Infection caused by pathogenic bacteria carrying antibiotic resistance genes (ARGs) is a serious challenge to human health. Water environment, including water and surface sediments, is an important repository of ARGs, and the activity of aquatic animal can affect the development of ARG pollution in the water environment. Macrobenthic invertebrates are an important component of aquatic ecosystems, and their effects on ARG development in aquatic environments remain unreported. The distribution of ARGs, including tetA gene, sul2 gene, and kan gene, in Chironomidae larvae is demonstrated in this study for the first time. The ARG distribution was related to sampling points, metal elements, and seasons. Animal models demonstrated that Chironomidae larvae enriched ARGs from water and passed them on to downstream predators in the food chain. Conjugative transfer mediated by resistant plasmids was crucial in the spread of ARG in Chironomidae larvae, and upregulated expression of trfAp gene and trbBp gene was the molecular mechanism. Escherichia in Proteobacteria and Flavobacterium in Bacteroidetes, which are gram-negative bacteria in Chironomidae larvae, are the primary host bacteria of ARGs confirmed via resistance screening and DNA sequencing of V4 region of 16S rRNA gene. Feeding experiments further confirmed that ARGs from Chironomidae larvae can be enriched in the fish gut. Research gaps in food chain between sediments and fish are addressed in this study, and Chironomidae larvae is an important enricher of ARGs in the freshwater environment.

Acid mine drainage (AMD) is one of the major environmental problems impacting aquatic ecosystems globally. We studied changes in the community composition of macroinvertebrates and amino acid (AA) profiles of dominant taxa along an AMD contamination gradient within the Dee River, Queensland, Australia to understand how AMD can affect the biomolecular composition of macroinvertebrates. Taxa richness and community composition of macroinvertebrates changed widely along the AMD gradient with significantly lower taxa richness recorded at the polluted sites compared to upstream and downstream sites. The Dipteran families: Chironomidae and Ceratopogonidae, the Odonata family Gomphidae, and the Coleoptera family Dytiscidae were the only families found at all sampling sites and were used here for AA analysis. There were significant variations in the AA profiles among the studied taxa. The AA profile of each taxon also varied among upstream, polluted and downstream sites suggesting that contamination of a river system with acid mine drainage not only alters the overall macroinvertebrate community composition but also significantly influences the AA profile of organisms that are tolerant to AMD. This study highlights the potential of using AA profiling to study the response of aquatic organisms to contamination gradients such as those associated with AMD.

Microplastics (MPs) as carriers of various contaminants have attracted more attentions in water environments. However, the interactions between typical MPs and norfloxacin (NOR) in natural water environments were still not systematically studied. In this study, the adsorption of NOR onto four typical types of MPs (polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC)) was investigated in simulated natural water and real surface water, and the adsorption mechanisms were deeply explored to provide fundamental understandings of the MPs-NOR complicated pollution. The results showed that the kinetics of NOR onto all MPs obeyed pseudo-second-order model, and was greatly slowed down at lower temperature or higher salinity. The intrinsic structure and surface area of MPs played important roles in the adsorption behaviors of NOR on these four types of MPs. The adsorption isotherm of NOR onto all MPs could be well described by linear model, with the Kd values following the order of PVC > PS > PE > PP (i.e. 6.229–11.901 L/μg) in simulated natural water. However, in surface water the adsorption isotherms of NOR on all MPs could be well fitted by Freundlich model. For all MPs, the adsorption of NOR was quite pH-dependent due to the electrostatic interactions. Furthermore, the salinity and the presence of dissolved organic matter (DOM) had significantly hindered the NOR adsorption. More importantly, compared with adsorption behaviors in simulated natural water, the competition of coexisting substances such as cations and NOM for adsorption sites and higher water pH dramatically reduced the adsorption of NOR onto all types of MPs in Jiang'an River, with the reduction rate of 19.7–41.2%. Finally, the mechanism studies indicated that the electrostatic attractions played a key role in the adsorption of NOR onto MPs, and π-π, H-bonding, polar-polar, and Van Der Waals interactions were also involved in adsorption processes.

