title: Personal exposure to ultrafine particles from PVC welding and concrete work during tunnel rehabilitation.
abstract: To investigate the exposure to number concentration of ultrafine particles and the size distribution in the breathing zone of workers during rehabilitation of a subsea tunnel.
  
  
  
  Personal exposure was measured using a TSI 3091 Fast Mobility Particle Sizer (FMPS), measuring the number concentration of submicrometre particles (including ultrafine particles) and the particle size distribution in the size range 5.6-560 nm. The measurements were performed in the breathing zone of the operators by the use of a conductive silicone tubing. Working tasks studied were operation of the slipforming machine, operations related to finishing the verge, and welding the PVC membrane. In addition, background levels were measured.
  
  
  
  Arithmetic mean values of ultrafine particles were in the range 6.26×10(5)-3.34×10(6). Vertical PVC welding gave the highest exposure. Horizontal welding was the work task with the highest maximum peak exposure, 8.1×10(7) particles/cm(3). Background concentrations of 4.0×10(4)-3.1×10(5) were found in the tunnel. The mobility diameter at peak particle concentration varied between 10.8 nm during horizontal PVC welding and during breaks and 60.4 nm while finishing the verge.
  
  
  
  PVC welding in a vertical position resulted in very high exposure of the worker to ultrafine particles compared to other types of work tasks. In evaluations of worker exposure to ultrafine particles, it seems important to distinguish between personal samples taken in the breathing zone of the worker and more stationary work area measurements. There is a need for a portable particle-sizing instrument for measurements of ultrafine particles in working environments.
authors.affiliation: Department of Industrial Economics and Technology Management, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Rikke Bramming
authors.initials: RB
authors.lastname: Jørgensen
authors.affiliation: Department of Occupational Medicine, St. Olav's Hospital, Trondheim University Hospital, Trondheim, Norway Department of Public Health and General Practice, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Morten
authors.initials: M
authors.lastname: Buhagen
authors.affiliation: Department of Occupational Medicine, St. Olav's Hospital, Trondheim University Hospital, Trondheim, Norway Department of Geology and Mineral Resources Engineering, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Solveig
authors.initials: S
authors.lastname: Føreland
mesh_terms: D000336:Aerosols; D000395:Air Pollutants, Occupational / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis*; D009664:Norway; D016273:Occupational Exposure / Q000032:analysis*; D010316:Particle Size; D052638:Particulate Matter; D011143:Polyvinyl Chloride; D014896:Welding
chemical_list: D000336:Aerosols; D000395:Air Pollutants, Occupational; D052638:Particulate Matter; D011143:Polyvinyl Chloride
keywords: FMPS; PVC welding; particle size distribution; personal exposure; ultrafine particles