Enfeng Liu

Burial in sediments as organic carbon (OC) is the key pathway for C reduction. However, the C fixation mechanisms in fishpond sediments remain unclear. In this study, sediments were taken from fishponds raising different fish species. Different OC fractions including microbial biomass C (MBC), enzymatic activities, and C uptake indices including microbial C use efficiency (CUE) were obtained. The microbial communities were identified using 16S rRNA high‐throughput sequencing. The genes, cbbL and cbbM, encoding Calvin‐Benson‐Bassham (CBB) cycle were analyzed to decipher the community assembly regulation of C‐fixing bacteria. Results indicated that the fishpond cultivating Channel catfish had higher OC and nutrients. Higher MBC and C uptake factors indicated that high nutrients facilitated MBC synthesis and OC burial via microbial activities. Different from enzymes involved in C and N cycles, alkaline phosphatase (AP) displayed a significantly positive correlation with OC fractions. This cooperativity revealed that AP dominated the organic phosphorus mineralization and phosphate increase in water, thereby promoting C assimilation and burial into sediments. Additionally, 16S rRNA and CBB cycle genes revealed that the microbial community structure remarkably varied with fishpond types. The nutrient‐rich fishpond exhibited a greater abundance of dominant bacterial genera. Aquaculture types coupling nutrient differences induced the microbial community regulation, which further triggered the CUE response and MBC enrichment. Generally, nutrient‐driven MBC accumulation and microflora shifts were key drivers of OC sequestration. These findings provide new insights into the mechanisms of OC fixation in fishponds and suggest potential Nature‐based Solutions for enhancing global C reduction management.

Metallurgy has left a millennia-scale environmental footprint, yet the scarcity of long-term Chinese records remains a critical gap in global atmospheric metal pollution history. Here, we reconstructed 3000-year records of atmospheric antimony (Sb), lead (Pb), cadmium (Cd), and mercury (Hg) pollution using radiometrically dated sediment cores from three alpine lakes (∼4000 m a.s.l.) in Yunnan Province, southwestern China─a region known as the Kingdom of Nonferrous Metals. Sb, Pb, and Cd pollution showed distinct spatiotemporal shifts tied to regional metallurgy. Sb and Pb pollution first occurred in northeastern Yunnan during the mid-1400s, whereas the onset in western Yunnan emerged ∼200 y later, driven by expanding copper/silver (Cu/Ag) smelting, distinct cupellation/sinter-reduction technologies, and the central metallurgical status of the northeast. Cd pollution in Yunnan emerged after the early 1700s, coinciding with rising zinc (Zn) and Cu production. Peak preindustrial Sb, Pb, and Cd pollution culminated between the early 1800s and 1900 CE, exhibiting well-defined spatiotemporal patterns before declining amidst societal instability. Since the 1950s, rapid industrialization has driven Cd pollution to unprecedented levels, whereas Sb and Pb levels remain below their preindustrial peaks despite recent concurrent increases. In contrast to Sb, Pb, and Cd, Hg pollution recorded in the lakes was highly consistent, increasing steadily from the mid-1400s, accelerating after the 1850s, and surging after the 1950s, with dominant source areas shifting from Europe, across the broader northern hemisphere, and ultimately centering in China. These findings highlight the profound impact of evolving metallurgical practices on atmospheric quality over three millennia.

Unlike conventional energy-intensive physical/chemical soil remediation, dietary regulation of As oral bioavailability represents a cost-effective, sustainable downstream intervention in environmental risk management and control. However, how distinct dietary structures regulate As bioavailability remains unelucidated, hindering a holistic understanding of corresponding exposure and health risks. To address this, a mouse bioassay was conducted to evaluate the relative bioavailability (RBA) of As in two soils with four typical diet structures (high-fat, high-protein, high-carbohydrate, and high-dietary fiber diets). The results showed that although the four diets promoted the gastrointestinal As dissolution by 1.1–1.7-fold, the high-dietary fiber diet decreased As-RBA by 9.49–13.2% and lowered the health risk by 0.50–0.70-fold, which was more effective than high-protein and high-carbohydrate diets. The decrease was associated with lower intestinal permeability, which correlated with a significant increase in the relative abundance of Roseburia and Lachnospiraceae, and a decrease in the apoptosis rate of mouse intestinal epithelial cells. In contrast, a high-fat diet increased As-RBA by 8.72–11.9% and raised the health risk by 1.33–1.38-fold, which was associated with a significant proliferation of Dubosiella and a significant inhibition of Roseburia. This study shows that a high-dietary fiber diet is associated with reduced As exposure and potential health risks, in parallel with favorable changes in gut microbiota, oxidative status, and intestinal permeability.

