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.

High Maternal Blood Mercury Level Is Associated with Low Verbal IQ in Children

The objective of the present study was to investigate the relationship of IQ in children with maternal blood mercury concentration during late pregnancy. The present study is a component of the Mothers and Children's Environmental Health (MOCEH) study, a multi-center birth cohort project in Korea that began in 2006. The study cohort consisted of 553 children whose mothers underwent testing for blood mercury during late pregnancy. The children were given the Korean language version of the Wechsler Preschool and Primary Scale of Intelligence, revised edition (WPPSI-R) at 60 months of age. Multivariate linear regression analysis, with adjustment for covariates, was used to assess the relationship between verbal, performance, and total IQ in children and blood mercury concentration of mothers during late pregnancy. The results of multivariate linear regression analysis indicated that a doubling of blood mercury was associated with the decrease in verbal and total IQ by 2.482 (95% confidence interval [CI], 0.749–4.214) and 2.402 (95% CI, 0.526–4.279), respectively, after adjustment. This inverse association remained after further adjustment for blood lead concentration. Fish intake is an effect modifier of child IQ. In conclusion, high maternal blood mercury level is associated with low verbal IQ in children.

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.

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.

The clinical analysis of mercury poisoning in 92 cases / 中华内科杂志

Objective To summarize the clinical features of mercury poisoning diagnosed by blood and urine tests for improving the diagnosis and treatment of the disease.Methods Poisoning causes,clinical manifestations,diagnosis,treatment and prognosis were retrospectively reviewed in 92 in-patients with mercury poisoning in our hospital from January 2000 to April 2010.Results Of the 92 patients,37 were male and 55 were female with an average age of 33.1(2-65)years old.The mercury poisoning was caused by occupational exposure and non-occupational exposure,such as iatrogenic exposure,life exposure and wrong intake or suicidal intake of mercury-containing substances,mainly through respiratory tract,digestive tract and skin absorption.The most common clinical symptoms were as the followings:nervous system symptom,such as memory loss in 50 eases(54.3%),fatigue in 34(37.0%),numb limb in 25 (27.2%),dizziness and headache in 22(23.9%),cacesthesia in 20(21.7%),fine tremor(finger tip,tongue tip,eyelids)in 15(16.3%),insomnia and more dreams in 12(13.0%);gastrointestinal symptoms:nausea in 16 (17.4%),abdominal pain in 14(15.2%),stomatitis in 5(5.4%);joint and muscle symptoms:muscle pain in 16(17.4%),joint pain in 5(5.4%);cardiovaseular system:chest tightness,hean palpitations in 6(6.5%);urinary system:edema in 9(9.8%);other system:hidrosis in 20(21.7%).After the treatment with sodium dimercaptopropane sulfonate (DMPS),the symptoms were gradually alleviated.Their gastrointestinal,cardiovascular symptoms were alleviated within 2 weeks;neurological symptoms were alleviated within 3 months;kidney damage showed a slower recovery and could be completely'alleviated within 6 months.Conclusions Because of its diverse clinical symptoms,the mercury poisoning was easy to misdiagnosis and missed diagnosis:therefore the awareness of the disease should be further enhanced.Leaving from the poisoning environment timely and giving appropriate treatment with DMPS will lead to a satisfactory prognosis.

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.

Association of Blood Mercury Level and Neurobehavioral Performance in Korean Elementary School Students / 대한산업의학회지

OBJECTIVES: This study was conducted to examine the effect of blood mercury on neurobehavioral performance in Korean elementary school students. METHODS: We measured the blood mercury concentration in 1,077 elementary school students from Seoul, Busan, Daegu and Gwangju, then the students underwent computerized neurobehavioral test. RESULTS: The mean concentration of blood mercury of study subjects was 2.10 microg/L. An increased blood mercury was associated with an increased reaction time in digit addition and symbol digit. CONCLUSIONS: The blood mercury concentration of study subjects was very high compared to findings in a foreign country. We found several associations between blood mercury level and neurobehavioral performance.

Blood Mercury Concentration and Related Factors in an Urban Coastal Area in Korea / 예방의학회지

OBJECTIVES: This study was carried out for the purpose of evaluating the blood mercury concentration of the residents of Busan, Korea, as well as the relationship between the mercury concentration and the pattern of fish consumption along with other epidemiological factors. METHODS: Two hundred ninety-three subjects (147 men and 146 women), who were aged 40 years or more, were recruited into this study between June and October 2009. The mean age of the subjects was 54.3 years (with a range of 40-70 years). Mercury concentrations in blood samples were measured using a gold-amalgam collection method. RESULTS: The geometric mean concentration of mercury in the total subjects was 8.63 microgram/L [range: 1.48~45.71 microgram/L]. The blood mercury concentration of the men (9.55 microgram/L) was significantly higher than that of the women (7.76 microgram/L). The blood mercury concentration of those who eat fish more than 4 times per week was higher than others, and was statistically significant (male p = 0.0019, female p = 0.0002). According to the multiple analysis, the blood mercury concentration was significantly affected by the consumed fish but other epidemiological factors were not related. CONCLUSIONS: It was found that the subjects who have consumed a large amount of fish may have high blood mercury concentration. It appears that fish consumption can influence blood mercury concentration. Therefore, guidelines for fish consumption that will decrease blood mercury concentration might be necessary in Korea.