Metal-resistant bacteria can reduce Cd accumulation in plants, but mechanisms underlying this effect are poorly understood. In this study, a highly effective Cd-resistant WRS8 strain was obtained from the rhizoshere soil of Triticum aestivum L. Yangmai-13 and identified as Pseudomonas taiwanensis based on 16S rRNA gene sequence analysis. Strain WRS8 was investigated for its effects on Cd availability and wheat tissue Cd contents and the related mechanisms using a hydroponic culture experiment. In strain WRS8-inoculated solution, the Cd concentration reduced and the pH and cell-adsorbed Cd increased with time. Strain WRS8 increased the wheat root and above-ground tissue dry weights by 11–36% compared to the controls. In strain WRS8-inoculated wheat plants, the Cd contents of the roots and above-ground tissues decreased by 78–85% and 88–94% and the Cd bioconcentration and translocation factors decreased by 78–85% and 46–58% at days 3 and 10, respectively, compared with the controls. The root surface-adsorbed Cd contents increased by 99–121% in the WRS8 strain-inoculated wheat plants at days 3 and 10 compared to the controls. Furthermore, strain WRS8 colonized the wheat root surfaces and interiors and reduced the expression levels of the LCT1 and HMA2 genes involved in Cd accumulation and transport in wheat roots by 46% and 30%, respectively, compared to the controls. In the Cd-contaminated soils, strain WRS8 significantly reduced the available Cd content by 20–24% and increased the pH compared to the controls. These findings showed the important role of strain WRS8 in reducing solution and soil Cd availability and suggested that strain WRS8 reduced the wheat tissue Cd accumulation by increasing root surface Cd adsorption and decreasing wheat root Cd uptake and transport-related gene expression and may provide a new and effective wheat rhizobacteria-enhanced approach for reducing wheat Cd uptake in Cd-polluted environments.

Vehicular emissions are known to be major contributors of airborne polycyclic aromatic hydrocarbons (PAHs) in cities. In order to assess the long-term contamination of PAHs along roads, we collected organic films from vehicle windows (26 private cars and 4 buses, in Shanghai, China) and used mathematical models to convert the film-bound PAH concentrations to the airborne PAH concentrations. The field measurements of airborne PAHs revealed that the partitioning and Level III fugacity model was suitable to estimate the airborne concentrations of high and low volatile PAHs (expect for naphthalene), respectively. The total airborne PAH concentrations along roads in Shanghai ranged from 0.83 to 3.37 μg m⁻³ and the incremental lifetime cancer risks (ILCRₜₒₜₐₗ) by exposure to PAHs along roads were greater than the USEPA lower guideline of 10⁻⁶, indicating non-negligible carcinogenic risks to drivers and passengers, especially via ingestion processes. This study provided a practicable method to investigate long-term air contamination of PAHs in vehicles and along roads based on film-bound PAH on vehicle windows. In addition, it was also possible to investigate the health risk in vehicles as a result of exposure to PAHs. Comparisons of PAHs between roads and shipping lanes also facilitated the delineation of vehicular and shipping PAH inventories.A capsule that summarizes the main finding of the work: Investigating film-bound PAH on vehicle windows is a practicable pathway to investigate the long-term contamination of PAHs in vehicles and along roads. This method can not only simplify the sampling processes, but the model calculations. The results also enabled investigations into ILCR in vehicles and specified source apportionment of traffic PAHs.

Reusing by-products such as cow bones in agriculture can be achieved thorough pyrolysis. The potential of bone-derived biochar as a promising material for metals immobilization in contaminated mining soils has not yet been sufficiently explored. Therefore, cow bones were used as biochar feedstock were pyrolyzed at 500 °C (CBL) and 800 °C (CBH) and. The two biochars were applied to a mine contaminated soil at 0 (control), 2.5, 5 and 10%, w/w, dosages; then, the soils were incubated and cultivated by maize in the greenhouse. Cadmium (Cd) and zinc (Zn) bioavailability and their sequentially extracted fractions (acid soluble, reducible, oxidizable, and residual fraction), soil microbial function, and plant health attributes were analyzed after maize harvesting. Bone-derived biochar enhanced the content of dissolved organic carbon (up to 74%), total nitrogen (up to 26%), and total phosphorus (up to 27%) in the soil and improved the plant growth up to 55%, as compared to the control. The addition of CBL altered the acid soluble fraction of both metals to the residual fraction and, thus, reduced the content of Zn (55 and 40%) and Cd (57 and 67%) in the maize roots and shoots, respectively as compared to the control. The CBL enhanced the β-glucosidase (51%) and alkaline phosphatase activities (71%) at the lower doses (2.5–5%) as compared to control, while the activities of these enzymes decreased with the higher application doses. Also, CBL improved the antioxidants activity and maize growth at the 2.5–5% application rate. However, the activity of the dehydrogenase significantly decreased (77%), particularly with CBH. We conclude that CBL, applied at 2.5–5% dose, can be utilized as a potential low cost and environmental friendly amendment for stabilization of toxic metals in contaminated mining soils and producing food/feed/biofuel crops with lower metal content.

