Lifestyle and Work related Factors Associated with Serum PFOA among Workers at Manufacturing Companies / 대한산업의학회지

OBJECTIVES: The objective of this study was to determine serum perfluorooctanoic acid (PFOA) concentrations and to investigate the relationship of lifestyle, health status and work-related factors among workers at manufacturing companies with possible occupational exposure to PFOA. METHODS: The study subjects were 315 workers (male 203, female 112) of manufacturing companies with possible exposure to PFOA from August to December, 2007. A questionnaire was administered to investigate lifestyle and work-related factors. Serum PFOA concentrations were analyzed by LCMS/ MS, and liver function and total cholesterol were also tested. RESULTS: Serum PFOA concentrations ranged from 1.0 to 40.9 ng/mL (mean 8.0 ng/mL). Serum PFOA concentrations increased with age. Male workers had higher PFOA concentration than female workers (male 9.0 ng/mL; female 6.3 ng/mL). According to stepwise multiple regression analysis, factors significantly associated with PFOA concentration were male, being older, higher total cholesterol, and lower body mass index. Adjusted for age and gender by logistic regression, dyeing and finishing textiles had significantly higher odds ratio (OR) of 6.16, and moulding patterns, moulds and industrial patterns (OR=4.84), sections for ships (OR=3.87), and plastics synthetic leather (OR=10.05) had marginally significantly high odds ratios. CONCLUSIONS: This study demonstrated the factors affecting serum PFOA concentration of workers at manufacturing companies. Further study is needed to ensure the effect of occupational exposure on serum PFOA concentration.

Factors Associated with Occupational Injuries of Ship-building Supply Workers in Busan / 대한산업의학회지

OBJECTIVE: This study was conducted to evaluate both personal and work-related factors associated with occupational injuries of ship-building supply workers in Busan, Korea. METHODS: A self-administered, questionnaire survey, asking both personal and work-related factors associated with occupational injuries, was administered to 1,651 workers from 64 different ship-building supply companies in Busan, Korea. All occupational injuries had occurred within the previous 5 years. The workers were divided into three sub-groups: Group I, under 4 day-sick leave, Group II, 4 day-sick leave and over, and Group III, which consisted of both Groups I and II. The statistical significance of the factors associated with occupational injuries underwent cross tabulation analysis for each group. Afterwards, the relationships between the factors which had statistical significance and the occurrence of occupational injuries were analyzed through multiple logistic regression by using the SPSS 12.0 K program. RESULTS: The prevalence of occupational injuries was 4.30% in Group II and 7.57% in Group III. The work activities which had the most frequent occupational injuries were 'Fit-up' and 'Welding', and 30.0% of injured workers were covered by workers' compensation in Group II. According to the multiple logistic regression analysis results, the factors which had statistical significance in occupational injury occurrence were education level above college (OR 2.78) and high level of fatigue (OR 2.18) in Group I, sleeping less than 5 hours per day (OR 3.47), high level of fatigue (OR 2.79) and working over 56 hours per week (OR 1.53) in Group II, and education level above college (OR 1.78), sleeping less than 5 hours per day (OR 2.98), poor sleep quality (OR 1.65) and high level of fatigue (OR 2.58) in Group III. CONCLUSION: This study demonstrated that several factors of ship-building supply workers such as sleep hours, sleep quality, fatigue, working hours, and educational level exerted a statistical effect on the occurrence of occupational injuries. In association with occupational injuries occurrence, these factors need to be controlled by proper methods such as effective safety education, work condition modification, and life style management.

