Fallout 3H in human tissue at Akita, Japan

The 3H concentration in Japanese human tissue samples is reported in this paper. Four brain, 10 liver, and nine lung samples from 11 cases were collected from Akita Prefecture in northern Japan from January to July 1986. The median of free-water 3H concentration was similar in these tissues and agreed well with the concentrations in the diet, including tap water. The median specific activity ratio of tissue-bound 3H to free-water 3H was 1.1 and was slightly lower than that in the diet. The specific activity ratio was also lower than that reported in the United States and significantly lower than in Italy.     

Further study on fallout 3H ingestion in Akita, Japan

To study fallout 3H ingestion in Japan, 16 separate food-group samples were collected from Akita City in northern Japan during early summer and late autumn in 1986. Furthermore, total diet samples which are duplicate composite food samples consumed by five or six persons for a period of 1 d were also obtained in Akita City. The 3H concentration in free water and that in a tissue-bound form were determined separately. Seasonal changes of 3H concentration in the food samples and the total diet samples were not found clearly. The average 3H concentration in the free water including tap water was 1.6 Bq L-1. The mean ratio of specific activity of tissue-bound 3H to that of 3H in free water was found to be 1.2. The average total 3H ingestion was estimated to be 4.0 Bq d-1, while the proportion of tissue-bound form 3H ingestion to total 3H ingestion was 11%. Cereal was the greatest contributing food group to ingestion of tissue-bound 3H. These findings were consistent with our previous results for food samples collected in 1985.     

Tritium concentration in Japanese rice

Polished rice samples harvested in 1985 were collected from 25 prefectures throughout Japan. Concentrations of both tissue free water tritium (TFWT) and organically bound tritium (OBT) were determined. Nearly uniform distribution of the TFWT and OBT concentrations was observed in Japan, taking into account a relatively large counting error. The average values for all Japanese polished rice were 2.69 +/- 0.74 Bq/L for the TFWT concentration, 2.01 +/- 0.78 Bq/L for the OBT concentration and 0.83 +/- 0.32 for the specific activity ratio. The TFWT concentration was within the range of tritium concentration of the land water reported by other researchers. The specific activity ratio below unity also confirmed by analyses of the 4 Chinese polished rice samples suggests that OBT in the rice is not equilibrated with TFWT or HTO in the environment because of isotope discrimination.     

Fallout 3H ingestion in Akita, Japan

To study fallout 3H ingestion in Japan, 16 separate food group samples were collected from Akita during 1985. The 3H concentration in free water and that in a tissue-bound form were determined separately. The average 3H concentration in the tissue-bound form was 2.2 Bq L-1, 1.7 times higher than in the free water of the food. The ingestions of 3H in the tissue-bound form and as free water in the diet were 0.60 Bq d-1 and 1.0 Bq d-1, respectively. Cereals represented the food group that contributed the most to the ingestion of tissue-bound 3H. Total 3H ingestion was estimated to be 4.1 Bq d-1. The contribution of the tissue-bound form to the total ingestion was 15%, considerably lower than reported for Italian diets. The ratio of 3H ingestion in the tissue-bound form to the free water form in the diet was similar to the ratio reported for New York City.     

Dose contribution from metabolized organically bound tritium after chronic tritiated water intakes in humans

Our earlier study of acute tritiated water intakes in humans has demonstrated that the dose contribution from metabolized organically bound tritium is less than 10% of the body water dose. To further demonstrate that the dose contribution from the organically bound tritium per unit intake of tritiated water is the same, regardless of whether the intake is acute (all at once) or chronic (spread over time), urine samples from six male radiation workers with chronic tritiated water intakes were collected and analyzed for tritium. These workers have a well-documented dose history and a well-controlled tritium bioassay database, providing assurance that their tritium intakes were in the form of tritiated water. Each month for a full calendar year, urine samples were collected from each exposed worker. The monthly concentration of tritiumin-urine for each exposed worker was no lower than 10(4) Bq L(-1) but no higher than 10(5) Bq L(-1). These urine samples were analyzed for tritiated water and organically bound tritium to determine the ratio of these tritiated species in urine. The average ratio of tritiated water to organically bound tritium in urine for each exposed worker was 330 +/- 129 (range, 297-589). In calculating the dose to these workers, we assumed that, under steady-state conditions, the ratio of the specific activity of tritium (3H activity per gH) in the organic matter and water fractions of urine is representative of the ratio of the specific activity of tritium in the organic matter and water fractions of soft tissue. A mathematical model was developed and used to estimate the dose increase from the metabolized organically bound tritium based on the ratio of tritiated water to organically bound tritium in urine. The resulting average dose from the organically bound tritium was 6.9 +/- 3.1% (range, 4.7-9.9%) of the body water dose for the six male workers, and agrees well with the value obtained from our acute tritiated water intakes study in humans. The observed dose contribution from organically bound tritium, relative to body water dose, is in agreement with current recommendations of assigning 10% of total body water dose for organically bound tritium in soft tissues after tritiated water intakes.     

