Fluoride (F) is an emerging pollutant that originates from multiple sources and adversely affects plant growth and nutrient bioavailability in soil. This greenhouse study investigated the effects of soil F (0, 10, 20, 50, 100, 200 mg kg⁻¹) on morpho-physiological growth characteristics of wheat, soil F contents, and bioavailability and uptake of F, phosphorus (P), sulphur (S), potassium (K), calcium (Ca), magnesium (Mg), aluminium (Al), iron (Fe), manganese (Mn), silicon (Si) and zinc (Zn) by wheat. Higher F significantly reduced plant height and number of leaves particularly at early growth stages and increased visible leaf injury index. Powdery mildew infestation coincided with leafy injury and was higher in elevated soil F treatments. Fluoride treatments (>50 mg kg⁻¹) significantly increased water (H₂O)- and calcium chloride (CaCl₂)-extractable F contents in soil. Water-extractable soil F contents from soil in all concentration were higher than CaCl₂-extractable F. This increased F bioavailability resulted in significantly higher F uptake and accumulation in live leaves, dead leaves and grains of wheat which followed order: live leaves > dead leaves > grains. Leaf injury index and number of dead leaves correlated significantly positively with soil H₂O- and CaCl₂-extractable F contents. Patterns of nutrient (P, K, S) and trace metals (Al, Ca, Mg, Fe, Mn, Si, Zn) varied significantly with F concentrations and between live and dead leaves, and grains except for Zn. Dead leaves generally had higher nutrients and trace metals than live leaves and grains. Fluoride contents in live leaves, dead leaves and grains showed positive correlations with nutrient elements but negative with trace metals. Number of dead leaves correlated negatively with Al, Ca, Fe, Mg, S and Si but positively with P and Zn contents in dead leaves whereas leaf injury index showed positive correlation with Fe, K, P, Si, Zn, S but negative with Al, Ca and Mg contents. These observations provided evidence of higher F uptake and associated impairment in nutrient and trace metal accumulation which caused leaf injury accompanied by powdery mildew infestation in wheat. However, further research in the region is required to confirm the relationship between F pollution, leaf injury and trace metal accumulation in crops under field conditions.

We reconstructed the palaeoenvironmental conditions of Cartagena Bay during the Holocene after a multidisciplinary study to identify natural variations and the anthropic processes of this coastal area. A total of 119 samples were recovered for amino acid racemization dating, 3 for radiocarbon dating (¹⁴C), and four sets of 80 samples for sedimentological and palaeontological determination, mineralogical content, biomarker and trace elements quantification. Two natural scenarios were identified from the variations of n-alkane indices and palaeobiological content. The first period (6650–5750 yr cal BP) was marked by the development of euhaline marine conditions with strong inputs from aquatic macrophytes and high biodiversity. After a hiatus, the area underwent a profound change, becoming a paucispecific brackish marsh environment with increasing inputs from land plants, with possible episodes of emersion with a greater presence from terrestrial gastropods (3600–300 cal yr BP). By combining trace element abundance and stanol distributions, our study also provides a novel approach to identify the predominant influence of anthropogenic factors in the last three millennia in the coastal record of Cartagena Bay. Findings confirmed that Pb mining and metallurgy began during the Bronze Age, with considerable inputs of this heavy metal into the atmosphere during Phoenician, Punic and particularly Roman times compared to the Middle Ages. Pollution by Cu and Zn was also observed during Punic and Roman times, and was first documented in the Middle Ages. In addition, faecal stanols, such as coprostanol, derived mainly from humans, and 24-ethylcoprostanol from herbivores were present, thereby indicating for the first time a continuous presence of human populations and significant pollution input since 3600 yr cal BP, this being greater in the late Bronze Age and Phoenician, Punic and Roman times than during Late Antiquity and the Middle Ages, when the city was in decline.

Modelling natural attenuation is crucial to managing pharmaceuticals. However, little is known about the mechanism behind their in-stream sorption. To better understand the in-stream attenuation of the highly sorptive antibiotics azithromycin (AZM) and levofloxacin (LVF), we monitored them in a 2.1-km stretch of the Asano River under diverse flow conditions. This stretch receives effluent directly from a sewage treatment plant (STP), which was a dominant source of the pharmaceuticals. Average distribution coefficients between dissolved and particulate phases (Kd,SPM) in the outflow river water were 6.3×105 L/kg for AZM and 7.5×104 L/kg for LVF, while those in the STP effluent were 1–2 orders of magnitude lower. Mass balances in the river stretch calculated by considering only dissolved phase (MBw) and both dissolved and particulate phases (MBs) were 8%–52% and 58%–102%, respectively, for AZM, and 58%–71% and 60%–105% for LVF. MBw<MBs is attributed to an increase in suspended particulate matter (SPM)-mediated mass flows in the river stretch, i.e., in-stream sorption to SPM, which was caused mainly by their much higher river Kd,SPM values than those in the effluent. Their river Kd,SPM values increased on higher-flow days with decreasing effluent content in the river water, resulting in the increase of their in-stream SPM sorption. Their in-stream loss from the entire water column (i.e., 100−MBs), which was attributable to their mass transfer from the overlying water to sediment through sorption, was decreased on higher-flow days by hydrological factors. A key finding is that AZM and LVF mostly entered the river stretch in the dissolved phase of STP effluent, whereas they existed substantially in the particulate phase in the outflow river water, especially on high-flow days.

