| Title: | Influence of airborne particulates on respiratory tract deposition of inhaled toluene and naphthalene in the rat |
| Author(s): | Roberts SM; Rohr AC; Mikheev VB; Munson J; Sabo-Attwood T; |
| Address: | "a Center for Environmental & Human Toxicology , University of Florida , Gainesville , FL , USA. b Electric Power Research Institute , Palo Alto , CA , USA. c Battelle Public Health Center for Tobacco Research , Columbus , OH , USA. d Department of Environmental and Global Health , University of Florida , Gainesville , FL , USA" |
| DOI: | 10.1080/08958378.2018.1438539 |
| ISSN/ISBN: | 1091-7691 (Electronic) 0895-8378 (Linking) |
| Abstract: | "OBJECTIVE: Most studies report that inhaled volatile and semivolatile organic compounds (VOCs/SVOCs) tend to deposit in the upper respiratory tract, while ultrafine (or near ultrafine) particulate matter (PM) ( approximately 100 nm) reaches the lower airways. The objective of this study was to determine whether carbon particle co-exposure carries VOCs/SVOCs deeper into the lungs where they are deposited. MATERIALS AND METHODS: Male Sprague-Dawley rats were exposed by inhalation (nose-only) to radiolabeled toluene (20 ppm) or naphthalene (20 ppm) on a single occasion for 1 h, with or without concurrent carbon particle exposure ( approximately 5 mg/m(3)). The distribution of radiolabel deposited within the respiratory tract of each animal was determined after sacrifice. The extent of adsorption of toluene and naphthalene to airborne carbon particles under the exposure conditions of the study was also assessed. RESULTS: We found that in the absence of particles, the highest deposition of both naphthalene and toluene was observed in the upper respiratory tract. Co-exposure with carbon particles tended to increase naphthalene deposition slightly throughout the respiratory tract, whereas slight decreases in toluene deposition were observed. Few differences were statistically significant. Naphthalene showed greater adsorption to the particles compared to toluene, but overall the particle-adsorbed concentration of each of these compounds was a small fraction of the total inspired concentration. CONCLUSIONS: These studies imply that at the concentrations used for the exposures in this study, inhaled carbon particles do not substantially alter the deposition of naphthalene and toluene within the respiratory tract" |
| Keywords: | "Administration, Inhalation Air Pollutants/*pharmacokinetics Animals Male Naphthalenes/*pharmacokinetics Particle Size Particulate Matter/*pharmacokinetics Rats, Sprague-Dawley Respiratory System/*metabolism Toluene/*pharmacokinetics Inhalation toxicology;" |
| Notes: | "MedlineRoberts, Stephen M Rohr, Annette C Mikheev, Vladimir B Munson, John Sabo-Attwood, Tara eng Research Support, Non-U.S. Gov't England 2018/02/22 Inhal Toxicol. 2018 Jan; 30(1):19-28. doi: 10.1080/08958378.2018.1438539. Epub 2018 Feb 21" |
