Effective and economically viable method to remove elevated metal(loid)s from farm and industrial lands remains a major challenge. In this study, magnetic biochar-based adsorbents with Fe₃O₄ particles embedded in a porous biochar matrix was synthesized via iron (Fe) treated biochar or thermal pyrolysis of Fe treated cedar sawdust. Application and separation of the adsorbent to a multi-contaminated soil slurry simultaneously removed 20–30% of arsenic, cadmium and lead within 24 h. Fast removal of multi-metal(loid)s result from the decrease in all operationally defined fractions of metal(loid)s, not limited to the exchangeable fraction. The direct removal of arsenic-enriched soil particles was observed via micro X-ray fluorescence maps. Furthermore, through comparison of biochars with different production methods, it has been found that magnetization after pyrolysis treatment leads to stronger metals/metalloids adsorption with a higher qₑ (bound sorbate) than other treatments but pyrolysis after magnetization stabilized Fe oxides on the biochar surface, indicating a higher biochar recovery rate (∼65%), and thus a higher metal(loid)s removal efficiency. The stability of Fe oxides on the surface of biochar is the determining factor for the removal efficiency of metal(loid)s from soil.

Accumulation and oral bioavailability of nickel (Ni) were rarely assessed for staple crops grown in high geogenic Ni soils. To assess exposure risk of geogenic Ni, soil, wheat, and rice samples were collected from a naturally high background Ni area and measured for Ni oral relative bioavailability (RBA, relative to NiSO₄) using a newly developed mouse urinary Ni excretion bioassay. Results showed that soils were enriched with Ni (80.5 ± 23.0 mg kg⁻¹, n = 58), while high Ni contents were observed in rice (2.66 ± 1.46 mg kg⁻¹) and wheat (1.32 ± 0.78 mg kg⁻¹) grains, with rice containing ∼2-fold higher Ni content than wheat. Ni-RBA was low in soil (14.8 ± 7.79%, n = 18), but high in wheat and rice with rice Ni-RBA (85.9 ± 19.1%, n = 9) being ∼2-fold higher than wheat (46.1 ± 21.2%, n = 16). A negative correlation (r = 0.61) was observed between Ni-RBA and iron content in rice and wheat, suggesting the low iron status of rice drives its high Ni bioavailability. The higher Ni accumulation and bioavailability for rice highlights that rice consumption was a more important contributor to daily Ni intake compared to wheat, while Ni intake from direct soil ingestion was negligible. This study suggests a potential health risk of staple crops especially rice when grown in high geogenic Ni areas.

Freshwater mussels are one of the most threatened taxonomic groups in the world, and many species are on the brink of local or global extinction. Human activities have altered mussel living conditions in a plethora of ways. One of the most destructive human-induced impacts on running waters is the catastrophic spill of harmful substances, which results in massive die-offs. Even though Finland is regarded as the world’s top country in terms of environmental regulation quality, riverine systems are not safe. In 2014, River Kokemäenjoki in western Finland experienced the worst NiSO4 spill in the country’s history, visibly affecting the mussel community – including protected Unio crassus – along the river. Because freshwater mussel toxicology is grossly understudied (particularly in Europe), any pollution –linked die-offs offer valuable opportunities to study the issue in natural environment. Here, we report the mussel investigations from 2014 and a follow-up study conducted in 2017 in order to assess the variation in species sensitivity on nickel pollution. In total, 104 sites were sampled, and over 20 000 mussels were identified and counted. Our results indicate that the most impacted species (i.e. that which experienced the highest spill-induced mortality) was Anodonta anatina (62%), followed by Unio pictorum (32%), U. crassus (24%) and Unio tumidus (9%). The underlying reason for the sensitivity of A. anatina is not resolved, hence more research is urgently needed. The low mortality among most of the species in 2017 highlights the temporal nature of the pollution impact and the recovery potential of the mussel community. However, the case is more complex with U. crassus population, which may be experiencing delayed impacts of the spill. Because nickel is one of the most commonly produced industrial metals in the world (hence the pollution incident risk is high) and River Kokemäenjoki hosts mussel community typical for European rivers, our results may benefit many researchers and stakeholders dealing with riverine environments.

