Indoor Air Quality in Photocopy Centers, Nanoparticle Exposures at Photocopy Workstations, and the Need for Exposure Controls.

Abstract

Photocopiers emit large amounts of nanoparticles (NP) and are a significant source of indoor air pollution. These emissions induce airway inflammation, irritation, and systemic oxidative stress in humans, lung injury and inflammation in animals, and cytotoxicity and epigenetic modifications in vitro. However, little is known regarding NP exposures at the workstation in the photocopy work environment, or the extent and use of emission controls. To survey the photocopy work environment with regards to emissions controls and to evaluate IAQ with emphasis on NP exposure at the operator's workstation. Work process, physical characteristics of the centers, and use of controls were recorded. Particle total number concentration (TNC), temperature, carbon dioxide, carbon monoxide, and percent relative humidity were measured during a random workday. Geometric mean (GM) TNC at workstations ranged between 1900 and 23000 particles cm-3, GSD 1.2-2.8, and maximum of 217000 particles cm-3. Fresh air ventilation was found to be less than American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) guidelines in 7 of 15 centers. Only one center used any type of emissions control. Elevated TNC at workstations was significantly correlated with number of copies (r = 0.72). While indoor/outdoor TNC ratios might be expected to be ≤1.0, the ratio here was >1.0 in 40% of centers visited, supporting the finding that copier emissions are a significant source of indoor air pollution. Number of copies per day was the most significant contributor to TNC. High NP concentrations at workstations were common and specific emission controls almost nonexistent. While 46% of copy centers had insufficient ventilation, high exposures were documented even for cases when ASHRAE ventilation guidelines per person were met or exceeded. We present various options to address IAQ in photocopy environment, including new clean photocopy technologies, engineering controls, and a comprehensive awareness campaign to improve the environmental health and safety, design, and operational conditions of these workplaces.