Dietary education may reduce blood cadmium and mercury levels in chronic kidney disease patients with higher blood cadmium and mercury levels / 고신대학교의과대학학술지

Background@#Exposure to cadmium and mercury is associated with renal dysfunction. This study aimed to investigate the possible ability of dietary education to decrease blood cadmium and mercury levels in patients with chronic kidney disease (CKD). @*Methods@#Twenty-seven patients with CKD were enrolled in this prospective, single-arm pilot study. Patients with blood cadmium levels ≥1.4 μg/L were instructed to reduce their intake of shellfish, while those with blood mercury levels ≥5.0 μg/L were asked to reduce their intake of externally blue-colored fish. @*Results@#Seven dialysis patients and 15 pre-dialysis patients completed the study. Compared with baseline, the blood cadmium (2.0±0.7 μg/L vs. 1.8±0.7 μg/L, p=0.031) and mercury levels (4.4±2.6 μg/L vs. 3.5±1.9 μg/L, p=0.005) after 1 year significantly decreased, although the dietary intake was not significantly different in patients with blood cadmium levels ≥1.4 μg/L and blood mercury levels ≥5.0 μg/L. In pre-dialysis patients, kidney function worsened after 1 year compared with that at baseline despite the reduction in blood cadmium and mercury levels. @*Conclusions@#Reduction of food intake containing cadmium and mercury may lower the blood cadmium and mercury levels in CKD patients with higher cadmium and mercury levels. Higher blood cadmium levels may cause renal disease progression in pre-dialysis patients, and further studies are necessary to determine the underlying mechanisms.

Changes in the activity times of 119 ambulance units according to the presence of fever or respiratory symptoms: comparison before and after the pandemic of COVID-19

Objective@#We sought to compare the activity times of the 119 service ambulance units before and after the coronavirus disease 2019 (COVID-19) pandemic based on emergency medical service reports. @*Methods@#This study analyzed the emergency medical service reports (1.26-10.31) of 69 ambulance units belonging to the Busan Fire Department in 2019 (before) and 2020 (after) the onset of the COVID-19 pandemic. This was a retrospective cross-sectional study to understand the changes in the activity times (response time, scene time interval, transport time interval, total prehospital time, turnaround time interval, and total activity time) according to the presence of fever or respiratory symptoms (symptom group). The data used for analysis included 150,771 cases, of which 79,121 were in 2019 and 71,650 in 2020, excluding incomplete transfer reports (128,082). @*Results@#There was a total decrease of 7,471 cases in 2020. Compared to 2019, the dispatch and transport distance, outer dispatch jurisdiction, and transport to university hospitals increased. That was found to be greater in the symptom group than in the no symptom group. In the yearly comparison of activity times, there were significant differences in all the activity times and an overall increase in 2020. The increase in the active times was greater in the symptom group than in the no symptom group. @*Conclusion@#In this study, the activity times of the 119 service ambulance units after the COVID-19 showed an increase compared to the pre-COVID period. Therefore, the concerned people must identify the factors which lead to delays and prepare a plan to shorten the activity times, thereby reducing the fatigue of paramedics and providing the means to enhance assistance for the well-being of patients.

Factors affecting the Intention to get COVID-19 Vaccine according to Employee’s Health Beliefs / 農村醫學 地域保健

Objectives@#The purpose of this study was to investigate the factors in which employee’s health beliefs affect their intention to get COVID-19 vaccines. @*Methods@#The participants of this survey were 237 emlpoyees living in Busan. Data were collected using structured online questionnaires from April 26th to May 6th, 2021. The data were analyzed in SPSS WIN version 25.0 using descriptive statistics, t-test, chi-square test, multiple logistic regression analysis. @*Results@#At the average score for each area of health beliefs regarding COVID-19, self-efficacy was 4.45 points, perceived sensitivity 4.71 points, perceived severity 3.59 points, perceived benefit 4.46 points, and perceived disability 2.19 points. Monthly income, perceived sensitivity, perceived severity, and perceived benefit were found to be factors affecting the intention to get COVID-19 vaccines. @*Conclusions@#In order to improve the vaccination intention of COVID-19, it is necessary for subjects to recognize the seriousness of the disease, increase their sensitivity to the disease, and actively promote and educate the community about the benefits of vaccination.