Factors Associated with Occupational Injuries of Ship-building Supply Workers in Busan / 대한산업의학회지

OBJECTIVE: This study was conducted to evaluate both personal and work-related factors associated with occupational injuries of ship-building supply workers in Busan, Korea. METHODS: A self-administered, questionnaire survey, asking both personal and work-related factors associated with occupational injuries, was administered to 1,651 workers from 64 different ship-building supply companies in Busan, Korea. All occupational injuries had occurred within the previous 5 years. The workers were divided into three sub-groups: Group I, under 4 day-sick leave, Group II, 4 day-sick leave and over, and Group III, which consisted of both Groups I and II. The statistical significance of the factors associated with occupational injuries underwent cross tabulation analysis for each group. Afterwards, the relationships between the factors which had statistical significance and the occurrence of occupational injuries were analyzed through multiple logistic regression by using the SPSS 12.0 K program. RESULTS: The prevalence of occupational injuries was 4.30% in Group II and 7.57% in Group III. The work activities which had the most frequent occupational injuries were 'Fit-up' and 'Welding', and 30.0% of injured workers were covered by workers' compensation in Group II. According to the multiple logistic regression analysis results, the factors which had statistical significance in occupational injury occurrence were education level above college (OR 2.78) and high level of fatigue (OR 2.18) in Group I, sleeping less than 5 hours per day (OR 3.47), high level of fatigue (OR 2.79) and working over 56 hours per week (OR 1.53) in Group II, and education level above college (OR 1.78), sleeping less than 5 hours per day (OR 2.98), poor sleep quality (OR 1.65) and high level of fatigue (OR 2.58) in Group III. CONCLUSION: This study demonstrated that several factors of ship-building supply workers such as sleep hours, sleep quality, fatigue, working hours, and educational level exerted a statistical effect on the occurrence of occupational injuries. In association with occupational injuries occurrence, these factors need to be controlled by proper methods such as effective safety education, work condition modification, and life style management.

The Actual Implementing Status of the Preplacement Medical Examination after the Annulment of the Preemployment Medical Examination / 대한산업의학회지

OBJECTIVES: We investigated the status of the preplacement medical examination after the revision of the industrial safety and health law on Oct. 7, 2005 by the Ministry of Labor. METHODS: Preplacement medical certificates of 6,507 recruits issued by two hospitals in Busan, Kyeongnam Province from Jan. 1 to Dec. 31, 2006 were reviewed. Telephone interviews were performed to the recruits with disease and self-reported questionnaires were administrated to health and safety personnel from May 1 to Sep. 30, 2007. RESULTS: Interviews were conducted with 185(56.1%) recruits with disease, 51(27.4%) of whom were rejected for employment due to the preplacement medical certificate. The questionnaire survey for the health and safety personnel revealed that 39(22.9%) personnel were unaware of the annulment of the preemployment medical examination. Eighty(48.8%) of the health and safety personnel answered that they performed a preplacement medical examination after employment, and 63(37.3%) made a practical application of the workers' placement. The recruits with chronic conditions were refused employment: 20 (11.8%) due to hypertension, 21(12.4%) diabetes mellitus and 22(13.0%) hyperlipidemia. The recruits with work-related diseases were also refused employments: 76(44.4%) due to lumbar spine abnormality and 75(43.8%) hearing loss. CONCLUSIONS: Despite the annulment of the pre-employment medical examination, a preplacement medical examination was often used to discriminate among healthy and diseased recruits. Employers must respect the law for the point of time of the preplacement medical examination and the payment of cost. The government should publicize the revision of the objectives of the law. We suggest that health professionals elucidate the job fitness through the development of the assessment tools and maintain the confidentiality of recruits.

Epidemiologic Characteristics of Occupational Lung Cancer in the Busan area / 대한산업의학회지

OBJECTIVES: The objectives of this study were to estimate the proportion of occupational lung cancer in the Busan area. METHODS: Occupational physicians of four university hospitals operating an occupational disease surveillance system in the Busan area actively interviewed all of the newly diagnosed, lung cancer cases about their characteristics and occupational histories through a survey questionnaire and chart review. To evaluate and agree on the work-relativity, the cases were presented in periodic meetings. RESULTS: A total of 301 lung cancer cases were interviewed, of which 50 (16.6%, all male, 27 probable and 23 possible) were related to occupational exposure. The exposure materials were asbestos, Cr, PAH etc. Pathologic findings included squamous cell carcinoma, adenocarcinoma and small cell carcinoma. CONCLUSIONS:The proportion of occupational lung cancer cases above the probable level was 9% and above the possible level was 17%. To develop the public health policy and to prevent further cancer death, the meaningful data from occupational cancer surveillance systems should be collected continuously for ongoing monitoring.

