Fine and ultrafine particles emitted from laser printers as indoor air contaminants in German offices

Abstract

Various publications indicate that the operation of laser printers and photocopiers may be associated with health effects due to the release of gaseous components and fine and ultrafine particles (UFP). However, only sparse studies are available that evaluate the possible exposure of office workers to printer emissions under real conditions. Therefore, the aim of our study was to assess the exposure of office workers to particulate matter released from laser printers and photocopiers. Concentrations of fine particles and UFP were measured before, during, and after the operation of laser printing devices in 63 office rooms throughout Germany. Additionally, the particles were characterized by electron microscopy and energy-dispersive X-ray spectroscopy. A significant increase of fine particles and UFP was identified in ambient workplace air during and after the printing processes. Particle fractions between 0.23 and 20μm emitted by the office machines significantly affect particle mass concentrations while printing 500 pages, i.e., during the printing process, PM(0.23-20), PM(2.5), and PM(10) concentrations increased in 43 out of the evaluated 62 office rooms investigated. Additionally, a significant increase was observed in submicrometer particles, with median particle number concentrations of 6,503 particles/cm(3) before and 18,060 particles/cm(3) during the printing process. Our data indicate that laser printers and photocopiers could be a relevant source of fine particles and particularly UFP in office rooms.