Microplastic pollution is a growing concern worldwide. Despite numerous studies showing the occurrence of microplastics in low-trophic level aquatic organisms, microplastic ingestion and contamination in cetaceans, especially those from Asian waters, has been rarely recorded. Here, we investigated stomach microplastic pollution in twelve Indo-Pacific humpback dolphins stranded along the Pearl River Estuary (PRE), China. We also compared microplastic abundances in dolphins stranded near populated urban areas (ZH, n = 6) with those stranded near rural areas (JM, n = 6). Microplastics were detected in all samples, with abundance ranging widely from 11 to 145 items individual⁻¹ (mean ± SD, 53 ± 35.2). Major microplastics were polypropylene and polyethylene fibers, with the size mostly ranging from 1 to 5 mm and the dominant colors of white or transparent. Humpback dolphins from ZH (73 ± 36.8 items individual⁻¹) exhibited a significantly higher average microplastic abundance than those from JM (33 ± 18.3 items individual⁻¹, p < 0.05). In particular, the highest microplastic concentration was identified in the dolphin (SC-ZH01) stranded near the mouth of the Pearl River, whereas the dolphin (SC-JM04) collected at the rural site contained the lowest concentration of microplastics, suggesting the important influence of land-based human activities on the accumulation of microplastics in the PRE. The identification of varied microplastic polymers indicated their complex source scenarios. This study suggests that, as one of top predators in the potential microplastic food chains, this cetacean species could likely serve as an endpoint biomonitoring species of microplastic pollution in the PRE or other similar estuarine ecosystems. Our results highlight the need for more studies towards better understanding the potential impacts of microplastics on this endangered species.

Although abundant evidence has suggested that early-life antibiotic exposure was associated with adipogenesis later in life, limited data were available on the effect of intrauterine antibiotic exposure on infant growth and growth speed. Additionally, few studies have investigated the role of the neonatal gut microbiota in the above association. In this study, we examined the association between intrauterine cumulative antibiotic exposure and infant growth and explored the potential role of the neonatal gut microbiota in the association. 295 mother-child pairs from the Shanghai Maternal-Child Pairs Cohort (MCPC) study were included, and meconium samples and infant growth measurements were assessed. Z-scores of length-for-age, weight-for-age (weight-for-age), and body mass index (BMI)-for-age (BMI-for-age) were calculated. Eighteen common antibiotics were measured in meconium. Multivariable linear regression models were applied to test the interrelationships between antibiotic exposure, diversity indicators, and the relative abundance of selected bacterial taxa from phylum to genus levels from least absolute shrinkage and selection operator (LASSO) and infant growth indicators. The detection rates of the 18 antibiotics, except for chlortetracycline, penicillin, and chloramphenicol, were below 10 %. Penicillin was found to be positively associated with infant growth at birth and with growth speed from 2 to 6 months. The Pielou and Simpson indexes were negatively associated with meconium penicillin. Nominally significant associations between penicillin and the relative abundances of several bacterial taxa from the phyla Proteobacteria, Bacteroidetes, and Firmicutes were found. The Pielou and Simpson indexes were also found to be negatively associated with infant growth. Among taxa selected from LASSO regression, the relative abundances of the phyla Actinobacteria and Firmicutes and order Bifidobacteriales were found to be significantly associated with weight and BMI growth speeds from 2 to 6 months. In conclusion, intrauterine antibiotic exposure can affect infant growth. The neonatal gut microbiota might play a role in the abovementioned association.

Aging is a leading cause of mortality for the elderly and DNA methylation age is reported to be predictive of biological aging. However, few studies have investigated the associations between multiple metals exposure and accelerated aging in the elderly. We performed a pilot study of 288 elderly participants aged 50–115 years and measured genome-wide DNA methylation and 22 blood metals concentrations. Measures of DNA methylation age were estimated using CpGs from Illumina HumanMethylation EPIC BeadChip. Linear mixed regression and Bayesian kernel machine regression (BKMR) models were used to estimate the individual and overall associations between multiple metals and accelerated methylation aging. Single metal models revealed that each 1-standard deviance (SD) increase in log-transformed vanadium, cobalt, nickel, zinc, arsenic, and barium was associated with a −2.256, −1.318, 1.004, −1.926, 1.910 and −1.356 changes in ΔAge, respectively; meanwhile, for aging rate, the change was −0.019, −0.013, 0.010, −0.018, 0.023, and −0.012, respectively (all P < 0.05). The BKMR models showed reverse U-shaped associations of the overall metals mixture with ΔAge and aging rate. Downward trends of ΔAge and aging rate were observed for increasing quantiles of essential metals mixture, but upward trends were observed for non-essential metals mixture. Further individual analysis of the BKMR revealed that the 95% confidence interval of ΔAge and aging rate associated with vanadium, zinc, and arsenic did not cross 0, when other metals concentrations set at 25th, 50th, and 75th percentile. Our findings suggest reverse U-shaped associations of the overall metals mixture with accelerated methylation aging for the first time, and vanadium, zinc, and arsenic may be major contributors driving the associations.

