Growing evidence suggests that microplastics can adsorb antibiotics and may consequently exacerbate effects on the health of exposed organisms. Our current understanding of the combined effects of microplastics and antibiotics on antibiotic resistance genes (ARGs) in soil invertebrates is limited. This study aimed to investigate changes in the microbiome and ARGs in Enchytraeus crypticus following exposure to a soil environment that contained both microplastics and antibiotics. Tetracycline (TC), polyamide (PA) and polyvinyl chloride (PVC) were used to construct microcosms of polluted soil environments (TC, PA, PVC, PA+TC, PVC+TC). The differences in microbiomes and ARGs were determined by bacterial 16S rRNA gene amplicon sequencing and high throughput quantitative PCR. The results show that compared with the Control or microplastics alone treatments, TC was significantly accumulated in E. crypticus when exposed to TC alone or in combination with microplastics (P < 0.05), but there were no significant differences about TC accumulation between TC, PA+TC, and PVC+TC treated E. crypticus (P > 0.05). Microplastics and TC significantly disturbed the microbial community, and decreased the microbial alpha diversity of E. crypticus (P < 0.05). However, there were no significant differences between TC, microplastics and their combined exposure treatments, and no toxic synergies on the diversity of E. crypticus microbiome between tetracycline and microplastics in soil environment. All the treatments increased the diversity of ARGs in E. crypticus (39–49 ARGs vs. 25 ARGs of control). In particular, treatments combining PVC and TC or PA and TC exposure resulted in greater ARGs abundance than the treatments when E. crypticus was exposed to PVC, PA or TC alone. These results add to our understanding of the combined effects of microplastics and antibiotics on the ARGs and microbiome of soil invertebrates.

Phthalates are widely used as binders and plasticizers in industrial and consumer products but show diverse toxicity. We investigated the level of human exposure to phthalates in Beijing, one of the most densely populated cities in the world. In this study, 12 metabolites of phthalates were measured in 70 spot urine samples collected from Beijing residents from August 2017 to April 2018 using ultra high-performance liquid chromatography tandem mass spectrometry. We found that metabolites of phthalates were ubiquitous in all urine samples. Total concentrations of phthalate metabolites ranged from 39.6 to 1931 ng mL⁻¹, with median concentrations were in decreasing order of children (371 ng mL⁻¹)> younger adults (332 ng mL⁻¹)> older adults (276 ng mL⁻¹). Mono-n-butyl phthalate (MnBP) was the predominant compound, and occurred at concentrations greater than those reported for people in other countries. The mean values of estimated daily intakes (EDIs) of ∑phthalate were 35.2, 10.3 and 10.9 ng (kg-bm)⁻¹ d⁻¹ for children, younger adults and older adults, respectively. EDIs of di-n-butyl phthalate (DnBP), di-iso-butyl phthalate (DiBP) and di-(2-ethylhexyl) phthalate (DEHP) exceeded reference values suggested by the US Environmental Protection Agency and the European Food Safety Authority. When concentrations were normalized to volume or creatinine-adjusted, hazard quotients (HQs) for 40 of 70 participants exhibited larger HQs >1 for individual phthalates, which was indicative of potential for adverse effects. Thus, exposure to phthalates might be a critical factor contributing to adverse health effects in Beijing residents. To the best of our knowledge, this is the first study to establish a pre-baseline level of urinary phthalate metabolites among residents in Beijing.

Soil organic matter (SOM) affects arsenic (As) and antimony (Sb) mobility in soils under waterlogged conditions by acting as an electron donor, by catalyzing redox–cycling through electron shuttling and by acting as a competing ligand. This study was set up to disentangle these different effects of SOM towards As and Sb sorption in anaerobic soils. Nine samples were taken at different depths in an agricultural soil profile to collect samples with a natural SOM gradient (<1–40 g soil organic carbon kg⁻¹). The samples were incubated either or not under waterlogged conditions in an anaerobic chamber for 63–70 days, and glucose (5 g C kg⁻¹) was either or not added to the anaerobic incubated samples as an electron donor that neither acts as an electron shuttle nor as a competing ligand. The solid-liquid distribution coefficients (KD) of As and Sb were measured at trace levels. The KD values of As decreased ∼2 orders of magnitude upon waterlogging the SOM rich topsoil, while no additional changes were observed when glucose was added. In contrast, smaller changes in the As KD values were found in the low SOM containing subsoil samples, unless glucose was added that mobilised As. The Sb KD values increased upon reducing conditions up to factor 20, but again only in the high SOM topsoil samples. Surprisingly, the Sb immobilisation during waterlogging only occurred in Sb amended soils whereas the geogenic Sb was mobilised upon reducing conditions, although total dissolved Sb concentrations remained low (<10 nM). The change in As and Sb sorption upon waterlogging was similar in the SOM rich topsoil as in the low SOM subsoil amended with glucose. This suggests that the SOM dependent changes in As and Sb mobility in response to soil waterlogging are primarily determined by the role of SOM as electron donor.

