Hypertonic Saline Nasal Rinse Intervention: Immunomodulatory Effects in Dairy Workers

Area of Science:

• Occupational health
• Environmental microbiology
• Respiratory medicine

Background:

• Dairy workers face increased occupational exposure to bioaerosols, containing inflammatory components that can lead to respiratory diseases.
• The upper respiratory microbiome may play a role in mediating inflammation caused by bioaerosol exposure.

Purpose of the Study:

• To investigate the effectiveness of a low-cost hypertonic saline nasal rinse intervention in modulating inflammatory responses in dairy workers exposed to bioaerosols.
• To assess the impact of saline nasal rinses on the microbial diversity of the upper respiratory tract in dairy workers.

Main Methods:

• Participants (n=45) were divided into hypertonic saline (n=23) and normotonic saline (n=22) rinse groups.
• Nasal rinses and personal breathing zone (PBZ) samples were collected pre- and post-shift for 5 days.
• PBZ samples were analyzed for particulate matter (PM) and endotoxin; nasal rinses were analyzed for inflammatory markers and microbial diversity (16S rRNA sequencing).

Main Results:

• PM and endotoxin levels were similar between groups, indicating comparable exposures.
• Post-shift levels of pro-inflammatory markers (IL-13, IL-1β, IL-6, IL-8, TNF-α) were significantly higher than pre-shift levels.
• No significant differences in inflammatory marker concentrations or nasal microbiome diversity (alpha and beta) were observed between the hypertonic saline intervention group and the control group.

Conclusions:

• Hypertonic saline nasal rinses did not demonstrate a significant modulation of inflammatory markers or nasal microbiome diversity in this cohort of dairy workers.
• The study suggests that while saline nasal rinses may not directly alter these specific markers, further research is warranted to evaluate their potential as a workplace intervention for respiratory health in agricultural settings.