PCB forensic science is the process of identifying the source(s) of polychlorinated biphenyls (PCBs) at a site in the context of a legal proceeding to aid in identifying the party(s) responsible for the cost of environmental remediation. The PCB forensic scientist should assemble and examine all the evidence and then develop opinions about sources, discharges, deposition, fate, transport, environmental impact, and other issues at dispute among the parties. PCBs are complex mixtures of compounds (Aroclors in USA) that can simultaneously reveal information about the source of the contamination, but also provide confounding and contradictory evidence. The issues are technically complex and the expert must systematically evaluate the facts, employ deep technical expertise, and use dispassionate judgment to provide expert opinions that assist the judge, jury, arbitrator, or allocator in rendering their decision as to the responsible party(s) or an apportionment of that responsibility. Different PCB products were used and disposed of that have characteristic congener mixture profiles. In the environment, these profiles can mix and weather over decades. Sampling and analysis can generate further uncertainties, notably the possible misidentification of Aroclors. The expert’s challenge is to present their opinions clearly and authoritatively without overrepresenting the facts and data. This paper focuses on PCB contamination of sediment in aqueous sediment and uses a case study to illustrate application of forensic principles.

Illicit drugs (IDs) and their metabolites are recognized as contaminants of emerging concern. After consumption, illicit drugs are partially metabolized and excreted unchanged in urine and feces or as active metabolites reaching wastewater treatment plants (WWTPs). Furthermore, most WWTPs are insufficient in the treatment of effluents containing IDs, which may be released into aquatic ecosystems. Once in the water or sediment, these substances may interact and affect non-target organisms and some evidences suggest that illicit drugs may exhibit pseudo-persistence because of a continuous environmental input, resulting in long-term exposure to aquatic organisms that may be negatively affected by these biologically active compounds. We reviewed the literature on origin and consumption, human metabolism after consumption, aquatic occurrences, and toxicity of the major groups of illicit drugs (opioids, cannabis, synthetic drugs, and cocaine). As a result, it could be concluded that illicit drugs and their metabolites are widespread in diverse aquatic ecosystems in levels able to trigger sublethal effects to non-target organisms, besides to concentrate in seafood. This class of emerging contaminants represents a new environmental concern to academics, managers, and policymakers, whose would be able to assess risks and identify proper responses to reduce environmental impacts.

Chlorophyll-a (Chl-a) is the main component of phytoplankton and an important index of water quality. Pearson correlation analysis is conducted on measured Chl-a concentration and band reflectance to determine the sensitive bands or multiband combinations of the Chl-a to input to a support vector machine (SVM) model. An indicator β is defined to evaluate the model performance of fitting and prediction. The model performs well with the lowest β (decision coefficient, (R²) = 0.774; root mean square error (RMSE) = 22.636 μg/L) of the validation set. The model test results prove that the model performs well. We analyze the impact factors of the model. The seasonal factor affects the model performance significantly; thus, samples from different seasons should be combined to train the model and inverse the water quality. Noise points reduce the model accuracy significantly; therefore, obvious outliers must be excluded at first. Additionally, the sampling method affects model accuracy, and systematic sampling in the descending order of Chl-a concentration is recommended. The combination of SVM algorithm and remote sensing technology provides a convenient, scientific, and real-time method to monitor and control water quality.

Environmental problems caused by mines have been increasing. As one of the most serious types of mining damage caused to the eco-environment, open pits have been the focus of monitoring and management. Previous studies have obtained effective results when evaluating the ecological quality of a mining area by using the remote sensing ecological index (RSEI). However, the calculation of RSEI does not consider that the ecological environmental impact is limited under natural conditions. To overcome this shortcoming, this paper proposes an improved RSEI based on a moving window model, namely the moving window-based remote sensing ecological index (MW-RSEI). This improved index is more in agreement with the First Law of Geography than RSEI. This study uses Landsat ETM/OLI/TIRS images to extract MW-RSEI information of a case area in Zhengzhou City, Henan Province, central China, in 2009 and 2018. The results revealed that the average value of MW-RSEI declined from 0.668 to 0.611 from 2009 to 2018, and the main drivers of the deterioration of the eco-environment were land use/cover (LUCC) changes, most of which were derived from urban expansion and mining. The serious impact of open pits on the eco-environment in mining areas is mainly due to their low vegetation cover; therefore, some effectively managed open pits can have a positive impact on the mining environment. The use of MW-RSEI provides valuable information on the eco-environment surrounding the open pit, which can be used for the rapid and effective monitoring of the eco-environment in mining areas.

This paper investigates whether the effect of female parliamentarians on environmental performance differs by the level of income. To that end, a threshold estimation approach is applied to a panel of 91 countries over the period 2002–2012. The results suggest the existence of income threshold effects in female parliamentarians-environmental performance nexus. Specifically, when it is above the income threshold value, the extent of this positive correlation is much greater than below it. It means that theoretically although the female parliamentarians have a higher awareness of environmental protection and a positive effect on environmental performance than men, the economic development of countries will affect the implementation of this effect. Countries tend to prioritize economic development when income levels are low, only in high-income countries will the proportion of female parliaments significantly improve the country’s environmental performance. These results provide some important implications for policymakers when considering the relationship between female parliamentarians and environmental performance.

