Global climate change (GCC) significantly affects aquatic ecosystems. Continual use of pyrethroid insecticides results in contamination of these ecosystems and concurrent GCC raises the potential for synergistic effects. Resistance to pyrethroids has been documented in Hyalella azteca, a common epibenthic amphipod and model organism. Resistant H. azteca can bioconcentrate elevated amounts of pyrethroids and represent a threat to consumers via trophic transfer. In the present study, a predator of H. azteca, the inland silverside (Menidia beryllina), was used to examine the impacts of GCC on pyrethroid bioaccumulation via trophic transfer from resistant prey organisms. M. beryllina were fed ¹⁴C-permethrin dosed pyrethroid-resistant H. azteca for 14 days at three salinities (6, 13 and 20 practical salinity units (PSU)) and two temperatures (18 and 23 °C). Fish were analyzed for total body residues, percent parent compound and percent metabolites. Gene expression in liver and brain tissue were evaluated to assess whether dietary bioaccumulation of permethrin would impact detoxification processes, metabolism, and general stress responses. M. beryllina bioaccumulated significant amounts of permethrin across all treatments, ranging from 39 to 557 ng g⁻¹ lipid. No statistically significant effect of temperature was found on total bioaccumulation. Salinity had a significant effect on total bioaccumulation, owing to greater bioaccumulation at 6 PSU compared to 13 and 20 PSU, which may be due to alterations to xenobiotic elimination. Permethrin bioaccumulation and the interaction with temperature and salinity elicited significant transcriptional responses in genes relating to detoxification, growth, development, and immune response. Given the increased prevalence of pesticide-resistant aquatic invertebrates, GCC-induced alterations to temperature and salinity, and the predicted increase in pesticide usage, these findings suggest trophic transfer may play an important role in pesticide bioaccumulation and effects in predatory fish.

Microorganisms can degrade petroleum hydrocarbons, providing the advantages of low cost and few side effects towards ecosystems. Here, we evaluated the mechanisms of microbial degradation of marine petroleum hydrocarbon using metagenomics and metatranscriptomics approaches in order to provide new insight into microbial degradation of petroleum hydrocarbon. Seawater samples were collected at a depth of ∼8 m from an area near a drilling platform in the Bohai Bay and metagenomic sequencing was used to evaluate the functional potential of these marine microbial communities. Metatranscriptomic sequencing, fluorescence in-situ hybridization experiments, and flow cytometry were also performed on the microbial communities of samples subjected to 12 different culture conditions. The data were also subjected to Weighted Gene Co-expression Network Analysis (WGCNA) and co-transcription data visualization to evaluate co-transcription of gene functions. Metagenomic sequencing indicated the presence of numerous genes that were related to petroleum hydrocarbon metabolism. Further, the high co-transcription of genes in multiple pathways, indicated that groups of genes were synergistically transcribed to metabolize petroleum hydrocarbons. Metatranscriptomics also showed that microbial metabolism was highly active in the enrichments and that the transcription of a large number of prokaryotic replication and repair genes were significantly up-regulated including those encoding for the type VI secretion system (T6SS) protein, DNA polymerase I, thymidine phosphorylase, mevalonate kinase, and two-component systems. Concomitantly, the transcription of ribosomal genes involved in translation and photosynthetic genes involved in energy metabolism were down-regulated. Overall, oil and oxygen presence can increase the oil-degradation rates and related genes’ transcription. Lot different metabolisms are co-regulated to exploit nutrients derived from the metabolism of petroleum hydrocarbons. Our analysis of metagenomic, metatranscriptomic and degradation data in this study show that a widespread gene spectrum involved in oil-degradation and the cooperation among genes is of great importance.

