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Radionuclide contamination in foods has been a public concern in Japan after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. To estimate time and regional trends of daily intake and annual committed effective dose of strontium-90 (90Sr) after the accident, we analysed Market basket samples using a low background 2π gas-flow counter. Samples were collected from six regions, once a year from 2013 to 2018. There appeared to be little variation in estimated daily intake and annual committed effective dose of 90Sr across the time periods and regions. The estimated maximum annual committed effective dose of 90Sr was 0.00076 mSv/year, a value sufficiently lower than the intervention exemption level, 1 mSv/year, in foods in Japan. There was no noticeable difference between the range of estimated daily intake of 90Sr in this study compared with daily intake measured before the FDNPP accident. These results suggested that no obvious increase in dietary intake of 90Sr was observed after the FDNPP accident, and that the effects on commercial foods from 90Sr due to the FDNPP accident were negligible. [ABSTRACT FROM AUTHOR]

We evaluated the performance of a gas chromatography–tandem mass spectrometry method for quantifying 16 polycyclic aromatic hydrocarbons (PAHs), which the Scientific Committee on Food and the Joint Food and Agriculture Organization of the United Nations/World Health Organization Expert Committee on Food Additives have considered to be of concern to human health and used the method to determine the PAH concentrations in smoked foods. Eighty-seven samples of smoked fish, smoked meat, smoked eggs, dried bonito flakes, and dried bonito–related soup-stock products (disposable powder packets for infusion, instant bouillons, and liquids) were purchased in Japan to analyze their content of the 16 PAHs. Because of the low certainty of some results, the analytical values for some PAHs (e.g., benzo[c]fluorene, chrysene, and dibenzo[a,h]pyrene) are given for informational purposes only. The highest median concentrations of benzo[a]pyrene and the sum of all the 16 PAHs (29 and 760 μg/kg, respectively) were found in the disposable powder packets, followed by dried bonito flakes (24 and 512 μg/kg, respectively), and instant bouillons (11 and 227 μg/kg, respectively). These concentrations were much higher than those in the other products tested. We also investigated the percentages of the PAHs transferred from dried bonito flakes and a disposable powder packet to soup stocks commonly prepared at home. These were extremely low (<4%), even though they contained relatively high concentrations of the PAHs. Finally, the intake of benzo[a]pyrene and the sum of the intakes of four PAHs, as a marker proposed by the European Food Safety Authority, were estimated based on the data from a Japanese food consumption survey and the mean concentrations found in smoked fish and smoked fish products. These estimates suggest intakes of PAHs pose a low concern for consumer health. GC-MS/MS method was evaluated for determining 16 PAHs in smoked foods. Relatively high concentrations of PAHs were found in dried bonito products. Transfer of PAHs from dried bonito products to soup stocks was extremely low. PAH intakes from smoked fish and their products pose little risk to consumers. [ABSTRACT FROM AUTHOR]

We determined the polychlorinated biphenyl (PCB) congeners in 101 marine fish obtained from tsunami-stricken areas following the Great East Japan Earthquake in 2011. In particular, to determine the degree of PCB contamination in the fish, we investigated the concentration of total PCB (∑PCB) and the proportions of 209 individual PCB congeners by high-resolution gas chromatography/high-resolution mass spectrometry. The ∑PCB concentration was 1.7–33 ng/g in fat greenling (n = 29), 0.44–25 ng/g in flounder (n = 36), and 1.6–86 ng/g in mackerel (n = 36), all values being much lower than the provisional regulatory limit in Japan. In the congener analysis, tetra-, penta-, hexa-, and hepta-chlorinated PCB congeners dominated in all samples (comprising over 86% of the ∑PCB). The proportions of the chlorinated PCB congeners were similar to the contamination patterns derived from Kanechlor in the environment, implying that the marine fish were not contaminated with fresh PCBs. [ABSTRACT FROM AUTHOR]

We determined the concentrations of dioxins (polychlorinated dibenzo- p -dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls) in 46 dietary supplement products, containing the oil of fish, marine mammals, or egg yolk, on the Japanese market between 2007 and 2014. Dioxins were detected in 43 of the 46 products tested at concentrations from 0.00015 to 67 pg TEQ/g. The highest concentration of dioxins was found in a shark liver oil product which varied insignificantly in five batches collected over a two-year period. The dioxin intakes from these five batches reached 2.3–2.8 pg TEQ/kg bw/day, or 58%–70%, respectively, of the Japanese tolerable daily intake (TDI) of 4 pg TEQ/kg bw/day. However, the dioxin intakes from most of the other products tested were less than 5% of the TDI. Although rare, supplements based on animal oils may contain relatively high concentrations of dioxins, leading to a substantial increase in dioxin intakes. [ABSTRACT FROM AUTHOR]