Improving Storage Policy in Korean Public Cord Blood Banks: Comparison of Quality between Long-Term and Short-Term Storage of Cord Blood / 대한수혈학회지

Background@#The decreased use of cord blood units (CBU) due to improvements in haploidentical transplantation is a financial burden for public cord blood banks. Currently, there is no guidance regarding the length of cryopreservation of CBU in Korean public banks. The relative quality of long-term storage CB (LTCB) and short-term storage CB (STCB) needs to be evaluated to establish a storage policy. @*Methods@#Thirty-four and thirty-one units of CB cryopreserved for less than one year and up to 14∼15.5 years, respectively, in the Busan Gyeongnam Public Cord Blood Bank were assessed. The total nucleated cells (TNCs), CD34+ cell counts, and colony-forming units-granulocyte monocyte (CFU-GM) were examined. The cell viabilities were evaluated by Eosin-Y exclusion staining and 7-aminoactinomycin D flow cytometry. The number of stored Korean public CB units from 2000 to 2016 was determined and categorized according to TNCs. @*Results@#The post-thawing viability of the STCBs measured by flow cytometry was consistently higher than that of the LTCBs (TNCs, 62.5% vs 57.3%; MNCs, 93.1% vs 88.9%; CD34+ cells 95.7% vs 94.0%). The CD34+ cell viability was significantly higher in STCB (P=0.03). The CFU-GM after thawing was higher in STCBs (61.5±23.4 vs 49.9±22.8 [0.95 mm 2 ] P=0.05). Of the 48,161 CB units stored until 2016, Dec, 9,493 (19.7%), which were stored until 2006, had been stored for more than 10 years. @*Conclusion@#LTCB with a low number of cells (＜0.7×10 9 cells) should be considered to exclude from storage for therapeutic purposes to improve the storage efficiency.

A study of relationship between blood mercury concentration and hypertension in residents living in old mine fields and related factors

BACKGROUND: In Korea, around the abandoned metal mines, heavy metals are being accumulating in the cultivated areas. Among exposed heavy metals, mercury is known to harm for cardiovascular system known to affect blood pressure. So, we studied the relationship between blood mercury level and hypertension in residents around abandoned metal mines. METHODS: From 2008 to 2011, we surveyed 7,055 residents in provinces affected by abandoned metal mines and collected data from 6 Hospitals. We conducted a personal questionnaire interview survey with residents on the basis of household questionnaires, sex, age, household income, smoking, and drinking items. Multiple logistic regression analysis was performed to investigate the association between blood mercury level and hypertension. RESULTS: We compared residents with low and high groups based on blood mercury level 5.8 μg/L, and higher group was significantly higher risk of hypertension than lower group (odds ratio [OR]: 1.277; 95% confidence interval [CI]: 1.135–1.436), also in adjusted model, higher group was significantly higher risk of hypertension than lower group (OR: 1.276; 95% CI: 1.117–1.457). CONCLUSIONS: This study showed a significant correlation between mercury and hypertension in residents around abandoned metal mines. Therefore, we should continuously monitor people who are higher than the standard value and the hypertensive patients.

