, 7-ethoxyresorufin-O-deethylase (EROD) assay for dioxin-like behavior and alkaline comet assay for genotoxicity were carried out in the human hepatocarcinoma cell line HuH-7 before and after bacterial treatment. Bioremediation for 15 days reduced toxicity, as shown by a 139-fold increase in black liquor’s LC₅₀value, a 343-fold reduction in benzo(a)pyrene equivalent value and a 5-fold reduction in olive tail moment. The EROD assay positively correlated with both the MTT and comet assays in post biodegradation toxicity evaluation.

Fast-growing metal-accumulating woody plants are considered potential candidates for phytoextraction of metals. Shuikoushan mining, one of the biggest Pb and Zn production bases in China, presents an important source of the pollution of environment during the last 100 years. Over 150 km²of fertile soil have been contaminated by the dust, slag, and tailings from this mining. The goal of the present work has been to determine the content of Pb, Zn, Cd, and Cu in wild woody plants (18 species) naturally growing in this area. Two hundred five plant and soil samples from 11 contaminated sites were collected and analyzed. In addition, to assess the ability of multi-metal accumulation of these trees, we proposed a predictive comprehensive bio-concentration index (CBCI) based on fuzzy synthetic assessment. Our data suggest some adult trees could also accumulate a large amount of metals. Pb concentrations in leaves of Paulownia fortunei (Seem.) Hemsl. (1,179 mg/kg) exceeded the hyperaccumulation threshold (1,000 mg/kg). Elevated Pb concentrations (973.38 mg/kg) were also found in the leaves of Broussonetia papyrifera (L.) Vent., with a Pb bio-concentration factor of up to 0.701. Endemic species, Zenia insignis Chun exhibited huge potential for Zn and Cd phytoextraction, with the highest concentrations of Zn (1,968 mg/kg) and Cd (44.40 mg/kg), characteristic root nodules, and fast growth rates in poor soils. As for multi-metal accumulation ability, native species B. papyrifera was calculated to have the most exceptional ability to accumulate various metals simultaneously (CBCI 2.93), followed by Amorpha fruticosa L. (CBCI 2.72) and Lagerstroemia indica L. (CBCI 2.53). A trend of increasing metal from trunks to leaves (trunks < branches < leaves) and towards fine roots has been shown by metal partitioning between tissues. The proposed CBCI would allow for the selection of suitable trees for phytoremediation in the future.

The Pseudomonas sp. P-1 strain, isolated from heavily petroleum hydrocarbon-contaminated soil, was investigated for its capability to degrade hydrocarbons and produce a biosurfactant. The strain degraded crude oil, fractions A5 and P3 of crude oil, and hexadecane (27, 39, 27 and 13 % of hydrocarbons added to culture medium were degraded, respectively) but had no ability to degrade phenanthrene. Additionally, the presence of gene-encoding enzymes responsible for the degradation of alkanes and naphthalene in the genome of the P-1 strain was reported. Positive results of blood agar and methylene blue agar tests, as well as the presence of gene rhl, involved in the biosynthesis of rhamnolipid, confirmed the ability of P-1 for synthesis of glycolipid biosurfactant.¹H and¹³C nuclear magnetic resonance, Fourier transform infrared spectrum and mass spectrum analyses indicated that the extracted biosurfactant was affiliated with rhamnolipid. The results of this study indicate that the P-1 and/or biosurfactant produced by this strain have the potential to be used in bioremediation of hydrocarbon-contaminated soils.

The heterogeneous ozonolysis of naphthalene adsorbed on XAD-4 resin was studied using an annular denuder technique. The experiments involved depositing a known quantity of naphthalene on the XAD-4 resin and then measuring the quantity of the solid naphthalene that reacted away under a constant flow of gaseous ozone (0.064 to 4.9 ppm) for a defined amount of time. All experiments were performed at room temperature (26 to 30 °C) and atmospheric pressure. The kinetic rate coefficient for the ozonolysis reaction of naphthalene adsorbed on XAD-4 resin is reported to be (10.1 ± 0.4) × 10⁻¹⁹ cm³ molecule⁻¹ s⁻¹(error is 2σ, precision only). This value is five times greater than the currently recommended literature value for the homogeneous gas phase reaction of naphthalene with ozone. The obtained rate coefficient is used to evaluate reaction artifacts from field concentration measurements of naphthalene, acenaphthene, and phenanthrene. The observed uncertainties associated with field concentration measurements of naphthalene, acenaphthene, and phenanthrene are reported to be much higher than the uncertainties associated with the artifact reactions. Consequently, ozone reaction artifact appears to be negligible compared to the observed field measurement uncertainty results.

Concentrations of aqueous-phase nonylphenol (NP), a well-known endocrine-disrupting chemical, are shown to be reduced effectively via reaction with lignin peroxidase (LiP) or horseradish peroxidase (HRP) and hydrogen peroxide. We systematically assessed their reaction efficiencies at varying conditions, and the results have confirmed that the catalytic performance of LiP toward NP was more efficient than that of HRP under experimental conditions. Mass spectrum analysis demonstrated that polymerization through radical–radical coupling mechanism was the pathway leading to NP transformation. Our molecular modeling with the assistance of ab initio suggested the coupling of NP likely proceeded via covalent bonding between two NP radicals at their unsubstituted carbons in phenolic rings. Data from acute immobilization tests with Daphnia confirm that NP toxicity is effectively eliminated by LiP/HRP-catalyzed NP removal. The findings in this study provide useful information for understanding LiP/HRP-mediated NP reactions, and comparison of enzymatic performance can present their advantages for up-scale applications in water/wastewater treatment.