In standard terrestrial ecotoxicological tests, soils usually are spiked with highly soluble metal salts leading to overestimation of bioavailability and introducing counterions that may contribute to toxicity. Leaching is suggested as an efficient method to avoid the effects of the associated counterions. The present study aimed at investigating the effects of leaching on the bioavailability and toxicity of Pb(NO₃)₂ and PbO to the potworm Enchytraeus crypticus in LUFA 2.2 soil freshly spiked or after 18 months ageing. Percolation decreased porewater Pb concentrations as well as the toxicity of both Pb forms. The influence of percolation differed between the two Pb forms and between freshly spiked and aged soils. Percolation slightly increased LC50s based on total soil Pb concentrations for Pb(NO₃)₂, but not for PbO, and only affected Pb toxicity to enchytraeid reproduction in freshly spiked soils. The differences in Pb uptake in E. crypticus and toxicity between the two Pb forms as well as between different treatments could be minimized by relating them to 0.01 M CaCl₂-extractable concentrations. In addition, body Pb concentrations could well explain enchytraeid survival across all soils and treatments, indicating its suitability as a good proxy for Pb toxicity in soil.

The present study introduces a mechanically robust, sealable SPME sampler for the on-site sampling and extraction of a wide range of untargeted pollutants in environmental waters. Spray-coating and dip coating methodologies were used to coat the surfaces of six stainless steel bolts with a layer of HLB/PAN particles, which served as the extractive substrate in the proposed device. In addition, this sampler was designed to withstand rough handling, long storage times, and various environmental conditions. In order to identify whether the sampler was able to stabilize extracted compounds for long periods of time, the effects of storage time and temperature were evaluated. The results of these tests showed no significant differences in the quantity and quality of the extracted chemicals following 12 days storage at room temperature, thus confirming the device's suitability for use at sampling sites that are far away from the laboratory facilities. The proposed device was also used to perform extraction and untargeted analyses of river waters in five different geographical locations. The constituent chemicals in the samplers were analyzed and determined using high-resolution HPLC-Orbitrap MS. Toxin and Toxin-Target Database was used as a reference database for toxins and environmental contaminants. Ultimately, over 80 tentative chemicals with widely varying hydrophobicities ranging within −2.43 < logP <11.9—including drugs, metabolites, wide ranges of toxins, pesticide, and insecticides—were identified in the samplers used in the different rivers. The log P values for the tentative analytes confirmed that the introduced device is suitable for the extraction and trace analysis of wide ranges of targeted and untargeted pollutants.

Microplastic (MP) pollution is an emerging issue in aquatic sciences. Little comparative information currently exists about the problem in coastal systems exposed to different levels of human impact. Here we report a year-long study on the abundance of MP in the water column of three estuaries on the east-coast of Australia. The estuaries are subject to different scales of human impact; the Clyde estuary has little human modification, the Bega estuary has a small township and single wastewater treatment works discharging to its waters, and the Hunter estuary which has multiple townships, multiple wastewater treatment plants, and heavy industry. MP abundance followed an expected pattern with the lowest abundance in the low-impact Clyde estuary (98 part. m³), moderate levels of MP in the moderately impacted Bega estuary (246 part. m³), and high MP abundance in the highly impacted Hunter estuary (1032 part. m³). The majority of particles were <200 μm and fragment-like rather than fiber-like. MP abundance was positively related to maximum antecedent rainfall in the Bega estuary, however there are no clear environmental factors that could explain MP variation in the other systems. MP were generally higher in summer and following freshwater inflow events. On the Hunter estuary MP abundance was at times as high as zooplankton abundance, and within the range of numbers reported in other highly impacted systems globally. The results confirm that higher levels of human impact lead to greater plastic pollution and highlight the need to examine aquatic ecosystems under a range of conditions in order to adequately characterize the extent of MP pollution in rivers and coastal systems.

