Estimation of daily cadmium intake from cadmium in blood or cadmium in urine.

OBJECTIVES: It would be quite convenient if daily dietary cadmium intake (Cd-D) can be estimated either from Cd in blood (Cd-B) or from Cd in urine (Cd-U). The aim of the study was to examine if Cd-D can be estimated from Cd-B or Cd-U. METHODS: The data available in a previous publication were employed for regression analyses between Cd-D and Cd-B, and between Cd-D and Cd-U. 30 sites in various prefectures throughout Japan were surveyed and 20 adult women/site on average provided food duplicate, peripheral blood, and second morning urine samples. Geometric means were taken as representative values and employed in regression analyses. RESULTS: Cd-D, Cd-B, and Cd-U(cr) [i.e., Cd-U after correction for creatinine (cr) concentration] distributed in ranges of 12.5-70.5 µg/day, 0.46-3.98 µg/l, and 1.16-11.02 µg/g cr, respectively. A close correlation was observed between Cd-D and Cd-B, and also between Cd-D and Cd-U(cr) with r = 0.76 and r = 0.79 (p < 0.001 for both), respectively. Both regression lines passed close to the origins. Application of 1.23 µg Cd/l blood and 1.26 µg Cd/g cr in urine (average levels for adult Japanese women) to the regression equations gave 16.5 and 11.5 µg Cd/day. CONCLUSIONS: The analyses suggested that it may be possible to estimate Cd-D from Cd-B or Cd-U. Cd-B-based estimation should be more respected. As variations in the estimation parameters and estimated values are inherent to field surveys, care should be taken in the application of the study results. Application on a group basis (and not on an individual basis) should be considered.

Food intake survey of kindergarten children in Korea: Part 1 food, energy, and nutrient intake.

OBJECTIVES: Nutrient intakes of children were surveyed at the time when a nation-wide shift took place in the Republic of Korea from agriculture-based to industrialized society. Taking advantage of the survey locations (see below), possible delay in nutritional improvement in rural areas (as compared with that in an urban area) was also examined. METHODS: In total, 108 4- to 6-year-old children (boys and girls in combination) in 4 kindergartens (KGs; 1 in Seoul and 3 in Jeju Island) participated in the survey in 2003-2004. 24-h food duplicate samples were prepared by the mother of each child. Food items in each duplicate sample were separated and coded with reference to the Dietary Reference Intake for Koreans (the 2005 version). Nutrient intake of the day was estimated from the code and weight followed by summation for daily intake. RESULTS: The children in the KG in Seoul studied were younger, and therefore were smaller in body size than those in other KGs. Thus, it was considered necessary to evaluate nutrient intake not only on a daily basis, but after adjustment for body weight. The AM daily intake of energy (protein in parenthesis) for the 108 children was 1479 kcal (55 g)/day or 69.8 kcal (2.6 g)/kg body weight/day. Evaluation by individual nutrient suggested that the intake was sufficient for almost all nutrients except for sodium and potassium. Sodium and potassium intake (2285 and 1840 mg/day, respectively) was in excess and insufficient, respectively, with potential risk of inducing hypertension later in life. CONCLUSIONS: Inter-KG difference was not remarkable and therefore urban-rural difference was not apparent. Nutrient intakes as a whole appeared to be sufficient urban and rural areas. Nevertheless, excess Na intake coupled with insufficient K intake was a common problem.

Food intake survey of kindergarten children in Korea: Part 2 increased dietary intake of tin possibly associated with canned foods.

OBJECTIVES: Dietary intake of tin (Sn) may be increased in some children in kindergartens in Korea. The present study was intended to examine this possibility and clarify the extent of the elevation. METHODS: 24-hour food duplicate and spot urine samples were collected in 2003-2004 from 108 4-6-year-old children (boys and girls combined) in 4 kindergartens (1 in Seoul and 3 in Jeju Island), as reported in a previous publication. These samples were employed in the present analyses to examine tin levels in the diet (including beverages) (Sn-D). A portion of the samples were wet-ashed, and the liquid samples were analyzed for Sn by the ICP-MS method. For statistical evaluation, χ (2) method and Smirnov's test for extreme value were used. RESULTS: Sn-D in the 108 cases distributed as extremely biased, and could be divided into two groups, i.e., those with <10 µg Sn/day (accounting for 90% of the cases), and those with >10 µg/day (for 10%). Sn-D in the former group was distributed quasi-normally with an AM (median) of 2.9 (2.5) µg/day. The maximum in the latter group was 3012 µg/day. No correlation was detected between Sn-D and Sn in urine (Sn-U). Comparison of the findings with published articles strongly suggested that the high Sn-D was due to consumption of foods (including beverages) preserved in tin-plated cans. No positive confirmation was however possible due to insufficient information on food records. CONCLUSIONS: About 10% of children surveyed had elevated Sn-D (up to 3 mg/day). It was quite possible that high Sn-D was associated with tin-canned food intake.

