The intensification of anomalous events of seawater warming and the co-occurrence with local anthropogenic stressors are threatening coastal marine habitats, including seagrasses, which form extensive underwater meadows. Eutrophication highly affects coastal environments, potentially summing up to the widespread effects of global climate changes. In the present study, we investigated for the first time in seagrasses, the transcriptional response of different plant organs (i.e., leaf and shoot apical meristem, SAM) of the Mediterranean seagrass Posidonia oceanica growing in environments with a different history of nutrient enrichment. To this end, a mesocosm experiment exposing plants to single (nutrient enrichment or temperature increase) and multiple stressors (nutrient enrichment plus temperature increase), was performed. Results revealed a differential transcriptome regulation of plants under single and multiple stressors, showing an organ-specific sensitivity depending on plants' origin. While leaf tissues were more responsive to nutrient stress, SAM revealed a higher sensitivity to temperature treatments, especially in plants already impacted in their native environment. The exposure to stress conditions induced the modulation of different biological processes. Plants living in an oligotrophic environment were more responsive to nutrients compared to plants from a eutrophic environment. Evidences that epigenetic mechanisms were involved in the regulation of transcriptional reprogramming were also observed in both plants’ organs. These results represent a further step in the comprehension of seagrass response to abiotic stressors pointing out the importance of local pressures in a global warming scenario.

Ocean acidification (OA) is expected to rise towards the end of the 21st century altering the life history traits in marine organisms. Upwelling systems will not escape OA, but unlike other areas of the ocean, cooling effects are expected to intensify in these systems. Regardless, studies evaluating the combined effects of OA and cooling remain scarce. We addressed this gap using a mesocosm system, where we exposed juveniles of the intertidal muricid snail Acanthina monodon to current and projected pCO₂ (500 vs. 1500 ppm) and temperature (15 vs. 10 °C) from the southeast Pacific upwelling system. After 9 weeks of experimental exposure to those conditions, we conducted three estimations of growth (wet weight, shell length and shell peristomal length), in addition to measuring calcification, metabolic and feeding rates and the ability of these organisms to return to the normal upright position after being overturned (self-righting). Growth, feeding and calcification rates increased in projected cooling conditions (10 °C) but were unaffected by pCO₂ or the interaction between pCO₂ and temperature. Instead, metabolic rates were driven by pCO₂, but a significant interaction with temperature suggests that in cooler conditions, metabolic rates will increase when associated with high pCO₂ levels. Snail self-righting times were not affected across treatments. These results suggest that colder temperatures projected for this area would drive this species growth, feeding and calcification, and consequently, some of its population biology and productivity. However, the snails may need to compensate for the increase in metabolic rates under the effects of ocean acidification. Although A. monodon ability to adjust to individual or combined stressors will likely account for some of the changes described here, our results point to a complex dynamic to take place in intertidal habitats associated with upwelling systems.

Nitrated and oxygenated polycyclic aromatic hydrocarbons (NPAHs and OPAHs) are receiving attention because of their high toxicity compared with parent PAHs. However, the experimental data of their physicochemical properties has been limited. This study proposed the gas chromatographic retention time (GC-RT) technique as an effective alternative one to determine octanol-air partition coefficients (KOA) and sub-cooled liquid vapor pressures (PL) for 11 NPAHs, 10 OPAHs, and 19 parent PAHs. The slopes and intercepts of the linear regressions between temperature versus KOA and PL were provided and can be used to estimate KOA and PL for the 40 targeted compounds at any temperature. The internal energies of phase transfer (ΔUOA) and enthalpies of vaporization (ΔHL) for all targeted compounds were also calculated using the GC-RT technique. High-molecular-weight compounds may release or absorb higher heat energy to transform between different phases. NPAHs and OPAHs had a non-ideal solution behavior with activity in octanol (γₒcₜ) in the range of 19–53 and 18–1,078, respectively, which is larger than the unity threshold. A comparison among four groups of PAH derivatives showed that a functional group (nitro-, oxygen-, chloro-, and bromo-) in PAH derivatives increased γₒcₜ for corresponding parent PAHs by tens (mono-group) to hundreds of times (di-group). This study suggests that the GC-RT method is applicable for indirectly measuring the physicochemical properties of various groups of organic compounds.