The aim of this study was to examine the effects of arbuscular mycorrhizal (AM) fungi, biochar (BC) addition and phosphorus (P) fertilizer applications on the mycorrhizal response, biomass and elemental uptake of Trifolium repens in cadmium (Cd)-polluted soils. The results showed that mycorrhizal colonization were significantly decreased by 100 mg P kg⁻¹ fertilizer input. Moreover, AM fungi, BC addition and P fertilizer significantly increased shoot biomass accumulation at all treatments. In the absence of BC, the nitrogen (N), potassium (K), calcium (Ca) and magnesium (Mg) contents in the shoots were not affected by AM fungi after P fertilizer application, but the P content in the shoots significantly increased in response to AM fungi. In the absence of BC, both AM fungi and P fertilizer significantly reduced the Cd concentrations in the plant tissues as well as the soil diethylenetriaminepentaacetic acid (DTPA)-Cd concentration. These results indicated that the translocation factors (TFs) were influenced only by BC addition and that the roots could accumulate greater amounts of Cd than the shoots. On the basis of the hygienic standard for feed in China, the shoot Cd concentration in white clover was below the maximum permitted Cd concentration (1 μg g⁻¹) across all treatments. Therefore, it is suggested that no negative mycorrhizal-white clover symbiotic relationships were observed and T. repens could be a suitable forage species for planting in soils with low concentrations of Cd contamination when BC and P fertilizer are applied.

Plastic pollution has become a pressing issue due to its persistence in the environment. Smaller plastics are more easily ingested, potentially exerting greater influences on organisms. In this study, the effects of polystyrene nanoplastics (NP) on the toxic effects, bioaccumulation, biodegradation and enantioselectivity of ibuprofen (IBU) in algae Chlorella pyrenoidosa were explored. The influences on the growth rate, chlorophyll a, total antioxidant capacity (T-AOC), reactive oxygen species (ROS) and lipid peroxidation (MDA) were evaluated after 96 h of exposure to a combination of polystryene NP (1 mg L⁻¹) and IBU (5–100 mg L⁻¹). The results indicated that the inhibitory effect of IBU on C. pyrenoidosa growth was alleviated in the presence of NP. For instance, the 96 h-IC₅₀ value for rac-IBU in the treatment lacking NP was 45.7 mg L⁻¹, and the corresponding value in the treatment containing NP was 63.9 mg L⁻¹. The co-exposure of NP led to a significant enhancement of T-AOC and slight reduction of ROS and MDA compared with the individual exposure (IBU) group, suggesting a decreased oxidative stress. In addition, treatment with NP led to a decreased bioaccumulation and accelerated biodegradation of IBU in C. pyrenoidosa and enhanced removal in the medium. The enantioselective toxicity, bioaccumulation and biodegradation of IBU were observed both in the absence and presence of NP. S-IBU exhibited a greater toxicity, and R-IBU was preferentially accumulated and degraded in C. pyrenoidosa. No interconversion of the two enantiomers occurred regardless of the presence of NP. This consequence implied that the influence of coexistent NP should be considered in the environmental risk assessment of pharmaceuticals and personal care products in aquatic environments.

Liquid hydrocarbon pipeline accidents, including leaks due to the illegal or unauthorized collection of petroleum from oil pipelines, are a widespread phenomenon that can lead to pollution that may negatively affect soil quality and plant growth. The aim of this study is to evaluate hydrocarbon uptake and accumulation in Zea mays plants grown on soil affected by spills of fossil fuels. The experiments were conducted in microcosm, mesocosm and field tests. The potential transfer of contaminants from soil to plant and their effects on plant growth were investigated. The results from both the laboratory and field experiments showed that the plants grew better in the uncontaminated soil than in the soil polluted by hydrocarbons. Despite their significantly lower aerial biomass, plants grown in contaminated soil did not show any significant differences in C > 12 concentration, either in shoots or roots, compared to the control plants. Thus, the decrease in plant yield might not be attributed to hydrocarbons accumulation in the plant tissues and may rather be due to a reduced soil fertility, which negatively affected plant growth.Under our experimental conditions, the hydrocarbons present in the contaminated soil were not absorbed by the plants and did not accumulate in plant tissue or in grains, thus avoiding the risk of them entering the food chain.