Food intake survey of kindergarten children in Korea: Part 3 cadmium and lead burden.

OBJECTIVES: This study was initiated to elucidate the extent of dietary exposure of children in Korea to two pollutant metals of cadmium (Cd) and lead (Pb). Possible urban-rural difference was also examined. METHODS: Food duplicate and morning spot urine samples were collected from 108 children in 4 kindergartens (KG) (1 KG in Seoul and 3 KGs in Jeju Island), as reported in a previous publication. The samples were analyzed for Cd and Pb by ICP-MS. RESULTS: Cd and Pb in food duplicate and urine samples were distributed approximately log-normally. Geometric means for Cd and Pb in food duplicate samples were 12.4 and 5.8 µg/day, or 0.58 and 0.27 µg/kg body weight/day, respectively, and the values for Cd and Pb in urine (as observed, i.e., with no correction for urine density) were 0.91 and 1.64 µg/L, respectively. 2.41 and 0.30 µg/day of Cd and Pb (accounting for 19.5 and 5.1%) came from boiled rice, the staple food. The levels of Cd and Pb burden among the children in the present survey were essentially the same with the levels reported for children in Pusan. The reasons for difference in the rank in Cd-D and Cd-U among the 4 KGs need further study. CONCLUSIONS: The observed levels of Cd and Pb exposure were more or less similar to what were reported for children in Pusan. No apparent urban-rural difference could be detected.

High iodine intake by preschool children in Miyagi prefecture, Japan.

OBJECTIVES: Standard Tables of Food Composition in Japan 2010 (FCT) remain incomplete for iodine contents. This survey was initiated to develop a method to cope with this shortage and to find daily iodine intake of preschool children in Japan. METHODS: Data were available for one-day food intake for 296 3- to 6-year-old children (the total cases). 128 samples (the selected cases) were analyzed by ICP-MS for iodine (the measured values). Iodine intake was also calculated using FCT assuming that iodine contents in missing items were zero (the calculated values). RESULTS: Measured and calculated values for the selected 125 cases (after exclusion of 3 extreme cases) gave geometric means (GM) of 117.6 and 101.8 µg/day. The measured/calculated ratio in GM, 117.6/101.8 = 1.155, was applied to the calculated values for total 296 cases to estimate iodine intake (the estimated values). GM for the estimated value was 175.2 µg/day and it was 8.93 µg/kg/day after adjustment for body weight for 296 children. There was no significant difference between boys and girls. DISCUSSION: The GM values for both the measured and estimated values (n = 125 pairs) were 117.6 µg/day. The agreement suggested that the factor employed, 1.155, was proper and adequate. Literature survey suggested that values on a body weight basis were comparable between the children and adults in Japan. The levels were higher than levels in east Asian countries. CONCLUSIONS: A correction method was developed for estimation of daily dietary iodine intake. The iodine intake level for preschoolers was comparable to levels for adult population.

High cadmium and low lead exposure of children in Japan.

