Characterizing the interactions between Cd and Zn with respect to the soil soluble Cd and crop Cd uptake allows the development of risk-based approaches to the performance of grain crops. By means of a three-year survey of 358 rice fields and 206 wheat fields across China, this study investigated the effect of Cd–Zn interactions on the phytoavailability of Cd to rice and wheat. The interactive nature between the Cd:Zn ratio and pH of soil affected crop Cd uptake, and the resulting grain Cd intake risk, were examined by the Free-Ion Activity-based model and probability analysis. In highly acidic rice soils (pH < 5.9), soil Zn had no effect on rice Cd uptake, whereas, under near-neutral conditions (pH > 5.9), a site-specific influence of soil Zn on grain Cd concentration was found. Soil Zn could inhibit Cd uptake and translocation by the plant in soil-wheat system when the soil Cd:Zn ratio decreased to 0.0083 and lower. Rice grain poses a significant health risk to local consumers due to its high Cd accumulation and its low Zn accumulation. In order to reduce the health risks from dietary Cd to local consumers, approximately 63.9% of the rice fields and 30.5% of the wheat fields require strategies ameliorating soil acidity in rice soils and increasing Zn concentrations in wheat soils.

Polycyclic aromatic hydrocarbons (PAHs) in soil are not only detrimental to environment but also to human health. Double dielectric barrier discharge (DDBD) plasma reactor used for the remediation of pyrene contaminated soil was studied. The performance of DDBD reactor was optimized with influential parameters including applied voltage, type of carrier gas, air feeding rate as well as pyrene initial concentration. The analysis of variance (ANOVA) results showed that input energy had a great effect on pyrene remediation efficiency followed by pyrene initial concentration, while, the effect of air feeding rate was insignificant. More specifically, the remediation efficiency of pyrene under air, nitrogen and argon as carrier gas were approximately 79.7, 40.7 and 38.2% respectively. Pyrene remediation efficiency is favored at high level of applied voltages and low level of pyrene initial concentration (10 mgkg⁻¹) and air feeding rate (0.85 L/min). Moreover, computation of the energy efficiency of the DDBD system disclosed that an optimal applied voltage (35.8 kV) and higher initial pyrene concentration (200 mgkg⁻¹) favored the high energy efficiency. A regression model predicting pyrene remediation under DDBD plasma condition was developed using the data from a face-centered central composite design (FCCD) experiment. Finally, the residual toxicity analysis depicted that the respiratory activity increased more than 21 times (from 0.04 to 0.849 mg O₂ g⁻¹) with a pyrene remediation efficiency of 81.1%. The study demonstrated the DDBD plasma technology is a promising method not only for high efficiency of pyrene remediation, but also recovering biological function without changing the physical-chemical properties of soil.

The aquatic environment takes on a key role in the dissemination of antimicrobial-resistant Enterobacteriaceae. This study assesses the occurrence of carbapenemase-producing Enterobacteriaceae (CPE) in freshwater samples from rivers, inland canals, and streams throughout Switzerland, and characterizes the isolated strains using phenotypic and NGS-based genotypic methods. CPE producing KPC-2 (n = 2), KPC-3 (n = 1), NDM-5 (n = 3), OXA-48 (n = 3), OXA-181 (n = 6), and VIM-1 (n = 2) were detected in 17/164 of the water samples. Seven Escherichia coli had sequence types (STs) that belonged to extra-intestinal pathogenic clonal lineages ST38, ST73, ST167, ST410, and ST648. The majority (16/17) of the carbapenemase genes were located on plasmids, including the widespread IncC (n = 1), IncFIIA (n = 1), and IncFIIB plasmids (n = 4), the epidemic IncL (n = 1) and IncX3 (n = 5) plasmids, a rare Col156 plasmid (n = 1), and the mosaic IncFIB, IncR, and IncQ plasmids (n = 3). Plasmids were composed of elements that were identical to those of resistance plasmids retrieved from clinical and veterinary isolates locally and worldwide. Our data show environmental dissemination of high-risk CPE clones in Switzerland. Epidemic and mosaic-like plasmids carrying clinically relevant carbapenemase genes are replicating and evolving pollutants of river ecosystems, representing a threat to public health and environmental integrity.

