The nasal mucus flow, lung function, subjective response, and psychometric performance of 16 young healthy subjects was studied during 6-h exposures to clean air and to 10, 40 or 100 ppm of toluene under controlled conditions. The toluene exposures did not affect nasal mucus flow or lung function. At 100 ppm irritation was experienced in the eyes and in the nose. There was a significant deterioration in the perceived air quality and a significant increased odor level during all exposures to toluene. The test battery investigated visual perception, vigilance, psychomotor functions, and higher cortical functions and comprised five-choice, rotary pursuit, screw-plate, Landolt's rings, Bourdon Wiersma, multiplication, sentence comprehension, and word memory tests. In these eight tests measuring 20 parameters, no statistically significant effects of the toluene exposure occurred. For three tests (multiplication errors, Landolt's rings, and the screw plate test) there was a borderline significance (0.05% less than p less than 0.10%). The subjects felt that the tests were more difficult and strenuous during the 100-ppm exposure, for which headache, dizziness, and feeling of intoxication were significantly more often reported. The exposures to 10 and 40 ppm did not result in any adverse effects.

Radioaerosols are being used increasingly to assess pulmonary ventilation in patients, and to study patterns distribution and rates of clearance in experimental studies. No completely satisfactory means have been developed to permit the safe and effective administration of suitable aerosols. In this report, a new system is described for producing and delivering monodisperse radioactive aerosol particles. The major advantages of the system are: (1) the monodispersion (σg=1.23) of the particles from modifier A; (2) 95% of the particles are less than 1 μm in diameter from modifier B, and (3) the method is simple and compact.

Under controlled conditions in an environmental chamber 16 healthy young volunteers were exposed to combinations of sulfur dioxide (SO2) (2.6 or 13 mg/m3) and inert plastic dust (2 or 10 mg/m3) or of SO2 (13 mg/m3) and dust (10 mg/m3) coated with vanadium. During periods of clean air and during exposures of 5-h duration nasal mucus flow rate, nasal airflow resistance, forced vital capacity, and subjective discomfort were measured. Reductions in nasal mucus flow rate, forced expiratory flow (FEF25-75%), and discomfort were related principally to the SO2 concentration. The combined effects of SO2 and dust were, at the most, additive, and there was no indication of potentiation effects. No effect could be attributed to the coating of the dust with vanadium.

Airway secretions were collected from the upper trachea of eight healthy nosebreathing mongrel dogs under general anesthesia, and the electrolytes and osmolality of these secretions were determined. Compared to plasma, secretions contained 15% higher Na+ and 33% higher Cl-, were 18% higher in osmolality, but had a lower Na+/Cl- throughout the 6-h experiments. When six nose-breathing dogs were exposed to air at 28.5 degrees C and 95% relative humidity, secretion osmolality became lower, but Na+/Cl- remained unchanged. In four other dogs, secretions approached the osmolality of plasma when inspired air was at 36.4 degrees C and 100% relative humidity. These secretions contained 22% higher Cl- and a lower Na+/Cl- than plasma. The differences between airway secretions and interstitial fluid suggest that secretions are formed by active Cl- transport. In another four dogs, secretion osmolality was higher with mouth breathing than breathing through the nose. Inasmuch as humidified and warmed air lowered and mouth breathing raised the osmolality of airway secretions, we postulate that the hyperosmolality of secretions results from water loss from the airway surface during conditioning of inspired air.

Tracheobronchial secretions (TBS) were collected in situ from intact, anesthetized dogs, and the protein composition and distribution were studied. TBS were separated into supernatant and pellet phases by centrifugation. The supernatant phase comprised 85%, by weight, of the secretory mixture; yet it contained only 58% of the total protein. Peptides of apparent molecular weights ranging from 16,000 to 154,000 daltons were present in the supernatant phase. Electrophoretic and immunochemical comparisons with canine serum suggested that certain of the peptides were of plasma origin including albumin, IgG, IgA, and IgM. Albumin and IgG comprised approximately 70% of the supernatant phase protein. Three percent of the total TBS protein was contributed by the peptide portion of mucous glycoproteins (mucins), and 97% of the mucin protein separated into the pellet phase. When compared to mucus collected from a canine tracheal pouch, TBS was less concentrated in mucins, and differences were observed in electrophoretic profiles between the two samples.

The effect of cholinomimetic stimulation on the quantity and composition of tracheobronchial secretions (TBS) collected from intact dogs was studied. After the administration of methacholine chloride, the collection rate of TBS increased over threefold within 10 min and returned to the control level by 50 min. Even though there was an increase in the total amount of protein collected, the protein concentration of the secretions decreased initially by 40%, returning to normal by 30 min. This was the result of an apparent dilution of the secretions by nonproteinaceous components. In addition, at 10 min, there was an increase in the protein associated with mucins. These responses were blocked by the preadministration of atropine. When TBS was separated into supernatant and pellet phases by centrifugation, we found that, following methacholine, there was a 35% increase in the ratio of albumin to IgG in the supernatant phase. These results suggest that the increased secretion due to methacholine may result, in part, by a selective filtration of fluid from the interstitial and/or vascular compartment(s) with proteins appearing in the secretory mixture based partially on their size.