Soy biodiesel and petrodiesel emissions differ in size, chemical composition and stimulation of inflammatory responses in cells and animals.
Debate about the biological effects of biodiesel exhaust emissions exists due to variation in methods of exhaust generation and biological models used to assess responses. Because studies in cells do not necessarily reflect the integrated response of a whole animal, experiments were conducted in two human cell lines representing bronchial epithelial cells and macrophages and female mice using identical particle suspensions of raw exhaust generated by a Volkswagen light-duty diesel engine using petrodiesel (B0) and a biodiesel blend (B20: 20% soy biodiesel/80% B0 by volume). Tailpipe particle emissions measurement showed B0 generated two times more particle mass, larger ultrafine particle number distribution modes, and particles of more nonpolar organic composition than the B20 fuel. Biological assays (inflammatory mediators, oxidative stress biomarkers) demonstrated that particulate matter (PM) generated by combustion of the two fuels induced different responses in in vitro and in vivo models. Concentrations of inflammatory mediators (Interleukin-6, IL-6; Interferon-gamma-induced Protein 10, IP-10; Granulocyte-stimulating factor, G-CSF) in the medium of B20-treated cells and in bronchoalveolar lavage fluid of mice exposed to B20 were ∼20-30% higher than control or B0 PM, suggesting that addition of biodiesel to diesel fuels will reduce PM emissions but not necessarily adverse health outcomes.
Department of Medicine and ‡School of Engineering, University of Vermont , Burlington, Vermont 05405, United States.
Naomi K
NK
Fukagawa
Muyao
M
Li
Matthew E
ME
Poynter
Brian C
BC
Palmer
Erin
E
Parker
John
J
Kasumba
Britt A
BA
Holmén
D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D056804:Biofuels / Q000633:toxicity; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002452:Cell Count; D002460:Cell Line; D018925:Chemokines / Q000378:metabolism; D005260:Female; D005742:Gasoline / Q000032:analysis*; D006801:Humans; D007249:Inflammation / Q000473:pathology*; D008810:Mice, Inbred C57BL; D018384:Oxidative Stress / Q000187:drug effects; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis / Q000633:toxicity; D013025:Glycine max / Q000737:chemistry*; D001335:Vehicle Emissions / Q000032:analysis* / Q000633:toxicity
D000975:Antioxidants; D056804:Biofuels; D018925:Chemokines; D005742:Gasoline; D052638:Particulate Matter; D001335:Vehicle Emissions