Everyone hates the office printer, including scientists who blame the printers for emitting dangerous amounts of ultra-fine particles. Scientists from Queensland University examined printers from Canon, Hewlett-Packard, Ricoh and Toshiba. Their findings don’t condemn any one brand: the HP LaserJet 4050 emitted no particles, while the the HP LaserJet 1320 and 4250 raised the particle count of the surrounding air tenfold. From the LA Times:
Morawska did not originally set out to study printers. She was invited by the Queensland Department of Public Works to measure air quality inside a six-floor office building near a busy road.