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Environment

Office Pollution

Computers and printers emit chemicals and particles into air

by Rachel Petkewich
December 24, 2007 | A version of this story appeared in Volume 85, Issue 52

Digital Data
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Credit: Courtesy of Randy Maddalena
Highest emissions occur just after computers are turned on.
Credit: Courtesy of Randy Maddalena
Highest emissions occur just after computers are turned on.

OFFICE EQUIPMENT may be more of a health hazard than you might think: Concern is growing over potentially harmful emissions from computers and printers in homes and offices.

These pollutants are described in scientific literature as either having known or potential toxicological effects. With efforts to make buildings more energy efficient by tightening air leaks and reducing ventilation, even low-level emissions can accumulate to concerning levels.

Sporadic studies have identified emissions from various kinds of office equipment. Researchers from Lawrence Berkeley National Laboratory (LBNL); the University of California, Berkeley; and Arizona State University, Tempe, have embarked on a systematic study of computer and printer emissions. At last month's Society of Environmental Toxicology & Chemistry's annual North American meeting in Milwaukee, Thomas E. McKone, deputy head of the indoor environment department at LBNL, presented their preliminary results.

No government regulations specifically address air emissions from office equipment. States establish building codes, but these do not encompass health risks.

Air pollutants such as particulate matter and volatile compounds have been associated with headache; fatigue; and irritation of the eye, nose, or throat. Some studies have indicated that such pollutants may disrupt endocrine systems.

"Indoor pollutants need to be minimized to protect human exposure," says Marilyn S. Black, chief scientist of Air Quality Sciences, an air testing firm in Marietta, Ga. Equipment can release a mixture of chemicals and particles, and synergistic reactions may occur, she adds.

With all of these issues in mind, the California Air Resources Board approached researchers at LBNL to characterize the nature and magnitude of emissions from computers and printers.

After surveying the relevant scientific literature to define the scope of their own study (Atmosph. Environ., DOI: 10.1016/j.atmosenv.2007.10.080) and soliciting input from industry advisers, the researchers decided to track volatile and semivolatile organic compounds, ozone, and particulate matter emitted by computers and printers.

In the first phase of the study, the researchers screened multiple computers or printers humming away in a room-scale stainless-steel chamber. Computers were equipped with software to keep them active for days. Printers printed in alternating cycles for about eight hours. Meanwhile, the scientists collected and analyzed air samples with recognized methods for each chemical group.

During the second phase, which is in progress, the group is conducting similar tests on each computer and printer unit as it operates in an isolated glass chamber.

The researchers purchased nine desktop computer systems and one laptop from different manufacturers. They rented two large, high-output laser printers and collected ink-jet and medium-duty laser printers from surrounding labs. "Our interest was in a carefully stratified sample of what is in the market instead of going after any specific brand," McKone said.

Analytical tests from the first phase of the study show that ozone and carbonyl concentrations did not change during experiments with computers and printers, but a finding indicates that computer makers may be moving away from using semivolatile, brominated flame retardants, McKone said. The researchers found that computers built in 2006 emitted brominated flame retardants. Those built in 2007 did not, though they emitted significantly higher levels of widely used substitutes, organophosphate flame retardants.

In addition, emissions in the test chambers of some volatile organic compounds (VOCs) such as phthalates decreased with time, but concentrations of others, including cyclic siloxanes, increased. The scientists found that the highest emissions of other VOCs—such as toluene, ethylbenzene, o-xylene, and styrene—occurred shortly after the machines are turned on.

COMPUTERS DO NOT emit particles, but printers do. In group tests inside the large steel chamber, the LBNL researchers found ink-jet printers had consistently low emissions of submicrometer-sized particles, which can be inhaled deeply into the lung, whereas particle emissions spiked when medium- and high-output laser printers were turned on.

Computer and printer companies say their products adhere to occupational health and safety standards, and some companies certify products under voluntary environmental labeling programs such as Europe's Blue Angel. Although many of these companies conduct studies on computer and printer emissions as part of product development, they consider the resulting data proprietary.

"As an industry, we are in the very early stages of researching ultrafine particle emissions," says Tuan Tran, a vice president of marketing for Hewlett-Packard.

The LBNL researchers plan to characterize more thoroughly the chemicals and particles emitted by office equipment with a goal of pinpointing the sources.

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