Pollution transfer and environmental health implications: network evolution and proximity mechanisms in the Yangtze River Delta, China

Key findings from this study

• The study found that the Yangtze River Delta pollution transfer network exhibits a core-periphery structure with core cities maintaining strong internal connections while diffusing pollution outward at the national scale.
• The authors report that economic proximity dominates intra-regional pollution transfers, whereas institutional and technological proximity exert greater influence on extra-regional transfers.
• The researchers demonstrate that public health proximity significantly enhances pollution transfer only when interacting with economic and institutional factors, establishing a structural linkage between pollution redistribution and environmental health inequality.

Overview

This study investigates the spatiotemporal evolution of pollution transfer networks across China's Yangtze River Delta from 2012 to 2023. The research uses off-site environmental penalty data from large-scale enterprises to construct and analyze pollution transfer relationships. The study examines how multidimensional proximity mechanisms—economic, institutional, technological, and public health—jointly drive pollution redistribution across regions and interact to reinforce environmental health inequality.

Methods and approach

The researchers constructed pollution transfer networks from regulatory penalty records and applied social network analysis alongside the geographical detector method. This approach identified structural characteristics of pollution transfer and quantified the independent and interaction effects of multidimensional proximity factors. The analytical framework treated pollution transfer as a networked process shaped by both direct proximity mechanisms and their nonlinear interactions.

Results

The pollution transfer network exhibits continuous expansion with a pronounced core-periphery structure centered on Shanghai, Hangzhou, Nanjing, and other major cities. Strong internal linkages within core urban centers combine with outward diffusion at the national scale. Pollution transfer intensity increased over the study period and displays significant proximity effects.

Economic proximity dominates intra-regional transfers, while institutional and technological proximity prove more critical for extra-regional transfers. Public health proximity alone contributes limited explanatory power to pollution transfer patterns. However, when public health proximity interacts with economic and institutional factors, it substantially enhances pollution transfer likelihood, indicating a structural coupling between pollution redistribution mechanisms and environmental health inequality.

The multidimensional proximity framework reveals that pollution transfer operates as an interaction-driven process rather than a simple aggregation of individual proximity factors. Geographic and administrative boundaries shape these mechanisms differentially across regions within and beyond the Yangtze River Delta.

Implications

The findings establish that pollution transfer constitutes a significant but underappreciated driver of environmental health inequality across regions. The core-periphery network structure concentrates environmental burdens in peripheral areas while allowing core cities to externalize exposure risks. This geographic redistribution requires governance frameworks that address pollution as a networked phenomenon rather than isolated local problems.

The dominance of economic and institutional proximity in shaping transfer patterns suggests that market forces and regulatory frameworks interact to channel pollution flows toward regions with lower institutional capacity. Regional collaborative governance must account for these structural mechanisms to prevent peripheral regions from becoming persistent pollution sinks. Integrated environmental and health management approaches require explicit attention to cross-boundary pollution dynamics and their cumulative health effects.

The interaction effects between public health proximity and economic factors indicate that health considerations alone prove insufficient to restrict pollution transfer. Effective governance requires simultaneous coordination of economic incentives, institutional capacity, and technological innovation across jurisdictions.

Scope and limitations

This summary is based on the study abstract and available metadata. It does not include a full analysis of the complete paper, supplementary materials, or underlying datasets unless explicitly stated. Findings should be interpreted in the context of the original publication.