Antibiotic resistance is a growing problem for ecosystem health and public healthcare. Hence, the transmission of antibiotic resistance from human and animal origins to natural environments requires careful investigation. In this study, nine antibiotic resistance genes (ARGs), three mobile genetic elements (MGEs), and their relations with antibiotics, heavy metals, and microbiota were investigated in 16 sample sites (Xinxiang, China). Fluoroquinolones (0.13–14.22 μg/L) were most abundant in hospital effluent and oxytetracycline (251.86–5817.47 μg/kg) in animal manure. Animal manure showed the highest levels of zinc (80.79–2597.14 mg/kg) and copper (32.47–85.22 mg/kg), possibly affecting the prevalence of intI1 and aac(6′)-Ib genes. Aminoglycoside and sulfonamide resistance genes (aac(6’)-Ib, aadA, and sul1) were the main ARGs in this area. In addition, the detected ARGs and MGEs were higher in animal manure than in hospital effluent, except for the sul1 gene. On the other hand, the incomplete removal of antibiotics (29.76–100%), heavy metals (31.25–100%), and ARGs (1–3 orders of magnitude) in MWWTPs resulted in the accumulation of these contaminants in the receiving river. Network analysis suggested that the potential hosts (Jeotgalibaca, Atopostipes, Corynebacterium_1, etc.) of ARGs were more predominant in animal manure rather than hospital effluent, indicating a higher ARG transfer potential in animal manure compared with hospital sources. These results provide useful insights into the different migration and dissemination routes of antibiotics, heavy metals, ARGs, and microbiota from anthropogenic and animal origins to their receiving environments via MWWTP discharge and manure fertilization.

At present, the simultaneous removal of organic dyes and heavy metals in complex wastewater has raised considerable concern, owing to their striking differences in physicochemical properties. Adsorption, as one of the few removal methods, has attracted extensive attention and gained popularity. Herein, a versatile EDTA and chitosan bi-functionalized magnetic bamboo biochar adsorbent (ECMBB) was synthesized for coinstantaneous adsorption of methyl orange (MO) and heavy metals (Cd(II) and Zn(II)). In this case, the as-synthesized ECMBB composites inherited favorable anionic MO removal performance from bamboo biochar (BB) obtained at 700 °C through electrostatic attraction, hydrogen bonding and π-π interaction, also enhanced the binding of cationic metals by introducing amino groups of chitosan and carboxyl groups of EDTA. In the unitary system, the removal of MO, Cd(II) and Zn(II) by three as-prepared adsorbents can be well illuminated by pseudo-second-order kinetic model and Langmuir isotherm theory. The saturated capture amounts of ECMBB at 25 °C are 305.4 mg g⁻¹ for MO, 63.2 mg g⁻¹ for Cd(II) and 50.8 mg g⁻¹ for Zn(II), which, under the same conditions, are 1.3, 2.6 and 2.5 times those of chitosan-modified magnetic bamboo biochar (CMBB) and 1.9, 6.1 and 5.4 times those of magnetic bamboo biochar (MBB), respectively. Remarkably, in MO-metal binary system, coexisting MO visibly enhanced the adsorption of Cd(II) and Zn(II), while coexisting heavy metals had no significant impact on MO adsorption. Furthermore, ECMBB exhibited no significant loss in adsorption efficiency even after eight adsorption-desorption experiments. This study lays the foundation for fabricating desired integrative biochar adsorbents in the simultaneous purification of organic and metallic pollutants from complex wastewater.