Association between employment status and sickness presenteeism among Korean employees:a cross-sectional study

Background@#Sickness presenteeism (SP) indicates “going to work while being ill.” The importance of SP has only recently been investigated, and the association between SP and employment status has been inconsistent across studies. Therefore, we conducted this study to explore the association between SP and employment status by using presenteeism propensity (PP), which can reflect the individual decision-making process. @*Methods@#The study population included employees participating in the 5th Korean Working Condition Survey. We analyzed data of only employees with at least one health event, which was calculated as the sum of SP and sickness absenteeism days. Employment status was grouped into 3 categories: stable employment, unstable employment (contract period ≥ 1 year), and unstable employment (contract period 0.5”). @*Results@#Unstable employees (contract period ≥ 1 year) had higher odds of PP than stable employees (odds ratio [OR]: 1.23, 95% confidence interval [CI]: 1.03–1.47), whereas unstable employees (contract period < 1 year) had lower odds of PP than stable employees (OR: 0.82, 95% CI: 0.71–0.96). @*Conclusions@#Employment status was associated with SP. Given the negative health impact of SP, social efforts, such as paid sick leave, are required to reduce SP and enhance the health status of unstable workers.

Association between employment status and sickness presenteeism among Korean employees:a cross-sectional study

Background@#Sickness presenteeism (SP) indicates “going to work while being ill.” The importance of SP has only recently been investigated, and the association between SP and employment status has been inconsistent across studies. Therefore, we conducted this study to explore the association between SP and employment status by using presenteeism propensity (PP), which can reflect the individual decision-making process. @*Methods@#The study population included employees participating in the 5th Korean Working Condition Survey. We analyzed data of only employees with at least one health event, which was calculated as the sum of SP and sickness absenteeism days. Employment status was grouped into 3 categories: stable employment, unstable employment (contract period ≥ 1 year), and unstable employment (contract period 0.5”). @*Results@#Unstable employees (contract period ≥ 1 year) had higher odds of PP than stable employees (odds ratio [OR]: 1.23, 95% confidence interval [CI]: 1.03–1.47), whereas unstable employees (contract period < 1 year) had lower odds of PP than stable employees (OR: 0.82, 95% CI: 0.71–0.96). @*Conclusions@#Employment status was associated with SP. Given the negative health impact of SP, social efforts, such as paid sick leave, are required to reduce SP and enhance the health status of unstable workers.

A cross-sectional study on the pulmonary function of residents in two urban areas with different PM10 concentrations: data from the fourth Korea national health and nutrition examination survey (KNHANES) 2007–2009

BACKGROUND: The present study aims to compare the pulmonary function of residents of Seoul special city (Seoul) and Jeju special self-governing province including Jeju city and Seogwipo city (Jeju), characterized by vastly different annual average airborne particulate matter with an aerodynamic diameter less ≤10 μm (PM10) concentrations, with the annual average PM10 concentration in Seoul being significantly higher than that in Jeju. METHODS: This cross-sectional study analyzed the pulmonary function test results and sociodemographic data of Korean adults ≥19 years of age derived from the 4th KNHANES, 2007–2009. A total of 830 individuals residing in Seoul or Jeju were included in this study. T-tests were used to analyze predicted values of forced expiratory volume in 1 sec (FEV1p), predicted values of forced vital capacity (FVCp) and FEV1/FVC ratio (FEV1/FVC), as dependent variables, to examine the differences in the subjects’ pulmonary function according to the city of residence. Stratified analysis was then performed to adjust for variables potentially affecting pulmonary function. The analysis was performed on subjects as a group and also following stratification according to sex and other variables. RESULTS: Seoul residents had a significantly lower FVCp than that of the Jeju residents (difference: 3.48%, p = 0.002). FEV1p, FVCp and FEV1/FVC of male Seoul residents were significantly lower than those of male Jeju residents (difference: 6.99, 5.11% and 0.03, respectively; p < 0.001, p = 0.001, p = 0.001). In male subjects, statistically significant results were obtained even after adjusting the influence of other variables through stratified analysis. CONCLUSION: The present analysis was based on cross-sectional data collected at one point in time. Therefore, unlike longitudinal studies, it does not establish a clear causal association between the variables. Nevertheless, this study found that pulmonary function among subjects residing in Seoul was significantly decreased compared to that of subjects residing in Jeju.

