Do printers pose health problems?

MILWAUKEE - Should laser printers come with a surgeon general's warning?

An Australian research team has found that some printers give off invisible particles as they operate, with the worst culprit emitting concentrations similar to those of secondhand tobacco smoke.

But that doesn't mean you need a mask every time you pass your printer.

The conclusions are based on a small subset of data, the researchers acknowledge, and raise many more questions than answers. Independent experts and a printer manufacturer say it would be premature to issue any warnings until researchers know exactly what chemicals make up the ultrafine particles. Some of the types of particles identified by the researchers can also be generated from simple activities such as burning a candle or making toast.

Even so, one of the researchers behind the study, physicist Lidia Morawska of Queensland University of Technology in Brisbane, Australia, said it wouldn't hurt to make sure printers are kept in open areas at a distance from users.

"This information should mainly guide manufacturers into designing printers that are low emitters," Morawska said. "In the meantime, if you can, put the printer in a separate well-ventilated area."

It's not clear that these ultrafine emissions are dangerous, according to Robert Hamers, the chairman of the chemistry department at the University of Wisconsin-Madison.

Each particle, up to 1,000 times smaller than a dust particle, is small enough that it can get drawn deeply into the lung's tiny sacs, Hamers said. But what it does once it gets there depends on its chemical composition.

For example, cigarette smoke is dangerous not because it contains tiny particles but because those particles include cyanide and carbon monoxide.