Studies on the health effects of long-term ozone exposure remain limited with mixed results. One potential source of this inconsistency is the difference in exposure time metrics. This study aimed to investigate the association between long-term exposure to ambient ozone and mortality in South Korea, using different exposure metrics. We also examined whether heterogeneity between previous studies was due to the different exposure metrics. The study population comprised 179,806 participants from the National Health Insurance Service-National Sample Cohort (2002–2015) residing in seven major cities in South Korea. Several ozone exposure metrics (year-round 24-h, year-round 8-h, warm-season 24-h, and warm-season 8-h) were calculated. Time-varying Cox proportional hazards models were used to estimate the association between ozone and all-cause and cause-specific mortalities. Random-effect meta-analysis and meta-regression analysis were performed to pool the effect estimates of previous studies and examine whether the exposure metric can explain the between-study heterogeneity. The hazard ratios (HRs) per 10 ppb increment in year-round 24-h ozone for all-cause (HR, 1.18; 95% CI, 1.07–1.29) and circulatory (HR, 1.52; 95% CI, 1.25–1.84) mortality were higher than those of the other metrics. Year-round 8-h ozone exhibited the largest association with respiratory mortality (HR, 1.43; 95% CI, 1.04–1.96). A meta-analysis of 29 previous studies and the present study showed the largest HR for all-cause mortality from studies using year-round 8-h exposure (HR, 1.014; 95% CI, 0.994–1.033). The exposure metric was significantly associated with effect estimates in the multivariable meta-regression model. In conclusion, in the population-based cohort in South Korea, we found positive associations between several long-term ozone exposure metrics and mortality. The different ozone exposure metrics exhibited heterogeneous effect estimates. A year-round 24-h average ozone metric also could be considered an alternative long-term standard for ozone.

Anthropogenic aquatic noise is recognised as an environmental pollutant with the potential to negatively affect marine organisms. Seismic surveys, used to explore subseafloor oil reserves, are a common source of aquatic noise that have garnered attention due to their intense low frequency inputs and their frequent spatial overlap with coastal fisheries. Commercially important Southern Rock Lobster (Jasus edwardsii) adults have previously shown sensitivity to signals from a single seismic air gun. Here, the sensitivity of J. edwardsii juveniles and puerulus to the signals of a full-scale seismic survey were evaluated to determine if early developmental stages were affected similarly to adults, and the range of impact. To quantify impact, lobster mortality rates, dorsoventral righting reflex and progression through moult cycle were evaluated following exposure. Exposure did not result in mortality in either developmental stage, however, air gun signals caused righting impairment to at least 500 m in lobsters sampled immediately following exposure, as had previously been reported in adults with corresponding sensory system damage following exposure. Impairment resulting from close range (0 m) exposure appeared to be persistent, as previously reported in adults, whereas juveniles exposed at a more distant range (500 m) showed recovery, indicating that exposure at a range of 500 m may not cause lasting impairment to righting. Intermoult duration was (time between moults) significantly increased in juveniles exposed at 0 m from the source, indicating the potential for slowed development, growth, and physiological stress. These results demonstrate that exposure to seismic air gun signals have the potential to negatively impact early life history stages of Southern Rock Lobsters. The similarity of both the impacts and the sound exposure levels observed here compared to previous exposure using a single air gun offer validation for the approach, which opens the potential for accessible field-based experimental work into the impact of seismic surveys on marine invertebrates.

Recycling of electronic waste (e-waste) and inevitable pollution under current technology have always been a concern of people. Generation and release of pollutants in the recycling process of e-waste are closely related to processing technology and equipment. In this paper, the pollution characteristics of different functional areas and critical processing units in formal e-waste dismantling base have been studied systematically and comprehensively. The results showed that the overall pollutants concentration in crushing workshop and cathode ray tube (CRT) monitor disposing workshop are much higher than other functional areas. Screen-cone glass separation for CRT monitor was the processing unit with the greatest exposure risk and the hazard index (HI) of Pb was 4.60. Pollutant emission factor of the main processing units was calculated and the waste printed circuit board (WPCB) crushing was the most polluted unit. Appropriate improvements in technology and equipment can effectively reduce the generation and release of pollutants. Some reasonable prospects about intelligent equipment and special technologies were proposed for e-waste disposal. All the results provided theoretical and data support for pollution control and technology upgrade of the formal e-waste dismantling base.

