| Human Breathing and Eye Blink Rate Responses to Airborne Chemicals James C. Walker, Martin Kendal-Reed, Mark J. Utell, and William S. Cain Abstract Increased levels of air pollution have been linked with morbidity and mortality, but mechanisms linking physiologic responses to quality of life and productivity issues remain largely unknown. Individuals often report irritation of the nose and/or eyes upon exposures to environmental contaminants. Evaluation of these self-reports would be greatly aided by the development of valid physiological markers. Chamber studies (unencumbered exposures) of nonsmoker responses to environmental tobacco smoke offer two candidate end points: a) Tidal volume increases and breathing frequency declines with stimuli that elicit only moderate irritation. b) Eye blink rate increases only with a concentration sufficiently high to cause progressive worsening of eye irritation with prolonged exposure. Experiments with very brief nasal-only presentations also suggest the value of breathing changes as sensitive markers of irritation: a) Tidal volume is inversely related to perceived nasal irritation (NI) intensity in both normal and anosmic (lacking olfactory input) individuals, although normals exhibit greater NI sensitivity. b) Inhalation duration, in both groups, declines only with trigeminal activation sufficient to cause readily perceptible NI in anosmics. Changes in eye blink rate and breathing may be useful in the investigation of irritation and other effects of air pollution, and could be quite useful in investigations of mixtures of volatile organic compounds. Key words: anosmic, breathing, environmental chamber, ETS, eye blink, human, olfactometer, olfactory, psychophysics, trigeminal. -- Environ Health Perspect 109(suppl 4) :507-512 (2001) . http://ehpnet1.niehs.nih.gov/docs/2001/suppl-4/507-512walker/abstract.html This article is based on a presentation at the Workshop on Inhaled Environmental/Occupational Irritants and Allergens: Mechanisms of Cardiovascular and Systemic Responses held 31 March to 2 April 2000 in Scottsdale, Arizona, USA. Address correspondence to J.C. Walker, FSUSRI, B-340 NHMFL, 1800 East Paul Dirac Dr., Tallahassee, FL 32306-2741 USA. Telephone: (850) 644-0140. Fax: (850) 645-3295. E-mail: jwalker@psy.fsu.edu This research was supported in part by the RJR-UNC Collaborative Olfactory Research Program ; Center for Indoor Air Research ; National Insititutes of Health grant DEO6957 to D.W. Warren, UNC Chapel Hill. Received 22 December 2000 ; accepted 22 March 2001. The full version of this article is available for free in HTML or PDF formats. |