Awareness of occupational hazards and personal protective equipment use among dental hygienists / 영남의대학술지

BACKGROUND: The aim of this study was to evaluate the awareness of occupational hazards and personal protective equipment use among dental hygienists (DHs).METHODS: A total of 271 self-administered questionnaires were obtained from 280 DHs working at dental hospitals or clinics in Daegu and Gyeongsangbuk-do, Korea.RESULTS: The occupational hazards included work involving dust (94.1%), volatile substances (86.0%), noise (97.0%), and light-curing units (96.7%). The proportion of dental hygiene tasks that participants perceived as harmful were 42.4%, 51.7%, 9.2%, and 31.4% in the same order as above. The proportion of participants who used dust-proof masks during work involving dust was 1.1%. Those who wore gas-proof masks and gloves for work using volatile substances were 0.7% and 31.2%, respectively. Participants who used goggles for work involving light-curing units were 31.0%. None of the participants used ear plugs for work involving noise. A total of 22.9% of the participants recognized the Material Safety Data Sheet, while 79.7% had never been educated about harmful work environments.CONCLUSION: When compared to exposure status and perception of occupational hazards, the level of protective equipment use was very low. Extra measures to increase DHs’ use of personal protective equipment are necessary.

Emotional labor and job types of male firefighters in Daegu Metropolitan City

BACKGROUND: Research on the emotional labor of firefighters is actively being carried out, but studies that analyze emotional labor separately by job types, working departments, and other conditions of firefighters are insufficient. The purpose of this study is to investigate the difference in emotional labor level between departments and other conditions of firefighters. METHODS: A total of 287 Korean firefighters were included for analysis. The demands of emotional labor and emotional damage were measured using the Korean Emotional Labor Scale. To analyze the conditions and factors affecting the emotional labor level of the firefighters, logistic regression analysis was performed using the emotional labor high risk group as a dependent variable. RESULTS: The average score of overall emotional labor level of the firefighters was 47.2 ± 17.3, and the prevalence of high risk firefighters with emotional labor was 27.1%. It was found that the emergency medical service and administration departments showed a higher prevalence of high risk emotional labor firefighters than did other departments. The result of multiple logistic regression analysis for the high risk emotional labor firefighters showed that the adjusted odds ratio of emergency medical service department compared to the reference group (the rescue department) was 2.89 (95% confidence interval [CI]: 1.02–8.24). CONCLUSIONS: Among the firefighters, the emergency medical service department is a high risk factor for emotional labor. Therefore, education and prevention training on emotional labor should be more thorough before work shifts.

Awareness of occupational hazards and personal protective equipment use among dental hygienists / 영남의대학술지

BACKGROUND@#The aim of this study was to evaluate the awareness of occupational hazards and personal protective equipment use among dental hygienists (DHs).@*METHODS@#A total of 271 self-administered questionnaires were obtained from 280 DHs working at dental hospitals or clinics in Daegu and Gyeongsangbuk-do, Korea.@*RESULTS@#The occupational hazards included work involving dust (94.1%), volatile substances (86.0%), noise (97.0%), and light-curing units (96.7%). The proportion of dental hygiene tasks that participants perceived as harmful were 42.4%, 51.7%, 9.2%, and 31.4% in the same order as above. The proportion of participants who used dust-proof masks during work involving dust was 1.1%. Those who wore gas-proof masks and gloves for work using volatile substances were 0.7% and 31.2%, respectively. Participants who used goggles for work involving light-curing units were 31.0%. None of the participants used ear plugs for work involving noise. A total of 22.9% of the participants recognized the Material Safety Data Sheet, while 79.7% had never been educated about harmful work environments.@*CONCLUSION@#When compared to exposure status and perception of occupational hazards, the level of protective equipment use was very low. Extra measures to increase DHs’ use of personal protective equipment are necessary.

