Department of Civil and Environmental Engineering, Faculty of Engineering, National University of Singapore, Singapore.
J Air Waste Manag Assoc. 2011 Nov;61(11):1093-101. doi: 10.1080/10473289.2011.604549.
Laser printers are one of the common indoor equipment in schools, offices, and various other places. Laser printers have recently been identified as a potential source of indoor air pollution. This study examines the characteristics of ultrafine particles (UFPs, diameter <100 nm) and volatile organic compounds (VOCs) emitted from laser printers housed in a commercial printing center. The results indicated that apart from the printer type, the age of printers, and the number of pages printed, the characteristics of UFPs emitted from printers also depend on indoor ventilation conditions. It was found that at reduced ventilation rates of indoor air, there was a rise in the number concentration of UFPs in the printing center. Interestingly, the contribution of UFPs to the total number of submicrometer-sized particles was observed to be higher at a sampling point far away from the printer than the one in the immediate vicinity of the printer. Black carbon (BC) measurements showed a good correlation (rs = 0.82) with particles in the size range of 100-560 nm than those with diameters less than 100 nm (rs = 0.33 for 50-100 nm, and rs = -0.19 for 5.6-50 nm particles). Measurements of VOCs in the printing center showed high levels of m-, o-, and p-xylene, styrene, and ethylbenzenes during peak hours of printing. Although toluene was found in higher levels, its concentration decreased during peak hours compared to those during nonoperating hours of the printing center.
激光打印机是学校、办公室和其他各种场所常见的室内设备之一。最近，激光打印机已被确定为室内空气污染的潜在来源之一。本研究考察了商业印刷中心内激光打印机排放的超细颗粒（UFPs，直径<100nm）和挥发性有机化合物（VOCs）的特性。结果表明，除了打印机类型、打印机的使用年限和打印页数之外，打印机排放的 UFPs 的特性还取决于室内通风条件。发现当室内空气通风率降低时，印刷中心内 UFPs 的数量浓度会上升。有趣的是，与打印机附近的采样点相比，远离打印机的采样点处 UFPs 对总亚微米级颗粒数的贡献更高。黑碳（BC）测量结果表明，与直径小于 100nm 的颗粒（50-100nm 粒径的 rs 值为 0.33，5.6-50nm 粒径的 rs 值为-0.19）相比，BC 与 100-560nm 粒径范围内的颗粒相关性更好（rs=0.82）。在印刷中心测量的 VOCs 显示，在打印高峰期间，间二甲苯、邻二甲苯和对二甲苯、苯乙烯和乙苯的含量较高。尽管甲苯的含量较高，但与印刷中心非运行时段相比，其浓度在打印高峰时段会下降。