With the regulation of perfluorooctanesulfonate (PFOS), 6:2 chlorinated polyfluoroalkyl ether sulfonate (6:2 Cl-PFESA) has been used as a potential PFOS alternative in electroplating. In this study, the uptake, translocation and phytotoxicity of PFOS and 6:2 Cl-PFESA in mung bean (Vigna radiata (Linn.) Wilczek.) were investigated. The uptake kinetics of PFOS and 6:2 Cl-PFESA fit the Michaelis-Menten equation well, suggesting that the uptake is a carrier-mediated process. The root concentration factor (RCF) of 6:2 Cl-PFESA (34.55 mL g⁻¹ dw) was 1.27 times that of PFOS (27.11 mL g⁻¹ dw), and the translocation factor (TF) of 6:2 Cl-PFESA (0.177) was 1.07 times that of PFOS (0.165). Exposure to 6:2 Cl-PFESA and PFOS both resulted in the inhibition of mung bean seedling development. Treatment with 6:2 Cl-PFESA and PFOS led to the concentration-dependent elevation of malondialdehyde (MDA), carbonyl groups, and phosphorylated histone H2AX (γ-H2AX) levels in mung bean roots. The MDA and carbonyl group contents induced by 6:2 Cl-PFESA were 1.10–1.35 and 1.03–1.14 times, respectively, those of PFOS. The hydroxyl free radical (·OH) levels in mung bean roots after exposure to PFOS and 6:2 Cl-PFESA were elevated significantly, and the ·OH levels induced by 6:2 Cl-PFESA were higher than those induced by PFOS. Hydroxyl free radical levels were positively correlated with the MDA and carbonyl group contents in mung bean roots (p < 0.05). The dynamic changes in some antioxidative enzyme activities in mung bean seedlings were determined, including peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT). The results demonstrated the phytotoxicities of 6:2 Cl-PFESA and PFOS to mung bean in the early developmental stage. 6:2 Cl-PFESA is more harmful to mung beans than PFOS. The production of hydroxyl radical is the mechanism that causes the toxicity of PFOS and 6:2 Cl-PFESA toward plants.

High concentration particulate matter 2.5 released from forest fires, in addition to direct burns and asphyxia, PM₂.₅ is one of the main pollutants which threaten the safety of forest fire fighter. Therefore, to assess spatial distribution of PM₂.₅, a simulation study was conducted. Fuel beds with different moisture contents and loads were constructed. 144 times burning experiments were carried out under different wind speeds by using wind tunnel device. PM₂.₅ particles at different spatial points were collected and calculated. The results show that, in the two of three variables interaction between wind speed, fuel load, and, except fuel moisture content, wind speed and fuel load are positively correlated with the PM₂.₅ concentrations. From PM₂.₅ concentration which collected at each point in the horizontal and vertical directions, the overall trend is that PM₂.₅ concentration increases along the horizontal downwind direction (C and D higer than A and B) and the vertical upward direction (A and C higer than B and D) Based on BP neural network, the spatial distribution model of PM₂.₅ concentration with single hidden layer was established. The prediction accuracy of modeling samples and validation samples is balanced when hidden layer node is 5. This study will help to make reference for PM₂.₅ occupational exposure standards, forest fire smoke management and forest fire management in China.

Herein, a pH-independent interpenetrating polymeric networks (Fe-SA-C) were fabricated from graphitic biochar (BC) and iron-alginate hydrogel (Fe-SA) for removal of Cr(VI) and Pb(II) in aqueous solution. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and scanning electron microscope (SEM) results demonstrated that graphitic BC interpenetration increased surface porosity and distorted surfaces of Fe-SA, which boosted availability of hydroxyl (-OH) group. Fe³⁺ as a cross-linking agent of the alginate endowed Fe-SA-C with positive surfaces (positive zeta potential) and excellent pH buffering capacity, while excessive Fe³⁺ was soldered on Fe-SA-C matrix as FeO(OH) and Fe₂O₃. Cr(VI) removal at pH of 3 by Fe-SA-C (20.3 mg g⁻¹) were 30.3% and 410.6% greater than that by Fe-SA and BC, respectively. Fe-SA-C exhibited minor pH dependence over pH range of 2–7 towards Cr(VI) retention. Greater zeta potential of Fe-SA-C over Fe-SA conferred a better electrostatic attraction with Cr(VI). FTIR and XPS of spent sorbents confirmed the reduction accounted for 98.5% for Cr(VI) removal mainly due to participation of –OH. Cr(VI) reduction was further favored by conductive carbon matrix in Fe-SA-C, as evidenced by more negative Tafel corrosion potential. Reductively formed Cr(III) was subsequently complexed with carboxylic groups originating from oxidation of –OH. Thus, Cr(VI) removal invoked electrostatic attraction, reduction, and surface complexation mechanisms. Pb(II) removal with excellent pH independence was mainly ascribed to surface complexation and possible precipitation. Thus, the functionalized, conductive, and positively-charged Fe-SA-C extended its applicability for Cr(VI) and Pb(II) removal from aqueous solutions in a wide pH range. This research could expand the application of hydrogel materials for removal of both cationic and anionic heavy metals in solutions over an extended pH range.

