Lung retention and metabolic fate of inhaled benzo(a)pyrene associated with diesel exhaust particles

Journal Article · Fri Mar 30 04:00:00 EST 1984 · Toxicol. Appl. Pharmacol.; (United States)

DOI:https://doi.org/10.1016/0041-008X(84)90052-8· OSTI ID:7188782

Sun, J D; Wolff, R K; Kanapilly, G M; McClellan, R O

The effect of ultrafine, insoluble, carrier particles on the lung retention and metabolic fate of inhaled PAHs was investigated with a radiolabeled model PAH, (/sup 3/H)benzo(a)pyrene (/sup 3/H-BaP). Fischer-344 rats were exposed (30 min) by nose-only inhalation to /sup 3/H-BaP adsorbed (approximately 0.1% by mass) onto diesel engine exhaust particles. The total mass concentration of these aerosols was 4-6 micrograms/liter of air with a mass median diameter of 0.14 micron. Lung clearance of the inhaled particle-associated /sup 3/H radioactivity occurred in two phases. The initially rapid clearance of this inhaled radiolabel had a half-time of less than 1 hr. The second, long-term component of lung clearance had a half-time of 18 +/- 2 days and represented 50 +/- 2% of the /sup 3/H radioactivity that had initially deposited in lungs. In contrast, previous inhalation studies with a pure /sup 3/H-BaP aerosol showed that greater than 99% of the /sup 3/H radioactivity deposited in lungs was cleared within 2 hr after exposure. By HPLC analysis, the majority of diesel soot-associated /sup 3/H radioactivity retained in lungs was BaP (65-76%) with smaller amounts of BaP-phenol (13-17%) and BaP-quinone (5-18%) metabolites also being detected. No other metabolites of BaP were detected in lungs of exposed rats. Tissue distribution and excretion patterns of /sup 3/H radioactivity were qualitatively similar to previous inhalation studies with /sup 3/H-BaP coated Ga2O3 aerosols. These findings suggest that inhaled PAHs may be retained in lungs for a greater period of time when these compounds are associated with diesel engine exhaust particles. These results may have significant implications for the health risks that may be involved with human exposure to particle-associated organic pollutants.

• Research Organization: Inhalation Toxicology Research Institute, Lovelace Biomedical and Environmental Research Institute, Albuquerque, New Mexico
• OSTI ID: 7188782
• Journal Information: Toxicol. Appl. Pharmacol.; (United States), Journal Name: Toxicol. Appl. Pharmacol.; (United States) Vol. 73:1; ISSN TXAPA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
AROMATICS
BENZOPYRENE
BIOLOGICAL HALF-LIFE
CHROMATOGRAPHY
CLEARANCE
CONDENSED AROMATICS
DIESEL ENGINES
DISTRIBUTION
ENGINES
EXHAUST GASES
FLUIDS
GASEOUS WASTES
GASES
HEAT ENGINES
HYDROCARBONS
INHALATION
INTAKE
INTERNAL COMBUSTION ENGINES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIQUID COLUMN CHROMATOGRAPHY
MAMMALS
METABOLISM
ORGANIC COMPOUNDS
PARTICLES
PARTICULATES
RATS
RODENTS
SEPARATION PROCESSES
TISSUE DISTRIBUTION
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES
WASTES