Assessment of leaching risk of trace metals, PAHs and PCBs from a brownfield located in a flooding zone

Migration and Accumulation Simulation Prediction of PPCPs in Urban Green Space Soil Irrigated with Recycled Water: A Review

The presence of pharmaceuticals and personal care products (PPCPs) in reclaimed water introduces an ongoing challenge as they infiltrate green space soils during irrigation, leading to a gradual buildup that poses considerable ecological risks. The simulation and forecasting of PPCPs accumulation in soil are pivotal for proactive ecological risk management. However, the majority of research efforts have predominantly concentrated on the vertical transport mechanisms of PPCPs in the soil, neglecting a holistic perspective that integrates both vertical and lateral transport phenomena, alongside accumulation dynamics. To address this gap, this study introduces a comprehensive conceptual model that encapsulates the dual processes of vertical and lateral transport, coupled with accumulation of PPCPs in the soil environment. Grounded in the distinctive properties of green space soils, we delve into the determinants governing the vertical and lateral migration of PPCPs. Furthermore, we consolidate existing simulation methodologies for contaminant transport, aiming to establish a comprehensive model that accurately predicts PPCPs accumulation in green space soils. This insight is critical for deducing the emission threshold of reclaimed water necessary for the protection of green space soils, informing the formulation of rational irrigation strategies, and anticipating future environmental risks. It provides a critical theoretical basis for more informed decision-making in the realm of urban water reuse and pollution control.

Brownfield-related studies in the context of climate change: A comprehensive review and future prospects

The global climate change events are expected to augment the vulnerability of persistent organic pollutants within the global brownfield areas to a certain extent, consequently heightening the risk crises faced by these brownfields amidst the backdrop of global environmental changes. However, studies addressing brownfield risks from the perspective of climate change have received limited attention. Nonetheless, the detrimental consequences of brownfield risks are intrinsically linked to strategies for mitigating and adapting to sustainable urban development, emphasizing the critical importance of their far-reaching implications. This relevance extends to concerns about environmental quality, safety, health risks, and the efficacy of chosen regeneration strategies, including potential secondary pollution risks. This comprehensive review systematically surveys pertinent articles published between 1998 and 2023. A selective analysis was conducted on 133 articles chosen for their thematic relevance. The findings reveal that: (1) Under the backdrop of the climate change process, brownfield restoration is necessitated to provide scientific and precise guidance. The integration of brownfield considerations with the dynamics of climate change has progressively evolved into a unified framework, gradually shaping a research paradigm characterized by "comprehensive + multi-scale + quantitative" methodologies; (2) Research themes coalesce into five prominent clusters: "Aggregation of Brownfield Problem Analysis", "Precision Enhancement of Brownfield Identification through Information Technology", "Diversification of Brownfield Reutilization Assessment", "Process-Oriented Approaches to Brownfield Restoration Strategies", and "Expansion of Ecological Service Functions in Brownfield Contexts"; (3) Application methodologies encompass five key facets: "Temporal and Spatial Distribution Patterns of Pollutants", "Mechanisms and Correlations of Pollution Effects", "Evaluation of Pollution Risks", "Assessment of Brownfield Restoration Strategies", and "Integration of Brownfield Regeneration with Spatial Planning". Future brownfield research from the climate change perspective is poised to reflect characteristics such as "High-Precision Prediction, Comprehensive Dimensionality, Full-Cycle Evaluation, Low-Risk Exposure, and Commitment to Sustainable Development".

Distribution, sources, and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in Kaokaowusu river sediments near a coal industrial zone

This study systematically analyzed the contents, compositions, and sources of polycyclic aromatic hydrocarbons (PAHs) in river sediments near an important energy and chemical base in northwest China. In addition, their possible adverse effects on the ecology and human health were assessed. The PAH concentrations in this study area ranged from 2641.28 to 16783.72 (ng/g dw). PAHs of medium molecular weight (3-ring and 4-ring) showed the largest proportion, followed by PAHs of higher molecular weight (5-ring and 6-ring). The results of molecular diagnostic ratios and principal component analysis revealed that PAHs in the region have complex sources, with incomplete combustion of local fossil fuels and traffic exhaust factors being the main sources. The total toxic equivalent concentration of PAHs varied from 10.05 to 760.26 ng/g, and according to the sediment quality guidelines, PAHs have high potential ecological risk in the lower reaches of the river. The mean effect range-median quotient for the region was 0.46, and the combined ecological risk was at moderate to high levels (21% probability of toxicity). The lifetime carcinogenic risks for adults and children exposed to PAHs were 2.95 × 10-3 and 1.87 × 10-2, respectively, which are much higher than the limit of 10-4, indicating moderate to high potential cancer risks. Therefore, the local government should consider taking some environmental remediation measures. This study can provide theoretical support for pollution prevention measures and ecological restoration strategies for rivers in resource-rich areas.

Exposure to polychlorinated biphenyls selectively dysregulates endothelial circadian clock and endothelial toxicity

Polychlorinated biphenyls (PCBs) are lipophilic and persistent environmental toxicants, which pose health threats to the exposed population. Among several organs and cell types, vascular tissue and endothelial cells are especially prone to PCB-induced toxicity. Exposure to PCBs can exert detrimental impacts on biological pathways, expression of transcription factors, and tight junction proteins that are integral to the functionality of endothelial cells. Because biological and cellular processes are tightly regulated by circadian rhythms, and disruption of the circadian system may cause several diseases, we evaluated if exposure to PCBs can alter the expression of the major endothelial circadian regulators. In addition, we studied if dysregulation of circadian rhythms by silencing the brain and muscle ARNT-like 1 (Bmal1) gene can contribute to alterations of brain endothelial cells in response to PCB treatment. We demonstrated that diminished expression of Bmal1 enhances PCB-induced dysregulation of tight junction complexes, such as the expression of occludin, JAM-2, ZO-1, and ZO-2 especially at pathologically relevant longer PCB exposure times. Overall, the obtained results imply that dysregulation of the circadian clock is involved in endothelial toxicity of PCBs. The findings provide new insights for toxicological studies focused on the interactions between environmental pollutants and regulation of circadian rhythms.

The effect of residential proximity to brownfields, highways, and heavy traffic on serum metal levels in the Detroit Neighborhood Health Study

Research in environmental sciences has demonstrated that land in close proximity to brownfields and heavily trafficked highways is contaminated with toxic metals. Despite this, little is known about the influence of brownfields and highways on metal levels in residents living nearby. We used data from 774 participants in the Detroit Neighborhood Health Study to estimate the effect of residential proximity to brownfields, highways, and present-day traffic on serum levels of lead, mercury, manganese, and copper using generalized estimating equations. We found that a 1 standard deviation increase in residential brownfield density within 200m was associated with increased serum lead levels (β: 0.04, 95% CI: -0.01, 0.09). The same modeled increase in a subset of historic industrial-use brownfields was associated with elevated serum mercury (β: 0.06, 95% CI: 0.03, 0.09). Increased highway and traffic density was positively associated with serum manganese (β: 0.02, 95% CI: 0.01, 0.04). Highway and traffic density was also positively associated with serum lead (β: 0.02, 95% CI: 0.01, 0.03) after restricting the analysis to participants who did not move during the study follow-up period. These findings draw attention to the importance of remediating polluted post-industrial sites in heavily populated areas, particularly as residents continue to move into densely populated cities around the globe.