Performance assessment on the Korean Computerized Neurobehavioral Test using a mobile device and a conventional computer: an experimental study

BACKGROUND: The Korean Computerized Neurobehavioral Test (KCNT) is a psychological assessment tool used as part of Workers’ Special Health Examinations in Korea. Due to the spread of mobile technology, this study aimed to compare results of the KCNT administered on a tablet PC versus a desktop computer, and, therefore, assess the clinical applicability of mobile devices. METHODS: A total of 72 participants enrolled in this study. Their age, sex, and years of formal education were collected during an interview, as well as their typing speed. The test battery comprised five subtests: Simple Reaction Time test, Choice Reaction Time test, Digit Addition test, Symbol-Digit Substitution test, and Finger Tapping Speed test. Participants repeated the KCNT test battery in a randomly assigned order using four different testing systems: a desktop computer equipped with a conventional 106-key keyboard (System 1), a desktop computer equipped with a simplified keyboard (System 2), a tablet PC with a simplified 17-key on-screen keyboard (System 3), and a tablet PC equipped with a simplified keyboard (System 4). RESULTS: Results of the Digit Addition test did not differ significantly for different testing systems. In contrast, results of the Simple Reaction Time test, Choice Reaction Time test, Symbol-Digit Substitution test, and Finger Tapping test were lower for the tablet PC (Systems 3 and 4) compared to the desktop computer (Systems 1 and 2). Systems 1 and 2 did not show significantly different results. Performance on System 3 was inferior to that on System 4, only for the Choice Reaction Time test and Finger Tapping Speed test. There were also significant differences in performance by computer familiarity when adjusted for age and education; however, the performance of each group on the test systems showed similar patterns. CONCLUSIONS: It is not recommended to use a tablet PC to administer the KCNT to evaluate neurobehavioral performance for the Simple Reaction Time test and Choice Reaction Time test; however, tablet PCs with an on-screen keyboard may be used to perform the Digit Addition test, and the Symbol-Digit Substitution test and Finger Tapping Speed test to a limited degree.

The associations between blood mercury levels and shark meat intake among workers in Gyeongsangbuk-do

BACKGROUND: Shark meat is used as sacrificial food in Gyeongsangbuk-do, and is a major source of dietary mercury. This study aimed to evaluate the effects of shark meat intake or the ritual of Jesa on blood mercury levels within workers living in Gyeongsangbuk-do. METHODS: This study was conducted from September 2016 to October 2016 in two cities of Gyeongsangbuk-do. To compare the differences between urban and rural areas, two workplaces each in Daegu as the urban area and Yeongcheon as the rural area were selected. General characteristics and characteristics related to shark meat consumption of the workers were acquired by personal interviews during their health examination. Blood mercury concentrations were analyzed by the gold amalgamation method using a direct mercury analyzer (DMA-80; Milestone Inc., Shelton, CT, USA). RESULTS: The shark consumption group had a higher blood mercury concentration than the non-consumption group. The levels of blood mercury increased with the frequency, annual intake, as well as most recent date of shark meat consumption. Moreover, the levels of mercury in blood increased according to the annual frequency of participation in Jesa (times per year) and the annual frequency of shark meat consumption during Jesa (times per year). CONCLUSIONS: Shark meat intake and the ritual of Jesa contributed to an increase in the blood mercury levels of workers in Gyeongsangbuk-do. Therefore, it is necessary to evaluate dietary exposure, occupational as well as other factors that may influence blood mercury concentrations in workers during their health examination, particularly in regions with high mercury exposures.

Urinary arsenic species concentration in residents living near abandoned metal mines in South Korea