Estimations of greenhouse gas (GHG) emissions from municipal wastewater treatment plants (MWTPs) remain significant uncertainties in China owing to a lack of reliable emission factors (EFs). This study developed a framework to obtain multi-level (technology, province, and nation) GHG EFs of MWTPs using a database containing 3107 MWTPs in China and published site-specific monitoring data. Results show that GHG EFs of different technologies range widely from 180.0 to 615.7 g CO₂-eq/t wastewater, and significant differences are also observed among different provinces in China (190.5–600.3 g CO₂-eq/t wastewater), which are generally lower than the previous estimates. It confirms the importance of more detailed technology classification and considering the technological disparity of different provinces in refining GHG estimations of MWTPs. To test the feasibility of the developed EFs, we compared GHG emissions from MWTPs based on multi-level EFs at different spatial and temporal scales. Similar estimation results imply that selecting corresponding EF depending on the availability of activity data would simplify GHG estimations of MWTPs without sacrificing much accuracy. This study contributes a set of well-developed EFs to improve the estimates of GHG emissions from MWTPs, and also offers a method to develop GHG EFs for other sectors.

Comparative investigations of microplastic (MP) occurrence in the global ocean are often hampered by the application of different methods. In this study, the same sampling and analytical approach was applied during five different cruises to investigate MP covering a route from the East-Siberian Sea in the Arctic, through the Atlantic, and into the Antarctic Peninsula. A total of 121 subsurface water samples were collected using underway pump-through system on two different vessels. This approach allowed subsurface MP (100 μm–5 mm) to be evaluated in five regions of the World Ocean (Antarctic, Central Atlantic, North Atlantic, Barents Sea and Siberian Arctic) and to assess regional differences in MP characteristics. The average abundance of MP for whole studied area was 0.7 ± 0.6 items/m³ (ranging from 0 to 2.6 items/m³), with an equal average abundance for both fragments and fibers (0.34 items/m³). Although no statistical difference was found for MP abundance between the studied regions. Differences were found between the size, morphology, polymer types and weight concentrations. The Central Atlantic and Barents Sea appeared to have more MP in terms of weight concentration (7–7.5 μg/m³) than the North Atlantic and Siberian Arctic (0.6 μg/m³). A comparison of MP characteristics between the two Hemispheres appears to indicate that MP in the Northern Hemisphere mostly originate from terrestrial input, while offshore industries play an important role as a source of MP in the Southern Hemisphere. The waters of the Northern Hemisphere were found to be more polluted by fibers than those of the Southern Hemisphere. The results presented here suggest that fibers can be transported by air and water over long distances from the source, while distribution of fragments is limited mainly to the water mass where the source is located.

Although a growing number of studies have reported microplastics (MPs) in biosolids and soils, there are significant differences in the concentrations found across different regions worldwide. This has raised questions about the quality of studies due to a lack of standardized sampling and analysis methods for detecting MPs in such complex samples. In this study, we applied a systematic quantitative literature review (SQLR) methodology to analyze studies reporting MPs in sludge/biosolids and agricultural soils. We also assessed the quality of individual studies on MPs in sludge/biosolids and soils based on the inclusion of quality assurance/quality control (QA/QC) procedures. There is limited understanding about MPs in soils with a history of biosolid application with only 9% of publications reporting MPs in biosolid-amended soil. There was almost eight orders of magnitude difference (3.4 × 10⁻⁵ to 9.4 × 10³ particles/g) between the highest concentrations of MPs in sludge/biosolid samples compared to the lowest virgin soil samples. The literature shows a consistency in the polymer types (polyester, PP and PE) and morphotypes (fibres and fragments) of MPs most frequently detected in biosolids and soils, suggesting a potential role of biosolids in soils MP pollution. Despite the large variations in the sizes of MPs, there was a negative correlation between the lowest size detected and concentrations reported. This indicates that current concentrations of MPs are influenced by the detection size. Our assessment shows that the majority of studies to-date lack critical QA/QC measures, particularly field blank, positive control and method validation. This highlights an urgent need for quality improvement of future research in this field to produce reliable data, ultimately crucial to assess the risk of MPs and derive suitable environmental guidelines. It is recommended that MPs studies methodically include QA/QC protocols at every step of the process to ensure the integrity of the data that is published.