Infections caused by carbapenem-resistant Enterobacteriaceae are a growing concern worldwide. Raoultella ornithinolytica is a species in the Enterobacteriaceae family which can cause hospital-acquired infections and is sporadically reported as carbapenem-resistant from human and environmental sources. In this study, we firstly report on an NDM-1-producing R. ornithinolytica, Rao166, isolated from drinking water in an animal cultivation area in China. In addition to carbapenem-resistance, Rao166 was resistant to several other antibiotics including gentamicin, sulfamethoxazole-trimethoprim, tetracycline and fosfomycin. Rao166 carried a novel IncFIC-type megaplasmid, 382,325 bp in length (pRAO166a). A multidrug resistance region, 60,600 bp in length, was identified in the plasmid containing an aac(3)-IId-like gene, aac(6′)-Ib-cr, blaDHA₋₁, blaTEM₋₁B, blaCTX₋M₋₃, blaOXA₋₁, blaNDM₋₁, qnrB4, catB3, arr-3, sul1, and tet(D). Results from virulence assays implied that Rao166 has considerable pathogenic potential. Although pRAO166a was found to be non-transmissible, dissemination of the NDM-1 producing strain may occur from well water to humans or animals through cross-contamination during food preparation or directly via drinking water, and potentially lead to difficult-to-treat infections. Thus, contamination of well water by this carbapenem-resistant and presumptively virulent strain of R. ornithinolytica should be considered a potential public health risk.

The transmission and accumulation of trace metals in marine food webs have a profound influence on the structure and function of marine environment. In order to quantitatively assess the trophic transfer behaviors of eight common metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) in simplified five-trophic level marine food webs, a total of 9929 biological samples from 61 studies published between 2000 and 2019, involving 154 sampling sites of 33 countries/regions, were re-compiled using meta-analysis. Based on concentration-trophic level weighted linear regression and predator/prey comparison, the food web magnification factor (FWMF) and the biomagnification factor (BMF) were calculated, respectively. The results showed dissimilar trophic transfer behaviors of these metals in global marine food webs, in which As and Ni tended to be efficiently biodiluted with increasing trophic levels (FWMFs < 1, p < 0.01), while Hg, Pb and Zn trophically biomagnified (FWMFs > 1, p < 0.05). However, Cd, Cr and Cu presented no biomagnification or biodilution trend (p > 0.05). The values of FWMFs were ranked as: Hg (2.01) > Pb (1.81) > Zn (1.15) > Cu (1.13) > Cr (0.951) > Cd (0.850) > Ni (0.731) > As (0.494). In terms of specific predator-prey relationship, Pb showed significant biodilution from tertiary consumers (TC) to top predators (BMF < 1, p < 0.05), whereas Cd and Cu displayed obvious biomagnification from primary consumers (PC) to secondary consumers (SC) (BMFs >1, p < 0.05). Additionally, when Cu and Zn were transferred from SC to TC, and primary producers to PC, clear biodilution and biomagnification effects were observed, respectively (p < 0.05). Further analysis indicated that the average concentration of Hg in five-trophic level marine food webs of developed countries (0.904 mg kg⁻¹ dw) was more noticeable (p < 0.05) than that of developing countries (0.549 mg kg⁻¹ dw).

The application of roadway deicing salts is increasing the salinity of freshwater systems. Increased salinization from salts, such as NaCl, CaCl₂ and MgCl₂, can have direct, negative impacts on freshwater organisms at concentrations found in nature. Yet, our understanding of how these salts can indirectly impact freshwater organisms by altering important ecological interactions, such as those between hosts and their parasites, is limited. Using a larval amphibian and infectious free-living helminth (i.e. trematode) model, we examined whether exposure to environmentally relevant concentrations of NaCl, CaCl₂ and MgCl₂ 1) influence trematode mortality; 2) alter amphibian-trematode interactions; and 3) alter larval amphibian activity (a behavior associated with parasite avoidance). We found that exposure to CaCl₂ greatly reduced trematode survival across all Cl⁻ concentrations (230, 500, 860 and 1000 mg Cl⁻ L⁻¹) while NaCl and MgCl₂ had no effect. When both host and parasites were exposed to the salts, exposure to NaCl, but not MgCl₂ or CaCl₂, increased infection. The lack of effect of CaCl₂ on infection was likely driven by CaCl₂ reducing trematode survival. Exposure to NaCl increased infection at 500 mg Cl⁻ L⁻¹, but not 230 or 860 mg Cl⁻ L⁻¹. Increased infection was not due to salt exposure altering tadpole behavior. Our results suggest that NaCl can negatively impact amphibian populations indirectly by increasing trematode infections in tadpole hosts.

