Exposure to 200 PPM of Methanol Increases the Concentrations of Interleukin-1β and Interleukin-8 in Nasal Secretions of Healthy Volunteers

Abstract

This study was designed to investigate subclinical irritating effects of methanol on functional and immunologic parameters in human respiratory epithelia. Twelve healthy, nonsmoking individuals were exposed to concentrations of 20 and 200 ppm of methanol in an exposure chamber. The concentrations of interleukin (IL)-8, IL-1β, IL-6, and prostaglandin E2 (PGE2) were monitored. The saccharin transport time test was used to evaluate mucociliary transport. Video interference contrast microscopy was used to determine the ciliary beat frequency of nasal epithelial cells. Subjective symptoms were assessed with a questionnaire. The median concentrations of IL-8 and IL-1β were significantly elevated after exposure to 200 ppm of methanol as compared to exposure to 20 ppm (IL-1β, 21.4 versus 8.3 pg/mL, p = .001; IL-8, 424 versus 356 pg/mL, p = .02). The release of IL-6 and PGE2 did not change significantly (IL-6, 10.3 versus 6.5 pg/mL, p = .13; PGE2, 13.6 versus 13.4 pg/mL), nor did the ciliary beat frequency or the saccharin transport time. Both IL-8 and IL-1β proved to be sensitive indicators for subclinical irritating effects of methanol in vivo. The German threshold limit of 200 ppm of methanol does not prevent subclinical inflammatory reactions of the nasal respiratory mucosa.