BACKGROUND: Arsenic is a carcinogenic heavy metal that has a species-dependent health effects and abandoned metal mines are a source of significant arsenic exposure. Therefore, the aims of this study were to analyze urinary arsenic species and their concentration in residents living near abandoned metal mines and to monitor the environmental health effects of abandoned metal mines in Korea. METHODS: This study was performed in 2014 to assess urinary arsenic excretion patterns of residents living near abandoned metal mines in South Korea. Demographic data such as gender, age, mine working history, period of residency, dietary patterns, smoking and alcohol use, and type of potable water consumed were obtaining using a questionnaire. Informed consent was also obtained from all study subjects (n = 119). Urinary arsenic species were quantified using high performance liquid chromatography (HPLC) and inductively coupled plasma mass spectrometry (ICP/MS). RESULTS: The geometric mean of urinary arsenic (sum of dimethylarsinic acid, monomethylarsonic acid, As3+, and As5+) concentration was determined to be 131.98 μg/L (geometric mean; 95% CI, 116.72–149.23) while urinary inorganic arsenic (As3+ and As5+) concentration was 0.81 μg/L (95% CI, 0.53–1.23). 66.3% (n = 79) and 21.8% (n = 26) of these samples exceeded ATSDR reference values for urinary arsenic (>100 μg/L) and inorganic arsenic (>10 μg/L), respectively. Mean urinary arsenic concentrations (geometric mean, GM) were higher in women then in men, and increased with age. Of the five regions evaluated, while four regions had inorganic arsenic concentrations less than 0.40 μg/L, one region showed a significantly higher concentration (GM 15.48 μg/L; 95% CI, 7.51–31.91) which investigates further studies to identify etiological factors. CONCLUSION: We propose that the observed elevation in urinary arsenic concentration in residents living near abandoned metal mines may be due to environmental contamination from the abandoned metal mine. TRIAL REGISTRATION: Not Applicable (We do not have health care intervention on human participants).

Effects of computer familiarity and computer type on the performance of Korean computerized neurobehavioral test

BACKGROUND: It is thought that computer familiarity has increased significantly since 2004 as well as the use of computers. This study aimed to evaluate the effects of computer familiarity and types of keyboard and computer on the performance of the Korean computerized neurobehavioral test (KCNT), and to identify which parameters of KCNT were affected by aforementioned factors. METHODS: A total of 85 subjects were classified into three groups of computer familiarity by Korean typing speed. Their age, gender and the level of education were also collected. The parameters of KCNT included simple reaction time, choice reaction time, addition, symbol digit, and finger tapping speed. The test was conducted using three types of computers: a laptop computer, a laptop computer with a simplified keyboard, and a desktop computer with a simplified keyboard. RESULTS: Parameters including the simple reaction time, choice reaction time, addition, and symbol digit, and the finger tapping speed of non-dominant hand showed no significant differences in the results among the three groups by computer familiarity after age and educational years were controlled as covariates. The mean reaction time of the simple reaction time and the choice reaction time with a simplified keyboard was significantly shorter compared to that with a typical keyboard. With regard to type of computer, the mean reaction time of the simple reaction time and the choice reaction time was significantly reduced when performed with the desktop computer with a simplified keyboard. CONCLUSIONS: Unlike previous study results, the choice reaction time, the addition, and the finger tapping speed of dominant hand were the only parameters affected by the computer familiarity. Both the type of keyboard and the type of computer significantly influenced the simple reaction time and the choice reaction time. Therefore, it is recommended to use a desktop computer with a simplified keyboard for such parameters.

Evaluation of mercury exposure level, clinical diagnosis and treatment for mercury intoxication

Mercury occurs in various chemical forms, and it is different to health effects according to chemical forms. In consideration of the point, the evaluation of the mercury exposure to human distinguished from occupational and environmental exposure. With strict to manage occupational exposure in factory, it is declined mercury intoxication cases by metallic and inorganic mercury inhalation to occupational exposure. It is increasing to importance in environmental exposure and public health. The focus on the health impact of exposure to mercury is more on chronic, low or moderate grade exposure—albeit a topic of great controversy—, not high concentration exposure by methylmercury, which caused Minamata disease. Recently, the issue of mercury toxicity according to the mercury exposure level, health effects as well as the determination of what mercury levels affect health are in the spotlight and under active discussion. Evaluating the health effects and Biomarker of mercury exposure and establishing diagnosis and treatment standards are very difficult. It can implement that evaluating mercury exposure level for diagnosis by a provocation test uses chelating agent and conducting to appropriate therapy according to the result. but, indications for the therapy of chelating agents with mercury exposure have not yet been fully established. The therapy to symptomatic patients with mercury poisoning is chelating agents, combination therapy with chelating agents, plasma exchange, hemodialysis, plasmapheresis. But the further evaluations are necessary for the effects and side effects with each therapy.

