Characterization of Biodiesel and Diesel Combustion Particles: Chemical Composition, Lipid Metabolism, and Implications for Health and Environment.

Biodiesel, derived from alkyl esters of vegetable oils or animal fats, has gained prominence as a greener alternative to diesel due to its reduced particle mass. However, it remains debatable whether biodiesel exposure has more severe health issues than diesel. This study performed high-resolution mass spectrometry to examine the detailed particle chemical compositions and lipidomics analysis of human lung epithelial cells treated with emissions from biodiesel and diesel fuels. Results show the presence of the peak substances of CHO compounds in biodiesel combustion that contain a phthalate ester (PAEs) structure (e.g., n-amyl isoamyl phthalate and diisobutyl phthalate). PAEs have emerged as persistent organic pollutants across various environmental media and are known to possess endocrine-disrupting properties in the environment. We further observed that biodiesel prevents triglyceride storage compared to diesel and inhibits triglycerides from becoming phospholipids, particularly with increased phosphatidylglycerols (PGs) and phosphatidylethanolamines (PEs), which potentially could lead to a higher probability of cancer metastasis.