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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    ABSTRACT: Photocopying in offices and printing centers releases nanoparticles that can reach the brain following inhalation. We examined whether subcytotoxic levels of airborne photocopy-emitted nanoparticles could potentiate perturbation of synaptic signaling in cultured neurons following exposure to amyloid-β (Aβ). Signaling was only transiently inhibited by Aβ or nanoparticles individually, but remained statistically reduced in cultures receiving both after 24 h. In vitro and in vivo studies with copier emitted nanoparticles have consistently demonstrated inflammation, oxidative stress, and cytotoxicity. Since Aβ can accumulate years before cognitive decline, subcytotoxic levels of nanoparticles are one factor that could potentiate Aβ-induced impairment of synaptic activity during these early stages.
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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.
    Journal of hazardous materials 06/2015; 298:351-360. DOI:10.1016/j.jhazmat.2015.06.021 · 4.53 Impact Factor
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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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