The association between blood cadmium level, frequency and amount of gejang (marinated crab) intake

BACKGROUND: Gejang (marinated crab) is a favorite traditional food and a main source of crab intake among Koreans. The present study aimed to identify the possibility of cadmium inflow to the body through gejang; accordingly, the relationship between gejang intake frequency and amount, and blood cadmium concentrations was investigated. METHODS: Using data from the first Korea National Health and Nutrition Examination Survey in the sixth period in 2013, means and standard errors of blood cadmium concentrations in relation to gejang intake frequency and amount, as well as the monthly intake of gejang, were obtained from 1381 participants for whom data regarding blood cadmium concentration measurements was available. RESULTS: After adjustment for confounding factors, a gejang intake frequency of four or fewer times per week and a monthly intake of 200 cm3 or less had no significant effect on blood cadmium concentrations. However, participants with gejang intake of at least five times per week had a weighted mean cadmium concentration of 2.12 μg/L (p < 0.001), and participants who had a gejang monthly intake of more than 200 cm3 had a weighted mean cadmium concentration of 1.76 μg/L (p < 0.001). CONCLUSION: These results suggest that to minimize the effect of gejang consumption on blood cadmium level, gejang intake should be limited to four or less times per week and 200 cm3 or less per month. Weekly intake of at least five times and monthly intake of more than 200 cm3 may increase blood cadmium levels.

Evaluation and management of lead exposure

Lead, which is widely used in industry, is a common element found in low concentrations in the Earth's crust. Implementations to reduce environmental lead concentrations have resulted in a considerable reduction of lead levels in the environment (air) and a sustained reduction in the blood lead levels of the average citizen. However, people are still being exposed to lead through a variety of routes in everyday commodities. Lead causes health problems such as toxicity of the liver, kidneys, hematopoietic system, and nervous system. Having a carcinogenic risk as well, the IARC classifies inorganic lead compounds as probably carcinogenic to humans (Group 2A). Occupational lead poisonings have decreased due to the efforts to reduce the lead concentrations in the working environment. In contrast, health hazards associated with long-term environmental exposure to low concentrations of lead have been reported steadily. In particular, chronic exposure to low concentrations of lead has been reported to induce cognitive behavioral disturbances in children. It is almost impossible to remove lead completely from the human body, and it is not easy to treat health hazards due to lead exposure. Therefore, reduction and prevention of lead exposure are very important. We reviewed the toxicity and health hazards, monitoring and evaluation, and management of lead exposure.

The association between long working hours and the metabolic syndrome: evidences from the 5th Korean National Health and Nutrition Examination Survey of 2010 and 2012

OBJECTIVES: This study was conducted in order to evaluate the association between the working hours of Korean employees and the metabolic syndrome and the effects of long working hours on metabolic syndrome based on the 5th Korean National Health and Nutrition Examination Survey (2010-2012). METHODS: Based on the 5th Korean National Health and Nutrition Examination Survey (2010-2012), 4,456 Korean employees without shift work, aged over 15, who work 30 hours or more per week were targeted in this study. The association between the general characteristics, including age, smoking, alcohol drinking, exercise, and the metabolic syndrome criteria defined by International Diabetes Federation (IDF) and weekly working hours were analyzed. In addition, the association between weekly working hours and the metabolic syndrome of the subjects stratified by gender was analyzed through multiple logistic regression analyses and generalized linear mixed model after adjusting the general characteristics. RESULTS: In the results of stratified analysis by gender, in male subjects, in comparison with the 30-39 weekly working hours group, there were no significant adjusted odds ratios to the other working hours groups. In female subjects, in comparison with the 30-39 weekly working hours group, there were no significant adjusted odds ratios to the other working hours groups. In addition, no trend associations were observed among weekly working hour groups in both stratified genders. CONCLUSION: No significant differences in prevalence of metabolic syndrome of the subjects stratified by gender were found according to weekly increasing working hours. However, due to some limitations of this study, further prospective studies may be necessary for verification.

