It’s official; outdoor air pollution is “carcinogenic to humans” and linked to significant increases in lung cancer per a recent classification established by the World Health Organization’s International Agency for Research on Cancer (IARC). Little evidence exists about which fuels cause the worst emissions with health consequences, and especially, exposure to particulate matter, which earned its own, separate IARC carcinogenic classification.

New research by Naomi Fukagawa, M.D., Ph.D., University of Vermont professor of medicine, Britt Holmén, Ph.D., associate professor of engineering, and colleagues, delves deeper – at the cellular and molecular levels – to determine the impact of petrodiesel vs. biodiesel emissions on the processes that may lead to disease.

“The expected increase in future use of biodiesel emphasizes the critical need to understand the health and environmental effects of biodiesel combustion,” say Fukagawa and colleagues.

Their study, published online in the journal Environmental Science & Technology, examines the underlying biological mechanisms affected by exposure to exhaust generated by a light-duty diesel engine using petrodiesel (B0) and a biodiesel blend (B20), composed of 20 percent soy biodiesel and 80 percent B0 by volume, in human lung epithelial and white blood cell lines, as well as in a mouse model.

The group compared tailpipe particle emissions measurements from the B0 and B20 fuels and conducted biological assays for inflammatory mediators and oxidative stress biomarkers to determine potential contributions to health outcomes.

Though the B20 fuel produced less particle mass than B0, say the study authors, their results showed that “the B20 particles may contribute to greater biological effects per mass than B0, leading to potentially greater health risks.”

“This study has important implications for human health/nutrition and raises issues related to the pressure to seek alternative energy sources,” says Fukagawa. With her co-authors, she adds that “future work is clearly needed to more thoroughly characterize the exhaust particles from biodiesel combustion under a wide range of engine operating conditions so that the real-world health effects of fuel switching can be quantified.”

In addition to Fukagawa and Holmén, co-authors on the paper include Muyao Li, M.D., UVM assistant professor of medicine; Matthew Poynter, Ph.D., UVM associate professor of medicine; and John Kasumba, doctoral student in environmental engineering.

Link to “Soy Biodiesel and Petrodiesel Emissions Differ in Size, Chemical Composition and Stimulation of Inflammatory Responses in Cells and Animals.”