Radionuclide contamination in foods has been a public concern in Japan after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. To estimate time and regional trends of daily intake and annual committed effective dose of strontium-90 ( 90 Sr) after the accident, we analysed Market basket samples using a low background 2π gas-flow counter. Samples were collected from six regions, once a year from 2013 to 2018. There appeared to be little variation in estimated daily intake and annual committed effective dose of 90 Sr across the time periods and regions. The estimated maximum annual committed effective dose of 90 Sr was 0.00076 mSv/year, a value sufficiently lower than the intervention exemption level, 1 mSv/year, in foods in Japan. There was no noticeable difference between the range of estimated daily intake of 90 Sr in this study compared with daily intake measured before the FDNPP accident. These results suggested that no obvious increase in dietary intake of 90 Sr was observed after the FDNPP accident, and that the effects on commercial foods from 90 Sr due to the FDNPP accident were negligible.

Between fiscal years 2014 and 2016, we surveyed the concentration of radioactive cesium in commercial foods produced in areas where there is a risk of radiation contamination due to the Fukushima Daiichi nuclear disaster. The number of samples with a concentration of radioactive cesium that exceeded the regulatory limit （100 Bq/kg for general foods） was 9 out of 1,516 （0.6％） in fiscal 2014, 12 out of 900 （1.3％） in fiscal 2015, and 10 out of 654 （1.5％） in fiscal 2016. Even though some samples were expected to be contaminated with radioactive cesium, because wild mushrooms and edible wild plants were intentionally included in this survey, the percentage of samples that exceeded the regulatory limit was only around 1％. The surveillance results confirmed that the pre-shipment food monitoring conducted by local governments was properly and efficiently performed, although continuous monitoring of the concentration of radioactive cesium in cultivated and wild mushrooms, edible wild plants, and wild animal meats is still required.

A validation study was performed on the Japanese official method to determine several elements (B, Cr, Mn, Cu, Zn, As, Se, Cd, Ba, Pb) in mineral water simultaneously using ICP-MS. The trueness, repeatability and reproducibility of the method were estimated to be in the ranges of 95-106, 0.2-1.4 and 0.4-4.2%, respectively. The values of every performance parameter fulfilled the requirements in the guidelines announced by the Ministry of Health, Labour, and Welfare of Japan, and the validity of the method was confirmed. The concentrations of the elements in mineral water products purchased from Japanese markets in 2013 and 2014 were surveyed using the method. All products met the specifications defined in the Japanese Food Sanitation Law. No clear relationship between the element concentrations and the survey year or the producing country was found.

We surveyed the concentration of radioactive cesium in foods purchased at markets in areas where possible contamination has been a concern after the Fukushima accident. In fiscal years 2012 and 2013, we surveyed 1,735 and 1,674 foods, respectively, using a NaI (Tl) scintillation spectrometer for the screening test and a γ-ray spectrometer with a germanium semiconductor detector for the final test. Only 3 and 4 samples (0.2% of our total samples) exceeded the regulatory limit (100 Bq/kg) for radioactive cesium in fiscal years 2012 and 2013, respectively. Our surveillance indicates that the pre-shipment monitoring of foods by local governments has been working effectively.

Radioactive contamination in foods is a matter of great concern after the Tokyo Electric Power Company's Fukushima Daiichi nuclear power plant disaster caused by the Great East Japan Earthquake. In order to estimate human intake and annual committed effective dose of radioactive materials, market basket and duplicate diet samples from various areas in Japan were analyzed for cesium-134 ((134)Cs), -137 ((137)Cs), and natural radionuclide potassium-40 ((40)K) by γ-ray spectroscopy. Dietary intake of radioactive cesium around Fukushima area was somewhat higher than in other areas. However, maximum committed effective doses obtained by the market basket and duplicate diet samples were 0.0094 and 0.027 mSv/year, respectively, which are much lower than the maximum permissible dose (1 mSv/year) in foods in Japan.