Radiation dose to mouse liver cells from ingestion of tritiated food or water

Tritium incorporated into tissues and DNA of mice was studied after daily ingestion of tritiated food or tritiated water. The tritiated food used was a commercial preparation mixed with brine shrimp that had been reared in tritiated sea water. After ingestion of tritiated food or water for up to 22 d, the specific activity of 3H in tissues was measured as tissue-free-water 3H, tissue-bound 3H, and DNA-bound 3H. Carbon-14 glucose was added to food and drinking water to compare the 3H intake from food with that from water. The specific activity of 3H in tissues was then corrected by the specific activity of 14C in tissues to determine the 3H incorporation from the same amount of ingested food and water. DNA-bound 3H after the ingestion of tritiated food was 4.6 times higher than that of tritiated water, while tissue-bound 3H was 2.2 times higher. The radiation dose to liver from 3H incorporated through food was twofold higher than from tritiated water, which was mainly from the high incorporation of 3H into DNA. Our results demonstrated that the dose calculation based on tissue-free-water 3H alone would under-estimate the radiation exposure of the human population exposed to tritiated food.     

Free water 3H concentration in diet samples collected from 1969 to 1988 in Akita, Japan

Fallout 3H concentrations in diet samples collected from 1969 to 1988 in Akita Prefecture are reported. Since the data for samples from the 1960's and 1970's are important to understand the long-term movement of 3H in the environment, we searched for old diet samples. Recently, diet samples collected in Akita Prefecture during 1969-1982 were found and subjected to 3H analysis. The samples were originally gathered for nutrition survey programs and had been stored in a refrigerated warehouse at -20 degrees C until we located them. The free water 3H concentrations in the samples were measured and are reported here. The present results are combined with already published data; together they show 3H concentrations exponentially decrease from 1969 to 1988 with an apparent half time of 5.9 y. Levels of diet free water 3H concentrations are also similar to measured and estimated precipitation 3H concentrations in Akita City.     

Tritium concentration in Akita City diet.

The 3H concentration in the diet of residents in Akita City, northern Japan, during autumn of 1987 and winter of 1988 was analyzed. Results were similar to those for spring and summer samples previously reported. No significant seasonal change of 3H concentration was observed. A simple model was constructed for estimating the mean residence time for organically-bound 3H in diet. However, more data about diet in the 1960s or 1970s are necessary for the estimation.     

Analysis of urine for pure beta emitters: methods and application

Bioassay for individual radionuclides is an essential and first step in estimation of radiation risk to nuclear facilities workers and people who are exposed to the contaminated environment in the event of a nuclear accident or radiological attack. Urine is a frequently used biological sample for this purpose. Tritium and (14)C are important radionuclides for workers in nuclear reactors and radiopharmaceutical laboratories. A method for the determination of tritium and (14)C in organic and inorganic forms in urine has been developed. It involves activated charcoal absorption of organic matter followed by combustion to separate tritiated water from organically-bound tritium. Inorganic (14)C from organically-bound (14)C, the separated tritium and (14)C were measured using liquid scintillation counting. Iodine-129, a long-lived beta emitter, is normally released to the atmosphere during the operation of nuclear facilities, especially in reprocessing plants. The high concentration of iodine in the thyroid makes this radionuclide an important source of exposure to exposed populations. A simple method has been developed in this work for the determination of (129)I in urine by anion exchange preconcentration, extraction purification and liquid scintillation counting. Using accelerator mass spectrometry, urine samples can be analyzed for low level (129)I in both organic and inorganic forms after active charcoal adsorption and solvent extraction separation. Condensed water collected daily from the reactor hall in a Danish research reactor and monthly urine samples from the staff working in the reactor building were collected from 2003-2010 and analyzed using this method, and the results are presented and discussed.     

