Environmental Science: Nano最新文献

Deep-sea sediments hold large quantities of critical rare earth-elements and yttrium (REY) sequestered in nanoparticulate biogenic fluorapatite (Ca₅(CO₃)_x(PO₄)_3−xF_1+x). Understanding their enrichment processes and improving recovery and mineral processing methods require atomic-scale information about their chemical form, but it is difficult to obtain. Here, we use novel high-energy-resolution fluorescence-detected extended X-ray absorption fine structure (HERFD-EXAFS) spectroscopy to elucidate the local structure of gadolinium (Gd) in the highly enriched REY deposit from the Clarion–Clipperton fracture zone (CCFZ) in the Pacific Ocean. Our findings reveal that Gd is neither incorporated into the apatite structure nor precipitated alongside Ce in a Ce–PO₄ precipitate. Instead, it is bound at short-range distances to Ca and PO₄ in a defective apatite-type bonding environment within an amorphous matrix that encases fluorapatite nanocrystals. Density functional theory (DFT) suggests that Gd and Y, whose atomic fraction is ten times higher than that of Gd, are not dispersed throughout the amorphous matrix, but are likely segregated at medium-range distances. The entrapment of Ce, Gd, and Y within an amorphous matrix explains, at the microscopic level, why REY can be easily recovered through straightforward acid leaching. This is due to the intrinsic instability of disordered atomic structures compared to crystalline phases. This research highlights the complementarity of HERFD-EXAFS and DFT calculations for atomic-scale analysis of trace elements in complex natural matrices. It establishes a basis for their use across diverse terrestrial and marine materials.

Worldwide research interest is focused on the effects of environmental pollution on maternal and child health. Micro(nano)plastics (MNPs) are emerging pollutants that have been confirmed to exist in humans and interfere with lipid metabolism. However, the degree of exposure to MNPs during early human life and the potential impact of prenatal exposure on offspring lipid metabolism are still not well understood. To investigate the issues, this study collected umbilical cord blood samples from 30 healthy fetuses in Chengdu, as well as first postnatal urine samples from 6 of them. MNPs, liver function indicators, and lipid profiles were measured and detailed questionnaire surveys were conducted. The MNPs abundance in cord blood (34.61 (26.64) μg g⁻¹) was significantly higher than in neonatal urine (8.42 (2.82) μg g⁻¹), and more types of MNPs were found in cord blood. Additionally, the total abundance of all MNPs types in cord blood showed a negative correlation with high-density lipoprotein cholesterol levels (r = −0.40, p < 0.05), and the abundance of polyamide 66 (PA66) had a positive correlation with triglyceride levels (r = 0.39, p < 0.05). Furthermore, the abundance of MNPs in cord blood showed a positive correlation with the frequency of maternal takeaway food consumption during pregnancy (r = 0.52, p < 0.01) and with the frequency of milk tea consumption (r = 0.44, p < 0.05). The exploratory results suggest that prenatal MNPs exposure accumulate in newborns, and may potentially contribute to lipid metabolism disorders. Meanwhile, maternal dietary habits may increase the risk of MNPs exposure during pregnancy. These findings highlight the risks of MNPs exposure during early human life and the potential hazards it may pose to offspring health, supporting the need for larger longitudinal studies.

Inhalation of exogenous heavy metal-containing nanoparticles (HM-containing NPs) poses considerable health risks, yet their source-specific industrial emissions remain poorly characterized. This study employed an automated isokinetic sampling system to collect particulate matter (PM), and used single particle inductively coupled plasma time-of-flight mass spectrometry (SP-ICP-TOF-MS) to quantify ten HM-containing NPs in the collected samples from 132 full-scale industrial plants across 13 sectors in China. Sn, Mn, Zn, and Cu exhibited particularly high particle number concentrations (PNCs), with hazardous waste incinerators (HWIs) and electric arc furnaces (EAFs) identified as dominant emission sources. Notably, HWIs emitted Sn-containing NPs at a peak PNC of 8.8 × 10¹¹ particles per g. Across the representative industrial sectors in China, Mn-, Sn-, and Zn-containing NPs were the most abundantly emitted, with estimated annual releases of 1.6 × 10²³, 4.6 × 10²², and 2.0 × 10²² particles, respectively. Coal-fired power plants and cement kilns co-processing solid waste also contributed significantly. Exposure assessment—based on a steady-state atmospheric model and standard U.S. EPA inhalation and dermal exposure equations—revealed that, in highly impacted provinces, adults face cumulative exposure to HM-containing NPs up to 10⁵ particles per kg body weight per day, while children's exposure levels are more than double. These findings provide the first large-scale quantification of HM-containing NP emissions across multiple industries, offering critical data for exposure assessment and risk management. The results highlight HWIs and EAFs as key sectors for prioritized emission control, particularly to reduce exposure risks associated with high-emission HM-containing NPs such as Sn, Mn, Zn, and Cu in densely populated industrial regions.

One of the main targets of nanoplastic (NP) toxicity is the gastrointestinal tract, where the gut microbiota acts as a crucial biological barrier, by regulating nutrient and energy metabolism and maintaining the immune defence system. Lactic acid bacteria (LAB) are key components of the human intestinal microbiota and include many of the most important health-promoting probiotic strains. It has been proposed that specific LAB strains can protect against human toxicity caused by polystyrene (PS) NPs. Despite these findings, it is still not completely clear how the physiology and functional traits of LAB are influenced by NPs. In this study, we report how PS and polytetrafluoroethylene NPs, having significantly different chemical compositions, affect the key surface-associated phenotypic traits of selected LAB and penetrate their cellular membranes. Here, we show that NPs, particularly PS-NPs, significantly affect the hydrophobicity and auto-aggregation of the bacterial strains, in a species- and strain-dependent manner. PS-NP exposure resulted in a marked reduction in surface hydrophobicity and, in most cases, a concomitant increase in auto-aggregation; notably, Bifidobacterium breve Reuter exhibited the highest sensitivity to PS-NPs. Accordingly, membrane permeability assays and TEM analysis revealed substantial loss of cell wall integrity and consequent internalization of PS-NPs by the bacterial cells. In terms of lifestyle transitions, PS-NP exposure promoted a shift from planktonic to biofilm-associated growth in LAB strains. Overall, these findings highlight the disruptive potential of NPs on bacterial physiology and viability, with implications for gut microbiota stability and probiotic efficacy. The differential responses observed emphasize the importance of strain-specific assessments when evaluating NP toxicity.