Factors associated with the treatment of chronic spontaneous urticaria in children

PURPOSE: Chronic spontaneous urticaria (CSU) in children is a common skin disorder, but its clinical course varies. We investigated the clinical course and associated factors for CSU treatment in children. METHODS: A total of 107 children, diagnosed with CSU from 2001 to 2016 in Dong-A University Hospital, who had been followed up for more than 6 months after treatment, were enrolled. The laboratory findings, and clinical aspects and courses were retrospectively investigated by a medical record review. We divided the 152 patients into 3 groups according to the treatment modalities: group 1, 1 antihistamine; group 2, more than 2 kinds of antihistamines; and group 3, antihistamines plus leukotriene receptor antagonist. RESULTS: The mean age of patients in group 3 was 3.4 years (range, 2.6–4.2 years), which was significantly lower than those at the other 2 group patients (P=0.01). The urticaria activity score (UAS) of group 3 (6.1 [5.7–6.6]) was significantly higher compared to those of the other 2 groups (P=0.01). The improvement rate of the condition in children with positive specific immunoglobulin E (sIgE) reactivity to food or inhalant allergens was significantly lower than that of children with negative sIgE reactivity (P=0.01). Sex, age, history of allergic diseases, disease duration, UAS, previous treatment, and treatment modality were not correlated with the symptom improvement rate. CONCLUSION: Younger children and those with higher UAS needed more medication to ensure the improvement in symptoms. Moreover, it took more time for the improvement in symptoms in children who were sensitized to food or inhalant allergens.

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).

A study on the relationship between job stress and nicotine dependence in Korean workers

BACKGROUND: Nicotine dependence and its severity are often determined by individuals’ psychosocial factors.This study purposed to analyze how Korean workers’ job stress is related with their nicotine dependence according to demographic and occupational characteristics in order to reduce smoking related to job stress and to establish objective indicators to be used in developing adequate smoking cessation strategies. METHODS: The subjects of this study were 4,639 workers who replied to the questionnaire survey. In addition, 1,948 current smokers were separated from non-smokers and ex-smokers, and the relationship between job stress and nicotine dependence was analyzed with the current smoker group. Nicotine dependence was tested using Fagerström’s Test of Nicotine Dependence, and stress was measured using a questionnaire on subjective stress felt by workers in their daily life and the short form of the Korean Occupational Stress Scale. RESULTS: The smoking rate was 54.1 % among men and 2.5 % among women. Nicotine dependence was significantly different according to interpersonal conflict, organization system and lack of reward (p < 0.05). As multivariate logistic analysis, job control, occupational climate and total stress score were statistical significant (p < 0.05). CONCLUSIONS: Job stress was found to be related with smoking status and nicotine dependence. Based on this result, it is suggested to enhance workers’ welfare for health promotion in workplace by improving their working environment in order to reduce job stress and consequently to decrease the smoking rate.

Public Awareness of Stroke and Its Predicting Factors in Korea: a National Public Telephone Survey, 2012 and 2014

The aim of this study was to investigate time trends in the public awareness of stroke and its predicting factors. The target population was 9,600 community-dwelling adults, aged 19–79 years, in 16 metropolitan cities and provinces in Korea. The survey samples in 2012 and 2014 were selected separately (entirely different sets of subjects) using a proportionate quota sampling method. Information concerning knowledge of stroke and demographics was collected by trained telephone interviewers using random digit dialing. After excluding subjects with a non-response or refusal to answer any question, the analyses included 8,191 subjects in 2012 and 8,127 subjects in 2014. Respondents’ awareness of stroke warning signs (numbness or weakness, difficulty speaking or understanding speech, dizziness, visual impairment, and severe headache) was highest for difficulty speaking or understanding speech (80.9% in 2012 and 86.4% in 2014). There were significant increases in the proportion of respondents understanding the appropriate action (i.e., calling an ambulance) at the time of stroke occurrence (59.6% to 67.1%), and in the proportion aware of the general need for prompt treatment (86.7% to 89.8%). In multivariable logistic regression analysis, older age, higher education level, higher household income, current non-smoking, exposure to stroke-related public relations materials, and experience of stroke education were significantly associated with both high knowledge of stroke warning signs and awareness of the need for prompt treatment. Between 2012 and 2014, the public’s awareness of stroke increased significantly. More specialized interventions, including public relations materials and education, should focus on subgroups who have lower stroke knowledge.

