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

Katherine R Landwehr; Jessica Hillas; Ryan Mead-Hunter; Andrew King; Rebecca A O'Leary; Anthony Kicic; Benjamin J Mullins; Alexander N Larcombe; WAERP

doi:10.1016/j.chemosphere.2022.136873

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

Chemosphere. 2023 Jan:310:136873. doi: 10.1016/j.chemosphere.2022.136873. Epub 2022 Oct 14.

Authors

Katherine R Landwehr¹, Jessica Hillas², Ryan Mead-Hunter³, Andrew King⁴, Rebecca A O'Leary⁵, Anthony Kicic⁶, Benjamin J Mullins³, Alexander N Larcombe⁷; WAERP⁸

Affiliations

¹ Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth, 6845, Western Australia, Australia; Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth, 6009, Western Australia, Australia. Electronic address: katherine.landwehr@telethonkids.org.au.
² Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth, 6009, Western Australia, Australia.
³ Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth, 6845, Western Australia, Australia.
⁴ Fluid Dynamics Research Group, School of Civil and Mechanical Engineering, Curtin University, Perth, Western Australia, Australia.
⁵ Department of Primary Industries and Regional Development, Perth, 6151, Western Australia, Australia.
⁶ Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth, 6845, Western Australia, Australia; Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth, 6009, Western Australia, Australia; Department of Respiratory and Sleep Medicine, Perth Children's Hospital, Nedlands, Perth, 6009, Western Australia, Australia; Centre for Cell Therapy and Regenerative Medicine, The University of Western Australia, Perth, 6009, Western Australia, Australia.
⁷ Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth, 6845, Western Australia, Australia; Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth, 6009, Western Australia, Australia.
⁸ Telethon Kids Institute, Centre for Health Research, The University of Western Australia, Nedlands, Perth, 6009, Western Australia, Australia; St. John of God Hospital, Subiaco, Perth, 6008, Western Australia, Australia.

PMID: 36252896
DOI: 10.1016/j.chemosphere.2022.136873

Abstract

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 < 0.01) whereas exposure to soy B20 generated the greatest number of changes in mediator release (including IL-6, IL-8 and TNF-α, p < 0.05) when compared to air exposed controls, with palm B20 and tallow B20 closely following. In contrast, canola B20 and WCO B20 were the least toxic with only mediators G-CSF and TNF-α being significantly increased. Therefore, exposure to palm B20, soy B20 and tallow B20 were found to be the most toxic and exposure to canola B20 and WCO B20 the least. The top three most toxic and the bottom three least toxic B20 fuels are consistent with their unblended counterparts, suggesting that feedstock type greatly impacts exhaust toxicity, even when biodiesel only comprises 20% of the fuel.

Keywords: Exhaust exposure; Health; In vitro exposure model; Toxicology of exhaust emissions; Vehicle emissions.

MeSH terms

Biofuels* / analysis
Biofuels* / toxicity
Cottonseed Oil
Gasoline / toxicity
Humans
Minerals
Particulate Matter* / analysis
Tumor Necrosis Factor-alpha
Vehicle Emissions / analysis
Vehicle Emissions / toxicity

Substances

Biofuels
Particulate Matter
Tumor Necrosis Factor-alpha
Cottonseed Oil
Vehicle Emissions
Gasoline
Minerals