Respiratory Disorders Resulting From Exposure to Low Concentrations of Ammonia: A 5-Year Historical Cohort Study.

OBJECTIVE This study aimed to investigate respiratory disorders associated with exposure to low concentrations of ammonia. METHOD This cohort study was conducted on 122 industrial workers. Data gathering were based on the officially registered data, the NMAM 6016 and the American Thoracic Society and European Respiratory Society protocols. RESULTS The prevalence rate of respiratory disorders significantly increased in the exposure group over 5 years (P < 0.05). The frequencies of these symptoms in the exposure group were significantly higher than non-exposure group (P < 0.05). Respiratory functions were decrease significantly in the exposure group and were lower than non-exposure group (P < 0.05). Exposure and the amount of exposure to ammonia had a significant relationship with respiratory disorders and respiratory functions (P < 0.05). CONCLUSION Exposure to ammonia lower than threshold limit value (TLV), can act as a risk factor of respiratory disorders.