Organic phosphorus (Po) mineralization is a major internal source of soluble reactive phosphorus (SRP) in lakes, yet the molecular and microbial mechanisms governing this transformation remain poorly understood. Here, we aim to elucidate these mechanisms by integrating excitation-emission fluorescence spectroscopy, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), and metagenomics across two contrasting ecological niches in Taihu Lake, namely the Cyanophyta-dominated and macrophyte-dominated regions. We also supplement our results with the findings from a global meta-analysis. We found that fulvic-associated Po (Fu-Po) dominated sedimentary Po inventories, whereas Po extracted with NaHCO₃ (NaHCO₃-Po) and microbial biomass Po (biomass-Po) exhibited higher decomposition potential. Fluorescence indices indicated increasing lability with depth, and humic-like materials exhibited a higher tendency to be decomposed under anoxia, accompanied by the accumulation of fulvic-like fractions. FT-ICR-MS revealed proteins and lignins as key constituents of humic-associated Po and Fu-Po, supporting their bioavailability, while NaHCO₃-Po was enriched in compounds with lipid-like CHOSP formulas, suggesting greater lability. Metagenomics identified phoD as the most abundant phosphatase-encoding gene, with rare but highly connected phoD-harboring taxa emerging as potential keystone regulators alongside abundant functional groups. Across global lake sediments, alkaline phosphatase activity, Po content, and phoD abundance were found to covary positively, and structural equation modeling highlighted Fu-Po as a disproportionate indirect driver of SRP replenishment via phoD-mediated phosphatase activity. These findings reveal a mechanistic cascade linking molecular composition to phoD-mediated enzymatic potential in Po mineralization, identifying Po bioavailability, rather than inorganic phosphorus pools alone, as a critical driver for reducing internal loading. Targeting this pathway could modulate Po mineralization mechanisms in sediments worldwide, offering valuable insights into the management of lake eutrophication under accelerating nutrient pressures.

Urban road dust is an important way for people to contact potentially toxic elements (PTEs). However, the correlation between the bioaccessibility of PTEs in road dust and the contribution rate of pollution sources has not yet reached a consensus. Road dust was divided into three particle sizes (<63, 63–125, and 125–250 μm). Then, the Mantel test was used to analyze the correlation between the contributions of the four pollution sources (composite sources, traffic sources, industrial sources, and fuel combustion) and the bioaccessibility of PTEs. Finally, by incorporating bioaccessibility into the health risk assessment system, Ni was identified as the priority lifetime carcinogenic risk element and fossil fuel combustion as the priority pollution source. The remediation target obtained by the probabilistic risk assessment of bioaccessibility guidance is 3.91 times the target value based on the total content and reduces carbon emissions by 22.6%. Overall, this study not only enhances the precision of identifying pollution sources and pollutants in complex urban environments by integrating PMF with the bioaccessibility of PTEs but also highlights the potential value of bioaccessibility in urban environmental management for carbon emission reduction. This facilitates the implementation of precise risk assessments and low-carbon sustainable development.

Dust deposition in northeastern Asia since the Last Glacial Maximum has previously been studied using a variety of archives. However, the mechanisms driving variability in dust are less well constrained. Here, we present records of the Nd‐Sr isotope and major element composition of sediments from Lake Tuofengling, a crater lake located in northeastern China, over the past ∼25 thousand years. The results indicate that the lithogenic fractions of the sediments are a mixture between aeolian dust and local volcanic detritus. Our provenance data suggest that the aeolian dust component is predominantly from the Mongolia Plateau, likely carried by the East Asian Winter Monsoon. Our isotope and calculated dust flux records exhibit similar changing patterns to proxies of global ice volume and the strength of Atlantic meridional overturning circulation, potentially implicating ice sheets and ocean circulation as the dominant drivers of the East Asian Winter Monsoon over this time interval.