Seyoung Lee

Evaluation of urinary cadmium and lead as markers of background exposure of middle-aged women in Korea: dietary intake as an influential factor.

The study was conducted to examine the validity of urinary cadmium (Cd) and lead (Pb) in comparison with the metals in blood as a biological marker of non-occupational exposure of general populations. Participants in four survey sites in Korea (107 non-smoking Korean women aged 30-49 years) offered peripheral blood, morning spot urine, and 24-h total food duplicate samples. Analysis of Cd and Pb was accomplished by graphite furnace atomic absorption spectrophotometry. The analyse levels were evaluated on an individual basis (n = 107) and also on a survey site basis, i.e. in terms of geometric means for the groups in the survey sites (n = 4). Cd in urine (as observed, or after correction for creatinine concentration or a specific gravity) correlated with Cd in blood on an individual as well as survey site basis, and tended to correlate with Cd in food duplicates on the survey site basis. Correlation of Pb in urine with Pb in blood was weaker than that of Cd in urine with Cd in blood both on the individual and survey site basis. Pb in urine correlated with Pb in food duplicates either weakly or even negatively when examined on a survey site basis. It was concluded that Cd in urine can be most probably employed as a biological marker of environmental Cd exposure of general population, whereas less support was obtained for Pb in urine as an exposure marker.

Frequency of sister chromatid exchange in chrysotile-exposed workers

Chrysotile, which is an industrial carcinogen, has been shown to induce a dose-dependent increase in the frequency of sister chromatid exchange (SCE) in vitro. Authors designed this study to examine the increase of SCEs frequency in the workers occupationally exposed to chrysotile. Heparinized whole blood samples from 45 chrysotile-exposed and 45 control volunteers were cultured for 72 h. The significant difference of SCE frequency was found between chrysotile-exposed workers and control group. The highest SCEs frequency was found in chrysotile-exposed smokers, and the lowest in control non-smokers. The effect of chrysotile exposure on SCEs was marginally significant after controlling the effects of age and smoking by multiple regression analysis.

Participation inequality in the National General Health Examination based on enterprise size

BackgroundHealth examinations are performed so that diseases can be identified and treated earlier. Several studies have evaluated the determinants of participation in health examinations including cancer screening, but few have evaluated the relationship between the size of the enterprise and their participation in Workers’ General Health Examinations (WGHE). The aim of the present study was to estimate the association of WGHE participation with the size of the enterprise and the type of policyholder.MethodsThe eligible population from 2006 through 2013 was extracted from the National Health Insurance Service (NHIS) database. The population size ranged from 14–17 million. After adjustment for age and gender, multiple logistic regression analysis was performed to estimate the odds ratios of participating in the WGHE (by age group) based on the type of policyholder (reference: public officers) and the size of the enterprise (reference: enterprise size ≥300 employees), respectively.ResultsWorkers employed at enterprises with <50 persons were less likely to participate in WGHEs than those employed at enterprises with ≥300 persons. After policyholders were stratified by type (non-office workers vs. public officers), a disparity in the WGHE participation rate was found between the different types of policyholders at enterprises with <50 employees (reference: those employed at enterprises with ≥300 employees); the odds ratios for subjects in their 40s and 50s were 0.2–0.3 for non-office workers vs. 0.8–2.0 for public officers.ConclusionWorkplace policyholders at small enterprises comprised a vulnerable group less likely to participate in WGHEs. Efforts should be made to raise the WGHE participation rate among the vulnerable employees belonging to small enterprises, as well as among their dependents.

0098 Evaluation of sleep problems and sleep hygiene for shift workers in korean steel manufacturing company

Objectives To estimate self-reported sleep health of shift workers and construct plans to minimise harm of the shiftwork. Methods A cross-sectional survey was conducted by using structured questionnaires on workers who were employed in a steel company. They divided into 3 groups (daytime workers, 4 teams 3 shifts, and other shifts). The survey contains questionnaires about demographic characteristics, sleep hygiene, condition of their work place, Insomnia Severity Index (ISI) and the Epworth Sleepiness Scale (ESS) to evaluate workers’ sleep disorder and daytime sleepiness. Among shift-workers, ‘insomnia group’ is compared to ‘normal sleep group’ with chi-square test. The multiple logistic regression analysis was performed to explore risk factors of ‘severe insomnia’. Results Workers with severe insomnia were 6.7% in other shifts group, and 2.3% in 4 teams 3 shifts group. There was no severe insomnia in daytime workers. Among 4 teams 3 shifts group, 12.9% workers complained severe daytime sleepiness. With the practice of sleep hygiene, generally the items for improving environment to sleep well showed higher rate in ‘severe insomnia group’ than ‘normal sleep group’. It might be that the workers who suffered from insomnia tried to overcome it. The items which disrupt sleep were concordantly higher in ‘insomnia group’ than in ‘normal sleep group’, suggesting that such kind of adverse sleep habits are negatively affect sleep of shift workers. Conclusion The results of present study suggest relationship between sleep hygiene and sleep disorders among shift workers. To minimise shift worker’s sleep problem, proper sleep hygiene is necessary.