Poyang Lake is the largest freshwater lake in China and a globally important wetland with various functions. Exploring the multidecadal trend of water quality and hydroclimatic conditions is important for understanding the adaption of the lake system under the pressure from multiple anthropogenic and meteorological stressors. The present study applied the Mann–Kendall trend analysis and Pettitt test to detect the trend and breakpoints of hydroclimatic, and water quality parameters (from the 1980s to 2018) and the trend of monthly–seasonal ammonia (NH₄-N) and total phosphorus (TP)concentrations (from 2002 to 2018) in Poyang Lake. Results showed that Poyang Lake had undergone a highly significant warming trend from 1980 to 2018, with a warming rate of 0.44 °C/decade in terms of annual daily mean air temperature. The wind speed and water level of the lake presented a highly significant decreasing trend, whereas no notable trend was detected for precipitation variations. The annual mean total nitrogen (TN), NH₄-N, TP, and permanganate index (CODMₙ) concentrations showed significant upward trends from the 1980s to 2018. Remarkable abrupt shifts were detected for TN, NH₄-N, and CODMₙ in around 2003. They were in accordance with the water level breakpoint of the lake, thus implying the important role of hydrological conditions in water quality variations in floodplain lakes. A significant increasing trend has been detected for Chl-a variations during wet season from 2008 to 2018, which could be attributed to the increasing trend of nutrient concentration during the nutrient-limited phase of Poyang Lake. These hydroclimatic and water quality trends suggest a high risk of increasing phytoplankton growth in Poyang Lake. This study thus emphasizes the need for adaptive lake eutrophication management for floodplain lakes, particularly the consideration of the strong trade-off and synergies between hydroclimatic conditions and water quality variations.

New toxicological research is still urgently needed to improve the current knowledge about the induction of some underlying mechanisms of toxicity by the different chemical fractions of ambient particulate matter (PM). This in vitro study sought also to better evaluate and compare the respective toxicities of fine particles (PM₂.₅₋₀.₃) and their inorganic and organic chemical fractions, and the respective toxicities of the organic chemical fractions of PM₂.₅₋₀.₃ and quasi-ultrafine particles (PM₀.₃). Human bronchial epithelial BEAS-2B cells were also exposed for 6–48 h to relatively low doses of PM₂.₅₋₀.₃ and their organic extractable (OEM₂.₅₋₀.₃) and non-extractable (NEM₂.₅₋₀.₃) fractions, and the organic extractable fraction (OEM₀.₃) of PM₀.₃. We reported that not only PM₂.₅₋₀.₃, but also, to a lesser extent, its inorganic chemical fraction, NEM₂.₅₋₀.₃, and organic chemical fraction, OEM₂.₅₋₀.₃, were able to significantly induce ROS overproduction and oxidative damage notwithstanding the early activation of NRF2 signaling pathway. Moreover, for any exposure, inflammatory and apoptotic events were noticed. Similar results were observed in BEAS-2B cells exposed to OEM₀.₃, rich of polycyclic aromatic hydrocarbons and their nitrated and oxygenated derivatives. In BEAS-2B cells exposed for 24 and 48 h to OEM₂.₅₋₀.₃ and OEM₀.₃, to a higher extent, there was an alteration of the levels of some critical proteins even though crucial for the autophagy rather than a real reduction of autophagy. It is noteworthy that the toxicological effects were equal or mostly higher in BEAS-2B cells exposed for 6 and/or 24 h to PM₂.₅₋₀.₃ from those exposed to NEM₂.₅₋₀.₃ or OEM₂.₅₋₀.₃, and in BEAS-2B cells exposed for 6 and/or mostly 24 h to OEM₀.₃ from those exposed to OEM₂.₅₋₀.₃. Taken together, these results revealed the higher potentials for toxicity, closely linked to their respective physical and chemical characteristics, of PM₂.₅₋₀.₃ vs NEM₂.₅₋₀.₃ and/or OEM₂.₅₋₀.₃, and OEM₀.₃ vs OEM₂.₅₋₀.₃.