Serious pollution is caused by heavy metals (HMs) emission during sludge combustion treatment, but the addition of minerals has the ability to alleviate the migration of HMs to the gaseous state. In this study, HMs (As, Cr, Zn and Cu) behavior, speciation, and environmental risk during sludge combustion with CaO and montmorillonite (MMT) additive was investigated in the lab-scale tube furnace. The results showed that the sludge combustion was mainly determined by volatile matter. In general, CaO inhibited the volatilization of Cr, Zn, and Cu, but promoted As volatilization. MMT inhibited the volatilization of HMs, but the effect was not obvious at high temperatures. Besides, the improvement of retention effect was not found for Cr and Cu with the increase of CaO at 1000 °C, there might exist threshold value for CaO on HMs retention process. Meanwhile, CaO increased acid-soluble fraction of As significantly at high temperatures, decreased residual fraction of Cr by oxidation, converted Zn and Cu to residual fraction. MMT increased the acid-soluble fraction of As and residual fraction of Cr. In view of the HMs environmental risk in ash, the combustion temperature of sludge was necessary to control under 1000 °C and minerals additive amount was needed to manage above 1000 °C.

The high antibiotic resistance gene (ARGs) contents in livestock manure pose a potential risk to environment and human health. The heap composting with an ambient temperature and thermophilic composting are two methods for converting livestock manure into fertilizer. This study investigated the variations in ARGs and mobile genetic elements (MGEs) and revealed potential mechanisms for ARGs removal using the two composting methods. The ARGs abundance were enriched by 44-fold in heap composting, among them, the macrolide-resistance genes increased significantly. On the contrary, the ARGs were removed by 92% in thermophilic composting, among them, tetracycline-resistance genes decreased by 97%. The bacterial hosts of ARGs were associated with the variations of ARGs and MGEs. The tetO was correlated with the most diverse bacteria in heap composting, and Bacteroidetes was the major host bacteria. While tetT was correlated with the most diverse bacteria in thermophilic composting, and Proteobacteria was the major host bacteria. Structural equation models showed that the enrichment of ARGs in heap composting was mainly correlated with bacterial communities, whereas, the removal of ARGs in thermophilic composting was directly affect by MGEs. Composting temperature directly affected the variations in ARGs. Higher and lower temperatures significantly decreased and increased, respectively, ARGs and MGEs abundance levels.

Air pollution and extreme heat have been responsible for more than a million deaths in China every year, especially in densely urbanized regions. While previous studies intensively evaluated air pollution episodes and extreme heat events, a limited number of studies comprehensively assessed atmospheric hot-and-polluted-episodes (HPE) – an episode with simultaneously high levels of air pollution and temperature – which have potential adverse synergic impacts on human health. This study focused on the Pearl River Delta (PRD) region of China due to its high temperature in summer and poor air quality throughout a year. We employed geostatistical downscaling to model meteorology at a spatial resolution of 1 km, and applied a machine learning algorithm (XGBoost) to estimate a high-resolution (1 km) daily concentration of particulate matter with an aerodynamic diameter ≤2.5 μm (PM₂.₅) and ozone (O₃) for June to October over 20 years (2000–2019). Our results indicate an increasing trend (∼50%) in the frequency of HPE occurrence in the first decade (2000–2010). Conversely, the annual frequency of HPE occurrence reduced (16.7%), but its intensity increased during the second decade (2010–2019). The northern cities in the PRD region had higher levels of PM₂.₅ and O₃ than their southern counterparts. During HPEs, regional daily PM₂.₅ exceeded the World Health Organization (WHO) and Chinese guideline levels by 75% and 25%, respectively, while the O₃ exceeded the WHO O₃ standard by up to 69%. Overall, 567,063 (95% confidence interval (CI): 510,357–623,770) and 52,231 (95%CI: 26,116–78,346) excessive deaths were respectively attributable to exposure to PM₂.₅ and O₃ in the PRD region. Our findings imply the necessity and urgency to formulate co-benefit policies to mitigate the region's air pollution and heat problems.