The agroeconomic benefits of the routine use of triazole fungicides on crops have been evident for more than 40 years. However, increasing evidence shows that residues of triazoles are ubiquitous in various foods and thus could pose a potential health risk to humans. We analyzed 3406 samples of 13 food commodities that were collected from markets in 9 regions across China, and assessed the health risk of both chronic and acute exposure to the triazoles for Chinese children (1–6 years old) and the general population. Among all samples, 55.52% had triazoles in concentrations of 0.10–803.30 μg/kg, and 29.77% of samples contained a combination of 2–7 triazoles. Tebuconazole and difenoconazole were the most commonly found triazoles in the foods, being detected in 33.44% and 30.45% of samples, respectively. Chronic and acute cumulative risk assessment for total triazoles based on a relative potency factor method revealed that exposure to triazoles from these particular commodities was below the levels that might pose a health risk (chronic hazard index range, 5.90×10⁻⁷ to 1.83×10⁻³; acute hazard index range, 7.77×10⁻⁵ to 0.39, below 1). Notably, dietary exposure risk for children was greater than that for the general population—particularly for the acute intake of mandarin, grape, and cucumber (acute hazard index values of 0.35–0.39). Despite the low health risk, the potential hazards of exposure to triazoles should raise public concern owing to their ubiquitous presence in common foods and potential cumulative effects.

The benefits of the artificial fixation of reactive nitrogen (Nr, nitrogen [N] compounds other than dinitrogen), in the form of N fertilizers and materials are huge, while at the same time posing substantial threats to human and ecosystem health by the release of Nr to the environment. To achieve sustainable N use, Nr loss to the environment must be reduced. An N-budget approach at the national level would allow us to fully grasp the whole picture of Nr loss to the environment through the quantification of important N flows in the country. In this study, the N budgets in Japan were estimated from 2000 to 2015 using available statistics, datasets, and literature. The net N inflow to Japanese human sectors in 2010 was 6180 Gg N yr⁻¹ in total. With 420 Gg N yr⁻¹ accumulating in human settlements, 5760 Gg N yr⁻¹ was released from the human sector, of which 1960 Gg N yr⁻¹ was lost to the environment as Nr (64% to air and 36% to waters), and the remainder assumed as dinitrogen. Nr loss decreased in both atmospheric emissions and loss to terrestrial water over time. The distinct reduction in the atmospheric emissions of nitrogen oxides from transportation, at −4.3% yr⁻¹, was attributed to both emission controls and a decrease in energy consumption. Reductions in runoff and leaching from land as well as the discharge of treated water were found, at −1.0% yr⁻¹ for both. The aging of Japan's population coincided with the reductions in the per capita supply and consumption of food and energy. Future challenges for Japan lie in further reducing N waste and adapting its N flows in international trade to adopt more sustainable options considering the reduced demand due to the aging population.

A pot experiment was carried out on brown soil polluted by dibutyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) to investigate the effects of biochar (BC) derived from corn straw and Fe–Mn oxide modified biochar composites (FMBC) on the bioavailability of DBP and DEHP, as well as ecosystem responses in rhizosphere soil after wheat ripening. The results indicate that the application of BC and FMBC significantly increases soil organic matter, pH, available nitrogen (AN), Olsen phosphorus, and available potassium (AK); reduces the bioavailability of DBP and DEHP; enhances the activities of dehydrogenase, urease, protease, β-glucosidase, and polyphenol oxidase; and decreases acid phosphatase activity. No changes in richness and diversity, which were measured by Illumina MiSeq sequencing, were observed following BC and FMBC application. The bacterial community structure and composition varied with DBP/DEHP concentrations and BC/FMBC additions in a nonsystematic way and no significant trends were observed. In addition, FMBC exhibited better performance in increasing soil properties and decreasing the bioavailability of DBP and DEHP compared with BC. Hence, the FMBC amendment may be a promising way of developing sustainable agricultural environmental management.

Two radon measurement stations located to the north and south of a NORM (Naturally Occurring Radioactive Materials) repository of phosphogypsum (southwest of Europe) were used to monitor radon behavior during 2018. The stations are located at opposing sides of the repository, one in Huelva City to the north and other one in a rural area to the south. This setup aimed to identify the influence of the NORM repository on each station and use radon levels as a marker of atmospheric transport in the local area. To achieve this, a comparison was carried out with other coastal stations in the south of Spain, finding higher average concentrations in Huelva City, ~3.3 Bq m⁻³. Hierarchical clustering was applied to identify days with different radon patterns at each Huelva station, detecting possible local radon transport events from the repository. Three events were investigated with WRF (Weather Research and Forecasting) and FLEXPART-WRF (FLEXible PARTicle dispersion model). It was found that both sampling sites required atmospheric stagnant conditions to reach high radon concentration. However, under these conditions the urban station showed high radon regardless of wind direction while the rural station also required radon transport from the repository, either directly or indirectly.