Thifluzamide is widely used in treatment of rice diseases and has potential toxicity on aquatic organism. Although previous studies have focused on the toxic effect of thifluzamide in zebrafish, no consistent conclusions have been reached. To help to elucidate the toxic mechanism, qualities of liver and mitochondria were evaluated. The global changes in the transcriptome of zebrafish after exposure to thifluzamide were measured. Based on this, the expression and activities of chitinase and succinate dehydrogenase (SDH) were further assayed. And the targeted site of thifluzamide in zebrafish was confirmed by dock study and co-exposure study. Here we report that developmental inhibition was observed along with presence of liver and mitochondrial damage. The expression of SDHa-d and genes related to mitochondrial DNA (mtDNA) replicate and mitochondrial complexes were significantly altered. And, as the top differentially expressed genes, the expression of chia.1-6 did show apparent changes, but differences of chitinase activity between exposure groups and the controls did not reach significance. In line with that, dock study showed that the binding potentials of thifluzamide toward zebrafish chitinase and SDH exhibited in the following order: SDH> chitinase. And sdhb-sdhc-sdhd (Qp site) showed the highest binding activity toward thifluzamide. The joint exposure (thifluzamide + Q10) significantly improved the survival of zebrafish compared with single thifluzamide exposure. These results indicate that SDH, especially Qp-site, may be the target of thifluzamide in zebrafish and inhibition of SDH activity may be at least in partial responsible for the toxicity of thifluzamide in zebrafish. In addition, the antagonistic effect of Q10 on thifluzamide toxicity in zebrafish suggests that Q10 may be a useful adjunct to detoxification.

Climate change will impact soil properties such as soil moisture, organic carbon and temperature and changes in these properties will influence the sorption, biodegradation and leaching of trace organic contaminants to groundwater. In this study, we conducted a modeling case study to evaluate atrazine and estrone transport in the subsurface under current and future climate conditions at a field site in central Nebraska. According to the modeling results, in the future, enhanced evapotranspiration and increased average air temperature may cause drier soil conditions, which consequently reduces the biodegradation of atrazine and estrone in the water phase. On the other hand, greater transpiration rates lead to greater root solute uptake which may decrease the concentration of atrazine and estrone in the soil profile. Another consequence of future climate is that the infiltration and leaching rates for both atrazine and estrone may be lower under future climate scenarios. Reduced infiltration of trace organic compounds may indicate that lower trace organic concentrations in groundwater may occur under future climate scenarios.

Polyphenols, pivotal secondary metabolites, are involved in plant adaption to abiotic stresses. Here, we investigated the role and metabolism profile of polyphenols under aluminum (Al) stress in different lettuce genotypes grown in 0.5 mM CaCl₂ solution with AlCl₃ (pH = 4.5). The complementary use of high-resolution mass spectrometry and quantitative biochemical approaches allowed the characterization of total and unique phenols, as well as their roles in Al tolerance. By comparing the most tolerant and sensitive genotype, 8 polyphenols, including 4 phenolic acids, 2 flavonoids, 1 xanthone and 1 unknown compound, were identified in the roots of the tolerant genotype. The total phenolic and flavonoid contents significantly increased in the tolerant genotype under Al stress. Seedlings with more phenolic accumulation usually performed greater Al tolerance. Meanwhile, principal enzymes related to phenolic biosynthesis significantly increased in roots of the tolerance genotype after Al treatment, with phenylalanine ammonia lyase (PAL), cinnamate 4-hydroxylase, and 4-coumarate coenzyme A ligase increased by 16, 18 and 30%, respectively. The elevated total phenolics were significantly suppressed by AIP, a highly specific PAL inhibitor. Consequently, the antioxidant capacity was inhibited, leading to lettuce sensitivity to Al stress. These results clearly suggested the enhancement of unique polyphenolic biosynthesis as an adaptive strategy of lettuce to Al stress by protecting plants from oxidative stress.

2,3,3,3-Tetrafluoro-2-(heptafluoropropoxy)propanoate (known as GenX) has been used as an alternative to perfluorooctanoic acid (PFOA) which was phased out of formulations for industrial and consumer product applications in 2015. While the effects of GenX on lab animals have been studied, little is known about its effects on plants. This study examined and compared the accumulation and toxicity of GenX and PFOA in the model plants Arabidopsis thaliana and Nicotiana benthamiana. Both plants showed reduction in biomass and root growth following exposure to PFOA or GenX in a dosage-dependent manner. The bioaccumulation factors (BFs) of GenX and PFOA were plant species-dependent, with higher BFs in A. thaliana compared to N. bethanminana. Additionally, GenX and PFOA were more readily accumulated into shoot tissues of A. thaliana than in N. bethanminana. Exposure to GenX also caused a reduction in chlorophyll content (18%) and total phenolic compounds (26%). However, GenX exposure increased superoxide dismutase activity and H₂O₂ content (1.6 and 2.6 folds increase, respectively) in N. benthamiana. Overall, our result suggest that GenX is bioaccumulative, and that its accumulation likely inhibits plant growth and photosynthesis as well as inducing oxidative stress.