Riverfront utilization structure shapes polycyclic aromatic hydrocarbon risks in the middle-lower Yangtze river.

Area of Science:

• Environmental Science
• Ecotoxicology
• Riverine Ecosystems

Background:

• Organic pollutants, particularly polycyclic aromatic hydrocarbons (PAHs), threaten large river ecosystems.
• PAHs are reliable tracers of human industrial and urban activities, crucial for pollution governance.
• Understanding PAH spatiotemporal dynamics is vital for assessing and mitigating riverine contamination.

Purpose of the Study:

• To investigate the spatiotemporal distribution of PAHs in the middle-lower Yangtze River.
• To assess the ecological risks posed by different types of PAHs to aquatic biota.
• To identify the drivers of PAH risks, focusing on riverfront utilization and industrial activities.

Main Methods:

• Analysis of dissolved and suspended particulate matter (SPM)-bound PAH concentrations.
• Ecological risk assessment focusing on medium- and high-molecular-weight (MMW/HMW) PAHs.
• Multivariate statistical analyses to correlate PAH risks with riverfront utilization and industrial factors.

Main Results:

• PAH concentrations varied widely, with elevated levels observed during the wet season, on southern banks, and downstream.
• MMW/HMW PAHs were identified as significant ecological risks to aquatic life.
• Riverfront utilization, especially industrial and port areas, was a primary driver of PAH risks and spatial heterogeneity.

Conclusions:

• Riverfront zoning and industrial configurations significantly influence PAH pollution dynamics and ecological risks in the Yangtze River.
• Optimizing riverfront utilization and upgrading industrial practices are essential for sustainable river management.
• Addressing PAH contamination requires a holistic approach to pollution control and resource management for the Yangtze River's ecological health.