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.

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.

Assessing Olfactory Function in Healthy Korean Children Using the Cross-Cultural Smell Identification Test and Butanol Threshold Test / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: There are no reported studies of olfactory function of Korean children, and the existing tests of olfactory function for Korean adults may not be suitable for very young children. This study assessed the applicability of the Butanol Threshold Test (BTT) and Cross-Cultural Smell Identification Test (CC-SIT) to children. SUBJECTS AND METHOD: A total of 79 children were included in the study: they were between 6-12 years of age, and had visited University Hospital Health Care Center between January 2012 and December 2013. All children were administered the BTT and CC-SIT. RESULTS: Using BTT, 69.62% of the sample was classified as moderate hyposmia. On the other hand, when CC-SIT was used, 45.57% of the sample was classified as moderate and 43.04% as mild hyposmia. CC-SIT and BTT scores were not correlated. Although gender and age were not taken into account in the test results, the CC-SIT could measure age-specific olfactory development. CONCLUSION: Our study provides fundamental data on the clinical use of the CC-SIT and BTT in healthy Korean children.

An Experience of Patient Involvement in the Pre-Transfusion Checking Process: A Single Center Study / 대한수혈학회지

BACKGROUND: Correct transfusion of blood product to the right patient requires multiple processes. Errors occurring in the pre-transfusion checking step can result in a serious incident. The role of patients in the safe blood transfusion practice has been investigated. METHODS: We have adopted patient involvement in bedside checking using patient's signature since 2010. We conducted a retrospective review of transfusion medical records during January 2013. The signatures of doctors, nurses, and patients were audited and the reasons for omitting patient's signature were examined. RESULTS: The practice of patient's signature was performed after the problems of procedures were improved. A total of 4697 blood products for 576 patients were issued. The first transfused products were 426 units of RBC (74.0%), 56 units of platelet (9.7%), and 34 units of fresh frozen plasma (5.9%). Completion of patient's signature was observed in 336 patients (63.5%). The reason for omitting patient's signature was operation (104, 18.1%), unclear consciousness or sedation (75, 13.0%), and neonate or infancy (7, 1.2%). CONCLUSION: Patient involvement in the pre-transfusion checking process by writing down the patient's own signature could be achievable. In case of no patient's signature as with an operation, sedation, and neonate or infancy, specific attention is required to ensure a safe transfusion practice.

The separation of arsenic metabolites in urine by high performance liquid chromatographyinductively coupled plasma-mass spectrometry

OBJECTIVES: The purpose of this study was to determine a separation method for each arsenic metabolite in urine by using a high performance liquid chromatography (HPLC)- inductively coupled plasma-mass spectrometer (ICP-MS). METHODS: Separation of the arsenic metabolites was conducted in urine by using a polymeric anion-exchange (Hamilton PRP X-100, 4.6 mm x 150 mm, 5 mum) column on Agilent Technologies 1260 Infinity LC system coupled to Agilent Technologies 7700 series ICP/MS equipment using argon as the plasma gas. RESULTS: All five important arsenic metabolites in urine were separated within 16 minutes in the order of arsenobetaine, arsenite, dimethylarsinate, monomethylarsonate and arsenate with detection limits ranging from 0.15 to 0.27 mug/L (40 muL injection). We used GEQUAS No. 52, the German external quality assessment scheme and standard reference material 2669, National Institute of Standard and Technology, to validate our analyses. CONCLUSIONS: The method for separation of arsenic metabolites in urine was established by using HPLC-ICP-MS. This method contributes to the evaluation of arsenic exposure, health effect assessment and other bio-monitoring studies for arsenic exposure in South Korea.

