Laryngeal and Voice Symptoms of Workers in a Chlorine Chemical Factory

Objective. Exposure to chlorine gas can cause many problems for people who work in chlorine chemical production factories. The present study was conducted to investigate the prevalence of laryngeal and voice symptoms and related factors among workers in a chlorine chemical production factory. Design. A case-control study. Patients and Methods. A total number of 208 workers, including 138 workers (13 females, 125 males) who work in a chlorine chemical production factory and 70 (three females, 67 males) workers of a non-chlorine producing factory (producing metal materials), participated in the study. All participants completed self-reported questionnaires to investigate laryngeal or voice problems. These questionnaires investigated workplace vocal health, presence of voice or laryngeal problems, voice symptoms and laryngeal discomforts, and complications of voice problems. Results. The prevalence of laryngeal or voice problems in the workers of the chlorine factory group (18.8%) was higher than in the control group (7%) and this difference was statistically signi ficant ( P = 0.018). For all of the voice and laryngeal symptoms, workers in the chlorine factory had more symptoms than workers in the control group. Results of a Chi-Square test showed that workers in the chlorine factory had more signi ficant vocal fatigue and dry throat symptoms than the control group ( P < 0.05). Regression logistic analyses showed that age ( P = 0.008; OR = 1.09; CI = 1.02 -1.17), inadequate humidity ( P = 0.015; OR = 2.78; CI = 1.21 -6.38), and unavailability of water ( P = 0.021; OR = 3.80; CI = 1.22 -11.76) raised the chances of increasing the laryngeal and voice symptoms among workers. The most common side effects of laryngeal symptoms and voice problems for workers were: dif ficulty speaking in crowded environments, low self-esteem while talking, need for repetition to understand speech, and anxiety when speaking. Conclusion. Laryngeal and voice problems were more prevalent in the chlorine factory workers group than in the control group. The factors of age, inadequate humidity, and unavailability of water increased the probability for laryngeal or voice symptoms among chlorine factory workers. These findings indicate the need for further research with this population.