Effect of Exercise Intensity on Unfolded Protein Response in Skeletal Muscle of Rat

Endoplasmic reticulum (ER) stress, unfolded protein response (UPR), and mitochondrial biogenesis were assessed following varying intensities of exercise training. The animals were randomly assigned to receive either low- (LIT, n=7) or high intensity training (HIT, n=7), or were assigned to a control group (n=7). Over 5 weeks, the animals in the LIT were exercised on a treadmill with a 10degrees incline for 60 min at a speed of 20 m/min group, and in the HIT group at a speed of 34 m/min for 5 days a week. No statistically significant differences were found in the body weight, plasma triglyceride, and total cholesterol levels across the three groups, but fasting glucose and insulin levels were significantly lower in the exercise-trained groups. Additionally, no statistically significant differences were observed in the levels of PERK phosphorylation in skeletal muscles between the three groups. However, compared to the control and LIT groups, the level of BiP was lower in the HIT group. Compared to the control group, the levels of ATF4 in skeletal muscles and CHOP were significantly lower in the HIT group. The HIT group also showed increased PGC-1alpha mRNA expression in comparison with the control group. Furthermore, both of the trained groups showed higher levels of mitochondrial UCP3 than the control group. In summary, we found that a 5-week high-intensity exercise training routine resulted in increased mitochondrial biogenesis and decreased ER stress and apoptotic signaling in the skeletal muscle tissue of rats.

The Association between Shift Work and the Metabolic Syndrome in Female Workers

OBJECTIVE: This study aimed to determine identify any association between shift work and the metabolic syndrome by comparing the prevalence rates of the metabolic syndrome in shift work groups and daytime work groups for female workers. METHODS: Based on data from health examinations carried out from April to December of 2012, we selected as our subjects 254 female workers from the Daegu area Dyeing Industrial Complex. We diagnosed the metabolic syndrome using the examination results, and information about age, whether or not they did shift work, job type, smoking habits, drinking habits, exercise habits, and past medical history was collected through self-administered questionnaire surveys and face-to-face interviews. The variables found in a univariate analysis to be significant in the occurrence of the metabolic syndrome - age, drinking habits, exercise habits, and shift work - were included in a logistic regression analysis of the risk of the metabolic syndrome for female workers. RESULTS: The prevalence rates of the metabolic syndrome for the total group of study subjects was 11.8%, for daytime workers was 2.8%, and for shift workers was 15.3%. A logistic regression analysis of the odds of the metabolic syndrome for female workers was conducted that included factors associated with the occurrence of the metabolic syndrome: age, drinking habits, exercise habits, and shift work. The results revealed that the odds ratio of the metabolic syndrome in the shift work group, 6.30 (95% CI 1.24-32.15), was significantly higher when compared with the daytime work group. CONCLUSION: Shift work appears to have an association with the metabolic syndrome in female workers. Accordingly, we believe that the attention of government agencies and business owners is needed together with the individual practice of health behaviors to manage the metabolic syndrome for the prevention of cardiovascular disease in female shift workers.

A Case of Lead Poisoning due to a Mixture of Talisman Ash

BACKGROUND: Lead is a metal that has no biological function useful for the human body. In Korea, non-occupational exposure to lead has mostly occurred through taking oriental medicine. However, in this paper we report a case of lead poisoning caused by ingesting talisman material. CASE PRESENTATION: A 16-year-old male patient complained of severe abdominal pain after taking cinnabar, a talisman material. He was diagnosed with lead poisoning accompanied by acute hepatitis. We confirmed that the cinnabar the patient took contained about 10% elemental lead. After symptom management, the patients' symptoms, liver function test results, and blood lead concentration level improved. CONCLUSION: Lead poisoning can be accompanied by hepatitis, although rarely. As we have confirmed that cinnabar as a talisman material is harmful to the human body, measures to prevent its misuse are needed.