BACKGROUND: Cadmium (Cd) is a wide-spread environmental pollutant with insidious toxicity to kidneys, and children are considered to be a high-risk group. Lead (Pb) is suspected to induce retardation in mental development in children. Daily foods are an important source of both Cd and Pb exposure for general population. Nevertheless, data on dietary exposure of children to Cd and Pb are still scarce in Japan. OBJECTIVES: This study was initiated to clarify the extent of exposure of children to Cd. Exposure to Pb, another environmental pollutant element, was also studied in combination. METHODS: Twenty-four-hour food duplicates and the first morning urine samples were collected from 296 children (159 boys and 137 girls at the ages of 3-6 years) in 15 kindergartens in Miyagi prefecture on the Pacific coast in north-east Japan; no environmental pollution with Cd has been known in the prefecture. Cd, Pb and iron in food duplicates and Cd in urine were analyzed by inductively coupled plasma-mass spectrometry. α(1)-Microglobulin (α(1)-MG) in urine was measured by the latex method. Log-normal distributions were confirmed for these analytes. RESULTS: The geometric mean (GM) values for dietary intake of Cd and Pb were 11.8 and 2.28 µg/day, or 4.20 and 0.84 µg/kg body weight/week, respectively, for total children studied. No significant difference was detected in dietary Cd and Pb intake between boys and girls of the same age (except for Pb on a µg/day basis at 6 years) as well as of all ages in combination. Trends of increase in Cd and Pb intake were observed parallel to age when calculated on a daily intake basis, but the trends disappeared after correction for body weight. No age-dependent increase was observed in α(1)-MG, despite there was an age-dependent increase in Cd. CONCLUSIONS: The dietary intake of Cd and Pb for children studied were 4.20 and 0.84 µg/kg body weight/week, respectively. International comparison of the present results with values reported in literature suggested that exposure of children in Japan was higher with regard to Cd, and lower regarding Pb, reproducing the observation in adult Japanese populations. For better health of children, efforts may be necessary to reduce high dietary exposure to Cd.

Dietary tin intake and association with canned food consumption in Japanese preschool children.

OBJECTIVES: Dietary intake of tin has seldom been studied in children although they probably have a high intake. This study was initiated to investigate dietary tin intake (Sn-D) of children in Japan. METHODS: In this study, 24-h food duplicate samples were collected from 296 preschool children in Miyagi prefecture, Japan. Sn in the samples were analyzed by inductively coupled-plasma mass spectrometry, after homogenization and wet digestion. RESULTS: Sn-D by the children was low, with 4.2 µg/day as a median. The distribution was however wide, from 0.4 µg/day up to >3 µg/day. Canned foods were the major dietary Sn source, whereas rice contributed essentially little. Sn-D among canned food consumers was 30.2 µg/day as a geometric mean (10.6 µg/day as a median), whereas Sn-D among the non-consumers of canned foods was distributed log-normally, with 3.3 µg/day as a geometric mean (2.5 µg/day as a median). Sn levels in urine did not differ between children who consumed canned foods on the day previous to urine collection and those who did not. The Sn-D was far below the provisional tolerable weekly intake (14 mg/kg body weight/week) set by the 2001 Joint FAO/WHO Expert Committee. Nevertheless, children took more Sn than adults when compared on a body-weight basis. CONCLUSIONS: Canned foods were the major source of dietary Sn intake for preschool children studied. Thus, median Sn-D was higher for the canned food consumers (10.6 µg/day) than for non-consumers of canned foods (2.5 µg/day). Sn-D by canned food-consuming children was, however, substantially lower than the provisional tolerable weekly intake. No difference was detected in Sn levels in urine between canned food-consuming and non-consuming children.

P.R4810K, a polymorphism of RNF213, the susceptibility gene for moyamoya disease, is associated with blood pressure.

BACKGROUND: Moyamoya disease-an idiopathic vascular disorder of intracranial arteries-is often accompanied by hypertension. RNF213 has been identified as a susceptibility gene for moyamoya disease. In the present study, the association of p.R4810K (G>A) with blood pressure (BP) was investigated in a Japanese population. METHODOLOGY/PRINCIPAL FINDINGS: Three independent study populations, the Nyukawa (n = 984), Noshiro (n = 2,443) and Field (n = 881) studies, joined this study. BP, body weight and height were measured. Past and present symptoms and disease and medication histories were assessed by interview. Associations of p.R4810K (rs112735431, ss179362673) of RNF213 with BP were investigated. Two linkage disequilibrium blocks were constructed for moyamoya patients with p.R4810K (n = 140) and the general population (n = 384) using 39 single nucleotide polymorphisms (SNPs) spanning 390 kb around RNF213. A total of 60 carriers (3 for AA genotype and 57 for GA genotype) were found in these samples, and the minor allele frequencies were 1.4 % in the Nyukawa and Field studies and 0.2 % in the Noshiro study. Regression analyses adjusted for age, sex and body mass index based on an additive model demonstrated significant associations with systolic BP (mmHg/allele): ß (standard error) was 8.2 (2.9) in the Nyukawa study (P = 4.7 × 10(-3)), 18.7 (5.4) in the Noshiro study (P = 4.6 × 10(-4)) and 8.9 (2.0) (P = 1.0 × 10(-5)) in the three populations. In contrast, diastolic BP showed significant associations only in the Noshiro study. Linkage disequilibrium blocks contained none of the BP-associated proxy SNPs reported by previous studies. CONCLUSIONS/SIGNIFICANCE: Our study suggests that p.R4810K of RNF213 is associated strongly with systolic BP.

