Resolving Spatially Varied PM_2.5 Toxicity in the Yangtze River Delta: Targeting Incomplete Combustion Sources

Area of Science:

• Environmental Science
• Toxicology
• Public Health

Background:

• Fine particulate matter (PM2.5) is a major environmental risk for premature death.
• PM2.5 mass concentrations have decreased, but source-specific toxicities are often ignored in air quality management.
• Unequal toxicity from different PM2.5 sources impacts health outcomes disproportionately.

Purpose of the Study:

• To conduct health-oriented source apportionment of PM2.5 in the Yangtze River Delta (YRD).
• To integrate source-specific toxicities with emission inventories for a toxicity-adjusted assessment.
• To inform targeted air quality policies for improved regional health equity.

Main Methods:

• Integrated field measurements, cellular assays, and high-resolution emission inventories.
• Calculated toxicity-adjusted population-weighted PM2.5 exposure.
• Analyzed correlations between residential combustion toxicity and city-level income.

Main Results:

• High toxicity-adjusted PM2.5 exposure observed in central/northern Anhui and along the Yangtze River.
• Residential solid fuel combustion was the primary contributor to PM2.5 toxicity, especially in winter (74.4%).
• Residential combustion toxicity was negatively correlated with city income (r = -0.83, p < 0.0001).

Conclusions:

• Controlling residential emissions offers significant toxicity reduction, particularly in low-income areas.
• Ship emission abatement may provide optimal cost-health benefits in coastal regions.
• Tailored air quality policies focusing on residential and ship emissions are crucial for regional health equity.