Effects of copy center particles on the lungs: A toxicological characterization using a Balb/c mouse model

Center for Nanotechnology and Nanotoxicology, Department of Environmental Health, Harvard School of Public Health , Boston, MA , USA , and.
Inhalation Toxicology (Impact Factor: 2.26). 07/2013; 25(9). DOI: 10.3109/08958378.2013.806614
Source: PubMed


Abstract Context: Printers and photocopiers release respirable particles into the air. Engineered nanomaterials (ENMs) have been recently incorporated into toner formulations but their potential toxicological effects have not been well studied. Objective: To evaluate the biological responses to copier-emitted particles in the lungs using a mouse model. Methods: Particulate matter (PM) from a university copy center was sampled and fractionated into three distinct sizes, two of which (PM0.1 and PM0.1-2.5) were evaluated in this study. The particles were extracted and dispersed in deionized water and RPMI/10% FBS. Hydrodynamic diameter and zeta potential were evaluated by dynamic light scattering. The toxicological potential of these particles was studied using 8-week-old male Balb/c mice. Mice were intratracheally instilled with 0.2, 0.6, 2.0 mg/kg bw of either the PM0.1 and PM0.1-2.5 size fractions. Fe2O3 and welding fumes were used as comparative materials, while RPMI/10% FBS was used as the vehicle control. Bronchoalveolar lavage (BAL) was performed 24 hours post-instillation. The BAL fluid was analyzed for total and differential cell counts, and biochemical markers of injury and inflammation. Results: Particle size- and dose-dependent pulmonary effects were found. Specifically, mice instilled with PM0.1 (2.0 mg/kg bw) had significant increases in neutrophil number, lactate dehydrogenase and albumin compared to vehicle control. Likewise, pro-inflammatory cytokines were elevated in mice exposed to PM0.1 (2.0 mg/kg bw) compared to other groups. Conclusion: Our results indicate that exposure to copier-emitted nanoparticles may induce lung injury and inflammation. Further exposure assessment and toxicological investigations are necessary to address this emerging environmental health pollutant.

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Available from: Philip Demokritou, Jan 18, 2014
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    • "Previously, systemic oxidative stress and upper airway inflammation in healthy individuals was reported in healthy individuals following a single day exposure in a photocopy center environment [18]. Nanoparticles emitted by copiers induce lung injury and inflammation in mice [12]. Extensive physicochemical and morphological characterization of emitted nanoparticles has shown the particles to be a mix of various metal/metal oxides [10]. "
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    • "A recent study conducted by our group documented upper airway inflammation and systemic oxidative stress in human volunteers at realistic exposure levels [7], which were substantiated with a series of in-vitro studies in human primary cell lines [12] [13] and instillation studies in mice [14]. In these studies, PM 0.1 were comparable in potency to welding fumes and several times more potent than copper oxide nanoparticles [12] [14]. Chronic inflammation in humans was recently documented [15]. "
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    ABSTRACT: Photocopiers emit high levels of nanoparticles (PM0.1). To-date little is known of physicochemical composition of PM0.1 in real workplace settings. Here we perform a comprehensive physicochemical and morphological characterization of PM0.1 and raw materials (toners and paper) at eight commercial photocopy centers that use color and monochrome photocopiers over the course of a full week. We document high PM0.1 exposures with complex composition and several ENM in toners and PM0.1. Daily geometric mean PM0.1 concentrations ranged from 3700 to 34000 particles/cubic-centimeter (particles/cm(3)) (GSD 1.4-3.3), up to 12 times greater than background, with transient peaks >1.4 million particles/cm(3). PM0.1 contained 6-63% organic carbon, <1% elemental carbon, and 2-8% metals, including iron, zinc, titania, chromium, nickel and manganese, typically in the <0.01-1% range, and in agreement with toner composition. These findings document widespread ENM in toner formulations and high nanoparticle exposures are an industry-wide phenomenon. It further calls attention to the need to substantially redesign the interface of this technology with workers and consumers. Copyright © 2015 Elsevier B.V. All rights reserved.
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    • "Size-selective PM sampling was performed using the Harvard Compact Cascade Impactor (CCI), which collects particles onto impaction substrates in three stages corresponding to PM 0.1 , PM 0.1–2.5 and PM 2.5–10 size fractions (Demokritou et al., 2004). After collecting the size-fractionated PM samples, the impaction substrates were removed from the CCI and the particles were extracted using an aqueous suspension methodology (Bello et al., 2013; Chang et al., 2013; Pirela et al., 2013). "

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