Sung-Kug Park

Measures for a closer-to-real estimate of dietary exposure to total mercury and lead in total diet study for Koreans

Previous Korean total diet studies (KTDSs) have estimated dietary exposure to toxic chemicals based on 110-120 representative foods selected from over 500 foods appeared in the Korea National Health & Nutrition Examination Surveys (KNHANES), which would result in a possible underestimation. In order to find measures for a closer-to-real estimate of dietary exposure to heavy metals, this study examined the feasibility of mapping foods to the representative foods in the KTDS by comparing estimates. In mapping, those foods not analyzed in the 2009 KTDS (443 out of 559 foods appeared in the 2007 KNHANES) were mapped to the 114 representative foods used in the 2009 KTDS based on the closeness in regards to biological systematics and morphological similarity. Dietary exposures to total mercury and lead were re-estimated using the content of total mercury and lead in 114 foods analyzed in the 2009 KTDS, food intake, and individuals own body weight for respondents in the 2007 KNHANES instead of mean body weight of Koreans used in the 2009 KTDS. The re-estimates of exposure with mapping were approximately 50% higher than the original estimates reported in the 2009 KTDS. In addition, mapping enabled the comparison of percentile distribution of the exposure among populations of different age groups. In conclusion, estimates via mapping resulted in a more comprehensive estimation of dietary exposure to heavy metals present in foods that Koreans consume.

Risk Assessment of Mercury through Food Intake for Korean Population

Hoon Choi, Sung-Kug Park, and Meehye Kim*Food Contaminants Divisions, Food Safety Evaluation Department, National Institute of Food and Drug Safety EvaluationAbstract The present study was conducted to assess the dietary exposure to mercury and the associated risks for Koreansresulting from their food intake. The probabilistic approach in the Monte Carlo simulation was used to estimate dietaryexposures. Based on several reports regarding heavy metals published by KFDA in the 2000s, 178 types of representativefoods were selected and data were collected on the occurrence of mercury. The contents of mercury in foods ranged:agricultural products 0.1 (fruits)-45.4 µg/kg (mushrooms), 3.7 µg/kg (meat), and 9.3 (Echinodermata, chordata)-194.9 µg/kg(fish). Others categories investigated were alcoholic beverages (0.7 µg/kg) and processed food (4.4 µg/kg). The mean and95th percentile for exposure to dietary mercury were 4.29 and 12.48 µg/day, corresponding to 13.6% and 39.7% of PTWI(Provisional Tolerable Weekly Intake), respectively. Therefore, overall level of mercury exposure for Koreans through foodintake is below levels recommended by JECFA, indicating the least possibility of risk, and is less than or similar to levelsreported in other countries.Keywords: mercury, risk assessment, food

In‐house–validated liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method for survey of acrylamide in various processed foods from Korean market

Acrylamide (AA) is a chemical found in starchy foods that have been cooked at high temperatures. The objective of this study is to monitor the levels of AA in a total of 274 samples of potato chips, chips (except potato chips), biscuits, French fries, breakfast cereals, chocolate products, tea, seasoned laver, and nut products sampled in Korean market. These processed foods include (1) potato chips, (2) chips (except potato chips), (3) biscuits, (4) French fries, (5) breakfast cereals, (6) chocolate products, (7) tea, (8) seasoned laver, and (9) nut products. Samples used for this study were cleaned up using HLB Oasis polymeric and Accucat mixed-mode anion and cation exchange solid-phase extraction cartridge. Liquid chromatography–tandem mass spectroscopy (LC-MS/MS) was validated in-house as an efficient analytical method for the routine analysis of AA in various food products. AA was detected with a Fortis dC18 (1.7 μm, 100 mm × 2.1 mm) column using 0.5% methanol/0.1% acetic acid in water as the mobile phase. Good results were obtained with respect to repeatability (RSDs < 5%). The recoveries obtained for a variety of food matrices ranged between 94.5% and 107.6%. Quantification during routine monitoring was sensitive enough to detect AA at a concentration of 10 μg/kg. A total of 274 food samples were analyzed for AA. The AA levels in the food groups were in the following order: potato chips > French fries > biscuits > tea > chips (except potato chips) > seasoned laver > breakfast cereals > chocolate products > nut products. AA was detected at levels ranging from not detectable to 1435 μg/kg.

Risk Assessment of Arsenic in Agricultural Products

The present study was carried out to assess exposure & risk for Korean by total and inorganic As intake through agricultural products. Total arsenic analysis was performed using microwave device and ICP-MS. 50% MeOH extraction and anion-exchange HPLC-ICP-MS method has been used to determine arsenic species. 329 samples covering 20 kinds of agricultural products were collected from various retail outlets and markets across Korea. The concentration of total As was in the range of 0.001~0.718 mg/kg, while inorganic and organic arsenic species in all samples was not determined. For risk assessment, probable daily intake was calculated and compared with provisional tolerable weekly intake (PTWI, 15 /kg b.w./week for inorganic arsenic) established by JECFA. The median daily exposure to total and inorganic As by intake of agricultural products except rice was ranged 0.0002~0.012, 0.0001~0.001 /kg b.w./day, corresponding to 0.01~0.5%, 0.002~0.1% of PTWI, respectively. The median level of total and inorganic As intake through rice was 0.603 and 0.041 /kg b.w./day, and 28.1% and 1.9% of PTWI, respectively. Therefore, the level of overall exposure to arsenic for Korean through agricultural products was below the recommended JECFA levels, indicating of least possibility of risk.

