Beware, computer users! Your office printer could be posing as much danger to your lungs as a drag on a cigarette, according to Australian scientists.

After an investigation, researchers from Queensland University of Technology have revealed that some laser printers emit potentially dangerous levels of tiny toner-like materials in the air which could harm one's lungs.

"These ultra-fine particles are capable of infiltrating the lungs and causing lasting damage on the scale of inhaled cigarette smoke," the Sydney Morning Herald reported, quoting researcher Prof Lidia Morawska as saying.

According to her, "These (printer) particles are tiny like cigarette smoke particles and, when deep inside the lung, they do the same amount of damage.

"The health effects from inhaling ultra-fine particles depend on particle composition, but the results can range from respiratory irritation to severe illness such as cardiovascular problems or cancer."

The conclusion came after the university's International Laboratory for Air Quality and Health examined 62 printers and found that 17 were "high-particle emitters".

The study, published in the American Chemical Society's Environment Science and Technology journal, found indoor particle levels in the office air increased five-fold during work hours due to printer use.

"Printers emitted more particles when the toner cartridge was new, and when printing graphics and images as they require greater quantities of toner," Prof Morawska was quoted by the daily.

However, she said that the emission levels varied a lot between different machine makes, models printer age, cartridge model and cartridge age.