title: Assessment of diesel particulate matter exposure in the workplace: freight terminals.
abstract: A large study has been undertaken to assess the exposure to diesel exhaust within diesel trucking terminals. A critical component of this assessment is an analysis of the variation in carbonaceous particulate matter (PM) across trucking terminal locations; consistency in the primary sources can be effectively tracked by analyzing trends in elemental carbon (EC) and organic molecular marker concentrations. Ambient samples were collected at yard, dock and repair shop work stations in 7 terminals in the USA and 1 in Mexico. Concentrations of EC ranged from 0.2 to 12 microg m(-3) among the terminals, which corresponds to the range seen in the concentration of summed hopanes (0.5 to 20.5 ng m(-3)). However, when chemical mass balance (CMB) source apportionment results were presented as percent contribution to organic carbon (OC) concentrations, the contribution of mobile sources to OC are similar among the terminals in different cities. The average mobile source percent contribution to OC was 75.3 +/- 17.1% for truck repair shops, 65.4 +/- 20.4% for the docks and 38.4 +/- 9.5% for the terminal yard samples. A relatively consistent mobile source impact was present at all the terminals only when considering percentage of total OC concentrations, not in terms of absolute concentrations.
authors.affiliation: Environmental Chemistry and Technology Program, University of Wisconsin, 660 N Park St, Madison, WI 53706, USA.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Sheesley
authors.forename: James J
authors.initials: JJ
authors.lastname: Schauer
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Smith
authors.forename: Eric
authors.initials: E
authors.lastname: Garshick
authors.forename: Francine
authors.initials: F
authors.lastname: Laden
authors.forename: Linsey C
authors.initials: LC
authors.lastname: Marr
authors.forename: Luisa T
authors.initials: LT
authors.lastname: Molina
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis*; D002244:Carbon / Q000032:analysis*; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis*; D008800:Mexico; D009930:Organic Chemicals / Q000032:analysis*; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D018570:Risk Assessment; D014481:United States; D001335:Vehicle Emissions / Q000032:analysis* / Q000633:toxicity; D017132:Workplace
chemical_list: D000395:Air Pollutants, Occupational; D009930:Organic Chemicals; D052638:Particulate Matter; D001335:Vehicle Emissions; D002244:Carbon