Toxics

Background: Nanoplastics (NPs), as emerging foodborne contaminants, can accumulate in the heart and induce toxic effects. However, whether NPs exert differential cardiac impacts depending on dietary habits remains unclear. Methods: In this study, mice subjected to different dietary patterns (Normal diet ND; High fat diet HFD; high-fructose diet, HFrD) were orally administered 80 nm polystyrene nanoplastics (PS-NPs) at a dose of 10 mg/(kg·day) for 1, 4, and 8 weeks. The fluorescence tracing, histopathological analysis, quantification of inflammatory and fibrotic markers, and transcriptomic sequencing were used to evaluate the distribution and hazardous effect of PS-NPs. Results: By the 8th week, significant fluorescence labeled PS-NPs accumulation was detected in the hearts of mice on HFD group and HFrD group. Histopathological and immunofluorescence analyses revealed that both HFD and HFrD groups exacerbated cardiac collagen deposition and inflammatory infiltration in PS-NP-exposed mice. Transcriptomic analysis further indicated that under HFD, PS-NP exposure primarily activated MAPK signaling pathway-mediated inflammation, thereby promoting fibrosis. In contrast, under HFrD, PS-NP80 amplified cardiac injury via the TNF signaling pathway. Conclusions: These findings demonstrate that dietary habits can aggravate the cardiac toxicity induced by foodborne nanoplastics, highlighting the importance of considering dietary patterns in the risk assessment of food contaminants.

This study focuses on the Lujiang Alum Mine, analyzing sources of acid mine drainage (AMD) generated during remediation activities. A numerical model of groundwater flow was constructed to simulate and predict the causes of AMD under the influence of remediation measures. Concurrently, hydrogen and oxygen stable-isotope-tracing techniques were employed to elucidate the pathways through which AMD occurred and the mechanisms underlying water acidification. A fully mixed model was established to quantify the rates of contribution from different water sources. The results indicate that the annual amount of acidic wastewater produced under the influence of disturbance via remediation is approximately 3.29 × 10⁵ m³. The fully mixed model based on environmental isotopes further revealed that the discharge of water from the first branch of the +85 m adit serves as the primary cause of AMD during the wet, normal, and dry seasons, with a contribution exceeding 50%. This is followed by recharge from Tianchi Lake, accounting for approximately 20–30%. In contrast, the contributions from seepage water from the roof of the +85 m adit and water from the Xiaofanshan Inclined Shaft are relatively minor. Based on these findings, we propose targeted strategies for source prevention and end-of-pipe treatment of AMD in the mining area. This work provides scientific support for the ongoing ecological restoration project at the Lujiang Alum Mine and offers valuable insights for AMD management in similar mines.

Tuber crops cultivated in basalt-derived soils are influenced by naturally high geochemical backgrounds, which may elevate heavy metal(loid) levels and associated health risks. To clarify the geochemical controls governing metal accumulation, this study analyzed rock, soil, and tuber (sweet potato and yam) samples from the Qiongbei volcanic area of Hainan Island, China. Concentrations of eight heavy metal(loid)s (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) and 22 nutrient-related indicators (N, P, K, SOC, S, Se, Fe, Mn, and their available fractions) were determined. Soil contamination and potential human health risks were evaluated using the pollution index and the health risk model. The results showed that 11.1–55.6% of soil samples exceeded pollution thresholds for Cr, Cu, Ni, and Zn, reflecting typical basaltic high-background characteristics. In contrast, heavy metal(loid) concentrations in tuber crops were relatively low and jointly regulated by parent material composition and soil nutrient status. Non-carcinogenic risks (HI) were below 1, indicating acceptable exposure levels, while carcinogenic risks were mainly associated with Cd, Cr, and Pb, with total carcinogenic risk (TCR) exceeding 1 × 10⁻⁴, suggesting potential health concerns. Strong correlations between soil nutrients (N, P, K, SOC, S, Se, Mn, and Fe) and plant uptake of As, Cd, Cu, and Cr indicate that nutrient availability plays a crucial role in controlling heavy metal(loid) bioavailability. The volcanic soils exhibited a “high total content–low bioavailability” pattern. Enhancing soil Se, SOC, available N, and slowly available K (SAK) can effectively reduce Cd and other high-risk metal accumulation in tuber crops. These findings elucidate the key geochemical processes influencing heavy metal transfer in volcanic agroecosystems and provide a scientific basis for safe agricultural utilization and health risk prevention in high-background regions.