Gene Expression Analysis in Basal Ganglia of Manganese-Exposed Rat Based on cDNA Array / 대한산업의학회지

OBJECTIVES: This study investigated the gene expression profile in basal ganglia of manganese-exposed rats based on cDNA array analysis. METHODS: For cDNA array, 25 male Sprague-Dawley rats (250+/-25 g) were intraperitoneally injected with 25 mg/kg B.W./day of MnCl2 (0.3 ml) for 10 days. For dose-related gene expression analysis, rats were intraperitoneally injected with 0.2, 1.0, and 5.0 mg/kg B.W/day of MnCl2 for 10 days. Control rats were injected with an equal volume of saline. RNA samples were extracted from brain tissue and reversetranscribed in the presence of [alpha32P]-dATP. Membrane sets of the Atlas Rat 1.2 array II and Toxicology array 1.2 kit (Clontech, Palo Alto, CA) were hybridized with cDNA probe sets. Northern blot hybridization method was employed to assess the dose-related gene expression. RESULTS: Fifty-two genes showed significant changes in expression of more than two-fold. Twentyeight were up-regulated and 24 were down-regulated in the manganese-exposed group compared to the control. Among the 52 genes, 28 genes including nuclear factor I-X1 (NF1-X1), neuroligin 2 and 3, mitochondrial stress-70 protein (MTHSP70), neurodegeneration-associated protein 1 (Neurodap1), multidrug resistance protein (MDR), and endoplasmic reticulum stress protein 72 (ERP72), were reported for the first time related to the manganese-induced neurotoxic-metabolism in the rat basal ganglia. According to the dose-related gene expression analyses, MTHSP70, Neurodap1 and ERP72 genes were up-regulated compared to the control even in the group exposed to low manganese dose (0.2 mg/kg B.W./day). CONCLUSIONS: Twenty-eight genes detected for the first time in this study were closely related to the manganese-induced neurotoxic-metabolism in the rat basal ganglia and further study of these genes can give some more useful information about the manganese metabolism.

Effects of Cadmium on Placental Function and Reproduction in Rats / 대한산업의학회지

OBJECTIVES: This study investigated the toxic effects of cadmium on placental function and reproduction in rats. For this study, the mRNA levels of the placental prolactin-growth hormone (PRL-GH) gene family, placental trophoblast cell frequemcy and reproductive data were analyzed. METHODS: Pregnant F344 Fisher rats (200 g+/-23 g) were intraperitoneally injected with 0, 0.5, and 5.0 mg/kg B.W/day of cadmium (CdCl2) dissolved in saline from days 7-11 or 16-20 of pregnancy, and were sacrificed at days 11 or 20, respectively. The mRNA levels were analyzed by Northern blot hybridization and reverse transcription-polymerase chain reaction. The hormone concentration was analyzed by radioimmunoassay and the frequemcy of the placental trophoblast cells was observed by histochemical study. Reproductive data were surveyed at day 20 of the pregnancy and after the births. Statistical analysis was carried out using the SAS program (version 8.1). RESULTS: The mRNA levels of the PRL-GH gene family were reduced dose dependently by cadmium. The mRNA levels of Pit-1a and -b isotype genes were also reduced by cadmium. The hormone concentration of PL-Iv and -II was decreased by cadmium. During the second half of pregnancy (days 11-21), a high dose of cadmium exposure significantly reduced the frequency of spongiotrophoblast and trophoblast giant cells that secrete the PRL-GH hormones. In the last stage of pregnancy (day 20), a high dose of cadmium exposure induced the apoptosis of spon-giotrophoblast cells in the junctional zone of the placenta. Reproductive data such as placental and infant weight, number of live fetuses were decreased, and number of resorptions and dead fetuses, post-implantation loss were increased significantly in the cadmium exposed group compared with the control. CONCLUSIONS: Cadmium disrupts the functions of the placenta and these effects leads to reproductive disorders in rats.

