Carps belonging to species Cyprinus carpio (carp) were fed on organic and inorganic selenium forms for 60 days to enable evaluating the biochemical profile of tissues exposed to fipronil (FPN) insecticide. Diphenyl diselenide [(PhSe)₂] (3.0 mg/kg) and sodium selenite (Na₂SeO₃) (0.75 mg/kg) were used as organic and inorganic selenium forms, respectively. Overall, the adopted organic and inorganic selenium forms were similarly capable of reestablishing oxidant and antioxidant stress parameters close to control levels. Fish exposed to fipronil have shown decreased acetylcholinesterase (AChE) activity in brain and muscle tissues. Brain tissues of fish supplemented with Na₂SeO₃ or (PhSe)₂ diets presented reestablished AChE levels in comparison to those of fish fed on standard diet. Liver tissues of fish fed on standard diet presented decreased δ-ALA-D activity after their exposure to FPN, whereas diets added with two selenium forms were efficient in reestablishing the levels of standard diets. Therefore, (PhSe)₂ and Na₂SeO₃ have potential to be used as supplementation factors in diets to feed C. carpio.

Agricultural production has a major impact on the environment. Indeed, the emissions from agricultural machinery have a significantly negative impact on ambient air, thereby contributing to Climate Change. This study analyses combine harvesters and justifies their optimization in order to increase resource efficiency as well as reduce any negative impact on the environment. Data from 90 combine harvesters in Lithuania and Latvia from 2016 to 2018 is collected using telematics, and the parameters that directly influence engine exhaust emissions are analyzed, such as operation time, grain unloading method, fuel consumption, and auto-steering, according to the engine-operating modes of harvesting, transportation, and idling. Statistically reliable strong correlations can be found between harvesting time and idling time, as well as between fuel consumption during harvesting and idling modes. On average, roughly 20% of the operating time consists of idling and roughly 15% of transportation; moreover, roughly 14% of the diesel fuel is used per year in the aforementioned engine modes. In addition, the auto-steering function enables the efficient use of diesel fuel (average cost per combine harvester is reduced by 0.2 t year⁻¹), thereby reducing air pollution (pollution per combine harvester is reduced on average by 0.6 t year⁻¹). The results suggest telematics system data can be effectively used for data analysis, problem identification, and decision-making with respect to pollution prevention and optimizing combine harvester operation. Graphical Abstract

To assess the ecological risk resulting from an accidental gasoline spill upstream from a wetland, groundwater and sediment sampling was carried out during two campaigns at the 48th and 52nd months after the spill had occurred. In total, 21 groundwater monitoring wells in the affected area were sampled plus an additional reference well located upstream from the accident location. Seven sediment sampling points were selected inside the wetland, plus a reference point upstream from the accident. Physicochemical parameters, BTEX (benzene, toluene, ethylbenzene, m-xylene, p-xylene and o-xylene) and metal concentrations were analysed to estimate the chemical risk. Acute (Allivibrio fischeri, Daphnia similis, Hyalella azteca) and chronic (Artemia salina and Desmodesmus subspicatus) toxicity assays were performed with groundwater and sediments elutriate to determine the ecotoxicological risk. Results from groundwater indicated an extreme chemical level of risk in14 out of 21 monitoring wells. These 14 wells also exhibited free-phase gasoline and lead (Pb) concentrations above the threshold values adopted by this study. The presence of Pb, however, could not be associated with the gasoline accident. High acute and chronic toxicities were reported for the majority of wells. Conversely, the risks associated with the sediments were considered low in most sampling points, and the ecotoxicity found could not be related to the presence of gasoline. Groundwater flow modelling results have evidenced the migration of the contamination plume towards the wetland. Thus, to prevent contamination from reaching the protected area, more effective groundwater clean-up techniques are still required.

