Biodiesel Exhaust Toxicity with and without Diethylene Glycol Dimethyl Ether Fuel Additive in Primary Airway Epithelial Cells Grown at the Air–Liquid Interface

Abstract

Biodiesel usage is increasing steadily worldwide as the push for renewable fuel sources increases. The increased oxygen content in biodiesel fuel is believed to cause decreased particulate matter (PM) and increased nitrous oxides within its exhaust. The addition of fuel additives to further increase the oxygen content may contribute to even further benefits in exhaust composition. The aim of this study was to assess the toxicity of 10% (v/v) diethylene glycol dimethyl ether (DGDME) added as a biodiesel fuel additive. Primary human airway epithelial cells were grown at the air-liquid interface and exposed to diluted exhaust from an engine running on either grapeseed, bran, or coconut biodiesel or the same three biodiesels with 10% (v/v) DGDME added to them; mineral diesel and air were used as controls. Exhaust properties, culture permeability, epithelial cell damage, and IL-6 and IL-8 release were measured postexposure. The fuel additive DGDME caused a decrease in PM and nitrous oxide concentrations. However, exhaust exposure with DGDME also caused decreased permeability, increased epithelial cell damage, and increased release of IL-6 and IL-8 (p < 0.05). Despite the fuel additive having beneficial effects on the exhaust properties of the biodiesel, it was found to be more toxic.

Zero-Carbon and Carbon-Neutral Fuels: A Review of Combustion Products and Cytotoxicity

“…Yang et al showed that PM10 produced by fuel blends composed of waste cooking oil/butanol/diesel (B10W20, B10W40) significantly reduced diesel-induced genotoxicity of A549 cells and diesel-induced mutagenicity of CHO-K1 cells [233]. Diluted engine exhaust from grapeseed, bran, or coconut biodiesel blended with 10% (v/v) diethylene glycol dimethyl ether (DGDME) resulted in reduced permeability, increased cell damage, and increased IL-6 and IL-8 release of primary human airway epithelial cells growing at the gas-liquid interface [234]. Collectively, these results suggest that these fuel blends are cytotoxic.…”