In a study conducted by Alina V. Chervinskaya and colleagues in St. Petersburg, Russia, the effects of dry sodium chloride aerosol (DSCA) on the respiratory tract of tobacco smokers were evaluated. The study involved 47 male smokers aged 35-60, all of whom had been smoking for at least 15 years and experienced chronic productive cough but did not have other chronic pulmonary diseases. Participants were divided into a test group (TG), who received 20 sessions of DSCA inhalation therapy, and a placebo group (PG). The results demonstrated that 88% of the smokers in the TG reported significant improvements, including easier cough and lighter, clearer sputum, while only 22% of those in the placebo group experienced similar benefits. The study also revealed a marked decrease in infection and adhesion indices of harmful bacteria in the TG, indicating improved mucosal defense.
The research further highlighted that DSCA inhalation improved local immunity by increasing secretory immunoglobulin A (SIgA) levels in the oropharyngeal mucosa of smokers in the TG, a sign of enhanced mucosal resistance to infection. In contrast, no significant changes were observed in the placebo group. Cytobacteriological analysis showed that the colonization of harmful bacteria such as *Streptococcus pneumoniae* and *Haemophilus influenzae* was reduced in the TG, suggesting that DSCA helps to reduce pathogenic microbial activity in the airways. This study concluded that DSCA inhalations could be a beneficial therapy for smokers, alleviating common symptoms like cough and sputum production while also enhancing mucosal immunity and resistance to infections.