Parabens (PBs) are widely used as preservatives in food, pharmaceuticals and personal care products (PCPs). Due to their potential characteristics, similar to endocrine-disrupting compounds, their safety in our daily products and frequent exposure to human health have become public concerns. Nevertheless, little information is available about the occurrence of PBs in outdoor environments and their implications for human exposure. In this study, seven pairs of gas- and particle-phase air samples and 48 soil samples from Harbin City, China, were collected for the analysis of eight typical PBs (including methyl-paraben, ethyl-paraben, propyl-paraben, isopropyl-paraben, butyl-paraben, isobutyl-paraben, benzyl-paraben, and heptyl-paraben), which have been frequently selected as target compounds in previous studies. Concentrations of ∑₈PBs in outdoor air samples were 253–1540 pg/m³ with a median of 555 pg/m³. The results of the gas-particle partitioning indicated that PBs had not reached equilibrium between the gas phase and particle phase. Concentrations of ∑₈PBs in the soil samples were <LOQ-5530 ng/kg dw. Higher concentrations of PBs were observed in soils from commercial and residential areas with extensive anthropogenic activities. Based on the inhalation rate of air and ingestion rate of soil, the estimated daily intake (EDI) was calculated. The EDI values (EDIₐᵢᵣ + EDIₛₒᵢₗ) for male adults, female adults and children were comparable, with mean values of 2.74 × 10⁻², 3.21 × 10⁻² and 2.70 × 10⁻² ng/kg-bw/day, respectively. All EDIs were much lower than the daily acceptable intake, indicating lower health risk with PB occurrence in outdoor environments. Finally, the total EDI from all external exposure routes (outdoor air, indoor air, soil, indoor dust, foodstuffs, pharmaceuticals and PCPs) was calculated for the first time. The total EDI was not consistent with that of the internal exposure, which provided new insight into future studies for human exposure assessment.

Although already eliminated in most industrial processes, mercury, as an essential ingredient in all energy-efficient lighting technologies, is still used in fluorescent lamp manufacturing. This study was conducted to investigate the atmospheric pollution caused by fluorescent lamp production and assess the associated public health risk in a large industrial and commercial city of south China, Zhongshan, which is a major production hub of lighting products. Concentrations of total gaseous mercury (TGM) in the atmosphere were measured over a total of 342 sites in the industrial, commercial, and residential areas. The average levels of TGM in the industrial, commercial, and residential areas prior to the landing of a typhoon were 12 ± 11, 3.6 ± 2.1, and 2.7 ± 1.3 ng⋅m⁻³, respectively. TGM concentrations in the industrial areas exhibited significant diurnal variation, with levels in the working hours being much higher than those in the non-working hours, which indicates that the high atmospheric mercury concentrations were contributed by local emissions, instead of regional transport. Most fluorescent lamp manufacturing activities in the city were shut down during a typhoon event, which resulted in a significant reduction in the average TGM level (down to 1.6 ± 1.8 ng⋅m⁻³) and rendered the difference in the average TGM levels in the industrial areas no longer significant between the working and non-working hours. Elevated TGM levels (up to 49 ng⋅m⁻³) were found near clusters of small-scale fluorescent lamp workshops in both industrial and commercial areas, which is indicative of significant emissions of mercury vapor resulting from obsolete equipment and production technologies. No significant non-carcinogenic risk was found for the general residents in the sampling area over the study period, while the risk for the workers in the fluorescent lamp manufacturing facilities and workshops could be higher. These findings indicate that fluorescent lamp manufacturing in the developing countries is a major source of atmospheric mercury.

