A recent Australian study will have you thinking twice about waiting for those printouts — not for the sake of the paper, but for your health. In the small study, published in the Aug. 1 issue of Environmental Science and Technology, researchers found that nearly 30% of the 62 printers they tested — including laser printers from Canon, HP, Toshiba and Ricoh — emitted high levels of ultrafine toner particles, which were potentially as hazardous as cigarette smoke. In one Brisbane office, the authors found, the concentration of particulate matter per square inch was five times higher during working hours than nonworking hours, and about 3.5 times higher inside than outside, where a freeway ran 130 yards from the building.
For the new study, Lidia Morawska, a physicist at the Queensland Institute of Technology, and her colleagues analyzed printer emissions in a large open-plan office environment. The good news was that 60% of the printers they tested, including eight HP LaserJet 4050 models, four Ricoh Aficio models and one Toshiba Studio, did not emit any particles. But of the 40% that did, many, such as the HP LaserJet 1320 and 4250 models, were classified as "high-level emitters." Emissions, researchers found, were printer-specific and fluctuated depending on the age of the toner cartridge and the amount of toner a document required. It was unclear exactly what mechanism dispersed the particles into the air, but researchers think it had to do with how laser-printer cartridges access and use dry toner or with the printer's mechanical abrasion, wear and age. It's likely that different printers emit particles in different ways.
HP says, in a statement, that it disagrees with the conclusion of the study and with some of its stronger assertions — and believes there is no link between printer emissions and a public health risk. The study's authors concede that more research is needed before they can make any recommendations about the public's printer-related behavior. This study, says Charles Weschler, a chemist and indoor air pollution expert at the Robert Wood Johnson Medical School, is "very much a first cut."
Though it may be premature to inaugurate the term "office lung," the new study highlights the fact that indoor air pollution can't be taken lightly. "It's important to appreciate that most of the air we breathe — whether in our homes, our cars or our offices — is indoors," says Weschler. The Environmental Protection Agency estimates that 90% of our time is spent indoors. According to Weschler, indoor pollution either seeps in from outside (such as particulate matter from car exhaust, ground-level ozone and noxious gases, like sulfur dioxide, which comes from fuel combustion and factories) or originates inside (tobacco smoke, cooking gas, vapors from paint). In general, concentrations of volatile organic compounds, like cleaning agents and pesticides, can sometimes be 10 times higher indoors than outdoors, says Weschler. With long-term exposure, these types of air pollutants can be linked to allergies and respiratory illness, or worse.
The EPA has not done any recent research on the health effects of printer emissions — Morawska's study is the most extensive to date — but Sharon Worthy of the U.S. Dept. of Labor says "historically laser printers have presented no known hazard in the workplace." But, according to the Washington-based nonprofit Environmental Working Group, which has conducted research on particulate pollution from automobiles, printers release the same type of fine particles that cars do. "What we need are standards up front so that the pollution we're subjected to don't pose health risks," says Jane Houlihan, the nonprofit's vice president for research. "Printers are just one of the many things we're exposed to during the day that are potentially harmful."