Correlation of light transmittance with asthma attack: fine water particles as a possible inducing factor of asthma.

BACKGROUND AND OBJECTIVES: It has been postulated that air-borne fine water particles (or mist) can induce asthma attacks in asthmatic children. To date, no attempt has been made to quantify the density of air-borne fine water particles with the aim of relating particle density to the etiology of asthma among children. The aim of this study was to investigate the relation of asthma attack frequency and the particle density evaluated in terms of light transmittance. METHODS: The density of fine water particles was quantified by measuring reductions in light transmittance at 250, 365 and 580 nm at an outdoor location when the surroundings were in darkness. The measurements were made at distances varying from 1 to 3 m from the light sources and performed every morning and evening for 1 year. Each day was separated into two half-day units [i.e., morning (from midnight to noon) and afternoon (from noon to midnight)]. The number of asthma attacks among 121 enrolled asthmatic children was counted for each unit. A possible correlation between the transmittance reduction and frequency of asthma attacks was assessed. RESULTS: A significant difference was observed in the extent of reduction in light transmittance at 365 nm between the units with asthma attacks and those without attacks. Furthermore, the reduction in the transmittance was more evident when more asthma attacks were recorded among the patients. No difference was detected in the reduction in light transmittance at 250 or 580 nm. CONCLUSIONS: These results support the hypothesis that air-borne fine water particles are among the etiological factors that induce asthma attacks in asthmatic children.

Past, present, and future of environmental specimen banks.

Environmental specimen banks are an essential part of the infrastructure of environmental sciences. They have various functions: (1) evaluation of governmental environmental policy-making and regulations; (2) a resource for animal health evaluation; (3) research tools to investigate time trends in ecosystems; (4) detection of newly emerging chemicals in the time trends; (5) validations of computer models for environmental phenomena; (6) source identification of contaminants; (7) a tool for food safety; (8) evaluation of genetic selection pressure due to environmental changes. In this review paper, we present a detailed description of the Kyoto University Human Specimen Bank (history, protocol and questionnaires) and provide brief outlines of other representative environmental specimen banks. We then review two illustrative cases in which environmental specimen banks have unveiled insidious contaminations of polybrominated diphenyl ethers and perfluorooctanoic acids. Finally, we give a perspective of new functions for environmental specimen banks in the next 20 years.

Estimation of dietary intake of cadmium from cadmium in blood or urine in East Asia.

BACKGROUND AND AIM: Cadmium (Cd) is an ubiquitous environmental toxic pollutant. As daily foods are an almost exclusive source of exposure for general populations, it is of public health importance to know the level of dietary intake of cadmium (Cd-D). The purpose of this study is to examine whether Cd in blood (Cd-B) or urine (Cd-U) correlates with Cd-D in East Asia, and in case it is, whether it is possible to estimate Cd-D from Cd-B or Cd-U. It should be added that the measurement of Cd-D is quite hand-consuming in practice. MATERIALS AND METHODS: Literature was retrieved for publication on Cd-B and Cd-U in combination with Cd-D. Twenty three data sets thus obtained for East Asia were subjected to regression analysis to investigate the possibility to estimate Cd-D from Cd-B or Cd-U. RESULTS: In Japan and Korea, large correlation coefficients (p > 0.7) were observed between Cd-B and Cd-D, as well as between Cd-U and Cd-D. In China, the coefficient was >0.7 between Cd-B and Cd-D. Furthermore, correlation was significant for Cd-B and Cd-D, as well as Cd-U and Cd-D, when 19 sets for Japan, Korea and China were combined for analysis. DISCUSSION: Major reasons for successful analysis may be predominant use of women-based data. Women have been less smoking than men in East Asia, and possible confounding effects of smoking on Cd exposure might be minimized. CONCLUSION: Based on significant correlations, Cd-D can be estimated from Cd-B or Cd-U in East Asia.

Historical and geographical aspects of the increasing perfluorooctanoate and perfluorooctane sulfonate contamination in human serum in Japan.

Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) have recently received attention due to their widespread contamination in the environment, as well as in wildlife and humans. We measured the PFOS and PFOA concentrations in historically recorded human serum samples at an age range between 20 and 59 years collected in Kyoto, 20 persons per each time point (n=100), and also the PFOS and PFOA concentrations in human serum samples at an age range between 20 and 59 years from 10 locations throughout Japan (n=200). The historical samples collected from 1983 to 1999 demonstrated that the PFOA concentrations in males and females from Kyoto have increased 4.4-fold and 4.3-fold at a rate of increase of 0.49 ng/ml/year and 0.42 ng/ml/year, respectively. In contrast, serum concentrations of PFOS reached a plateau in the late 1980s. There are also regional differences in both the PFOS and PFOA serum concentrations. The concentrations in serum [geometric mean (geometric standard deviation)] (ng/ml) in 2003-2004 ranged from 7.6(1.6) in the town of Matsuoka in Fukui prefecture to 27.8(1.6) in Kyoto city, and ranged from 2.3(1.5) in Matsuoka to 14.5(1.3) in Osaka city for PFOS and PFOA, respectively.

Large-scale evaluation of the current level of polybrominated diphenyl ethers (PBDEs) in breast milk from 13 regions of Japan.

Polybrominated diphenyl ethers (PBDEs) were measured in 2004 in 105 breast milk samples collected from 13 regions of Japan (Hokkaido, Akita, Miyagi, Tokyo, Gifu, Fukui, Kyoto, Hyogo, Wakayama, Shimane, Yamaguchi, Kochi and Okinawa). Six congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153 and BDE-154) were determined by gas chromatography /mass spectrometry (GC/MS). Total PBDE levels ranged from 0.01 to 23.0 ng/g lipid (geometric mean (GM), 1.34 ng/g lipid). BDE-47 (GM, 0.66 ng/g lipid, 59% of sigmaPBDE) was the most abundant congener present in breast milk and was detected in 99% of the samples. Total PBDE levels were higher in northern Japan than in other regions. We analyzed the effects of occupation, age, smoking status, alcohol consumption and number of deliveries on total PBDE levels. None of these factors were significantly associated with the level of PBDEs. The present study revealed that the current level of exposure to PBDEs in Japan is lower than that in the USA or Sweden. GMs (ng/g lipid) (GSD, geometric standard deviation) and medians (ng/g lipid) of PBDE levels in each district are as follows: Hokkaido 2.70 (1.70), 2.74; Akita 4.49 (2.19), 5.44; Miyagi 1.77 (4.37), 1.11; Tokyo 1.39 (2.09), 1.63, Gifu 2.83 (4.79), 2.23; Fukui 1.05 (2.34), 1.18; Kyoto 1.31 (2.95), 1.33; Hyogo 1.02 (2.69), 0.88; Wakayama 1.33 (3.80), 1.70; Shimane 0.83 (2.51), 0.66; Yamaguchi 1.74 (2.82), 1.76; Kochi 0.50 (2.69), 0.74 and Okinawa 1.91 (2.75), 1.22. This is the first large-scale study of current PBDE levels in breast milk in Japan.

[How much does partially hydrolyzed guar gum affect the weight, moisture and hardness of feces?].

OBJECTIVE: The ministry of Health, Labor and Welfare recommends Japanese people to intake a certain amount of dietary fiber, believing that incorporating more dietary fiber into our diet can reduce the risk of colorectal cancer. The present study aimed to demonstrate and confirm the theory's validity by applying it to reality-to what extent is the intake of partially hydrolyzed guar gum (PHGG) useful in promoting bowel movements, and what problems are involved? We therefore investigated to what extent PHGG affects the weight, moisture and hardness of feces when healthy female students consumed PHGG as a supplement. METHOD: During two fourteen-day sessions in spring and autumn, 9 healthy female students took the same diets. During the first session, the students were provided a strict dietary formula, while during the second session, they were administered an amount of 12.5 g/day PHGG (purity 80%, equivalent to 10 g of dietary fiber) dissolved in adequate amount of water at the end of each meal. Feces of the subjects were collected and weighted just after defection. A moisture meter was used to measure fecal moisture and a rheometer was used to measure fecal hardness. Fecal conditions and intestinal motility were also examined. RESULTS: (1) Due to the PHGG intake, the fecal bulk increased in 4 subjects and decreased in 2 subjects, significantly, out of 9. (2) Due to the PHGG intake, the fecal condition softened in 3 subjects while significantly hardening in 4 subjects. (3) The PHGG intake induced an increased of fecal moisture in 5 subjects, while moisture decreased in 2 subjects. (4) Fecal hardness measured more than 150 g/cm when it is classified as "frozen hard". (5) A significant inverse correlation could be seen between fecal hardness and fecal bulk, and between fecal hardness and its moisture. When PHGG was administered a significant inverse correlation could be seen between fecal hardness and its moisture. CONCLUSION: The conclusion is that the PHGG intake resulted in increase of the fecal bulk for 4 subjects and fecal moisture for 5 out of 9 subjects, but decrease of fecal hardness in 3 subjects; the benefit of bowel movements provided by the PHGG intake, however, varied greatly among the subjects.