In order to ensure compliance of raw bean paste products with the Japanese Food Sanitation Law, we examined the performance characteristics of an analytic procedure based on steam distillation followed by carbonate-pyrazolone assay to determine cyanogenic compounds in raw bean paste. The present method includes a procedure for decomposition cyanogenic glycosides using linamarase due to the possibility that cyanogenic glycoside-hydrolyzing enzymes might be deactivated in raw bean pastes. The performance of the method was evaluated using two types of bean paste spiked with a cyanogenic glycoside (linamarin) corresponding to cyanide ion concentrations of 5 and 10 mg/kg. The trueness of the method was 86-90%, and the repeatability (RSD) was 1.0-2.4%, while the intermediate precision (RSD) was 2.6% to 4.9%. A surveillance of cyanogenic compounds in 28 raw bean pastes manufactured in Japan was then carried out with the validated method. One sample contained 15 mg/kg (as hydrogen cyanide), while the other samples contained less than 5 mg/kg.

The Tokyo Electric Power Company's Fukushima Daiichi nuclear power plant disaster after the Great East Japan Earthquake has caused radioactive contamination in food. Using the market basket method, total diet samples in Tokyo, Miyagi prefecture and Fukushima prefecture were analyzed for cesium-134 and -137 (radioactive cesium) and naturally occurring potassium-40 (radioactive potassium) in order to estimate the committed effective doses of these radioactive materials from food. Doses were calculated on the assumption that "not detected" corresponded to zero or to half the limit of detection (values in brackets). The estimated doses of radioactive cesium in Tokyo, Miyagi and Fukushima were 0.0021 (0.0024), 0.017 (0.018) and 0.019 (0.019) mSv/year, respectively. Although the doses in Miyagi and Fukushima were more than 8 times the dose in Tokyo, they were significantly lower than the maximum permissible dose (1 mSv/year) determined by the Ministry of Health, Labour and Welfare, Japan. The estimated doses of naturally occurring radioactive potassium in these areas were in the range of 0.17-0.20 (0.18-0.20) mSv/year, and there were no significant differences between the areas.

In testing, it is necessary to obtain the correct measured values that reflect analyte concentrations in the lot. Control of the analytical performance and appropriate sampling are essential to obtain the correct values. In the present study, we estimated the distribution of the analyte concentrations in specific food product lots and examined the influence of the sample size and the number of analytical runs on the variability of the testing results. The combinations of analyte and food studied were pesticide residues in fresh vegetables, nitrate in fresh vegetables, and food additives in processed meat products. The results of our study suggested the following: an increase in the sample size beyond a certain number does not efficiently reduce the variability of the test results; the specific sample size required to maintain the variability of the testing results at an appropriate level depends on the breadth of distribution of concentrations in the lot and the precision of the analysis; and increasing the number of analytical runs was more efficient in reducing the variability of the testing results than increasing the sample size, when the breadth of distribution of concentrations in the lot was narrow enough to be comparable with the analytical precision.

This document outlined the quality assurance of measurements in the chemical analysis practiced in the food testing in Japan. The quality required for a measurement is the confidence, but necessary degree of confidence is dependent on the intended use of the measurement. The recognition of the purpose of measurement is important in quality assurance of measurements. Once the required quality is decided, the quality of the measurement is assured by various quality assurance means. The international documents about quality assurance of measurement are introduced in this document, as well as the domestic notifications enforced in Japan. Means such as the validation of analytical method and the internal quality control are explained. The concept of the measurement uncertainty is also introduced.

In order to investigate cadmium contents in foods sold in Japan, cadmium levels in 40 seafood samples and 30 chocolate samples were measured by means of atomic absorption spectrometry and ICP-OES. We first confirmed the validity of the method according to the guidelines of the Ministry of Health, Labour and Welfare. Among 40 seafood samples investigated, cadmium was detected in 31 samples, in which the concentration exceeded half the LOQ (0.025 mg/kg), and the level was ranged from 0.03 to 0.38 mg/kg. We could not find any sample containing cadmium in excess of 2 mg/kg, which the Codex Alimentarius sets as the maximum standard value. Among 30 chocolate samples, cadmium was detected in 21 samples, and the level ranged from 0.025 to 0.54 mg/kg.

In Japan, discussions on the regulation and labeling of trans-fat (TF) have under way for several years in the Food Safety Commission and the Consumer Affairs Agency. However, administrative measures for TF have not yet been taken, partly because of the insufficiency of scientific data in Japan. To provide data about the TF intake by Japanese, we determined the levels of TF contained in total diet samples and in food samples that were served as individual meals (one-serving samples). We analyzed 5 groups of total diet samples prepared in 11 regions throughout Japan, and 5 categories of one-serving samples using the GC-method after verifying its performance. The estimated daily intake of TF based on the analytical results of the total diet samples was around 500 mg and no significant difference was observed in the intake of the TF among the 11 surveyed regions. On the other hand, many one-serving samples classified into "hamburger", "pizza" and "Western food" categories contained more than 500 mg of TF per serving, the standard value in the labeling regulation in the United States. If these one-serving meals are taken to represent one meal out of 3 in a day, the intake of TF can easily be expected to exceed the daily intake estimated through the analysis of the total diet samples.

