Lead, Mercury, and Cadmium Exposure in the Korean General Population

BACKGROUND: Lead (Pb), mercury (Hg), and cadmium (Cd) are well-known environmental pollutants. They are unnecessary in the biological processes of humans. This study was performed to estimate the representative background exposure levels to the metals by measuring concentrations in whole blood of the Korean general population. METHODS: This population-based cross-sectional study included 4,000 subjects (1,886 males and 2,114 females) 0–83 years of age in 2010 and 2011. Adult subjects (≥ 19 years of age) were collected by sex- and age-stratified probability method, and preschool- and school-aged subjects were recruited by a cluster sampling method. Written consent was provided prior to blood sampling. Pb and Cd blood concentrations were determined by a flameless atomic absorption spectrophotometry, and blood Hg was analyzed by a direct Hg analyzer. RESULTS: The geometric mean, median and 95th percentile of blood Pb was 1.82 µg/dL, 1.83 µg/dL, and 3.78 µg/dL, respectively. The respective values were 2.92 µg/L, 2.87 µg/L, 9.12 µg/L for Hg, and 0.56 µg/L, 0.59 µg/L, 2.20 µg/L for Cd. Blood Pb and Hg were higher in males than in females, but no sex difference was observed, respectively, in subjects 0–4 years of age for Pb and in subjects less than 20 years for Hg. However, blood Cd was higher in females than in males and no sex difference was observed in subjects < 30 years of age. CONCLUSION: This study provides representative data of human exposure to Pb, Hg, and Cd covering whole age groups of the general population in Korea.

Estimates of Radiation Doses and Cancer Risk from Food Intake in Korea

The aim of this study was to estimate internal radiation doses and lifetime cancer risk from food ingestion. Radiation doses from food intake were calculated using the Korea National Health and Nutrition Examination Survey and the measured radioactivity of 134Cs, 137Cs, and 131I from the Ministry of Food and Drug Safety in Korea. Total number of measured data was 8,496 (3,643 for agricultural products, 644 for livestock products, 43 for milk products, 3,193 for marine products, and 973 for processed food). Cancer risk was calculated by multiplying the estimated committed effective dose and the detriment adjusted nominal risk coefficients recommended by the International Commission on Radiation Protection. The lifetime committed effective doses from the daily diet are ranged 2.957-3.710 mSv. Excess lifetime cancer risks are 14.4-18.1, 0.4-0.5, and 1.8-2.3 per 100,000 for all solid cancers combined, thyroid cancer, and leukemia, respectively.

Korean research project on the integrated exposure assessment of hazardous substances for food safety

OBJECTIVES: This survey was designed to conduct the first nationwide dietary exposure assessment on hazardous substances including the intakes of functional food and herbal medicine. In this paper, we introduced the survey design and the results of the dietary exposure status and internal exposure levels of lead (Pb), cadmium (Cd), and mercury (Hg). METHODS: We selected 4867 subjects of all ages throughout Korea. We conducted a food survey, dietary survey, biomonitoring, and health survey. RESULTS: Pb and Cd were the highest (median value) in the seaweed (94.2 mug/kg for Pb; 594 mug/kg for Cd), and Hg was the highest in the fish (46.4 mug/kg). The dietary exposure level (median value) of Pb was 0.14 mug/kg body weight (bw)/d, 0.18 mug/kg bw/d for Cd, and 0.07 mug/kg bw/d for Hg. Those with a blood Pb level of less than 5.00 mug/dL (US Centers for Disease Control and Prevention, reference value for those 1 to 5 years of age) were 99.0% of all the subjects. Those with a blood Cd level with less than 0.30 mug/L (German Federal Environmental Agency, reference value for non-smoking children) were 24.5%. For those with a blood Hg level with less than 5.00 mug/L (human biomonitoring I, references value for children and adults, German Federal Environmental Agency) was 81.0 % of all the subjects. CONCLUSIONS: The main dietary exposure of heavy metals occurs through food consumed in a large quantity and high frequency. The blood Hg level and dietary exposure level of Hg were both higher than those in the European Union.

Korean research project on the integrated exposure assessment of hazardous substances for food safety

OBJECTIVES: This survey was designed to conduct the first nationwide dietary exposure assessment on hazardous substances including the intakes of functional food and herbal medicine. In this paper, we introduced the survey design and the results of the dietary exposure status and internal exposure levels of lead (Pb), cadmium (Cd), and mercury (Hg). METHODS: We selected 4867 subjects of all ages throughout Korea. We conducted a food survey, dietary survey, biomonitoring, and health survey. RESULTS: Pb and Cd were the highest (median value) in the seaweed (94.2 mug/kg for Pb; 594 mug/kg for Cd), and Hg was the highest in the fish (46.4 mug/kg). The dietary exposure level (median value) of Pb was 0.14 mug/kg body weight (bw)/d, 0.18 mug/kg bw/d for Cd, and 0.07 mug/kg bw/d for Hg. Those with a blood Pb level of less than 5.00 mug/dL (US Centers for Disease Control and Prevention, reference value for those 1 to 5 years of age) were 99.0% of all the subjects. Those with a blood Cd level with less than 0.30 mug/L (German Federal Environmental Agency, reference value for non-smoking children) were 24.5%. For those with a blood Hg level with less than 5.00 mug/L (human biomonitoring I, references value for children and adults, German Federal Environmental Agency) was 81.0 % of all the subjects. CONCLUSIONS: The main dietary exposure of heavy metals occurs through food consumed in a large quantity and high frequency. The blood Hg level and dietary exposure level of Hg were both higher than those in the European Union.

Heavy Metal Risk Management: Case Analysis

To prepare measures for practical policy utilization and the control of heavy metals, hazard control related institutions by country, present states of control by country, and present states of control by heavy metals were examined. Hazard control cases by heavy metals in various countries were compared and analyzed. In certain countries (e.g., the U.S., the U.K., and Japan), hazardous substances found in foods (e.g., arsenic, lead, cadmium, and mercury) are controlled. In addition, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) recommends calculating the provisional tolerable weekly intake (PTWI) of individual heavy metals instead of the acceptable daily intake (ADI) to compare their pollution levels considering their toxicity accumulated in the human body. In Korea, exposure assessments have been conducted, and in other countries, hazardous substances are controlled by various governing bodies. As such, in Korea and other countries, diverse food heavy metal monitoring and human body exposure assessments are conducted, and reducing measures are prepared accordingly. To reduce the danger of hazardous substances, many countries provide leaflets and guidelines, develop hazardous heavy metal intake recommendations, and take necessary actions. Hazard control case analyses can assist in securing consumer safety by establishing systematic and reliable hazard control methods.

Investigation of the Bovine Leukemia Virus Proviral DNA in Human Leukemias and Lung cancers in Korea

The bovine leukemia virus (BLV) is the causative agent of enzootic bovine leucosis. This study investigated the presence of the BLV in leukemia (179 acute lymphoblastic leukemia, 292 acute myeloid leukemia and 46 chronic myelogenous leukemia cases) and 162 lung cancer patients (139 adenocarcinoma, 23 squamous cell carcinoma) to determine if the BLV is a causative organism of leukemia and lung cancer in Koreans. A BLV infection was confirmed in human cells by PCR using a BLV-8 primer combination. All 517 cases of human leukemia and 162 lung cancer were negative for a PCR of the BLV proviral DNA. In conclusion, although meat has been imported from BLV endemic areas, the BLV infection does not appear to be the cause of human leukemia or lung cancer in Koreans. These results can be used as a control for further studies on the BLV in Koreans.