No one would subject people to chlorine gas exposure on purpose, but an industrial accident that did so yielded useful data on how much gas people can take without getting harmed.
The significant health threat posed by chlorine gas leaks and spills, a common occurrence around the globe, was recently assessed in a study of workers exposed to the toxic gas in a workplace accident.
Presented in the Annals of Occupational and Environmental Medicine, the study highlighted the strong correlation between the duration of such exposure and the number and persistence of respiratory symptoms.
The study was based on employee-related data and medical records connected to at an incident at a printed circuit board factory located in Incheon, South Korea in August 2014. Chlorine gas, unrelated to the facility’s manufacturing process, was released as a consequence of a worker error that combined sodium chlorate and copper chloride in the factory’s waste storage tank.
The study data were derived from self-administered questionnaires, physical exams, chest x-rays, and dental erosion tests of 47 of the plant’s 52 workers, each of whom experienced some degree of exposure to the leak. The 47 subjects were divided into “high” and “low” exposure groups, defined as having been subjected to the gas for more or less than 10 minutes, respectively.
Of the 20 subjects in the low exposure group, 12 reported experiencing more than a single acute respiratory symptom, while 24 of the 27 workers in the high exposure group did so. Upper airway conditions were very common in the subjects, with cough, sore throat, and phlegm identified most often.
The period of “acute respiratory symptoms” was calculated as the number of days that a worker experienced at least one of the following symptoms: sore throat, coughing, sputum, wheezing, or other respiratory condition. The maximum duration of symptoms among the low-exposure subjects was 5 days versus 25 days among those classified as high-exposure.
Potential Cardiovascular, dermatological, and several other conditions that were assessed through physical examinations did not present in a statistically significant manner, though they showed “higher prevalence rates in the higher exposure group.” Moreover, relying on the Cox proportional hazard method, the study concluded that duration of exposure was solely determinative of the degree of respiratory response, thus excluding other factors such as weight and gender, among others (hazard ratio 2.087 95% CI = 1.119, 3.890).
The ability of employees to recognize and respond to the toxic gas, and the route taken to remove themselves from the affected area, were the two key factors in determining individual exposure time.
Therefore, the authors hope to leverage their findings to promote increased awareness of the risks of chlorine gas leaks, and greater workplace preparedness and communication regarding this ubiquitous issue among employers and employees.