| Diesel Particulate Matter (DPM) |
Carbonaceous material represents an important constituent of atmospheric aerosols. Carbonaceous aerosols can be thought of as being comprised of organic carbon (OC), (which includes a mix of organic compounds, some of which are semivolatile, as well as naturally occurring vegetation); and elemental carbon (EC), (the light-absorbing portion of particulate carbon that has been related to soot). In the atmosphere, the main sources of carbonaceous material are anthropogenic and include biomass burning, motor vehicles and industrial sources. Combustion derived aerosols have been hypothesized as potentially contributing to the observed link between atmospheric particulate matter and health effects. Diesel Particulate Matter (DPM) consists of solid EC particles with adsorbed and condensed hydrocarbons and sulfates. The tiny particles (about 0.2μm in diameter) are present in diesel fuel. Studies over the past ten years have correlated occupational exposure to DPM with an increased risk of cancer. These findings have prompted regulations and guidelines for DPM. In particular, the Mine Safety and Health Administration (MSHA) has proposed standards pertaining to DPM exposure. The new regulations use special analytical methods for monitoring DPM exposure (e.g., NIOSH Method 5040). RJLG’s analysis of organic carbon (OC) and elemental carbon (EC) is performed using the Desert Research Institute Thermal/Optical Carbon Analyzer (DRI Model 2001). This instrument is the basis for the NIOSH 5040 method for the measurement of OC and EC on quartz filters. The EC concentration from this analysis is used as a surrogate to estimate DPM exposure. The methodology is based on the preferential volatilization of OC and EC compounds at different temperatures and oxidation conditions from exposed quartz microfiber filters. This analyzer aids in the determination of organic carbon (OC) and elemental carbon (EC) in aerosols, such as diesel particulate, for ambient air quality, and environmental exposure assessments. RJ Lee Group’s clients include private companies, government regulatory agencies, commercial laboratories, and universities. Applications for this analytical service include:
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