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Pulmonary and Hematological Effects in Rats Following a Single Inhalation Exposure to Ce02 Nanoparticles
Citation:
DREHER, K. L., A. D. LEDBETTER, R. H. JASKOT, M. L. ODEGAARD, R. Snyder, AND N. Coates. Pulmonary and Hematological Effects in Rats Following a Single Inhalation Exposure to Ce02 Nanoparticles. Presented at Society of Toxicology (SOT) annual Meeting, Washington, DC, March 06 - 10, 2011.
Impact/Purpose:
The data provide the first evidence that a single acute exposure to low concentrations of Ce02 NPs can induce a transient hematological effects and persistent lung injury
Description:
Engineered nanomaterials have unknown environmental and health implications due to their novel properties and/or by-products associated with their applications. Combustion studies have shown nanoCe-enabled fuel additives alter the physicochemical properties of diesel emissions (DE) resulting in increased levels of nanoscale particles containing aggregates of Ce02 NPs. The health effects associated with exposure to Ce02 NPs, or DE produced using nanoCe02 additives, are unknown. To examine the health effects of Ce02 NP exposure, a low consumption generating system was developed capable of producing Ce02 NPs displaying similar 1degree size and aggregate size ranges observed in DE produced with a nanoCe02 additive. Rats were exposed to a single 6h inhalation to either air or Ce02 NPs with a primary diameter of 4 -6 nm in the 14 -300 nm size range having a CMD 47 -69 nm, GSD 1.89 -2.0 at either: 0.25,0.5, or 1.9 rng/m3. Pulmonary toxicity/physiology and hematological effects were examined in control and exposed rats at various post-exposure time points up to 1 month. Pulmonary edema, cytotoxicity and inflammation were evaluated by alterations in bronchoalveolar lavage fluid (BALF): protein, albumin, LDH and cellular differential levels, respectively, while hematological effects were assessed by alterations in blood: WBC, RBC, lymphocyte and hematocrit. Exposure to 1.8 mg/m3 Ce02 NPs produced no alterations in pulmonary physiology. Significant increase in all BALF endpoints was detected as early as 12 -24hr post-exposure and remained elevated over control levels at 1 mon post-exposure. Significant decrease in WBC and lymphocytes was observed only at 24h post-exposure. Similar pulmonary effects were observed in rats exposed to 0.5 mg/m3 Ce02 NPs while no pulmonary effects were seen in rats exposed to 0.25 rng/m3 Ce02 NPs. The data provide the first evidence that a single acute exposure to low concentrations of Ce02 NPs can induce a transient hematological effects and persistent lung injury. This abstract does not reflect EPA policy.