The present study evaluated the interactive effects of global change and heavy metals on the growth and development of three soybean [Glycine max (L.) Merrill] cultivars and the consequences on yield and food safety. Soybean cultivars (Alim 3.14 from Argentina, and ES Mentor and Sigalia, from Germany) were grown until maturity in heavy metals polluted soils from the Rhine Valley, Germany, at two CO₂ concentrations (400 and 550 ppm) and heat stress (HS) episodes (9 days with 10 °C higher than maximum regular temperature) during the critical growth period in controlled environmental chambers. Different morpho-physiological parameters, heavy metal concentration in aerial organs, seed quality parameters, and toxicological index were recorded. The results showed that no morphological differences were observed related to CO₂. Moreover, Alim 3.14 showed the highest yield under control conditions, but it was more sensitive to climatic conditions than the German cultivars, especially to heat stress which strongly reduces the biomass of the fruits. Heavy metals concentration in soil exceeds the legislation limits for agricultural soils for Cd and Pb, with 1.6 and 487 mg kg⁻¹ respectively. In all cultivars, soybeans accumulated Cd in its aerial organs, and it could be translocated to fruits. Cd concentration in seeds ranged between 0.6 and 2.4 mg kg⁻¹, which exceed legislation limits and with toxicological risk to potential Chinese consumers. Pb levels were lower than Cd in seeds (0.03–0.17 mg kg⁻¹), and the accumulation were concentrated in the vegetative organs, with 93% of the Pb incorporated. Moreover, pods accumulated 11 times more Pb than seeds, which suggests that they act as a barrier to the passage of Pb to their offspring. These results evidence that soybean can easily translocate Cd, but not Pb, to reproductive organs. No regular patterns were observed in relation to climatic influence on heavy metal uptake.

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.

In this study, we assessed the impact of zinc oxide (ZnO) and iron oxide (FeO) (<36 nm) nanoparticles (NPs) as well as their sulphate salt (bulk) counterpart (0, 25, 100 mg/kg) on rice growth and seed quality as well as the microbial community in the rhizosphere environment of rice. During the rice growing season 2021–22, all experiments were conducted in a greenhouse (temperature: day 30 °C; night 20 °C; relative humidity: 70%; light period: 16 h/8 h, day/night) in rice field soil. Results showed that low concentrations of FeO and ZnO NPs (25 mg/kg) promoted rice growth (height (29%, 16%), pigment content (2%, 3%)) and grain quality parameters such as grains per spike (8%, 9%), dry weight of grains (12%, 14%) respectively. As compared to the control group, the Zn (2%) and Fe (5%) accumulations at their respective low concentrations of NP treatments showed stimulation. Interestingly, our results showed that at low concentration of both the NPs the soil microbes had more diversity and richness than those in the bulk treated and control soil group. Although a number of phyla were affected by the presence of NPs, the strongest effects were observed for change in the abundance of the three phyla for Proteobacteria, Actinobacteria, and Planctomycetes. The rhizosphere environment was notably enriched with potential streptomycin producers, carbon and nitrogen fixers, and lignin degraders with regard to functional groups of microorganisms. However, microbial communities mainly responsible for chitin degradation, ammonia oxidation, and nitrite reduction were found to be decreased. The results from this study highlight significant changes in several plant-based endpoints, as well as the rhizosphere soil microorganisms. It further adds information to our understanding of the nanoscale-specific impacts of important micronutrient oxides on both rice and its associated soil microbiome.

The coastal megacity Shanghai is located in the center of the Yangtze River Delta, a dominant flame retardants (FRs) production region in China, especially for organophosphate esters (OPEs). This prompted us to investigate occurrence and seasonal changes of atmospheric OPEs in Shanghai, as well as to evaluate their sources, environmental behavior and fate as a case study for global coastal regions. Atmospheric gas and particle phase OPEs were weekly collected at two coastal sites - the emerging town Lingang New Area (LGNA), and the chemical-industry zone Jinshan Area (JSA) from July 2016–June 2017. Total atmospheric concentrations of the observed OPEs were significantly higher in JSA (median of 1800 pg m⁻³) than LGNA (median of 580 pg m⁻³). Tris(1-chloro-2-propyl) phosphate (TCPP) was the most abundant compound, and the proportion of three chlorinated OPEs were higher in the particle phase (55%) than in the gas phase (39%). The year-round median contribution of particle phase OPEs was 33%, which changed strongly with seasons, accounting for 10% in summer in contrast to 62% in winter. Gas and particle phase OPEs in JSA exhibited significant correlations with inverse of temperature, respectively, indicating the importance of local/secondary volatilization sources. The estimated fluxes of gaseous absorption were almost 2 orders of magnitude higher than those of particle phase deposition, which could act as sources of organic phosphorus to coastal and open ocean waters.