Low sulfur fuel oils (LSFOs) with less than 0.5% sulfur content have been mandated for marine vessels by the International Maritime Organization since 2020. However, owing to the low dispersibility and high viscosity of LSFOs, their oceanic spills are difficult to clean using conventional response systems. In this study, we propose a superhydrophilic and hygroscopic ramie to clean spilled LSFO. To this end, a raw ramie fiber, which is intrinsically hydrophobic, was treated using a mild alkali to remove its waxy, rough, and gummy veneer and reveal a smooth surface. This substantially improved its hygroscopic nature, superhydrophilicity, and water-retention, while preserving its mechanical durability in dry and wet environments. The hygroscopic ramie exhibited underwater superoleophobicity and self-cleaning abilities against highly adhesive LSFOs. Two proofs-of-concept are demonstrated in this study—an oil-proof glove for maximizing oil repellency and a direct oil-scooping device for simple and continuous recovery of spilled oil with high efficiency.

Although BHPF has been widely used in plastic manufacturing as a substitute for BPA, current evidence suggests that BHPF also causes harmful effects on reproduction. However, effects of BHPF on mammalian early pregnancy are still poorly defined. This study aimed to explore the effects of BHPF on early pregnancy, especially decidualization and embryonic development in mice and human beings. The results showed that 50 and 100 mg/kg BHPF exposure reduced birth weight, and implantation site weight on the day 8 of pregnancy in mice. Because BHPF inhibits both embryo development and artificial decidualization in mice, suggesting that the detrimental effects of BHPF should be from its effects on embryo development and decidualization. Under in vitro decidualization, 10 μM BHPF inhibits decidualization and leads to disordered expression of Lamin B1 and collagen in mice. In addition, 10 μM BHPF also inhibits decidualization, and causes disordered expression of both collagen III and Lamin B1 under human in vitro decidualization. However, collagen III supplementation can rescue BHPF inhibition on decidualization. Further, our study demonstrates that BHPF impairs human decidualization through the HB-EGF/EGFR/STAT3/Collagen III pathway. Taken together these data suggest that exposure to BHPF impairs mouse and human decidualization during early pregnancy.

Ozone levels have been declining in the Los Angeles, CA, USA area for the last four decades, but there was a recent uptick in the 4th highest daily maximum 8-h (MDA8) ozone concentrations from 2014 to 2018 despite continued reductions in the estimated precursor emissions. In this study, we assess the emissions and meteorological impacts on the 4th highest MDA8 ozone concentrations to better understand the factors affecting the observed MDA8 ozone using a two-step generalized additive model (GAM)/least squares approach applied to the South Coast Air Basin (SoCAB) for the 1990 to 2019 period. The GAM model includes emissions, meteorological factors, large-scale climate variables, date, and the interactions between meteorology and emissions. A least squares method was applied to the GAM output to better capture the 4th highest MDA8 ozone. The resulting two-step model had an R² of 0.98 and a slope of 1 between the observed and predicted 4th highest MDA8 ozone. Emissions and the interactions between the maximum temperature and emissions explain most of the variation in the peak MDA8 ozone concentrations. Declining emissions have lowered the 4th highest MDA8 ozone concentration. Meteorology explains the higher than expected 4th-high, ozone levels observed in 2014–2018, indicating that meteorology was a stronger forcer than the continued reductions in emissions during that time period. The model was applied to estimate future ozone levels. Meteorology developed from climate modeling of the representative concentration pathway (RCP) scenarios, and two sets of emissions were used in the application. The modeling results indicated climate trends will push ozone levels slightly higher if no further emissions reductions are realized and that of two emissions trajectories modeled, the more stringent is required to reliably meet the federal ozone standard given annual meteorological variability.

Most bitumen in the Alberta oil sands (Canada) is extracted by thermal in-situ recovery. Despite the widespread use of in-situ bitumen extraction, little information is available on the release of petroleum hydrocarbons by this method to adjacent land and water. Here we analyzed the composition and abundance of parent and alkylated polycyclic aromatic compounds (PACs) in 11 radiometrically-dated lake sediment cores collected near in-situ operations at Cold Lake Alberta to assess potential petroleum contamination sources to surrounding lakes over the past century. Like open-pit mining areas, alkylated PACs in Cold Lake sediments were elevated compared to unsubstituted parent PACs and increased coeval with the onset of bitumen extraction in the area. Diagnostic ratios and pyrogenic indices showed that PAC sources to these lake sediments were dominantly pyrogenic, likely from historic forest fires, however they shifted to more petrogenic sources coeval with expanding oil sands extraction at Cold Lake. PACs in sediment from regional lakes are weakly correlated to their proximity to in-situ oil wells, once corrected for lake area. These results suggest that in-situ operations, via diesel-fueled vehicular emissions and the combustion of natural gas for steam generation, are a source of PACs to nearby lakes, but PACs did not exceed Canadian sediment quality guidelines for the protection of aquatic life.

