Abstract Number: 689 Working Group: Health Related Aerosols
Abstract Effects of biodiesel emissions on public health are not completely understood. Conflicting data in the recent literature highlight the challenges of drawing conclusions from studies utilizing different engine, fuel, and operating conditions that produce variable concentrations of harmful pollutants. The ability to identify the biodiesel fuel and engine technology that pose the lowest health risk will be a key component of biodiesel sustainability. Variation in how PM is sampled and prepared for use in biological studies may have significant effects on experimental outcomes. Oxidative stress as a response to reactive oxygen species (ROS) is believed to be the common mechanism leading to inflammation. However, not all exhaust particles generate ROS to the same degree. Development of a reliable and easy method for screening PM samples produced from a range of experimental conditions (e.g. fuel source, combustion parameters, exhaust filters) for their potential to induce oxidative stress will enable investigators to efficiently define those conditions linked to adverse health outcomes.
The objective of this study was to evaluate PM sampling techniques of biodiesel exhaust to be used in studies to determine biological effects. Emissions from a light-duty diesel Volkswagen engine run on various blends of biodiesel and petrodiesel were collected into ethanol using impingers. Two approaches to concentrate the suspensions were compared followed by determination of the effects of the PM on ROS generation and redox-sensitive inflammatory pathways in cell and animal models. Results from the abiotic dithiothreitol (DTT) consumption assay identified PM suspensions with greater ROS capacity and, consequently, greater potential for inducing inflammatory responses. Data confirmed that suspensions with higher ROS capacity were associated with evidence of cytotoxicity and inflammation.