Antimicrobial resistance genes (ARGs) and virulence factor genes (VFGs) constitute a serious threat to public health, and climate change has been predicted to affect the increase in bacterial pathogens harboring ARGs and VFGs. However, studies on bacterial pathogens and their ARGs and VFGs in permafrost region have received limited attention. In this study, a metagenomic approach was applied to a comprehensive survey to detect potential ARGs, VFGs, and pathogenic antibiotic resistant bacteria (PARB) carrying both ARGs and VFGs in the active layer and permafrost. Overall, 70 unique ARGs against 18 antimicrobial drug classes and 599 VFGs classified as 38 virulence factors were detected in the Arctic permafrost region. Eight genes with mobile genetic elements (MGEs) carrying ARGs were identified; most MGEs were classified as phages. In the metagenome-assembled genomes, the presence of 15 PARB was confirmed. The soil profile showed that the transcripts per million (TPM) values of ARGs and VFGs in the sub-soil horizon were significantly lower than those in the top soil horizon. Based on the TPM value of each gene, major ARGs, VFGs, and these genes in PARB from the Arctic permafrost region were identified and their distribution was confirmed. The major host bacteria for ARGs and VFGs and PARB were identified. A comparison of the percentage identity distribution of ARGs and VFGs to reference databases indicated that ARGs and VFGs in the Arctic soils differ from previously identified genes. Our results may help understand the characteristics and distribution of ARGs, VFGs, and these genes in PARB in the Arctic permafrost region. This findings suggest that the Arctic permafrost region may serve as potential reservoirs for ARGs, VFGs, and PARB. These genes could pose a new threat to human health if they are released by permafrost thawing owing to global warming and propagate to other regions.

Pyrethroids are a class of widely used insecticides. Our recent epidemiological study of Chinese women reported that pyrethroid exposure was positively associated with the risk of primary ovarian insufficiency (POI). In this study, we utilized cypermethrin (CP), the most frequently detected pyrethroid in the environment, to recognize how lifelong and low-dose exposure to pyrethroids affects ovarian functions and the underlying mechanism(s). Female mice were exposed to CP at doses of human dietary intake of 6.7 μg/kg/day, an acceptable daily intake (ADI) of 20 μg/kg/day, or the chronic reference dose (RfD) of 60 μg/kg/day, starting from gestational day 0.5 until 44-week-old. We assessed effects on fertility, serum hormone levels, ovarian follicular development and ovarian transcriptomic profiles. Chronic exposure to CP at doses of ADI and RfD caused a significant reduction in the size of the primordial follicle pool on postnatal day (PND) 5 and the number of all types of follicles in 44-week-old mice, lower estrogen and higher gonadotropin levels, as well as decreased fertility. Significant increase in apoptosis and decrease in cell proliferation were observed in CP-exposed ovarian follicles from PND 5 and 44-week-old mice. Ovarian transcriptomic data showed that the pro-apoptotic protein BMF and the cell cycle inhibitor p27 were significantly up-regulated in CP-exposed ovaries. Cyp17a1, Cyp19a1 and Hsd17b1 genes involved in the key steps of steroidogenesis were down-regulated in the ovaries of female mice exposed to CP. This study first reported that lifelong exposure to CP at doses of ADI or RfD caused an ovarian phenotype similar to human POI in female mice and provided a mechanistic explanation. Our findings suggest that lifelong exposure to pyrethroids of low doses, which are recommended as ‘safe’ dosages, may have a significant impact on the ovarian health of female mammals and humans.