A three-dimensional hydrodynamic-antibiotic model is developed to investigate the transport and dilution of sulfamethoxazole (SMX) in the Upper Gulf of Thailand (UGoT). The simulation produced a spatially averaged annual mean SMX concentration of 0.58 μgm−3, which varied slightly between seasons assuming a temporally constant river SMX loading observed in August. In contrast, the horizontal distribution of SMX concentrations strongly varied with season because of the changing residual currents. In addition, SMX is diluted to concentrations lower than 10% of those in river waters a short distance offshore of the estuaries. To better understand this behavior, we examined the relationship between salinity and SMX concentrations in the UGoT. The annual budget demonstrates that 98% of SMX in the UGoT is removed by natural decomposition. As the concentrations of fluvial pollutants in the UGoT depend on their river loading and decomposition rates, functions were derived to predict pollutant concentrations and flushing times based on the river input flux and half-life.

Due to the unreasonable use and discharge of the aquaculture industry, over standard of the antibiotics has been frequent in different types of water environments, causing adverse effects on aquatic organisms. Lycopene (LYC) is an esculent carotenoid, which is considered to be a strong antioxidant. This study was designed to explore the therapeutic effect of LYC on antibiotic (sulfamethoxazole (SMZ)) induced intestinal injury in grass carp Ctenopharyngodon idella. The 120 carps (the control, LYC, SMZ, and co-administration groups) were treated for 30 days. We found that treatment with LYC significantly suppressed SMZ-induced intestinal epithelial cell damage and tight junction protein destruction through histopathological observation, transmission electron microscopy and detection of related genes (Claudin-1/3/4, Occludin and zonula occludens (ZO)-1/2). Furthermore, LYC mitigated SMZ-induced dysregulation of oxidative stress markers, including elevated malondialdehyde (MDA) levels, and consumed super oxide dimutese (SOD), catalase (CAT) activities and glutathione (GSH) content. In the same treatment, LYC reduced inflammation and apoptosis by a detectable change in pro-inflammatory factors (tumor necrosis factor-alpha (TNF-β), interleukin (IL)-1β, IL-6 and IL-8), anti-inflammatory factors (transforming growth factor-beta (TGF-β) and IL-10) and pro-apoptosis related genes (p53, p53 upregulated modulator of apoptosis (PUMA), Bax/Bcl-2 ratio, caspase-3/9). In addition, activation of autophagy (as indicated by increased autophagy-related genes through AMPK/ATK/MTOR signaling pathway) under the stress of SMZ was also dropped back to the original levels by LYC co-administration. Collectively, our findings identified that LYC can serve as a protectant agent against SMZ-induced intestinal injury.

In this critical review, we explored the most recent advances about the fate of antibiotics on biological wastewater treatment plants (WWTP). Although the occurrence of these pollutants in wastewater and natural streams has been investigated previously, some recent publications still expose the need to improve the detection strategies and the lack of information about their transformation products. The role of the antibiotic properties and the process operating conditions were also analyzed. The pieces of evidence in the literature associate several molecular properties to the antibiotic removal pathway, like hydrophobicity, chemical structure, and electrostatic interactions. Nonetheless, the influence of operating conditions is still unclear, and solid retention time stands out as a key factor. Additionally, the efficiencies and pathways of antibiotic removals on conventional (activated sludge, membrane bioreactor, anaerobic digestion, and nitrogen removal) and emerging bioprocesses (bioelectrochemical systems, fungi, and enzymes) were assessed, and our concern about potential research gaps was raised. The combination of different bioprocess can efficiently mitigate the impacts generated by these pollutants. Thus, to plan and design a process to remove and mineralize antibiotics from wastewater, all aspects must be addressed, the pollutant and process characteristics and how it is the best way to operate it to reduce the impact of antibiotics in the environment.

Biodegradation is responsible for most contaminant removal in plumes of organic compounds and is fastest at the plume fringe where microbial cell numbers and activity are highest. As the plume migrates from the source, groundwater containing the contaminants and planktonic microbial community encounters uncontaminated substrata on which an attached community subsequently develops. While attached microbial communities are important for biodegradation, the time needed for their establishment, their relationship with the planktonic community and the processes controlling their development are not well understood. We compare the dynamics of development of attached microbial communities on sterile substrata in the field and laboratory microcosms, sampled simultaneously at intervals over two years. We show that attached microbial cell numbers increased rapidly and stabilised after similar periods of incubation (∼100 days) in both field and microcosm experiments. These timescales were similar even though variation in the contaminant source evident in the field was absent in microcosm studies, implying that this period was an emergent property of the attached microbial community. 16S rRNA gene sequencing showed that attached and planktonic communities differed markedly, with many attached organisms strongly preferring attachment. Successional processes were evident, both in community diversity indices and from community network analysis. Community development was governed by both deterministic and stochastic processes and was related to the predilection of community members for different lifestyles and the geochemical environment.