Aerosols generated by hardcopy devices and other electrical appliances

In recent years the pollution of indoor air with ultrafine particles has been an object of intensive research. Several studies have concurred in demonstrating that outdoor air makes only a limited contribution to polluting indoor air with ultrafine particles, provided significant sources in the immediate neighborhood are absent. Nowadays, electrical devices operated in homes and offices are identified as particle emission sources. A comparison of the emission rates can be made by calculating the total number of particles released with respect to the operating time. The identified particles are condensed semi-volatile organic compounds with a low percentage of non-volatile inorganic components. To characterize the indoor exposure to airborne particles, an algorithm has been developed which permits a realistic calculation of the particle intake and deposition in the human respiratory tract from measured size and time resolved particle number concentrations following the model of the International Commission on Radiological Protection.

► 27 Laser printers were studied for their particle emission characteristics.
► The indoor/outdoor ratio of particle concentrations was investigated.
► Realistic particle exposure scenarios with multiple print cycles were set up.
► The applied exposure model allowed estimation of particle deposition in the lung.
► The described procedure is useful for a health-related risk assessment.