Spatiotemporal Distribution of 6PPD-Q in China Revealed by a National-Scale Quantification Framework

Area of Science:

• Environmental Science
• Environmental Chemistry
• Toxicology

Background:

• 6PPD-quinone (6PPD-Q), a derivative of tire antioxidant 6PPD, is a widespread contaminant with ecotoxicological and health concerns.
• Large-scale spatiotemporal emission dynamics, environmental fate, and human exposure levels of 6PPD-Q are not well understood.

Purpose of the Study:

• To establish a nationwide quantitative framework for assessing 6PPD-Q pollution dynamics and human exposure risks in China.
• To delineate spatiotemporal patterns of 6PPD-Q pollution and identify high-risk areas and populations.

Main Methods:

• Integrated high-resolution emission inventories, multimedia environmental fate modeling, and multi-pathway human exposure analysis.
• Analyzed national 6PPD-Q emissions from 2013 to 2023.
• Assessed human exposure routes and estimated daily intake for different age groups.

Main Results:

• National 6PPD-Q emissions surged by approximately 97.5% between 2013 and 2023, driven by vehicle growth.
• Highway traffic and soil reservoirs are significant emission sources, indicating a need for monitoring beyond urban water bodies.
• Pollution hotspots are concentrated in densely populated and topographically constrained regions.
• Children exhibit higher estimated daily 6PPD-Q intake than adults, with soil ingestion as the primary exposure pathway.

Conclusions:

• The developed framework effectively quantifies 6PPD-Q pollution and associated risks.
• Findings support targeted risk evaluation and regulatory interventions for 6PPD-Q.
• Expanded monitoring strategies are crucial for managing this ubiquitous environmental contaminant.