Diclofenac has been detected in water and terrestrial matrices, causing severe changes in the environment. This is due to the fact that it is one of the most widely used nonsteroidal anti-inflammatory drugs in the world. The advanced oxidation processes (AOPs) of photo-peroxidation and heterogeneous photocatalysis were tested in this work using UV-C and solar radiation to degrade diclofenac in aqueous solutions. To monitor the efficiency of the degradation processes an ultrahigh performance liquid chromatography with ultraviolet detection at a wavelength of 285 nm was applied. Both processes were found to be efficient (> 78%) after 60 min of treatment, being possible to determine the reaction kinetics for each one of them. Intermediate formation was also observed after 60 min which were also degraded by increasing the treatment time to 120 min. For the treatments using UV-C radiation, an order of 1.0 was observed, while the treatments that applied solar radiation obtained an order of 0.2 for the photocatalysis and 0.8 for photo-peroxidation.

Alkylphenols (APₛ)—nonylphenol (NP) and octylphenol (OP)—are well-known environmental contaminants due to their widespread application and have been identified as endocrine-disrupting chemicals. A novel APₛ-tolerant fungus designated F6 was isolated from the bottom sediments of the coastal part of the Eastern Gulf of Finland (Neva Bay) and was identified as Aspergillus tubingensis F6 based on ITS sequencing and morphological analysis. The APₛ presence caused morphological and ultrastructural changes in fungal cells. Major differences were detected in mitochondria, vacuoles, and cell walls. Nonenzymatic antioxidants—pigments, reduced glutathione, exopolysaccharides—played important roles in A. tubingensis F6 resistance to APₛ toxicity. A low level of lipid peroxidation showed that the protective effects of the antioxidant system were sufficient despite the fact that antioxidant enzymes activity levels were low. Another defense response employed by A. tubingensis F6 against the tNP- and 4-tert-OP-induced stress was based on the ability of the strain to efficiently utilize xenobiotics. After 120 h of cultivation, < 10% of APₛ (initially added to the culture at 100 mg/l) remained in the culture medium of A. tubingensis F6. The APₛ degradation by A. tubingensis F6 led to the formation of nontoxic products. These data indicate the potential role for A. tubingensis F6 in APₛ degradation in natural environments, as well as its possible biotechnological application in wastewater treatment to remove xenobiotics with endocrine activity. To our knowledge, this is the first report demonstrating that marine-derived fungus A. tubingensis strain is capable of utilizing branched-chain NP and OP.

Mercury (Hg) in the environment has been receiving considerable attention in recent years, but little is known about Hg accumulation in trees. We analyzed Hg in tree rings from four tree species at the Hubbard Brook Experimental Forest in New Hampshire to determine whether Hg concentrations are more influenced by soil Hg concentrations, which have been stable or increasing due to the cumulative retention of historical atmospheric Hg deposition, or by atmospheric Hg deposition, which has declined in recent decades. Declining concentrations from the top to the bottom of the bole (p < 0.001) and from older to newer tree rings (p = 0.001) suggest that foliar uptake of Hg is more important than root uptake. Ten sugar maple clones planted in six blocks at the Heiberg Forest in New York State showed significant genetic control of sap Hg concentration (p = 0.02), which was not related to soil Hg concentration differences across blocks. Clones could differ in stomatal uptake, root uptake, or translocation of Hg. Better understanding of the source of Hg in wood is needed to forecast future changes in Hg cycling in forested ecosystems.

Effects of imidacloprid and iprodione, isolated and in mixture, were assessed by using seed germination and root growth test, flow cytometry, and chromosomal aberrations test on Allium cepa root meristem. The highest concentrations of imidacloprid, including field concentration, increased the frequency of sub-G₁ particles, decreased the frequency of nuclei in G₂/M, increased the coefficient of variation of G₁ (CVG₁) and the frequency of aberrant cells, and inhibited the mitotic index culminating in the reduction in root length. All doses of iprodione also presented cytogenotoxic action. The highest concentration of the fungicide affected the growth of A. cepa roots. In response to exposure to pesticide mixtures, the cell cycle of A. cepa was blocked in the G₁ phase. The mixtures with low doses of the pesticides significantly decreased the mitotic index, and as a consequence, the genotoxicity was reduced. In the mixtures with the highest doses of the agrochemicals, the blockage of the cell cycle was insufficient for damage repair, resulting in a significant increase of chromosomal aberrations. The results suggest caution in the use of pesticides doses that induce cytological abnormalities in non-target organisms.