Extensive use of magnetic iron oxide (magnetite) nanoparticles (IONP) has raised concerns about their biocompatibility. It has also stimulated the search for its green synthesis with greater biocompatibility. Addressing the issue, this study investigates the molecular nanotoxicity of IONP with embryonic and adult zebrafish, and reveal novel green fabrication of iron oxide nanoparticles (P-IONP) using medicinal plant extract of Phyllanthus niruri. The synthesized P-IONP was having a size of 42 ± 08 nm and a zeta potential of −38 ± 06 mV with hydrodynamic diameter of 109 ± 09 nm and 90emu/g magnetic saturation value. High antibacterial efficacy of P-IONP was found against E.coli. Comparative in vivo biocompatibility assessment with zebrafish confirmed higher biocompatibility of P-IONP compared to commercial C-IONP in the relevance of mortality rate, hatching rate, heart rate, and morphological abnormalities. LC₅₀ of P-IONP and C-IONP was 202 μg/ml and 126 μg/ml, respectively. Molecular nano-biocompatibility analysis revealed the phenomenon as an effect of induced apoptosis lead by dysregulation of induced oxidative stress due to structural and functional influence of IONP to Sod1 and Tp53 proteins through intrinsic atomic interaction.

This study reveals the impact of biomass burning (BB) on secondary organic aerosols (SOA) formation in the North China Plain (NCP). Filter samples were analyzed for secondary inorganic aerosols (SIA), oxalic acid (C2) and related aqueous-phase SOA compounds (aqSOA), stable carbon isotope composition of C2 (δ13C(C2)) and aerosol liquid water content (ALWC). Based on the PM2.5 loadings, BB tracer concentrations, wildfire spots and air-mass back trajectories, we distinguished two episodes from the whole campaign, Episode I and Episode II, which were characteristic of regional and local BB, respectively. The abundances of PM2.5 and organic matter in the two events were comparable, but concentrations and fractions of SIA, aqSOA during Episode I were much higher than those during Episode II, along with heavier δ13C(C2), suggesting an enhanced aqSOA formation in the earlier period. We found that the enhancement of aqSOA formation during Episode I was caused by an increased ALWC, which was mainly driven by SIA during the regional BB event. Our work showed that intensive burning of crop residue in East Asia can sharply enhance aqSOA production on a large scale, which may have a significant impact on the regional climate and human health.

Bioremediation has gained global prominence as an effective method for treating hydrocarbon-contaminated drill mud waste (HCDW). However, the problem of low nutrient content, bioavailability and microbial presence remain largely unresolved. In this study, the synergistic effects of compost, cow bile and bacterial culture on the degradation rate of HCDW was investigated. A homogenized HCDW sample (80 kg) obtained from 25 different drill mud tanks was divided into 20 portions (4 kg each) and each adjusted to 1.4% nitrogen content + 20 ml cow bile (i.e., basic treatment). Pure cultures of Brevibacterium casei (Bc) and Bacillus zhangzhouensi (Bz) and their mixture (BcBz) were subsequently added to 12 of the amended HCDW (basic) to undergo a 6-week incubation. A portion of the unamended HCDW (2 kg) was used as control. Initial pH, electrical conductivity and surface tension values of the HCDW were 8.83, 2.34 mS/cm and 36.5 mN/m, respectively. Corresponding values for total petroleum hydrocarbon (TPH), total nitrogen and total plate count bacteria were 165 g/kg, 0.04% and 4.4 × 10² cfu/ml. The treatments led to a substantial reduction in TPH (p < 0.05) while the control had no significant effect (p > 0.05). TPH reduction after the experimental period occurred in the order: basic + BcBz (99.7%) > basic + Bz (99.5%) > basic + Bc (99.2%) > basic (95.2%) > control (0.06%). Multiple regression analysis revealed significant effect of total plate count, pH, CN ratio and electrical conductivity (R² = 0.87, p = 0.05) on the degradation of TPH in the HCDW. The study demonstrates strong interactive effects of compost, cow bile and bacteria culture on the remediation of HCDW, which can be applied to boost the efficiency of the bioremediation technique.