Thomas K. Fitzgerald

Nasal Inhalation Challenge Studies with Sidestream Tobacco Smoke

Environmental tobacco smoke (ETS) exposure is associated with rhinitis symptoms (i.e., runny nose and congestion) in some people. In an effort to better understand these symptoms, we recruited 18 historically ETS-sensitive subjects from the community and exposed them for 15 min to clean air and for 15 min to sidestream tobacco smoke (STS, 45 ppm carbon monoxide). Symptoms were recorded (0 = absent, 5 = severe), and posterior rhinomanometry was performed. There were significant changes in rhinitis symptoms (1.3 +/- 0.4 pre- versus 6.1 +/- 0.5 post-STS, p less than .05); nasal airway resistance (2.86 +/- 0.2 pre- versus 4.49 +/- 0.6 post-STS, p less than .05), and maximum inspiratory flow (2.74 +/- 0.3 pre- versus 2.14 +/- 0.3 post-STS, p less than .05). A spectrum of individual responsiveness to ETS was observed, and nasal resistance increased from 0% to 265%. Increased nasal resistance occurred primarily at the upstream or flow-limiting segment of the nasal airway.

Acute respiratory response to prolonged, moderate levels of sidestream tobacco smoke

Environmental tobacco smoke (ETS) is a significant component of indoor air pollution yet the acute upper respiratory response has not been well studied. The goal of this study was to determine the response of healthy subjects to moderate levels of sidestream tobacco smoke (SS). Twenty-three subjects were challenged on 2 separate days to clean air or SS (2 h, 15 ppm carbon monoxide, at rest). Subjects completed symptom questionnaires, posterior rhinomanometry, and body plethysmography. Average total and differential cell counts and albumin concentration were determined on nasal lavage samples. The urinary cotinine: creatinine ratio was used as a biomarker of exposure. Following SS exposure, irritant and rhinitis symptoms increased, nasal resistance rose from 4.9+/-0.4 to 6.3+/-0.6 cm H2O/L/s and specific airway conductance decreased from 0.14+/-0.01 to 0.13+/-0.01 cm H2O(-1) s(-1). Total cell counts, neutrophils, and albumin were unchanged. An increased nasal congestive response did not correlate with an increased cotinine: creatinine ratio. A history of ETS rhinitis did not predict an increased group response to smoke, but individuals with the largest physiologic and inflammatory response were historically ETS sensitive. In summary, healthy normal subjects demonstrate nasal congestion with exposure to moderate levels of SS without evidence of increased nasal vascular permeability.

Tobacco Smoke Upper Respiratory Response Relationships in Healthy Nonsmokers

This study determined exposure-response relationships to side-stream tobacco smoke (2 hrs; 0, 1, 5, and 15 ppm CO) in 29 healthy nonsmoking young adults. Sixteen subjects had no history of environmental tobacco smoke rhinitis (ETS-NS) while 13 subjects had a history of ETS rhinitis (ETS-S). Eye irritation and odor perception showed a statistically significant exposure response in both groups; headache was significant in ETS-S and nose irritation was significant in ETS-NS subjects. Significant postexposure (P1) symptoms were first reported at 1 ppm CO among both groups, but in 3/9 symptoms were significantly greater at this exposure level in ETS-S subjects. Nasal congestion, rhinorrhea, and cough increased significantly at 15 ppm CO only. In ETS-S subjects, nasal volume decreased and nasal resistance increased in an exposure-response fashion. ETS-NS subjects had a qualitatively different shape to the exposure-response curve; significant dimensional reductions in mid- and posterior nasal volume occurred with exposure at 1 ppm CO but not at 5 ppm CO and reductions in posterior nasal volume occurred at 15 ppm CO exposure. These studies indicate subjective and objective response relationships with exposure to sidestream tobacco smoke at concentrations from 1 to 15 ppm CO. Some differences are noted among the two subject groups in the magnitude of some symptoms at the lowest exposure level and in the qualitative shape of the acoustic rhinometry and nasal resistance exposure-response curves.

EVALUATION OF ACOUSTIC RHINOMETRY AND POSTERIOR RHINOMANOMETRY AS TOOLS FOR INHALATION CHALLENGE STUDIES

Objective measures of upper respiratory function are needed to understand the effects of inhaled toxicants on the nasal passages. Acoustic rhinometry (AR) is a simple new technique that determines nasal volume by measuring the cross-sectional area of the upper airway as a function of the distance along the nasal passage. This study compares acoustic rhinometry with the more traditional posterior rhinomanometry (NAR) and correlates these objective measures with the symptom of nasal congestion. Healthy young adults (n = 29) were studied on 4 days, each separated by at least 1 wk, in a climate-controlled environmental chamber for 6 h, with exposure to clean air or sidestream tobacco smoke (SS) (2 h, 1, 5, and 15 ppm CO). The coefficient of variation for single measurements was 8-15% (AR) and 4% (NAR); for across-day measurements it was 15-25% (AR) and 13-15% (NAR); and for between days it was 19-27% AR and 17-21% (NAR). These coefficients were similar in subjects with a history of environmental tobacco smoke sensitivity (ETS-S) and those with no history of ETS sensitivity (ETS-NS). At baseline, the perception of unilateral nasal congestion was significantly correlated with unilateral nasal dimensions or nasal resistance; the symptom of baseline bilateral nasal congestion (estimated for both nasal passages simultaneously) correlated less well with objective measures of nasal patency. Under challenge conditions (SS at 1-15 ppm CO), there were typically significant correlations between changes in unilateral congestion and both unilateral rhinomanometry and acoustic rhinometry, but correlations of bilateral congestion and measurable dimensions were much lower. ETS-S and ETS-NS subjects differed in correlations between bilateral subjective and objective measures: ETS-S subjects showed significant correlation between baseline congestion and NAR; in contrast, ETS-NS subjects showed significant correlation between baseline congestion and acoustic rhinometry. These results indicate that NAR and AR are complementary tests for use in inhalation challenge studies and have different correlations with nasal congestion under baseline and challenge conditions.

A Portable Air Cleaner Partially Reduces the Upper Respiratory Response to Sidestream Tobacco Smoke

Abstract Environmental tobacco smoke (ETS) is a common indoor pollutant which often causes acute upper respiratory tract symptoms and measurable nasal congestion. This study evaluated the effect of a room air cleaner on the response to sidestream tobacco smoke (SS) in 12 healthy, nonsmoking adults with previously documented subjective and objective upper respiratory congestive responses to SS. Each subject served as his or her own control and was exposed in a climate-controlled chamber on 2 days, each separated by at least 2 weeks, to SS (15 ppm carbon monoxide, 2 hours, at rest) in the presence of a functioning (AC) or sham room air cleaner. Subjects recorded symptoms and underwent posterior rhinomanometry and acoustic rhinometry. The AC significantly reduced the concentration of particles, total organic vapors, and nicotine, but not carbon monoxide. The AC reduced symptoms of headache [1.4 ± 0.3 sham (net postexposure) versus 0.5 ± 0.2 AC, p < 0.001, analysis of variance] and rhinorrhea (1.8 ± 0.4 sham ...