title: Exposure to diesel exhaust fumes in the context of exposure to ultrafine particles.
abstract: OBJECTIVE
  Diesel exhaust fumes emission is a significant source of ultrafine particles, the size of which is expressed in nanometers. People occupationally exposed to diesel exhaust particles include mainly workers servicing vehicles with engines of this type. This article presents the analysis of measurements of ultrafine particle concentrations occurring in the bus depot premises during the work connected with everyday technical servicing of buses.
  
  
  METHODS
  The measurements were carried out in the everyday servicing (ES) room of the bus depot before, during and after the work connected with bus servicing. Determinations included: particle concentrations in terms of particle number and particle surface area, and mass concentrations of aerosol.
  
  
  RESULTS
  Mean value of number concentration of 10- to 1000-nm particles increased almost 20-fold, from 7600 particles/cm3 before starting bus servicing procedures to 130 000 particles/cm3 during the bus servicing procedures in the room. During the procedures, the mean surface area concentration of particles potentially deposited in the alveolar (A) region was almost 3 times higher than that of the particles depositing in the tracheo-bronchial (TB) region: 356.46 μm2/cm3 vs. 95.97 μm2/cm3, respectively. The mass concentration of the fraction of particulate matter with aerodynamic diameter 0.02-1 μm (PM1) increased 5-fold during the analyzed procedures and was 0.042 mg/m3 before, and 0.298 mg/m3 while the procedures continued.
  
  
  CONCLUSIONS
  At the time when bus servicing procedures continued in the ES room, a very high increase in all parameters of the analyzed particles was observed. The diesel exhaust particles exhibit a very high degree of fragmentation and, while their number is very high and their surface area is very large, their mass concentration is relatively low. The above findings confirm that ultrafine particles found in diesel exhaust fumes may be harmful to the health of the exposed people, and to their respiratory tract in particular.
authors.affiliation: Nofer Institute of Occupational Medicine, Łódź, Poland (Department of Physical Hazards). stellab@imp.lodz.pl.
authors.forename: Stella
authors.initials: S
authors.lastname: Bujak-Pietrek
authors.affiliation: Nofer Institute of Occupational Medicine, Łódź, Poland (Department of Physical Hazards).
authors.forename: Urszula
authors.initials: U
authors.lastname: Mikołajczyk
authors.affiliation: Textile Research Institute, Łódź, Poland (Scientific Department of Unconventional Technologies and Textiles).
authors.forename: Irena
authors.initials: I
authors.lastname: Kamińska
authors.affiliation: Textile Research Institute, Łódź, Poland (Scientific Department of Unconventional Technologies and Textiles).
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Cieślak
authors.affiliation: Nofer Institute of Occupational Medicine, Łódź, Poland (Department of Environmental Epidemiology).
authors.forename: Irena
authors.initials: I
authors.lastname: Szadkowska-Stańczyk
mesh_terms: D016902:Air Pollution, Indoor / Q000032:analysis; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis; D018986:Motor Vehicles; D016273:Occupational Exposure / Q000032:analysis*; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D052638:Particulate Matter; D001335:Vehicle Emissions
keywords: SEM/EDS analysis; diesel engine exhaust; occupational exposure; particles number concentration; particles surface area concentration; ultrafine particles