Retention and clearance of inhaled submicron carbon black particles

Journal Article · Sun Jan 01 04:00:00 EST 1989 · J. Toxicol. Environ. Health; (United States)

DOI:https://doi.org/10.1080/15287398909531244· OSTI ID:6323632

Strom, K A; Johnson, J T; Chan, T L

Carbon black aerosols were used as a probe of the pulmonary retention and clearance of submicron particles. Male Fischer rats (COBS CD) were exposed for 20 h/d, 7 d/wk for 1, 3, or 6 wk to either 7 +/- 2 mg/m3 carbon black or filtered air. The submicron aerosol (mass median aerodynamic diameter, MMAD, 0.24 microns) was generated with a Wright dust feed-cyclone system. Lung and hilar lymph node particle burdens were determined immediately following the exposure and at preselected intervals up to 1 yr postexposure. After 1-, 3-, and 6-wk exposures, the lung burdens were 1.1 +/- 0.1, 3.5 +/- 0.2, and 5.9 +/- 0.1 mg, respectively. One year after a 1-, 3-, or 6-wk exposure, 8%, 46%, and 61% of the initial lung burden remained in the lungs. Initially, the hilar lymph nodes contained 0.2%, 0.9%, and 2.0% of the lung burdens in the 3 exposure groups, respectively. At 1 yr postexposure, particle translocation from the lungs led to a rise in lymph node burdens to 1%, 21%, and 27% of the initial lung burden. The retention of carbon black in both the lungs and lymph nodes combined was 9%, 67%, and 89% for the 1-, 3-, and 6-wk exposed animals. Lung clearance was modeled as a compartmental system consisting of four lung compartments and a regional lymph node compartment. The results from the model are similar for carbon black and diesel engine exhaust particles. However, the compartmental kinetics of carbon black differed in two ways: the deposition efficiency in the alveolar region was lower than that for diesel exhaust particles, and there was earlier transport of particles to the regional lymph nodes. These results showed that when lung burdens reached 0.8 mg, lung clearance was decreased by 50% and lymphatic transport of insoluble particles was increased.

• Research Organization: General Motors Research Laboratories, Warren, MI (USA)
• OSTI ID: 6323632
• Journal Information: J. Toxicol. Environ. Health; (United States), Journal Name: J. Toxicol. Environ. Health; (United States) Vol. 26:2; ISSN JTEHD
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOLOGICAL MODELS
CARBON
CARBON BLACK
CLEARANCE
DIESEL ENGINES
DISTRIBUTION
ELEMENTS
ENGINES
EXCRETION
EXHAUST GASES
FLUIDS
GASEOUS WASTES
GASES
HEAT ENGINES
INHALATION
INTAKE
INTERNAL COMBUSTION ENGINES
LUNG CLEARANCE
LYMPH NODES
LYMPHATIC SYSTEM
MAMMALS
NONMETALS
PARTICLE SIZE
PARTICLES
PARTICULATES
RATS
RETENTION
RODENTS
SIZE
TISSUE DISTRIBUTION
VERTEBRATES
WASTES