ABSTRACT
Previous studies have shown that blood levels of carbon monoxide increase during cigarette smoking. It has generally been assumed that increases in blood levels of carbon monoxide could be interpreted as evidence that deep lung penetration of cigarette smoke had occurred. This study was designed to examine whether increased blood levels of carbon monoxide could result from absorption in the nasal and oral cavities. The nasal and oral cavities of cynomolgus monkeys were exposed, independently of the lungs, to cigarette smoke under rigorous smoking conditions. Pre- and post-exposure blood levels of carbon monoxide were measured. As a positive control, similar volumes of cigarette smoke were passed directly into the lungs, thus bypassing the oral and nasal cavities, and blood levels of carbon monoxide were again measured. The results indicate that absorption of carbon monoxide in the oral and nasal cavities is negligible under the heavy smoking regimen employed here, and hence, would be negligible under normal smoking conditions.
Subject(s)
Carbon Monoxide/blood , Mouth Mucosa/metabolism , Nasal Mucosa/metabolism , Smoke , Absorption , Animals , Haplorhini , Lung/metabolism , Macaca fascicularis , Plants, Toxic , NicotianaSubject(s)
Detergents/toxicity , Enzymes/toxicity , Respiration/drug effects , Animals , Body Weight/drug effects , Dust/analysis , Enzymes/blood , Enzymes/immunology , Female , Growth/drug effects , Haplorhini , Macaca fascicularis , Male , Particle Size , Respiratory Function Tests , Respiratory Tract Diseases/pathologyABSTRACT
Three groups composed of rats, rabbits, and monkeys were exposed for 26 weeks to 1,2,4-trichlorobenzene (-TCB), and one group of each species was used as a control group. The nominal exposure concentrations of 1,2,4-TCB were 25.0, 50.0, and 100.0 ppm. Pulmonary function and operant behavior tests in monkeys, ophthalmoscopic examinations in rabbits and monkeys, and measurement of body weights and hematologic and serum biochemical determinations in all species were conducted before and during the exposure period. At termination of 1, 3, and 6 months of exposure, microscopic examination of selected rat tissues was performed. Microscopic changes were seen in the parenchymal of livers and kidneys from all groups of rats exposed to 1,2,4-TCB when sacrificed after 4 and 13 weeks of exposure, but no exposure-related abnormalities or other effects were seen after 26 weeks of exposure in any species.