Health Impact Assessment of Free Immunization Program in Jinju City, Korea / 예방의학회지

OBJECTIVES: This study was conducted to assess the potential health impacts and improve the quality of the free immunization program in Jinju City by maximizing the predicted positive health gains and minimizing the negative health risks. METHODS: A steering committee was established in September 2010 to carry out the health impact assessment (HIA) and began the screening and scoping stages. In the appraisal stage, analysis of secondary data, a literature review, case studies, geographic information systems analysis, a questionnaire, and expert consultations were used. The results of the data collection and analyses were discussed during a workshop, after which recommendations were finalized in a written report. RESULTS: Increased access to immunization, comprehensive services provided by physicians, the strengthened role of the public health center in increasing immunization rates and services, and the ripple effect to other neighboring communities were identified as potential positive impacts. On the other hand, the program might be inaccessible to rural regions with no private clinics where there are more at-risk children, vaccine management and quality control at the clinics may be poor, and vaccines may be misused. Recommendations to maximize health gains and minimize risks were separately developed for the public health center and private clinics. CONCLUSIONS: The HIA provided an opportunity for stakeholders to comprehensively overview the potential positive and negative impacts of the program before it was implemented. An HIA is a powerful tool that should be used when developing and implementing diverse health-related policies and programs in the community.

Posttraumatic Stress Disorder and Related Factors in Male Firefighters in a Metropolitan City / 대한산업의학회지

OBJECTIVES: This study was conducted in order to evaluate the prevalence of posttraumatic stress disorder (PTSD) and related factors in male firefighters in Daegu, Korea. METHODS: A total of 1,261 firefighters from fire stations in Daegu were the subjects of this study. Each firefighter completed a questionnaire on general and occupational matters, experience of traumatic events, and impact of event scale (IES). The IES questionnaire was administered to subjects in order to determine the high risk group for PTSD. We calculated the IES score and determined that an individual was abnormal if the IES score was over 26. RESULTS: The average IES score of the firefighters was 11.0+/-14.3, and the prevalence of high risk firefighters with PTSD was 15.1%. It was found that 40 years of age, fire sergeant, and emergency medical service personnel showed higher prevalence of PTSD than other groups. The most experienced event among traumatic events was 'witness death of victims or patients'. The results of multiple logistic regression analysis for the high risk PTSD group showed that fire sergeant (OR=2.28, 95% CI: 1.28~4.06), fire lieutenant (OR=2.47, 95% CI: 1.14~5.37), fire captain (OR=2.88, 95% CI: 1.11~7.45), firefighting department (OR=2.04, 95% CI: 1.00~4.17), emergency medical service personnel (OR=3.68, 95% CI: 1.47~9.23), total frequency of traumatic events experienced (OR=1.01, 95% CI: 1.00~1.02), and total type of traumatic event experienced (OR=1.35, 95% CI: 1.25~1.46) were significant variables with regards to the reference group (fire fighter and administration department). CONCLUSIONS: These findings indicate that the prevalence of PTSD in firefighters is higher than that in the general population, and fire sergeant, fire lieutenant, fire captain, emergency medical service personnel, firefighting department, total frequency of traumatic events experienced, and total type of traumatic event experienced were significant variables for the PTSD high risk group.

Estimation of Secondhand Smoke Exposure in Clubs Based on Urinary Cotinine Levels / 영남의대학술지

BACKGROUND: Increasing numbers of young people go to clubs. In Korea, however, no studies have been conducted regarding the exposure of club patrons to secondhand smoke. The present study was conducted to evaluate the degree of club customers' exposure to secondhand smoke. METHODS: The study subjects included 10 male and 12 female non-smokers. The investigational site was a club located in Daegu. Urine samples were collected before exposure to secondhand smoke in the club and 6 hours after a 3-hour exposure. The urine cotinine levels were measured via the LC-MS/MS method. A survey was conducted to collect data regarding the subjects' smoking experiences and the degree of exposure to secondhand smoke in their daily lives. RESULTS: The average urine cotinine level increased from 1.09 microg/L to 5.55 microg/L (p<0.05). No significant difference existed in the change in urine cotinine level between the male and female subjects. In addition, there was no significant difference in the change in urine cotinine level by the degree of exposure to secondhand smoke in daily life. CONCLUSIONS: The average urine cotinine level in all the subjects significantly increased after exposure to secondhand smoke. This is the first study on exposure to secondhand smoke in clubs; these results can be used to craft measures that reduce exposure to secondhand smoke in public places, such as clubs.

