Symptoms of PTSD according to individual and work environment characteristics of Korean railroad drivers with experience of person-under-train accidents.

OBJECTIVE: The purpose of this study is to collect basic data on the prevalence pattern of posttraumatic stress disorder (PTSD) in Korean railroad drivers exposed to person-under-train accidents according to the individual and working environmental characteristics. METHODS: Questionnaires were sent to all the railroad drivers accompanying active service now by company post. A total of 639 of the 800 questionnaires sent out were returned, showing a response rate of 79.9%. The Impact of Event Scale was utilized to address psychological status of railroad drivers after exposure to person-under-train accident. RESULTS: Score of PTSD, intrusion, and avoidance ranged from 9.6 to 13.2, from 4.2 to 6.1, and from 5.4 to 7.2 according to individual characteristics and ranged from 11.44 to 12.70, from 5.03 to 5.67, and from 6.41 to 7.04 according to working environmental characteristics, respectively. CONCLUSION: This study demonstrated that Korean railroad drivers who experienced person-under-train accident expressed adverse symptoms physically and psychologically more than those who did not experience it. Apart from effect of train driver's age, a wide range of individual and working environmental factors appear to have no association with the level of posttraumatic distress following a person-under-train accident.

Analysis of factors associated with the workers' health status using periodic health examination data by size of enterprises.

This study was conducted to determine whether the size of an enterprise can make a difference to workers' health and to examine those factors, which influence workers' health. The subjects of this study included 26,324 workers employed in manufacturing industry who received medical examinations at the Industrial Health Center at Yonsei University in 1995, 1996 and 1997. Medical examination data were used as a measure of health. Each enterprise was classified by size into three categories: Small scale enterprises (SSE) that employ no more than 50 regular employees; middle scale enterprise (MSE) that employ from 50 to 300 regular employees; and large scale enterprise (LSE) that employ more than 300 regular employees. Health conditions, according to the size of the enterprise, were determined by comparing prevalence rates, and direct standardization methods were used based upon the Korean population, as a standard population, in order to adjust for differences in population structure. 1. The findings of the medical examinations showed that, the prevalence rate in SSEs was higher than in MSEs or LSEs, but that this relationship was reversed after standardizing for sex and age. 2. Logistic regression analysis showed that, although subjects of advanced age, prolonged work history, and male gender had higher risks of disease, the size of the enterprise had no significant effect upon these risks.

Effects of ethanol and phenobarbital on hemoglobin adducts formation in rats exposed to benzidine and Direct Black 38.

The objective of this study was to evaluate the effects of pretreatment of ethanol (EtOH) and phenobarbital (PB), which are known to affect the metabolism of xenobiotics, in the formation of hemoglobin adducts in rats administered with benzidine (BZ) and Direct Black 38 (DB38). The experimental rats were divided into BZ and DB38 groups; each group was subdivided into control, EtOH, and PB groups. Blood samples were separated into hemoglobin and plasma immediately after obtaining and basic hydrolysis was done to convert the adducts into aromatic amines. Hydrolyzed BZ, monoacetylbenzidine (MABZ), and 4-aminobiphenyl (4ABP) were separated by reversed-phase liquid chromatography without derivatization. Then, quantitative analyses were performed using a high performance liquid chromatograph equipped with an electrochemical detector. The amount of metabolites was expressed in the hemoglobin binding index (HBI). As a result, the formations of hemoglobin in BZ-, MABZ-, and 4ABP-HBI of BZ-EtOH and BZ-PB groups were increased compared with those of BZ-control group. In DB38 group, all of HBIs except for BZ-HBI were increased more than those of DB38-control group regardless of the pretreatment. These results are attributable to the fact that EtOH and PB induced N-hydroxylation is related to the formation of hemoglobin adducts. They indicate that EtOH not only increases the adduct formation by inducing N-hydroxylation but also induces N-acetylation. PB induced N-hydroxylation and increased the adduct formation in BZ group, but decreased the adduct formation in DB38 group due to decreasing azo reduction. These results suggest that the effects of EtOH or PB should be considered in biochemical monitoring of BZ and DB38 for the assessment of intermittent exposure to BZ and DB38.