The exposure of healthy volunteers to 200 ppm 1,1,1-trichloroethane increases the concentration of proinflammatory cytokines in nasal secretions

Abstract

Objectives: Irritating effects of organic solvents have usually been measured by means of questionnaires. The aim of the present study was to evaluate the sensitivity of different methods of detecting subclinical irritating effects. Methods: Twelve healthy, non-smoking students were exposed to 200 ppm and to 20 ppm 1,1,1-trichloroethane in an exposure chamber, using a crossover design. The amounts of interleukins (IL)-1β, IL-6 and IL-8 and prostaglandin E₂ (PGE₂) in nasal secretions were measured. Mucociliary transport time was determined with the saccharine test. Ciliary beat frequency of nasal epithelial cells was measured with video-interference contrast microscopy. Subjective symptoms were assessed by questionnaire. Results: Concentrations of ILs were significantly elevated after exposure to 200 ppm 1,1,1-trichloroethane (IL-1β 82.4 vs. 28.8 pg/ml (medians), P=0.003; IL-6 12.2 vs. 7.2 pg/ml, P=0.01; IL-8 549 vs. 424 pg/ml, P=0.007), whereas the other parameters remained unchanged. Conclusion: The interleukins measured proved to be sensitive indicators of irritating effects of 1,1,1-trichloroethane. The German threshold limit (MAK value) of 200 ppm 1,1,1-trichloroethane does not prevent the subclinical inflammation of nasal mucosa.