The number of claims of Industrial Accidents Compensation Insurance (IACI) for mental illness has increased. In particular, the approval rate was higher in cases with confirmed incident circumstances such as adjustment disorder, acute stress disorder, and post-traumatic stress disorder. With increased numbers of filed IACI applications and their approval rates, the need to evaluate various work-related incidents and stressors consistently is also increasing.

In January 2015–December 2017, among the cases of industrial accidents filed for mental illness and suicide by the Korea Workers' Compensation and Welfare Service, 76 filed or approved adjustment disorder cases were included. The cases of adjustment disorder were applied in this study to the “Criteria for Recognition of Mental Disorders by Psychological Loads” established in Japan in 2011 and investigated if cases were approved/rejected consistently. Additionally, features with the greatest influence on approval/rejection were examined quantitatively.

The number of applications more than doubled from 2015 to 2017, with the approval rate rising from 66.7% to 90.6%. Among the major categories, applications of adjustment disorder related to “interpersonal relationships” were the largest number of applications. Applications related to “sexual harassment”, “interpersonal relationships”, and “accidents and experiences including fires” showed relatively higher approval rate. The approval rate was the lowest in the case of “change in the amount and quality of work”.

Approved cases tend to have special precedents and strong intensity. The main reasons for the rejection were that there were no special precedents and that the intensity of the case was weak. These 2 were the most important factors in determining approval/rejection.

In Korea, Carbon disulfide (CS₂) toxicity was an important social problem from the late 1980s to the early 1990s but there have been few large-scale studies examining the prevalence of diseases after CS₂ exposure discontinuance. So we investigated past working exposure to CS₂ characteristics from surviving ex-workers of a rayon manufacturing plant including cumulative CS₂ exposure index. Furthermore, we studied the prevalence of their chronic diseases recently after many years.

We interviewed 633 ex-workers identified as CS₂ poisoning-related occupational diseases to determine demographic and occupational characteristics and reviewed their medical records. The work environment measurement data from 1992 was used as a reference. Based on the interviews and foreign measurement documents, weights were assigned to the reference concentrations followed by calculation of individual exposure index, the sum of the portion of each time period multiplied by the concentrations of CS₂ during that period.

The cumulative exposure index was 128.2 ppm on average. Workers from the spinning, electrical equipment repair, and motor repair departments were exposed to high concentrations of ≥10 ppm. Workers from the maintenance of the ejector, manufacturing of CS_2, post-process, refining, maintenance and manufacturing of viscose departments were exposed to low concentrations below 10 ppm. The prevalence for hypertension, coronary artery disease, cerebrovascular disease, diabetes, arrhythmia, psychoneurotic disorder, disorders of the nervous system and sensory organ were 69.2%, 13.9%, 24.8%, 24.5%, 1.3%, 65.7%, 72.4% respectively.

We estimated the individual cumulative CS₂ exposure based on interviews and foreign measurement documents, and work environment measurement data. Comparing the work environment measurement data from 1992, these values were similar to them. After identified as CS₂ poisoning, there are subjects over 70 years of average age with disorders of the nervous system and sensory organs, hypertension, psychoneurotic disorder, cerebrovascular disease, diabetes, coronary artery disease, and arrhythmia. Because among ex-workers of the rayon manufacturing plant, only 633 survivors recognized as CS₂ poisoning were studied, the others not identified as CS₂ poisoning should also be investigated in the future.