Fine Particle (Nanoparticle) Emissions on Minnesota Highways

Project summary:

The Center for Diesel Research (CDR) was awarded a $1.5M contract from the Coordinating Research Council (CRC). The purpose of the contract is to conduct on-highway diesel chase experiments to determine the size distribution of diesel aerosol with emphasis on nanoparticles (< 100 nm), and to develop methods that allow these ambient size distributions to be duplicated in the diesel test laboratory. CDR was also awarded a Health Effects Institute (HEI) contract to validate methods to estimate exposure to diesel aerosol. The HEI study will focus on determining exposure to diesel aerosol at a number of locations within the UMN bus transit system; including bus stops, on buses, parking and maintenance garages. Personal and area sampling will be conducted. A natural extension of these research programs is the measurement and characterization of urban and suburban roadway aerosol in the Twin Cities area with an emphasis on nanoparticles in congested and non-congested areas. The study will quantify and characterize nanoparticle concentration and size distribution, and confirm or contradict previous laboratory studies that suggest there may be high nanoparticle concentrations over roadways that should be an environmental health concern. Recent laboratory studies in our lab, at Ford, MTU and others have suggested that nanoparticle emissions from spark ignition (SI) and diesel engines are a potential environmental health concern. Emissions from SI engines are much more speed and load dependent than diesel engines. High speed and load conditions, e.g., freeway cruise and hard acceleration may produce emissions similar to diesel engines, but under less severe conditions particulate matter emissions are considerably lower. This finding is of concern because of the interest in possible health effects related to nanoparticles and the fact that SI engines may be a much larger source of these particles than previously thought. The objectives of this proposal are to use metho