Sandra Pirela, Ramon Molina, Christa Watson, Joel Cohen, Dhimeter Bello, Philip Demokritou, Joseph Brain
The use of engineered nanoparticles to enhance the quality and features of everyday products has become more common as technology advances. Unfortunately, environmental health and safety assessments related to this new technology are lacking. Particularly, there is a lack of studies examining the effect of “real world” engineered nanoparticle exposures, such as those emitted from copier machines. In this study, copier emitted ENPs collected from a Boston area copy center were fractionated and sampled by size using the previously developed Harvard Compact Cascade Impactor (CCI). The ENPs were fractionated in three distinct size fractions, namely PM0.1, PM0.1-2.5 and PM 2.5-10. The collected particles were extracted from the impaction substrates using an aqueous extraction protocol. The extracted ENPs were then stabilized in RPMI and 10% fetal bovine serum (FBS) and consequently characterized for hydrodynamic diameter and zeta potential via dynamic light scattering (DLS) with a Malvern Zetasizer Nano ZS The hydrodynamic diameter of ENPs in solution corresponded with the size fractions of particles collected with the CCI. We then studied their pulmonary effects in 8-wk-old male Balb/c mice after lung instillation. Groups of mice were instilled with 0.2, 0.05, or 0.01 mg/kg of for each size fraction (PM0.1, PM0.1-2.5 and PM 2.5-10). All mice were humanely killed 24 hrs post-instillation, and bronchoalveolar lavage (BAL) was performed. The BAL were analyzed for cellular and biochemical markers of lung injury and inflammation, such as myeloperoxidase, lactate dehydrogenase, hemoglobin, albumin, neutrophil and other cell type numbers. We found that the pulmonary effects PM<0.1 were highest among the 3 particle sizes. Specifically, there was an increase in the number of neutrophils in BALF from mice instilled with particles of PM<0.1, as well as higher levels of LDH, MPO and albumin, when compared with the other two particles of PM 0.1 to 2.5 and PM 2.5 to 10. These preliminary data suggest that nanoparticles emitted from newly engineered toner ink compositions can have deleterious effects on the lungs of those exposed to the particles.