Reliable attribution is crucial for understanding various climate change issues. However, complicated inner-interactions between various factors make causation inference in atmospheric environment highly challenging. Taking PM₂.₅-Meteorology causation, which involves a large number of non-Linear and uncertain interactions between many meteorological factors and PM₂.₅, as a case, we examined the performance of a series of mainstream statistical models, including Correlation Analysis (CA), Partial Correlation Analysis (PCA), Structural Equation Model (SEM), Convergent Cross Mapping (CCM), Partial Cross Mapping (PCM) and Geographical Detector (GD). From a coarse perspective, the Top 3 major meteorological factors for PM₂.₅ in 190 cities across China extracted using different models were generally consistent. From a strict perspective, the extracted dominant meteorological factor for PM₂.₅ demonstrated large model variations and shared a limited consistence. Such models as SEM and PCM, which are capable of further separating direct and indirect causation in simple systems, performed poorly to identify the direct and indirect PM₂.₅-Meteorology causation. The notable inconsistence denied the feasibility of employing multiple models for better causation inference in atmospheric environment. Instead, the sole use of CCM, which is advantageous in dealing with non-linear causation and removing disturbing factors, is a preferable strategy for causation inference in complicated ecosystems. Meanwhile, given the multi-direction, uncertain interactions between many variables, we should be more cautious and less ambitious on the separation of direct and indirect causation. For better causation inference in the complicated atmospheric environment, the combination of statistical models and atmospheric models, and the further exploration of Deep Neural Network can be promising strategies.

Robust antimicrobial capability is crucial for marine organisms survival in complex ocean environments. Although the detrimental impacts of emergent pollutants on cellular immune response of marine bivalve mollusks were increasingly documented, the effects of bisphenol A (BPA) and microplastics (MPs) on humoral immune response and hemocyte chemotactic activity remain unclear. Therefore, in this study, the toxicities of BPA and MPs, alone or in combination, to the antimicrobial ability, humoral immune response, and hemocyte chemotactic activity were investigated in the blood clam Tegillarca granosa. Our data demonstrated that exposure of blood clams to BPA, MPs, and BPA-MPs for 2 weeks lead to significant reductions in their survival rates upon pathogenic bacterial challenge, indicating evident impairment of antimicrobial ability. Compared to control, the plasma of pollutant-incubated blood clams exhibited significantly less antimicrobial activity against the growth of V. harveyi, suggesting significant reduction in humoral immune effectors including defensin, lysozyme (LZM), and lectin. Moreover, hemocytes migration across the polycarbonate membrane to the serum containing chamber was markedly arrested by 2-week exposure to BPA, MPs, and BPA-MPs, suggesting a hampered chemotactic activity. In addition, the intracellular contents of ROS and protein carbonyl in hemocytes were markedly induced whereas the expression levels of key genes from the MAPK and actin cytoskeleton regulation pathways were significantly suppressed upon exposure. In this study, it was also found that BPA-MP coexposure was significantly more toxic than single exposures. In summary, our findings revealed that exposure to the pollutants tested possibly impair the antimicrobial ability of blood clam through (1) reducing the inhibitory effect of plasma on bacterial growth, the contents of humoral immune effectors, and the chemotactic activity of hemocytes, (2) interrupting IL-17 activation of MAPK signal pathway, (3) inducing intracellular ROS, elevating protein carbonylation levels, and disrupting actin cytoskeleton regulation in hemocytes.

Plastics are produced and used in large quantities worldwide (e.g. as food packaging). In line with this, plastic particles are found throughout the ecosphere and in various foods. As a result, plastics are also present in energy-rich waste biomass derived from the food industry, supermarkets, restaurants, etc. These waste streams are a valuable source for biogas production but can also be used to feed insects that in turn upcycle it into new high-value biomass. In both applications, the remaining residue can be used as fertilizer. Due to the present plastic particles, these applications could pose a continued threat to the environment, and both human and animal health. Therefore, the need of determining the (micro)plastic content to assess the potential danger is rising. In this research, a closed-vessel microwave-assisted acid digestion method was developed to accurately determine meso- and microplastic contents in food (waste) matrices by solubilising this food matrix. Polyvinyl chloride (PVC) food packaging foil was used to develop the method, using a full factorial design with three parameters (nitric acid concentration (c(HNO₃)), temperature (T), and time (t)). According to this model, the best practical conditions were c(HNO₃) = 0.50 mol/L, T = 170 °C, and t = 5.00 min. Subsequently, the method was tested on five other plastics, namely high- and low-density polyethylene (HDPE and LDPE), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET), mixed with a food matrix, resulting in a mean plastic recovery of 102.2 ± 4.1%. Additionally, the polymers were not oxidised during the microwave digestion. For PVC and PS hardly any degradation was found, while HDPE, LDPE, and PP showed slight chain degradation, although without recovery loss. In conclusion, the method is an accurate approach to quantify the total meso- and microplastic content in food (waste) matrices with minimal change in their intrinsic characteristics.