The Finnish Institute of Occupational Health (KTL) has concluded that laser printers emitted ultrafine particles during use, according to an article by the Finnish News Agency STT. It said although health effects of the emission have yet to be established, office ventilation systems should be examined to ensure they function properly. KTL tested four common makes and models of laser printer under laboratory conditions; it discovered that fine-particle levels rose significantly while 200 pages were printed. The origin or composition of the particles weren't identified in the study, and the KTL said more studies are needed. In a study last year, Queensland University of Technology in Australia analyzed emissions of 62 laser printers and said the emissions are on par with those of cigarette smoke and internal combustion engines, STT reported. (See also: Printer Particles Pose Risk; HP Refutes Printer Study)