In order to develop more environmentally benignant insecticides, the Ligusticum pteridophyllum Franch. rhizomes essential oil and supercritical fluid (SFE-CO₂) extract were obtained by two published techniques, hydrodistillation and SFE-CO₂. The chemical components of this two tested samples were identified by using gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detector (GC-FID). Repellent activity and contact toxicity of the obtained samples and myristicin against the adults of Tribolium castaneum (Coleoptera: Tenebrionidae), Lasioderma serricorne (Coleoptera: Anobiidae), and Liposcelis bostrychophila (Psocoptera: Liposcelididae) were compared. Nineteen components were identified in the SFE-CO₂ extract. Twelve components were identified in the L. pteridophyllum rhizomes essential oil. SFE-CO₂ extract exhibited higher contact toxicity against T. castaneum, L. serricorne, and L. bostrychophila (LD₅₀ = 69.60 μg/adult, 14.58 μg/adult, and 1.69 μg/cm², respectively) than that of L. pteridophyllum rhizomes essential oil (LD₅₀ = 87.99 μg/adult, 89.82 μg/adult, and 7.87 μg/cm², respectively). Besides, myristicin (LD₅₀ = 36.46 μg/adult) showed superior contact toxicity against T. castaneum than that of the L. pteridophyllum rhizomes essential oil and SFE-CO₂ extract. It possessed potentially practical significance to develop L. pteridophyllum rhizomes into plant pesticide or repellent agent for these stored insect controls. Graphical abstract .

As a cost-effective, environmentally friendly remediation technology, phytoremediation is defined as the use of green plants to remove pollutants from the environment or render them harmless and has been applied to a variety of contaminated sites throughout the world. There is a prominent phenomenon in which publications about phytoremediation increase each year and involve an increasing number of subject categories. This paper adopts the scientometric analysis method to assess the current state and explore the trends of phytoremediation research based on the bibliographic records retrieved from the Web of Science Core Collection (WoSCC). The results of this paper clearly answer the following questions. (1) What are the publishing characteristics of research on the topic of phytoremediation? What are the characteristics of academic collaboration in phytoremediation research? (2) What are the characteristics and development trends of phytoremediation research? (3) What are the hotspots and frontiers of phytoremediation research? Overall, the research method provides a new approach for the assessment of the performance of phytoremediation research. These results may help new researchers quickly integrate into the field of phytoremediation, as they can easily grasp the frontiers of phytoremediation research and obtain more valuable scientific information. This study also provides references for the follow-up research of relevant researchers.

Reptiles are an important part of vertebrates and are the primitive terrestrial vertebrates. However, lots of reptile species are endangered or susceptible to extinction. It is no doubt that contaminants are one of the important reasons for the decline of the lizard population. In this study, the selective metabolism of triadimenol (TN) in the male Eremias argus lizards and the toxic effects of TN on lizards were studied. TN chiral isomers were separated and detected by HPLC-MS/MS system with Lux Cellulose-1 column. Tissue distribution experiments showed the existence of stereoselectivity biotransformation of TN enantiomers among organs in lizards, and RR-TN preferentially emerged over the other enantiomers. The antioxidant enzymes (SOD, CAT, GST) activities and MDA content assays demonstrated that TN induced oxidative stress in most organs, especially in the liver, and the histopathology analysis showed the severe liver and testis damage caused by 14-day continuous TN gavage. The reproductive effects of TN-induced reflected in the increased sex hormone testosterone. This research confirms that TN could induce hepatic and reproductive toxicity of E. argus lizard.

Liver injury is one of the adverse effects of methotrexate (MTX). Ferulic acid (FA) is an antioxidant phytochemical that confers hepatoprotective efficacy; however, its effect against MTX hepatotoxicity remains unexplored. This study investigated the role of FA in modulating oxidative stress, inflammation, Nrf2/HO-1 signaling, and PPARγ in MTX-administered rats. Following oral FA supplementation for 15 days, rats received a single dose of MTX at day 16 and samples were collected at day 19. MTX provoked multiple histological manifestations, including degenerative changes, steatosis, inflammatory cells infiltration and hemorrhage, and altered serum transaminases, bilirubin, and albumin. Reactive oxygen species, lipid peroxidation, and nitric oxide were increased in the liver of rats that received MTX. FA prevented all histological alterations, ameliorated liver function markers, suppressed oxidative stress, and boosted antioxidants in MTX-induced rats. FA reduced serum TNF-α and IL-1β, and hepatic NF-κB p65, Bax, and caspase-3, whereas increased Bcl-2, Nrf2, NQO1, HO-1, and PPARγ. In conclusion, FA prevented MTX hepatotoxicity by activating Nrf2/HO-1 signaling and PPARγ, and attenuating oxidative stress, inflammation, and cell death.

The native state of lignocellulosic biomass is highly resistant to enzymatic hydrolysis and the fermentation process of biofuel production. Brown-rot fungi use an extracellular Fenton system to degrade lignocellulosic biomass in the initial stages of decay. In this work, the combined effects of Mn²⁺, Fe²⁺, and NO₃⁻ inducers were evaluated based on the activities of hydrolytic enzymes and Fe³⁺ reduction as well as the catechol-type compound production during wheat straw pretreatment by the brown-rot fungus Gloeophyllum trabeum. Weight loss and chemical changes were evaluated to establish the culture conditions for stimulating wheat straw degradation using a central composite design. The results showed that weight loss and the Fe³⁺-reducing activity were promoted at the highest concentrations of Fe²⁺. A positive effect on catechol compound production by the addition of Mn²⁺ and NO₃⁻ was observed. Cellulase activity was increased at the highest concentration of NO₃⁻. The multiple optimizations of G. trabeum culture conditions in wheat straw resulted in 11.3% weight loss and 0.47 total crystallinity index at 0.24 M NO₃⁻, 0.95 mM Fe²⁺, and 0.85 mM Mn²⁺ after 40 days. The wheat straw pretreatment by G. trabeum for 10 days increased glucose recovery. The results indicated that the wheat straw pretreatment using G. trabeum with biodegradation inducers could be a complementary step to physicochemical pretreatment of lignocellulosic biomass for production of second-generation ethanol.