Office printers study made no health claims

Office printers may emit dangerous levels of pollution that could have the same effect on the lungs as smoking, the Daily Mail reported. The toner used in copiers and printers gives out an ultra-fine dust, which if inhaled “can harm your lungs as much as cigarette smoke”, the paper reported on August 1 2007. Office printers should “come with a health warning”, it went on to say, as this dust can “increase the risks of lung disease, heart disease a, strokes and cancer”.

The investigation of 62 laser printers found that nearly 30% of the printers emitted toner particles into the air, and the researchers say that that these “ultra-fine particles … can penetrate deep into the lungs where they can pose a significant health risk." The Daily Mirror claimed that “printers at work cause lung cancer”.

Reading these reports you might think that the original study examined the health effects of printer dust. However, this research did not look at the effect of the emissions on the lungs; it tested several printers and analysed the number of particles and size of particles emitted from a variety of office printers and it is not possible to draw any firm conclusions on health-related printer safety at this time.

Where did the story come from?

The research was carried out by Congrong He, Lidia Morawska and Len Taplin of the International Laboratory for Air Quality and Health of the University of Queensland, Brisbane, Australia. The study was funded by Queensland Department of Public Works and was published in the journal, Environment, Science and Technology .

What kind of scientific study was this?

The researchers had previously identified office printers to be a potential source of indoor pollution and this was an experimental study designed to examine the particle emissions coming from different printers in a single open-plan office.

The study was conducted on the fourth floor of an air-conditioned office building where there were several types of printer and photocopier. Air samples were taken using an experimental flow-through chamber and the measurement of any particles emitted was carried out in the laboratory. 

The study was conducted in three stages. The first measured the concentration of particles in the open-plan office and outdoors in general for a 48-hour period. Next, measurements were taken for each of the 62 printers in the building immediately before and immediately after printing one page to see the difference in air particle levels.

The three printers that had been identified in the office to emit either low, medium or high concentrations of particles where then tested in a sealed testing chamber. During this further testing, the background measurements in the chamber were taken until the air particle level was low; then printing commenced and air concentration measures were taken during the print job; finally, the time taken for the concentration of particles in the air to return to low (between 30 and 300 minutes) was recorded.

What were the results of the study?

The researchers found that 37 of the printers tested (60%) did not emit any particles, and of the 40% that did emit particles, 27% (17 printers) emitted particles at a high level. Of the three different types of printer tested, each emitted different sizes of particle. The printers with the two higher emission rates were found to give out slightly finer particles. The size of the particles emitted seemed to be related to printer type, toner, and cartridge age. The number of particles emitted seemed to be greater with higher toner coverage and newer cartridges, however none of these results gave strong links.

What interpretations did the researchers draw from these results?

The researchers conclude that this is important new information that suggests that making the correct choice of printer can affect the concentration of particles in the office. They say that further study is required to provide fuller information on particles emitted by printers and their chemical composition.

What does the NHS Knowledge Service make of this study?

This study indicates an area for possible further environmental research. However, currently no health-related conclusions can be drawn from it.

• Most importantly, the study authors, quite rightly, make no assumptions about any possible links between printer particles in the air and ill health. There can be no conclusion from this research that printer emissions are as harmful to you as cigarette smoke, cause lung cancer or any other harmful disease. 
• This is a very small study carried out on a single office in Australia. Research in this area is extremely limited. From this study alone we can have no idea of the level of contribution that additional factors make to indoor pollution, for example, photocopiers, air conditioning units, or outdoor traffic.