Biodiesel feedstock determines exhaust toxicity in 20% biodiesel: 80% mineral diesel blends

• Published in: Chemosphere (Oxford) 2023-01, Vol.310, p.136873-136873, Article 136873
• Main Authors: Landwehr, Katherine R., Hillas, Jessica, Mead-Hunter, Ryan, King, Andrew, O'Leary, Rebecca A., Kicic, Anthony, Mullins, Benjamin J., Larcombe, Alexander N.
• Format: Article
• Language: English
• Subjects: Exhaust exposure; Health; In vitro exposure model; Toxicology of exhaust emissions; Vehicle emissions
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2022.136873

To address climate change concerns, and reduce the carbon footprint caused by fossil fuel use, it is likely that blend ratios of renewable biodiesel with commercial mineral diesel fuel will steadily increase, resulting in biodiesel use becoming more widespread. Exhaust toxicity of unblended biodiesels changes depending on feedstock type, however the effect of feedstock on blended fuels is less well known. The aim of this study was to assess the impact of biodiesel feedstock on exhaust toxicity of 20% blended biodiesel fuels (B20). Primary human airway epithelial cells were exposed to exhaust diluted 1/15 with air from an engine running on conventional ultra-low sulfur diesel (ULSD) or 20% blends of soy, canola, waste cooking oil (WCO), tallow, palm or cottonseed biodiesel in diesel. Physico-chemical exhaust properties were compared between fuels and the post-exposure effect of exhaust on cellular viability and media release was assessed 24 h later. Exhaust properties changed significantly between all fuels with cottonseed B20 being the most different to both ULSD and its respective unblended biodiesel. Exposure to palm B20 resulted in significantly decreased cellular viability (96.3 ± 1.7%; p