Risk Assessment of Lead and Cadmium through Mushrooms

Hoon Choi, Sung-Kug Park, Bum-Noh Lee, and Meehye Kim*Food Contaminants Divisions, Food Safety Evaluation Department, Korea Food and Drug AdministrationAbstract The present study was carried out in order to assess the dietary exposure as well as the risk for lead (Pb) andcadmium (Cd) exposure through mushrooms among the Korean population. Various samples (n=536) covering 17 kindsof mushrooms were collected from retail outlets and markets in Korea. The contents of Pb were 0.005 (King oyster)-0.026(Matsutake) mg/kg in raw mushrooms and 0.014 (Oyster)-16.411 (Manna lichen) mg/kg in dry mushrooms, respectively.The contents of Cd were 0.002 (Enoki)-0.205 (Hericium erinaciium) mg/kg in raw mushrooms and 0.021 (Vegetableworms)-2.650 (Agaricus blazei Muill) mg/kg in dry mushrooms, respectively. The mean dietary exposure of Pb for thegeneral population was 0.053µg/day, taking 0.03% of provisional tolerable weekly intake (PTWI). The mean dietaryexposure of Cd for the general population was 0.168µg/day, corresponding to 0.37% of provisional tolerable monthlyintake (PTMI). Therefore, the level of the overall dietary exposure to heavy metals through mushroom for the Koreanpopulation was far below the recommended JECFA levels, indicating little possibility of concern.Keywords: mushroom, lead, cadmium, monitoring, risk assessment

The Study on the Analysis Method of Tetrodotoxin in Puffer Fish

The current standard for testing tetrodotoxin (TTX) in foodstuffs is the mouse bioassay (MBA) in Korea as in many other countries. However, this test suffers from potential ethical concerns over the use of live ani- mals. In addition, the mouse bioassay does not test for a specific toxin thus a sample resulting in mouse incapacitation would need further confirmatory testing to determine the exact source toxin (e.g., TTX, STX, brevotoxin, etc.). Fur- thermore, though the time of death is proportional to toxicity in this assay, the dynamic range for this proportional relationship is small thus many samples must be diluted and new mice be injected to yield a result that falls within the quantitative dynamic range. Therefore, in recent years, there have been many efforts in this field to develop alternative assays. High performance liquid chromatography (HPLC) coupled with mass spectrometry (MS) has been emerged as one of the most promising options. A LC-MS-MS method involves solid-phase extraction (SPE) and followed by analysis using an electrospray in the positive ionization mode and multiple reactions monitoring (MRM). To adopt LC-MS-MS method as alternative standard for testing TTX, we performed a validation study for the quantification of TTX in puffer fish. This LC-MS-MS method showed good sensitivity as limits of detection (LOD) of 0.03~0.08 µg/g and limits of quantification (LOQ) of 0.10~0.25 µg/g. The linearity (r 2 ) of tetrodotoxin were 0.9986~0.9997, the recovery were 80.9~103.0% and the relative standard deviations (RSD) were 4.3~13.0%. The correlation coefficient between the mouse bioassay and LC/MS/MS method was higher than 0.95.

Risk Assessment of Arsenic and Mercury in Mushrooms

The present study was carried out to assess the dietary exposure and the risk for arsenic (As) and mercury (Hg) through mushrooms intake. Various samples (n

Radiological Dose Assessment and Survey of a Radioactive Contamination in Foodstuffs

Radiological dose assessments and surveys of a radioactive contamination have been performed for domestic and imported foodstuffs since 2003. The following samples among the imported foodstuffs were selected from open markets; one group is imported foodstuffs and the other group is domestic foodstuffs produced from around nuclear facilities. These included imported samples from a country associated with the Chernobyl nuclear accident, samples produced around nuclear power plants or nuclear tests, and foodstuffs reported as radioactively contaminated materials in a foreign country. After pretreatments such as a drying and homogenization, the samples were analyzed. Only the 137Cs radionuclide was measured from among the regulation radionuclides(137Cs, 134Cs, 131I) of the Korea food code. All foodstuffs except Inonotus Obliquus (Chaga mushooms) were less than 25.24 Bq/kg or below the minimum detectable activity (MDA). The average activity concentrations of 203 mushroom samples was 38.60 Bq/kg but the effective dose was also far less than 1 mSv/yr. Based on the radiological dose assessments and surveys of a radioactive contamination, the radioactivity of the domestic and imported foodstuffs has not shown any significant levels during recent years in Korea.