For many years, the dispersal of modified clay (MC) has been used to control harmful algal blooms (HABs) in coastal waters of China. MC flocculation efficiency can be influenced by many factors in variable and complex natural environments, including high concentrations of dissolved organic matter (DOM) in the water to be treated. Since many HABs occur in nearshore waters where DOM concentrations are high, this is a significant problem that requires urgent attention. This study involved the use of humic acid as a representative form of DOM to study the influence of organic matter on the MC flocculation process. At high concentrations, humic acid was adsorbed onto MC particles, resulting in a decrease in surface potential and an increase in electrostatic repulsion between the clay particles; this decreased the MC settling rate and increased the water clarification time. Flocs were characterized by their relatively small particle size, high particle concentration, and low collision efficiency, which together resulted in slow clarification of the water after MC spraying. Based on the mechanism of the DOM-MC interaction and combined with the Derjaguin-Landau-Verwey-Overbeek theory and theoretical considerations of clay surface modification, the “ionic atmosphere compression” method was used to improve MC flocculation efficiency in high-organic water. This method increased the ionic strength of the clay stock solution by adding salt, thereby compressing the ionic atmosphere of MC particles and lowering the potential barrier, allowing the MC particles in the treated water to flocculate rapidly and form large flocs, followed by further floc growth and rapid settling via differential sedimentation. The settling rate of MCs improved by a factor of two and the removal efficiency of the HAB cells increased by 7–28%. This study provides important baseline information that will extend the application of MC to HAB control in water bodies with high organic loadings.

Interest in the potential human health of semi-volatile organic chemicals (SVOCs) in indoor and outdoor environments has made the exposure assessment and source appointment a priority. In this study, paired indoor and outdoor atmospheric fine particle (PM₂.₅) samples were collected from 15 homes representing five typical urban cities in southern China. Four typical SVOCs, including 16 congeners of polycyclic aromatic hydrocarbons (PAHs), 13 congeners of organophosphorus flame retardants (OPFRs) and 8 congeners of polybrominated diphenyl ethers (PBDEs), as well as tetrabromobisphenol A (TBBPA) and its three debrominated congeners were analyzed. The highest total concentrations were found for OPFRs, followed by PAHs, PBDEs, and TBBPA. The indoor concentrations of two alkyl-OPFR isomers, tributylphosphate (TBP) and tris (2-butoxyethyl) phosphate (TBEP), were 4.3 and 11 times higher, respectively, than those of outdoors (p < 0.05). Additionally, the ratios of indoor to outdoor concentrations of alkyl-OPFR isomers varied greatly, suggesting that these compounds originated mainly from different household goods and products used in individual homes. The outdoor concentrations of PAHs and highly brominated PBDEs (BDE-209) typically exceeded the indoor concentrations. Significant correlations were also found between indoor and outdoor PM₂.₅ samples for PAHs and BDE-209, indicating that outdoor sources such as vehicle exhausts and industrial activities strongly influence their atmospheric occurrence. Additionally, the concentrations of debrominated TBBPA derivatives were higher than those of TBBPA in over 33% of both indoor and outdoor air particle samples. Nevertheless, our results indicated that inhalation exposure to typical SVOCs posed no non-carcinogenic risks to the human body. Although we observed notable differences in the sources, occurrences, and distributions of typical SVOC congeners, more studies using matched samples are still needed to unambiguously identify important indoor and outdoor sources in order to accurately assess the contributions of different sources and the associated human exposure risks.

Landfills, as well as other waste management facilities are well-known bioaerosols sources. These places may foment antibiotic-resistance in bacterial bioaerosol (A.R.B.) due to inadequate pharmaceutical waste disposal. This issue may foster the necessity of using last-generation antibiotics with extra costs in the health care system, and deaths. The aim of this study was to reveal the multi-antibiotic resistant bacterial bioaerosol emitted by a sanitary landfill and the surrounding area. We evaluated the influence of environmental conditions in the occurrence of A.R.B. and biological risk assessment. Antibiotic resistance found in the bacteria aerosols was compared with the AWaRE consumption classification. We used the BIOGAVAL method to assess the workers' occupational exposure to antibiotic-resistant bacterial bioaerosols in the landfill. This study confirmed the multi-antibiotic resistant in bacterial bioaerosol in a landfill and in the surrounding area. Obtained mean concentrations of bacterial bioaerosols, as well as antibiotic-resistant in bacterial bioaerosol (A.R.B.), were high, especially for fine particles that may be a threat for human health. Results suggest the possible risk of antibiotic-resistance interchange between pathogenic and non-pathogenic species in the landfill facilities, thus promoting antibiotic multi-resistance genes spreading into the environment.