The present paper reports on the interrelationships of fish, parasites and the bioaccumulation of hazardous organic compounds in the Zemplínska Šírava water reservoir in eastern Slovakia, which is heavily polluted with polychlorinated biphenyls (PCBs). The concentrations of these contaminants were measured in various fish matrices (dorsal and abdominal muscle tissues, hepatopancreas, intestine wall and adipose tissue) of the freshwater bream, Abramis brama (Cyprinidae), and in its intestinal parasite Caryophyllaeus laticeps (Cestoda), which was used for the first time as a model for a PCB bioaccumulation study. Regarding the fish, the highest concentrations of PCBs were found in the intestine, followed by hepatopancreas and muscle tissues. The amounts of PCBs were higher in abdominal muscles than in their dorsal parts. Concentrations of ∑PCBs above the limits set by European regulations were detected in both muscle parts in the fish, confirming the persistent unfavorable conditions in this locality and high risk for biota and humans. Based on bioconcentration factor values (BCFs), PCBs reached much higher levels in cestodes compared to bream matrices. Some significant differences in PCB amounts between infected and uninfected bream were determined. Fulton's condition factor (CF) significantly differed in infected and non-infected fish (p ˂ 0.05), with CF values surprisingly lower in fish free of parasites compared to parasitized fish, which suggests a “mutualistic” relationship between the parasite and its host.

Composting is an effective technology to recycle organic solid waste as a green resource. However, pharmaceutical fermentation residue (PFR) contains a variety of pollutants, such as residual drug and antibiotic resistance genes (ARGs), which limits the green cycle of using PFR as a resource. To promote the green recycling of PFR, this study evaluated the characteristics of abundance and the response relationship of ARGs during the process of rapid composting. Different rapid composting samples were collected, and DNA was extracted from each sample. The absolute abundance of ARGs was quantified using quantitative PCR, and the microbial community structure was identified using high-throughput sequencing. The results showed that ermB, ermF, tetM and tetQ were reduced by 89.55%, 15.10%, 89.55%, and 82.30% respectively, and only sul2 increased by approximately 5-fold. Mobile genetic elements (MGEs) directly affected the changes in abundance of ARGs. As typical MGEs, intl1 and intl2 decreased by 3.40% and 54.32%, respectively. Potential host microorganisms important factors that affected ARGs and MGEs. A network analysis indicated that the potential host microorganisms were primarily distributed in Firmicutes and Proteobacteria at the phylum level. The pH and content of water-extractable sulfur were physicochemical parameters that substantially affected the abundance of potential host microorganisms through redundancy analysis. Industrial-scale rapid composting could reduce the number of ARGs and shorten the composting cycle, which merits its popularization and application.

The application of hydrogen peroxide (H₂O₂) to control harmful algal blooms is affected by algal density and species. In the present study, a simulation field study was carried out to evaluate the removal of cyanobacteria with high algal density (chlorophyll a of approximately 220–250 μg/L) and low algal density (chlorophyll a of approximately 30–50 μg/L) using 10, 20 mg/L H₂O₂ and 5 mg/L H₂O₂. The dynamics of algal biomass, nutrients, microcystins, phytoplankton, and zooplankton were measured within 7 d. The results showed that 5 mg/L H₂O₂ effectively eliminated algal biomass (measured as chlorophyll a and phycocyanin) and inhibited 50% of the photosynthetic activity of the cyanobacteria at 7 d in the low algal cell density group, while the same inhibition rate was observed in the high algal cell density group when the H₂O₂ was 20 mg/L. However, using a high dosage of H₂O₂, such as 10 mg/L, to suppress cyanobacteria with high biomass could result in a dramatic increase in nutrients and microcystins in the water column. The portion of eukaryotic algae, such as Chlorophyta, Bacillariophyta and Euglenophyta, in the phytoplankton community increased with increasing H₂O₂ concentrations; moreover, the dominant species of cyanobacteria changed from the nontoxic genus Dactylococcopsis to the toxic genus Oscillatoria, which may result in acute toxicity to zooplankton. Our results demonstrated that the application of H₂O₂ to control cyanobacterial blooms at the early stage when algal cell density was low posed less potential ecological risks and may have increased the diversity of the phytoplankton community.