Occupational disease surveillance system in Busan, Ulsan, Kyung-Nam area / 대한산업의학회지

OBJECTIVE: Occupational medicine specialists in the Busan, Ulsan and Kyung-Nam areas established an area-based occupational disease surveillance system and used this system to collected case information for the purpose of preventing occupational diseases METHODS: 11 hospitals participated in this system. The authors selected five main diseases, which were hand-arm vibration syndrome (HAVS), work-related musculoskeletal disorder (WRMSD), occupational asthma, occupational skin disease and occupational lung cancer and established their case definitions. All cases were reported on the web, and real time analysis was conducted. RESULTS: Between Apri1 2001 and April 2003, 192 cases of HAVS, 118 cases of WRMSD, 33 cases of occupational asthma, 17 cases of occupational skin disease and 17 cases of occupational lung cancer (for a total of 377 cases of these five main diseases) were reported. Most of the HAVS cases came from shipbuilding, and 172 of them (92.7 %) were associated with grinding. Of the four main types of WRMSD, carpal tunnel syndrome (CTS) was the most prevalent with 46 cases and shipbuilding was also the main industry involved (83.9 %). The ergonomic risk factors involved mainly associated with the hand. In 19 (57.6 %) and 4 (12.1 %) cases of occupational asthma, the agents included isocyanate and welding fume, respectively. 64.7 % of the cases of occupational skin diseases were contact dermatitis, and organic solvents and welding fume were the main agents involved. The causative agents of occupational lung cancer included Cr, welding fume, PAH, Ni, etc. 10 (58.8 %) of the cases were diagnosed as squamous cell carcinoma and 5 (29.4 %) as adenoma. CONCLUSION: This result showed that an area-based occupational disease surveillance system might provide an effective method of evaluating the prevalence of such diseases, however the Busan, Ulsan and Kyung-Nam provinces are too large to be treated as individual areas. Therefore, the authors suggest that each province should establish its own surveillance system.

Risk Factors of Work-related Musculoskeletal Symptoms Among Ship-yard Workers / 대한산업의학회지

OBJECTS: This study was conducted to prepare the primitive data of work-related musculoskeletal disorders (WMSDs) among ship-yard workers in order to set up management and prevention strategies by investigating the risk factors for WMSD symptoms. METHODS: We carried out a self-administered questionnaire survey of 7,237 blue-collar workers during October 2001, in a ship-yard of Kyungsangnam Province. We collected 2,223 questionnaires and analysed 1,985. The questionnaires included demographic data, quick exposure check (QEC) for ergonomic risk factors, and Karasek's job content questionnaires (JCQ) for job stress. WMSDs were evaluated by the National Institute of Occupational Safety and Health (NIOSH) surveillance criteria. RESULTS: Multiple logistic regression analysis was used to examine the relationship between risk factors and musculoskeletal symptoms. From the results, significant variables were age, maximum weight of manual handling material, frequency of the back movement during manual handling tasks, deviation or bending of the wrists/hands position, excessively bent or twisted head/neck, job dissatisfaction, and high job demand. CONCLUSIONS: In order to reduce musculoskeletal disorders of ship-yard workers, it is recommended to reduce the frequency of back movement during manual handling tasks, wrists/hand deviation or bending, and neck bending or twisting. In addition, devoted effort is needed to increase job satisfaction and to reduce job demand.