The performance characteristics of an analytical method for cyanogenic compounds were evaluated. Specifically, we tested the trueness, repeatability and intermediate precision of the method using a spectrophotometric-based detection system for 4-pyridinecarboxylic acid and pyrazolone after steam distillation. The pH adjustment of the distillate was revealed to affect the trueness of the measurements. A pH of approximately 6 was found to be optimal. The targeted quantitation limit of the cyanide ion was set to 5 mg/kg. The performance of the method was evaluated using beans spiked with cyanide ion at one to two times the quantitation limit (5-10 mg/kg). The trueness of the method was between 78-90%, and the repeatability and intermediate precision were between RSD 1.2% to 6.0%. A surveillance of cyanogenic compounds in beans retailed in Japan was then carried out. All the results were below the quantitation limit of 5 mg/kg.

This paper puts forward a method for determining the infection order of influenza between adults and children from the daily variations in the amount of influenza anti-viral agents treated at a pharmacy. The time series of Tamiflu Capsule for adults and Tamiflu Dry Syrup for children are compared by means of the cross-correlation function. The results from pharmacies located in Tokyo and Kanagawa show that the influenza infection period of adults is earlier than that of children, indicating the infection order: first adults and second children. However, a pharmacy in Saitama yields no clear result.

This paper puts forward a method for estimating the infection route and speed of influenza from the daily variations in the amount of influenza formulations supplied at distant city pharmacies. The cross-correlation function between the time variations at the pharmacies indicates as for the drug sales, how many days a pharmacy lags behind another pharmacy. The comparison of the time lags between the pharmacies can lead to the estimation of the infection route of influenza. Taking into account the distance between the locations of the pharmacies, we can calculate the infection speed of influenza. Three pharmacies located in Tokyo and its vicinity (Saitama and Kanagawa) are taken as an example. The thrust of this paper is to introduce the new strategy that can take full advantage of the information every pharmacy has in possession.

Inter-laboratory evaluation studies were conducted for the ELISA methods for allergic substances (buckwheat). Extracts of snack, bun and udon spiked with buckwheat standard protein at a level of 5-20 ng/mL as sample solutions were analyzed in replicate at 10 laboratories. Coefficients of variation (CVs) of the ELISA methods using a Buckwheat Protein ELISA Kit (Buckwheat kit) and a FASTKIT Buckwheat ELISA kit (Buckwheat ELISA kit) were mostly below 10%. Mean recoveries of the buckwheat standard protein from the food extracts were over 40% in the two ELISA methods. Repeatability relative standard deviations of buckwheat standard protein in three food extracts were in the ranges of 6.8-78.5% and 5.0-33.9% for the Buckwheat kit and the Buckwheat ELISA kit, respectively. Reproducibility relative standard deviations of buckwheat standard protein in three food extracts were 11.9-69.5% and 16.5-34.1% for the Buckwheat kit and the Buckwheat ELISA kit, respectively. The detection limits of both ELISA methods were 1 ng/mL in sample solutions. These results suggest that the notified ELISA methods are reliable and reproducible for the inspection of buckwheat protein levels in extracts of snack, bun and udon.

Inter-laboratory evaluation studies were conducted for ELISA methods for allergic substances (peanuts). Extracts of biscuit, sauce, chocolate and butter spiked with peanut standard protein at a level of 5-20 ng/mL as sample solutions were analyzed in replicate in 10 laboratories. Coefficients of variation (CVs) of the ELISA methods using a Peanut Protein ELISA Kit (Peanut kit) and a FASTKIT Peanut ELISA kit (Peanut ELISA kit) were mostly below 10%. Mean recoveries of the peanut standard protein from the food extracts were over 40% in the two ELISA methods. Repeatability relative standard deviations of peanut standard protein in four food extracts were in the ranges of 15.2-49.7% and 3.0-28.3% for the Peanut kit and the Peanut ELISA kit, respectively. Reproducibility relative standard deviations of peanut standard protein in four food extracts were 23.5-44.4%, 9.6-28.4% for the Peanut kit and the Peanut ELISA kit, respectively. The detection limits of both ELISA methods were 2-2.5 ng/mL in sample solutions. These results suggested that the notified ELISA methods are reliable and reproducible for the inspection of peanut protein levels in extracts of biscuit, sauce, chocolate and butter.