Recently, novel-nanomaterials with excellent sorption capacities, mild stability, and environmental-friendly performance, have enabled massive developments in capturing heavy metal ions. This review firstly introduces the preparation and modification of novel-nanomaterials (e.g., MOFs, nZVI, MXenes, and g-C₃N₄). Then, the heavy metal ions’ sorption properties and the impact of environmental conditions have been discussed. Subsequently, the sorption mechanisms are verified through batch experiments, spectral analysis, surface complexation models, and theoretical calculations. Finally, the applications prospects of novel-nanomaterials in removing heavy metal ion polluted water have also been discussed, which provide perspective for future in-depth research and practical applications.

Microorganisms are ubiquitous in the atmosphere, where they can disperse for a long distance. However, it remains poorly understood how these airborne microorganisms vary and which factors influence the microbial distribution in different anthropogenic activity regions. To explore the regional differences of bacteria and fungi in airborne particles, PM₂.₅ and PM₁₀ samples were collected in the urban and rural areas of Hangzhou. The bacterial and fungal communities in the urban atmosphere was more similar to each other than those in the rural atmosphere. Analyses conducted by the concentration weighted trajectory model demonstrated that the local environment contributed more to the similarity of airborne bacteria and fungi compared with the atmospheric transport. The concentrations of local air pollutants (PM₂.₅, PM₁₀, NO₂, SO₂ and CO) were positively correlated with the similarity of the bacterial and fungal communities. Additionally, the concentrations of these air pollutants in the urban site were about 1.5 times than those in the rural site. This implicated that anthropogenic activity, which is the essential cause of air pollutants, influenced the similarity of airborne bacteria and fungi in the urban area. This work ascertains the outdoor bacterial and fungal distribution in the urban and the rural atmosphere and provides a prospective model for studying the contributing factors of airborne bacteria and fungi.

The toxic sensitivity in different physiological levels of chromium (Cr) contaminated soils with environmentally equivalent concentrations (EEC) was fully unknown. The earthworm Eisenia fetida was exposed to a Cr-contaminated soil at the EEC level (referred to as Cr-CS) to characterize the induced toxicity at the whole body, organ, tissue, subcellular structure and metabolic levels. The results showed that the survival rate, weight and biodiversity of the gut microorganisms (organ) had no significant difference (p > 0.05) between control and Cr-CS groups. Qualitative histopathological and subcellular evaluations from morphology showed earthworms obvious injuries. The organelle injuries combined with the metabolic changes provided additional evidence that the Cr-CS damaged the nucleus and probably disturbed the nucleic acid metabolism of earthworms. 2-hexyl-5-ethyl-3-furansulfonate, dimethylglycine, betaine and scyllo-inositol were sensitive and relatively quantitative metabolites that were recommended as potential biomarkers for Cr-CS based on their significant weights in the multivariate analysis model. In addition, the relative abundance of Burkholderiaceae, Enterobacteriaceae and Microscillaceae of the earthworm guts in the Cr-CS group significantly increased, particularly for Burkholderiaceae (increased by 13.1%), while that of Aeromonadaceae significantly decreased by 5.6% in contrast with the control group. These results provided new insights into our understanding of the toxic effects of the EEC level of Cr contaminated soil from different physiological levels of earthworms and extend our knowledge on the composition and sensitivity of the earthworm gut microbiota in Cr contaminated soil ecosystems. Furthermore, these toxic responses from gut microorganisms to metabolites of earthworms provided important data to improve the adverse outcome pathway and toxic mechanism of the Cr-CS if the earthworm genomics and proteomics would be also gained in the future.

Various crustaceans are farmed using aquaculture, and food deprivation or fasting can occur due to changing of environmental or management strategies. However, the molecular mechanisms underlying responses to starvation in crustaceans remain unclear. To address this, 12 hepatopancreas transcriptomes were compared for oriental river prawn (Macrobrachium nipponense) from four fasting stages (0, 7, 14 and 21 d). Gene Ontology functional annotation and Kyoto Encyclopaedia of Genes and Genomes pathway enrichment analysis of differentially expressed genes were subsequently performed. During the early stages of starvation (0–7 d), drug metabolism via the cytochrome P450 pathway and metabolism of xenobiotics by the cytochrome P450 pathway were enriched, suggesting that they metabolised compounds generated under starvation stress. As starvation proceeded (7–14 d), the retinol (vitamin A) metabolism pathway was activated, based on three up-regulated genes (CYP3, ADH and UGT), along with the two p450 pathways. Meanwhile, vitamin A was gradually consumed. As acute starvation was reached (14–21 d), vitamin A deficiency decreased the mRNA expression levels of IGF-I that is involved in the mTOR signalling pathway, which ultimately affected the growth and development of M. nipponense. Our results implicate drug/xenobiotic metabolism by cytochrome P450s in adaptation to starvation stress. Furthermore, metabolic cascades (CYP and retinol pathways) and growth (mTOR signalling) pathways are clearly triggered in crustaceans during starvation. The findings expand our understanding of the genes associated with hepatopancreas functioning in M. nipponense, and the underlying molecular mechanisms that govern the responses of crustaceans to starvation stress.

