Reduced Organic Nitrogen Dominates Atmospheric Organic Particle Toxicity

YALING ZENG, Xin Yang, Southern University of Science and Technology

     Abstract Number: 85
     Working Group: Health-Related Aerosols

Abstract
Despite decades of efforts to control air pollution, the global disease burden attributable to atmospheric particles remains alarmingly high. Atmospheric particles contain thousands of organic molecules, yet most remain chemically unidentified and toxicologically uncharacterized. This fundamental knowledge gap challenges the conventional view that particle mass concentration and a few known toxicants are the primary drivers of air pollution health risks. Here, we performed a comprehensive molecular and toxicological investigation of atmospheric particles from urban environments, integrating non-target analysis of high-resolution mass spectrometry, protein adductomics-based internal exposure assessment, and multi-endpoint toxicity prediction. We reveal that reduced organic nitrogen (RON) compounds, despite their low diversity, dominate the multi-organ toxicity of atmospheric particles, surpassing traditionally emphasized oxygenated organics. RON compounds show strong binding affinity to human serum albumin, enabling their transport and distribution to peripheral organs. This mechanism facilitates systemic toxicity, inducing respiratory, neurological, hepatic, renal, and hematological damage. Our findings uncover a previously overlooked mechanism of particulate toxicity and call for a paradigm shift in air quality management, highlighting the urgent need to regulate organic nitrogen emissions to mitigate global public health risks.