Secular trends and geographical variations in the dietary intake of polybrominated diphenyl ethers (PBDEs) using archived samples from the early 1980s and mid 1990s in Japan.

A retrospective exposure assessment among the general population for polybrominated diphenyl ethers (PBDEs) was conducted using dietary surveys. We analyzed samples of food duplicate portions collected in the early 1980s (1980 survey: N=40) and the mid 1990s (1995 survey: N=39) from female subjects (5 participants from each of 8 sites per survey except for one site) living throughout Japan, from the north (Hokkaido) to the south (Okinawa). The study populations in the 1980 and 1995 surveys were different, but lived in the same communities. We measured four PBDE congeners [2,2',4,4'-tetrabrominated diphenyl ether (tetraBDE): #47; 2,2',4,4',5-pentaBDE: #99; 2,2',4,4',6-pentaBDE: #100; and 2,2',4,4',5,5'-hexaBDE: #153] in the diet. #99 was the most abundant congener in the diet (49% of the total PBDEs), followed by #47 (33%), #100 (12%) and #153 (6%). Regional variations found in the 1980 survey decreased in the 1995 survey. The total daily intake of PBDEs (ng/d) [GM (GSD)] in the 1980 survey [91.4 (4.1)] was not significantly different from that in the 1995 survey [93.8 (3.4)] for the total population, nor did it differ among the sites including Shimane, in which a 20-fold increase in serum concentrations was observed in the same population1). In consideration of the significant increases in the serum concentration, inhalation may be more important than food ingestion as the route of human exposure to PBDEs.

Rice as the most influential source of cadmium intake among general Japanese population.

The objective of the present study is to examine whether rice is still a leading source of cadmium (Cd) burden among general populations in Japan. For this purpose, 10 prefectures were selected from all over Japan (including the northern- and southern-most Hokkaido and Okinawa prefecture, respectively). Cadmium levels in urine of never-smoking women (corrected for creatinine; Cd-Ucr) were compared with the rice- and wheat product-based Cd intake, which were estimated from Cd contents in rice and wheat (in the forms of bread, noodle and flour) consumed by residents in the areas, and per-capita daily consumption of rice and wheat. Stepwise multiple regression analysis taking Cd-Ucr as a dependent variable and rice- or wheat product-based Cd intakes as independent variables showed that rice was the most influential and almost exclusive variable with a partial correlation coefficient of 0.770-0.832, explaining 59-69% of total variation in Cd-Ucr. The effects of other sources including wheat were essentially negligible.

Applicability of food composition tables as a tool to estimate mineral and trace element intake of pre-school children in Japan: a validation study.

Because dietary intakes of some minerals (including trace elements), especially iron (Fe), are insufficient for the needs of the general Japanese population, accurate estimation of mineral intake is important. This capability is especially necessary to preserve the health of Japanese children. Therefore, the current version of food composition tables (FCT) in Japan was evaluated for validity as tools to estimate dietary intake of minerals for children. For this purpose, 24h food duplicate samples were collected from 292 pre-school children in Miyagi prefecture, Japan. From the weights of items and food codes, intakes of nine minerals were estimated taking advantage of the FCT. In parallel, amounts of minerals in each duplicate samples were instrumentally measured by ICP-AES for Ca, Cu, Fe, Mg, Mn, P and Zn, and by flame AAS for K and Na, both after wet-ashing. The distributions of the mineral amounts were essentially normal. The comparison of the FCT-based estimates (E) and instrumental measures (M) showed that the E/M ratio was close to 1 for Ca, K, Mn, P and Zn, suggesting that E may be a surrogate of M for Ca, K, Mn, P and Zn on a group basis. The ratio being larger than 1.2 for Cu, Fe, Mg and Na indicates that a risk of over-estimation exists when E is relied upon in place of M. On an individual basis, significant differences were detected for all 9 minerals suggesting that the use of E as a surrogate for M should be practiced with care for the estimation of mineral intake.

