The average dietary exposure to lead (Pb) in male and female Japanese individuals >1 year of age was estimated using 280 total diet samples representing 14 food groups from 10 areas over a two-year period. A probabilistic exposure estimation was performed using a two-dimensional Monte Carlo simulation (2D-MCS) with a Bayesian estimation that consided the uncertainty of the estimation process. The Bayesian estimation was performed using the likelihood function with cumulative distribution function between the lower and upper boundary values for no-detected values. The median dietary exposure to Pb was estimated as 5.82 μg/person/day. The 90% interval was 2.51–16.9 μg/person/day. Comparison with previously reported Pb exposure values indicates that the estimation of Pb exposure distribution using total diet samples is reasonable. The contribution to Pb exposure was highest in the order of food group 8 (light-colored vegetables, mushrooms, and seaweeds: 20.0±16.1%)>food group 1 (rice and rice products: 12.3±19.0%)>food group 10 (fish and shellfish: 10.5±13.9%). Owing to the high uncertainties of contribution ratios, it was not possible to identify dominant food groups contributing to Pb exposure. However, it was evident that the uncertainty of the estimation of Pb exposure was influenced by the uncertainty of Pb concentration than the uncertainty of food consumption rate. In particular, the effect of uncertainty from the Pb concentration of the food group 1 was 68.2%. When the margin of exposures were calculated, the estimated probabilities that a value would be <1 were 14.5% for developmental neurotoxicity to children (1–6 years old), 0.13% for blood pressure and 0.93% for kidney disease in Japanese individuals ≥1 year of age. The findings suggest that the health risk due to dietary Pb exposure is small but not negligible.

This study aimed to characterize the adverse events of dietary supplements provided by medical professionals and to examine whether there are challenges when applying each case to the causality evaluation algorithm. Data from 290 individual cases collected by the Tokyo Metropolitan Government in cooperation with the Tokyo Medical Association and Tokyo Pharmaceutical Association were analyzed. The causality evaluation algorithm that was used in this study was reported previously. Female patients accounted for 73% of those who experienced adverse events. Both male and female patients who had adverse events were in their 60s and 70s. Many of the participants had underlying diseases and aimed to improve their medical conditions. Furthermore, skin symptoms were the most common. Many of the supplements were made from natural substances, with an average of 7.7 ingredients in each product. More than half of the products were used for less than one month. In most cases, symptoms improved after discontinuation of the products or after the administration of medications. When each event was applied to the causality assessment algorithm, it was necessary to understand the information as follows: in cases of product discontinuation with simultaneous medications recovery was not concluding the product discontinuation, and the physician’s judgement should be place as objective evidence. The algorithm was successfully applicable to cases provided by medical professionals and the evaluated results for all cases were 30% possible and 62% highly possible. The evaluated results indicate the relationship between products/ingredients and the symptom, and by adding information on the symptom and its severity, it is possible to clarify the phenomenon to be noted.

The conventional analysis method has problems with extraction efficiency, operability, and reproducibility. In this study, we attempted to solve these problems and improve the analytical method to obtain sufficient extraction efficiency and good operability and accuracy. The conventional method was able to get sufficient extraction in dried meat products, where the extraction efficiency of the conventional method was low, by increasing the concentration of sodium hydroxide solution at the time of homogenization. Suction filtration after adding the defoaming agent was added allowed for accurate volume adjustment. The turbidity of the extract caused by insufficient addition of zinc acetate solution was removed by increasing the amount of zinc acetate solution that was added. Turbidity caused by starch was removed by adding pancreatin. The RSD of the quantitative values was improved by adding sodium hydroxide solution and 80–90℃ water and immediately homogenizing. Furthermore, by changing the dilution factor of the extract solution in the colorimetric method, the inhibition of coloration by reducing substances was suppressed, and more accurate quantitative values could be obtained than with the conventional method. The recovery rate was 78.5–105% (RSD 0.7–5.8%), which was a good result. This method was considered to be a useful analytical method that can contribute to improving the inspection accuracy of nitrite ion analysis.

A simultaneous analytical method was developed for the determination of alkyl furans (Furan, 2-methylfuran, 3-methylfuran and 2,5-dimethylfuran) in processed foods by headspace-GC-MS. Single-laboratory validation data of furan, 2-methylfuran, 3-methylfuran and 2,5-dimethylfuran showed good precision and accuracy. The mean recoveries ranged from 92 to 116%, the intermediate precision (RSDi) ranged from 0.9 to 12.9%. The level of LOQ ranged from 0.5 to 1.2 μg/kg (coffee), from 3.5 to 4.1 μg/kg (soy sauce), from 0.4 to 1.3 μg/kg (other foods: clear apple juice, infant formula and baby food), respectively. This method has the sensitivity to detect low levels of furan and alkyl furans contaminated in various foods and is thus applicable to surveillance for risk management in food safety.

A simple and reliable analytical method has been developed for the determination of pantothenic acid in food. For the high-protein food, 20 mL of water was added to 2 g of sample, and after homogenization extraction, 1 mL of 15% zinc sulfate solution was added, mixed well, centrifuged, and the supernatant was filtered to make the test solution. For the low-protein food, 20 mL of 1% formic acid solution was added to 2 g of sample, homogenized, extracted, centrifuged, and the supernatant was filtered to make the test solution. The HPLC separation was carried out on a L-column2 ODS column with 0.02 mol/L phosphate solution (pH 3.0)- acetonitrile (95 : 5) as the mobile phase, and detected at 200 nm. The LC-MS/MS conditions were L-column2 ODS as the separation column, 5 mmol/L ammonium formate (containing 0.01% formic acid)-methanol (85 : 15) as the mobile phase, and multiple reaction monitoring (MRM) was used for detection. The recoveries of pantothenic acid in milk powder and nutritional food products were more than 88% with high precision. As a result of analyzing commetrcially available foods labeled as containing pantothenic acid, analytical values almost identical to the labeled values were obtained, and a high correlation was observed between the values obtained by HPLC and LC-MS/MS.

A method for the rapid analysis of multiclass residual veterinary drugs in poultry muscle, egg, and raw milk was validated in accordance with Japanese guidelines. Using LC-MS/MS, 20 veterinary drugs, including sulfonamides, coccidiostats, and macrolides were analyzed in one injection. Analytes were extracted from the samples with acetonitrile and then dehydrated and salted out using magnesium sulfate, trisodium citrate, and sodium chloride. This method was assessed by performing recovery tests of chicken muscle, duck muscle, egg, and raw milk spiked with 20 new target analytes at concentrations of 10 and 100 µg/kg. According to this method, 17 out of 20 target analytes satisfied the guideline criteria in chicken muscle and duck muscle, and all 20 target analytes met the criteria in egg and raw milk. The limit of quantification was less than MRLs for all analytes. Residues were detected in 4 out of 99 samples and analyzed using the validated method, finding that the levels of all residues were lower than the limits of quantification. These results suggest that continuous monitoring for a new trend of veterinary drugs is necessary.