Small invisible dangers from printers in the office environment

BACKGROUND Particulate air pollution was demonstrated to have serious short and long-term health effects, in particular in indoor environments. There is little literature data available to compare particle number concentrations measured in the office environment. Objective of this study is to investigate the particle number concentration levels in a controlled dynamic office environment. METHODS A Kanomax Model 3887 Handheld Laser Particle Counter was used for continuous (3 h), repeated (sample time 60s with logging interval of 10 min) and real-time measurements of total number concentrations of particles in the range from 0.3 µm to 5 µm. The particle counter has a calibrated flow rate of 2.83 L/min,verified to ± 5%accuracy. Particle concentrations were studied in a work environment characterized by the presence of three printers. Measurements were performed in different conditions: when printers were off,immediately after the printers had printed one page and after 20 minutes of operative printing process. Same measurements were taken with more or individually printers switched on and with air intake and/or emission switched on/off. All statistical analyses were conducted using SPSS 17.0. RESULTS Preliminary analysis of the particle number concentrations showed clear variation (one-way ANOVA, p<0.005) during printing time and printers “at rest” in each environmental condition of air intake and/or emission. The average number concentration for particle with diameter of 0.3 – 0.5 – 5 µm during printing time were 9.21 x 106 m-3 (±7.32 x 104 m-3 SD), 5.09 x 105 m-3 (±4.93 x 104 m-3 SD), 4.24 x 103 m-3 (±1.62x 103 m-3 SD) respectively, values about three times higher than that during non operative printing process. Particle concentration was not depending significantly on the number of pages printed. The switching on of the air extractor showed to decrease significantly the 5 µm particle number concentrations (p<0.005). Further investigations are underway. CONCLUSIONS The control and the possibility of cutting down such emissions allow to hypothesize procedures and control measures for exposed workers’ protection. The widespread use of information technology in private homes, mostly by young people, makes it an interesting topic beyond the occupational medicine.