Estimation of dietary Pb and Cd intake from Pb and Cd in blood or urine.

Successful trials were made to estimate the dietary daily intake of lead (Pb) and cadmium (Cd) via foods from the levels of the metals in blood or urine. In practice, 14 and 15 reports were available for Pb and Cd in blood (Pb-B and Cd-B), urine (Pb-U and Cd-U) and 24-h diet duplicates (Pb-D and Cd-D), respectively, from which 68 pairs each of Pb or Cd in blood and food duplicates [each being geometric mean (GM) values for the survey sites] were obtained. Regression analysis revealed that there was a significant correlation between Pb-B and Pb-D, and also between Cd-B and Cd-D, suggesting that it should be possible to estimate both Pb-D and Cd-D from Pb-B and Cd-B, respectively. For Cd-U, the number of available cases was limited (20 pairs), but a significant correlation was detected between Cd-U (as Cd-U(cr), or Cd levels in urine as corrected for creatinine concentration) and Cd-D. Care should be taken in estimating Pb-D from Pb-B, as the ratio of Pb-D over Pb-B may decrease as a function of increasing Pb-B levels. The Pb-D (µg/day) for typical Japanese women with Pb-B of 15 µg/l was best estimated to be 13.5 µg/day. No Cd-B- or Cd-U(cr)-dependent change was detected in case of Cd. The best estimate of Cd-D for Cd-B at 1.5 µg/l should be about 19.4 µg/day.

Effects of variations in cadmium and lead levels in river sediments on local foods and body burden of local residents in non-polluted areas in Japan.

This study was initiated to examine if variations in the concentrations of cadmium (Cd) and lead (Pb) in water environment may affect metal levels in local foods and body burden of local residents in non-polluted areas in Japan. Two nationwide databases have been made available on concentrations of Cd in locally harvested brown rice and of Cd and Pb in sediments in local river beds. These data were combined with published data on metal concentrations in polished rice, food duplicates, and blood and urine from the residents. Cd in river sediments correlated significantly with those in brown rice, food duplicates, blood, and urine. Cd in food duplicates correlated with Cd in rice. In contrast, Pb concentrations in the river sediments either did not correlate or correlated only weakly with Pb in biological materials or food duplicates. Possible implication of the different behavior between Cd and Pb regarding the intensity of correlation was discussed with reference to the different routes of exposure to the elements. In conclusions, the Cd body burden on local residents in Japan is significantly influenced by Cd levels in water in the general environment, whereas water-borne Pb did not show clear correlation with the Pb body burden.

Paradoxical increases in serum levels of highly chlorinated PCBs in aged women in clear contrast to robust decreases in dietary intakes from 1980 to 2003 in Japan.

OBJECTIVE: Exposure to polychlorinated biphenyls (PCBs) is considered to have culminated between 1950 and 1970 in Japan, and exposure through diet, the major exposure route, has decreased significantly over the last 10 years. The primary goal of the present study was to investigate the long-term trends and congener profiles of serum and dietary levels of PCBs using historical samples. METHODS: Using banked samples collected in 1980, 1995, and 2003 surveys, we determined the daily intakes and serum concentrations of 13 PCB congeners (#74, #99, #118, #138, #146, #153, #156, #163, #164, #170, #180, #182, and #187) in women. RESULTS: The total daily PCB intake [ng/day, geometric mean (geometric standard deviation)] decreased significantly from 523 (2.5) in 1980 to 63 (3.2) in 2003. The serum total PCB level (ng/g lipid) in women <40 years of age decreased significantly from 185 (1.8) in 1980 to 68 (1.8) in 2003. In contrast, the level in women >50 years of age increased significantly from 125 (1.7) in 1980 to 242 (1.7) in 2003. Specifically, the serum concentrations of hexa (#138, #146, #153, #156, #163, and #164) and hepta (#170, #180, #182, and #187) congeners increased significantly. A comparison of the serum PCB levels of women born from 1940 to 1953 revealed that their serum total PCB level was significantly higher in the 2003 survey [242 (1.7), n = 9] than in the 1995 [128 (2.0), n = 17] surveys. This increase in the total PCB level was attributable to increases in the hepta congener groups. CONCLUSION: Present results suggest a decreased rate of elimination of hepta congeners with aging in females, rather than a birth-generation phenomenon.