The Actual State of Industrial Accidents in Small-medium Manufacturing Industries / 산업간호학회지

PURPOSE: This study was conducted to assess reported industrial accidents and non-reported industrial accidents that took place in 63 small and medium sized manufacturing industries located in Daegu and Gyeongsangbuk-do in the year of 2009. METHODS: During the period from January to December 2009, the number of industrial accidents that happened each month was examined according to the characteristics of industry, industrial accidents, workers with industrial accidents, treatment, as well as causes and treatment of the non-reported. RESULTS: The total incidence rate of industrial accidents was 3.48%, of which only 0.31% reported. The incidence rate in packing and distribution among manufacturing workplace, and in the industry with 50~99 employees, was higher than the other groups. Of the non-reported, over 80% in required under 10 days of medical treatment, and 56% in required cost of less than 100,000 won. Kappa values were 0.771 concurrence in opinions for causes of non-reported, and 0.571 concurrence in opinions for management termination of non-reported between the employees and employer. CONCLUSION: It is suggested that more supportive policy and precise, nationwide survey on the actual state of industrial accidents, including non-reported cases, be implemented to efficiently manage industrial accidents.

Association Between Blood Lead Concentration and Computerized Neurobehavioral Performance in Korean Elementary School Students / 대한산업의학회지

OBJECTIVES: This study was conducted to evaluate association between computerized neurobehavioral performance and blood lead concentration in Korean elementary school students. METHODS: The subjects were 1,077 elementary school students of Seoul, Busan, Daegu and Gwangju. Blood lead concentration was measured and computerized neurobehavioral performance tests were performed. RESULTS: Blood lead concentration of the subjects was in the range of 0.20 and 7.39 microg/dl. The geometric mean of the subjects' blood lead concentration was 1.41 microg/dl. As blood lead concentration increased, reaction time to the symbol digit tended to increase significantly and linearly. As a result of LOWESS(locally weighted scatterplot smoothing), increasing reaction time to the symbol digit was observed. CONCLUSIONS: As blood lead concentration under the CDC (center for disease control and prevention) reference value increased, reaction time to the symbol digit tended to increase. But, as the number of subjects over 3 microg/dl is small, it is difficult to make a definite conclusion. If confounding variables are controlled properly in a follow-up study, we can obtain a more definite conclusion.

The Relationship Between Amalgam Tooth Fillings and Concentration of Blood Mercury in Elementary School Students in Korea / 대한산업의학회지

OBJECTIVES: The adverse health effects of mercury in dental amalgam have not yet been clarified. This study was conducted to examine the effects of dental amalgam on the concentration of blood mercury in Korean children. METHODS: A total of 1,275 students were enrolled in the elementary school in Seoul, Incheon, and Daegu. The number and location of dental amalgam filling of teeth were ascertained by oral examination. Dietary habits-including frequency of seafood intake-and other demographic factors were obtained from the children's parents. The concentration of blood mercury was measured by an atomic absorption spectrophotometer to which a hydride generator was installed. RESULTS: The geometric mean of blood mercury concentration was 1.91 microg/L. It was found that elementary school students in Seoul and the 4th grade elementary school students have the lowest concentration of blood mercury among the study groups. Both linear and secondary linear increase of the concentration of blood mercury, depending on the number of dental amalgam fillings, were statistically significant (p-trend < 0.01, p-quadratic < 0.01). As a result of multiple regression analysis on the blood mercury concentration of elementary school students, the regression coefficient (beta) of a dental amalgam filling was found to be 0.027 (standard error = 0.014, p = 0.048). CONCLUSIONS: In children, the dental amalgam fillings were significantly contribute to the concentration of blood mercury. To accurately assess the effect of dental amalgam on the concentration of body mercury, further studies using the concentration of urine mercury are needed.