Rapid development of Bohai and Yellow Sea Economic Rim has led to the concern of emerging contamination of marine environments. This study investigated the spatial distribution of antibiotic resistance genes (ARGs) in Bohai and Yellow Sea areas. A large scale sampling from Bohai Sea, Yellow Sea and the major cities along the coastline from the mouth of Yalu River to the Yangtze River was performed. The spatial distribution of target ARGs based on the absolute abundances was in the trend of river water ≈ coastal water > the Bohai Sea > the Yellow Sea, inshore > offshore and inner bay > bay mouth. The total absolute abundances of selected ARGs in the coastal waters (1.23 × 10⁴–3.94 × 10⁵ copies/mL) were about 1–4 orders of magnitude higher than those in the sea (21.1–8.00 × 10³ copies/mL). The abundances of ARGs fluctuated greatly in the Yellow Sea and the coastal areas. Sulfonamide resistance genes hold the highest abundances in the Bohai and Yellow Sea (up to 2.13 × 10³ copies/mL of sul1 and 6.23 × 10³ copies/mL of sul2), followed by tetracycline and quinolone resistance genes, while qnrA hold the highest abundances in coastal areas (up to 3.66 × 10⁵ copies/mL). The distribution coefficients of target genes between sediments and corresponding water samples were more than 1.0 in the majority of different aquatic systems. According to the principle component analysis and redundancy analysis, water samples collected from the sea clustered together while those from the coastal zone and rivers were separated. Ammonium and nitrate played important roles in the distribution and variation of ARGs. Co-occurrence network analysis revealed that the potential multi-antibiotics resistant bacteria were detected with higher abundances in the Yellow Sea than in the Bohai Sea. These observations provided a comprehensive new insight into the pollution status of ARGs in the Bohai and Yellow Sea areas.

This technique for setting guideline values differs from that currently used by regulatory agencies throughout the world. Data for benzene were evaluated from epidemiological studies on human populations (29 studies). Exposure durations were evaluated in terms of Long Term Exposure (LTE) and Lifetime Exposure. All data was reported as Lowest Observed Adverse Effect Levels (LOAEL) and converted into exposure doses using Average Daily Dose (ADD) and Lifetime Average Daily Dose (LADD). These values were plotted as a Toxicant Sensitivity Distribution (TSD) which was the cumulative probability of LOAEL-ADD and LOAEL-LADD. From the TSD plots, linear regression equations gave correlation coefficients (R2) ranging from 0.69 to 0.97 indicating normal distributions. Guideline Values (GVs) for LTE (8hr/day) and Lifetime (24hr/70yrs) exposure to benzene were calculated using data from human epidemiological studies as 5% level of cumulative probability (CP) of LOAEL–ADD and LOAEL–LADD from the cumulative probability distributions (CPD). The derived guideline values from the human epidemiological studies were 92 μg/kg/day for LTE and 3.4 μg/kg/day for lifetime exposure. GV for LTE is appropriate for occupational exposure and GV derived for lifetime exposure appropriate for the general population. The guideline value for occupational exposure limit was below all the guideline values developed by regulatory agencies. But the general population guideline is within the range of values formulated by European Union, ATSDR, EPAQS, USEPA and OEHHA for air quality for the general population. This is an alternative method which eliminates the application of safety factors and other sources of errors in deriving guideline values for benzene.