Relationship between Dietary Mercury Intake and Blood Mercury Level in Korea

This study was performed to evaluate the effect of dietary factors for mercury exposure by comparing with blood mercury concentration. Study population consisted of 1,866 adults (839 men and 1,027 women) in randomly-selected 30 districts in southeast Korea. Dietary mercury intake was calculated from food frequency questionnaire (FFQ) on seafood items and 24 hr recall record. Blood mercury concentration was measured with atomic absorption spectrometry. Mean age of the subjects was 43.5 +/- 14.6 yr. The FFQ showed that mercury-laden fish (tuna, shark) and frequently-eating fish (squid, belt fish, mackerel) were important in mercury intake from fish species. The recall record suggested that fish and shellfish was a highest group (63.1%) of mercury intake and had a wide distribution in the food groups. In comparison with the blood mercury concentration, age group, sex, household income, education, drinking status and coastal area were statistically significant (P < 0.001). In multiple regression analysis, coefficient from the FFQ (beta = 0.003) had greater effect on the blood mercury than the recall record (beta = 0.002), but the effect was restricted (adjusted R2 = 0.234). Further studies with more precise estimation of dietary mercury intake were required to evaluate the risk for mercury exposure by foods and assure risk communication with heavily-exposed group.

Blood Cadmium Concentration of Residents Living near Abandoned Metal Mines in Korea

The purpose of this study was to investigate demographic and lifestyle variables and blood cadmium concentrations in residents living near abandoned metal mines in Korea. Blood cadmium concentrations were measured in 15,161 subjects living around abandoned metal mines (exposed group, n = 14,464) and compared with those living in designated control areas (control group, n = 697). A questionnaire was provided to all subjects to determine age, gender, mine working history, times of residence, smoking habits and dietary water type. The geometric mean (95% confidence intervals) of blood cadmium concentration (1.25 [1.24-1.27] microg/L) in the exposed group was significantly higher than in the control group (1.17 [1.13-1.22] microg/L). Mean residence time and mine working history in the exposed group were significantly higher than in the control group. Blood cadmium concentrations increased with increasing age, and residence time in both groups, and blood cadmium concentrations were higher in current-smokers than in non-smokers in both groups. This study shows the geometric mean of blood cadmium concentration in abandoned mining areas are higher than in non-mining areas in the general adult Korean population.

Association between Low-level Mercury Exposure and Neurobehavioral Functions in Korean Adults Living in a Coastal City

OBJECTIVES: The aim of this study was to determine the association between low-level mercury exposure and neurobehavioral functions in adults living in coastal regions of Korea. METHODS: We selected 172 adults aged 20-65 years living in a city in the coastal region of Korea. A sociodemographic survey was conducted, mercury levels in the blood, urine, and hair were measured, and the associations according to computerized neurobehavioral tests were determined using univariate analysis. After adjustment for associated variables, a multivariate linear regression analysis was performed. RESULTS: The geometric mean mercury levels in the blood, urine, and hair were 5.41 microg/L (range, 0.00-15.84 microg/L), 1.17 microg/g-creatinine (range, 0.00-32.86 microg/g-creatinine), and 1.37 mg/kg (range, 0.42-6.56 mg/kg), respectively. Variables that were associated with simple reaction time according to the neurobehavioral test results were age and urine mercury level. Variables associated with choice reaction time were the recent use of Korean traditional medicine and urine mercury level. Variables associated with the right-hand finger tapping speed test were age, gender, smoking behavior, education level, monthly household income, and urine mercury level. Variables associated with the left-hand finger tapping speed test were age, gender, education level, and urine mercury level. After adjustment for associated variables, there was no significant association between urine mercury level and simple reaction time (beta=25.96; p=0.47), choice reaction time (beta=50.37; p=0.32), or the number of left-hand finger taps (beta=-1.54; p=0.21). However, urine mercury level was significantly associated with the number of right-hand finger taps (beta=-3.86; p=0.01). CONCLUSIONS: We found no evidence that low-level mercury exposure in adults is associated with deficits in neurobehavioral functions. A longer follow-up study is required to confirm this conclusion.