Sensing of pathogens by specialized receptors is the hallmark of the innate immunity. Innate immune response also mounts a defense response against various allergens and pollutants including particulate matter present in the atmosphere. Air pollution has been included as the top threat to global health declared by WHO which aims to cover more than three billion people against health emergencies from 2019 to 2023. Particulate matter (PM), one of the major components of air pollution, is a significant risk factor for many human diseases and its adverse effects include morbidity and premature deaths throughout the world. Several clinical and epidemiological studies have identified a key link between the PM existence and the prevalence of respiratory and inflammatory disorders. However, the underlying molecular mechanism is not well understood. Here, we investigated the influence of air pollutant, PM₁₀ (particles with aerodynamic diameter less than 10 μm) during RNA virus infections using Highly Pathogenic Avian Influenza (HPAI) – H5N1 virus. We thus characterized the transcriptomic profile of lung epithelial cell line, A549 treated with PM₁₀ prior to H5N1infection, which is known to cause severe lung damage and respiratory disease. We found that PM₁₀ enhances vulnerability (by cellular damage) and regulates virus infectivity to enhance overall pathogenic burden in the lung cells. Additionally, the transcriptomic profile highlights the connection of host factors related to various metabolic pathways and immune responses which were dysregulated during virus infection. Collectively, our findings suggest a strong link between the prevalence of respiratory illness and its association with the air quality.

The pollution of farm soils by the plasticizer dibutyl phthalate (DBP) should be researched owing to the extensive use of plastic film. We investigated the influence of DBP on microbial communities and enzyme activities in rhizosphere and non-rhizosphere soil during the different growth stages of wheat and determined the response through simulations. The results indicated that protease, polyphenol oxidase, and β-glucosidase activity in soil decreased with increasing DBP dosage, while dehydrogenase, urease, and acid phosphatase activities increased. Moreover, the effects of DBP on soil enzyme activity gradually weakened with DBP degradation. Dibutyl phthalate has a certain inhibitory effect on the activity, diversity, and heterogeneity of microorganisms in soil. In addition, DBP can increase the utilization of amines and carboxylic acids and decrease the utilization of carbohydrates and amino acids by soil microorganisms. According to the Gaussian and molecular docking analysis, we considered that monobutyl phthalate and DBP could affect the utilization of amino acids by Proteobacteria. The enzyme activity, microbial activity, and heterogeneity of rhizosphere soil were higher than those of non-rhizosphere soil. Microbial carbon source utilization in rhizosphere and non-rhizosphere soils depends on wheat growth, soil type, and DBP dosage. Owing to the widespread presence of DBP in agriculture, negative effects of phthalic acid esters should be considered in relation to soil quality and food safety in future.

We quantified the transport and transformation of Cd in historically contaminated soil (OS) and artificially contaminated soil (NS), treated with 3% (w/w) rice straw biochar prepared at 400 °C (BC400) and 700 °C (BC700) under combined dry-wet and freeze-thaw cycles for 72 days simulating the natural aging process of 8 years. An improved three-layer mesh experiment was developed to simulate the natural situation in field. The result showed that the total Cd concentration increased in the biochar but decreased in the soil, suggesting that Cd was transported from the soil into the biochar during the aging process. The total Cd concentration in BC400 treated with both soils was higher than that in BC700 treated with both soils, however, BC700 displayed stronger ability on immobilizing Cd than BC400 because the Tessier exchangeable Cd fraction in BC700 treated both soils was lower than that in BC400 treated with both soils. The average Tessier exchangeable Cd fraction in the soil and biochar decreased in all treatments during the aging process, indicating that Cd tended to be more stable in the soil for a long term. The result also showed that biochar could immobilizate Cd by decreasing the Tessier exchangeable Cd fraction of soil and biochar, and the quantitative contributions of biochar and soil to Cd immobilization were different in OS and NS treated with BC400 and BC700. The biochar contribution to the reduction in Tessier exchangeable Cd fraction accounted for 40–85% in NS treated with BC400 and 54–82% in NS treated with BC700. However, in OS treated with biochar, the biochar contribution accounted for nearly 100%, and soil had almost no contribution. In summary, OS did not contribute to Cd immobilization, while NS contributed nearly 50% to Cd immobilization, and BC700 was more effective in immobilizing Cd than BC400.

The effects of increasing concentrations of suspended mineral coal dust on the energetic physiology of the Caribbean scallop Argopecten nucleus were studied, at a concentration range that is environmentally relevant and representative of areas proximate to coal loading and shipping ports. Adult hatchery-produced animals were exposed to different concentrations of coal dust, i.e. 0, 2, 9 and 40 mg L⁻¹. At increasing concentrations of coal dust, the rates of filtration and pseudofeces production increased, while the rates of ingestion and absorption remained constant. The rates of oxygen consumption and ammonium excretion decreased, as well as the absorption efficiency and the scope for growth. Suspended coal dust particles, at concentrations higher than or equal to 2 mg L⁻¹, were ingested preferentially over microalgae by A. nucleus, causing reductions in its absorption capability, metabolism and in the amount of energy for growth and reproduction, thus generating physiological stress.