This panel study aimed to evaluate the associations between short-term exposure to indoor and outdoor PM₂.₅ and anxiety in schoolchildren. During 3 waves in March, July, and November 2018 with 7 days per wave, 52 children aged 10 years were recruited from two schools in a city in Korea. To assess outdoor exposure, we used PM₂.₅ concentration measures for every hour at the national measurement station (NMS) closest to the two participating schools. To assess indoor exposure, we measured PM₂.₅ concentration at the children’s homes and in classrooms, based on 30-min average. Based on time-activity logs, personal average daily exposure values were calculated for each participant, according to exposure values assessed at 30-min intervals by location. Children’s anxiety was assessed via the Korean version of the State Anxiety Inventory for children every day during each wave. Linear mixed effects model was conducted to analyze the association between PM₂.₅ exposure and anxiety using repeated measurements. Personal exposure to PM₂.₅ by time-activity log was the highest in March and at home. A low correlation coefficient was observed between PM₂.₅ concentrations at home and at the NMS (ρ = 0.36, p < 0.0001) whereas a high correlation coefficient was observed between PM₂.₅ concentrations in classrooms and at the NMS (ρ = 0.64, p < 0.0001). There was no association between PM₂.₅ exposure and anxiety in children based on the analysis of repeated measurements during the study period. Since previous studies reported controversial results, long-term follow-up studies are needed in various regions to further investigate the associations between PM₂.₅ exposure and children’s mental health.

Nitrate-denitrifying anaerobic methane oxidation (Nitrate-DAMO) process is a novel bioprocess which couples anaerobic oxidation of methane (AOM) with nitrite/nitrate reduction. In this study, one Nitrate-DAMO culture contains both DAMO bacteria (62.2%) and DAMO archaea (26.5%). The environmental conditions, temperature, pH, and dissolved oxygen were found to affect Nitrate-DAMO activity significantly. When temperature was below 35 °C, Nitrate-DAMO reaction rate dropped as temperature decreased, and when temperature was above 35 °C, Nitrate-DAMO reaction rate decreased as temperature rose; Nitrate-DAMO reaction rate reached maximum at 35 °C. When pH was below 6.5, Nitrate-DAMO reaction rate decreased with the decrease of pH, and when pH was above 7.5, Nitrate-DAMO reaction rate decreased as pH rose; the maximum Nitrate-DAMO reaction rate appeared at both pH 6.5 and 7.5. Nitrate-DAMO activity was inversely proportional to dissolved oxygen concentration, which meant the existence of dissolved oxygen inhibited Nitrate-DAMO process.

In this paper, RE-CHAR® biochar, produced by a wood biomass pyrolysis process, which is usually applied as a soil fertilizer, was investigated for a novel use, that was as adsorbent for remediating a lead-contaminated solution. Firstly, a deep physical and chemical characterization of RE-CHAR® biochar was carried out. Then, the adsorption capacity of lead from 50 to 100 mg/L solutions was determined under batch and continuous flow conditions. Kinetics of the batch adsorption process were very rapid and complete removal was achieved within 4-h contact time at both Pb concentrations, using a biochar dosage of 5 g/L. These data were best fitted by the pseudo-second-order model, with the rate constant and the equilibrium capacity equal to kₛ = 0.0091 g/min and qₑ = 9.9957 mg/g at 50 mg/L Pb and kₛ = 0.0128 g/min and qₑ = 20.1462 mg/g at 100 mg/L Pb, respectively. The Langmuir isotherm model best fitted the equilibrium data at both Pb concentrations, with the Langmuir constant and maximum adsorption capacity equal to b = 11.5804 L/mg and qₘₐₓ = 4.6116 mg/g at 50 mg/L Pb and b = 2.8933 L/mg and qₘₐₓ = 9.5895 mg/g at 100 mg/L Pb. Continuous flow column tests showed that adding biochar to the soil of the adsorbent bed significantly extended the breakthrough and exhaustion times, with respect to the column filled with soil only. The Thomas model best fitted the experimental data of the breakthrough curves, with the constant kTH = 5.28 × 10⁻⁵ mL/min/mg and the maximum adsorption capacity q₀ = 334.57 mg/g which was comparable to the values reported for commercial adsorbents. Based on these results, it can be assessed that RE-CHAR® biochar can be used as an effective adsorbent for lead removal from water solutions even at high concentrations.