Diesel particulate matter exposure to railroad train crews

Exposure assessments were conducted aboard diesel locomotives. Results were evaluated to determine variables that affect exposure to DPM (diesel particulate matter) and to assess use of EC (elemental carbon) and OC (organic carbon) as surrogates for DPM. National Institute for Occupational Safety and Health Method 5040 was used for collection and analysis of samples in locomotives and in nonrailroad settings. The level of EC, but not OC, in locomotives was found to be significantly affected by position of exhaust stacks and windows. EC ranged from < 1 to 45 micrograms/m3 with a geometric mean (GM) of 3.7 micrograms/m3 and OC ranged from 4 to 4570 micrograms/m3 with a GM of 36.3 micrograms/m3. Background measurements of EC ranged from < 1 to 8 micrograms/m3 and OC levels were 4 to 84 micrograms/m3. This study confirms that train crew exposure to DPM is much lower than exposures for miners, is comparable to background urban exposures, and is lower than but comparable to exposures for truck drivers. It also indicates that EC levels are highly predictive of diesel exhaust exposure whereas OC levels are not, and that open windows and exhaust stack(s) in front of the locomotive cab have a significant effect on EC.