Professionals working in polluted areas may present increased clinical airways symptoms and dysfunction. Rhinopharyngeal retrograde clearance (RRC) has been used to improve mucus clearance in infants with bronchitis and bronchiolitis, and instillation the nasal cavity with saline has been used to reduce nasal inflammation in rhinitis and sinusopathies. The aim of this study was to assess the effects of RRC and RCC combined with saline (RRC+S) on nasal mucociliary clearance (MCC), mucus surface property, cellularity and airways symptoms in professional motorcyclists.

Male motorcyclists (mean age 36 years) were recruited and randomly assigned to RRC or RRC+S. Subjects were assessed at baseline and 15 days after interventions for saccharin test, mucus contact angle, cellularity in nasal lavage and airways symptoms with the use of SNOT-20 questionnaire. Data were analyzed by two-way ANOVA for repeated measures with Bonferroni´s correction. A passive monitoring-system of nitrogen dioxide was used to assess the individual air pollution exposure along the study period. The association between nitrogen dioxide and the airways outcomes was analyzed by Spearman correlation test.