Fluoride concentrations in typical Brazilian foods and in infant foods

OBJECTIVE: To determine fluoride concentrations in the typical Brazilian meal (rice with beans) and in processed infant foods, and to estimate their contribution towards dental fluorosis. METHODS: The foods were purchased at supermarkets in the cities of Piracicaba and Campinas, Southeastern Brazil. The processed infant foods were bought in 2001 and the rice and beans in 2003, and they were analyzed immediately. Three brands of rice, three brands of beans and 36 samples of infant foods were analyzed, divided into five groups: ready-to-eat, porridges, formulated foods, powdered milk and others. For the rice and beans, fluoride concentrations were determined in the raw grains and after they were cooked with fluoridated (0.7 ppm) or distilled water. All the fluoride analyses were performed using a specific electrode. A dose of 0.07 mg/kg/day was considered to be the upper limit of fluoride exposure in terms of fluorosis risks. RESULTS: The fluoride concentrations found in the grains of rice and beans were low. However, they increased 100 to 200-fold after cooking in fluoridated water. Even so, they were lower than what is found in some processed foods. A meal of rice and beans prepared with fluoridated water would be responsible for 29% of the threshold dose for fluoride intake in terms of acceptable fluorosis; the contribution from some processed foods reaches 45%. CONCLUSIONS: The typical Brazilian food, even when prepared with fluoridated water, is safer in terms of the risk of dental fluorosis than are some processed infant foods.     

南京市环境介质及食品放射性水平监测与分析

目的 通过对南京市饮用水、气溶胶及市售食品中总α和总β放射性水平监测和分析,掌握本市环境介质和食品中总α和总β放射性水平.方法 采集水源水、出厂水、气溶胶、鸡肉、猪肉、茎菜、根菜、生鲜牛乳、叶菜、面粉、水果、大米、茶叶、鱼及螃蟹15种样品,将样品进行前处理后,用LB4008型四路低本底αβ测量仪测定总α和总β活度浓度....     

苏南农村地区土壤、大米和井水重金属污染现状

摘要:目的 了解苏南农村地区土壤、大米等重金属污染情况。方法 采用分层整群抽样方法,在苏南农村东、南、西、北、中5个方位及市区采集环境及食物样品,用ICP-MS检测其中重金属含量。结果 18份土壤样品重金属Cd、As、Pb平均含量为（1.150±0.860）mg/kg,（46.232±40.313）mg/kg,（55.855±32.690）mg/kg,超标率分别达77.78%、38.89%和27.78%,Cr、Hg含量均低于限值;内梅罗污染指数评价显示,苏南农村土壤整体达轻度污染,其中2、5号点土壤达重污染,1号点达中污染,其余各点土壤重金属污染已处警戒范围。井水、大米中重金属低于GB5749-2006和GB2715-2005标准限量。结论 苏南农村地区井水、大米尚未受Cd、As、Pb、Cr、Hg 5种重金属污染,但土壤已不同程度受到Cd、As、Pb污染,Cd＞As＞Pb,应引起重视。     

Tritium dynamics in juvenile rainbow trout, Salmo gairdneri

Juvenile rainbow trout, Salmo gairdneri, were maintained in tritiated water, fed a tritiated diet or both, and the specific activity of 3H in the fish was determined during and following 3H exposure. Tissue water 3H-equilibrated rapidly with the ambient water (estimated half-life less than 30 min) and maintained a steady-state specific activity similar to ambient. In contrast, the steady-state specific activity of organically bound 3H was significantly affected by that of the diet. The steady-state specific activity of organically bound 3H of trout maintained in tritiated water but fed non-tritiated diets was approximately 20% of that of the ambient water. This steady-state specific activity was achieved relatively quickly (half-life approximately 1 d) and presumably reflects the exchangeable H of the fish. For trout fed a tritiated diet, in either tritiated or non-tritiated water, steady-state specific activities of organically bound 3H were on the order of 80% of that of the diet. These steady-state specific activities were reached much more slowly (estimated half-lives of 18-32 d) and are likely to represent the accumulation of non-exchangeable 3H in the organic material of the trout.     

Free water 3H concentrations in serum samples collected during 1969-1992 in Akita,Japan

The measurements for human and environmental samples from the 1960's and 1970's are important to understand the long-term transfer of 3H from the environment to the human body. The authors have previously reported 3H concentrations in diet samples collected in Akita Prefecture during 1969-1988. Serum samples from persons living in Akita Prefecture during 1969-1992 were recently obtained. The samples were originally gathered for medical examinations and stored in freezers at -20 degrees C. Composite samples from 100 persons on average were made for analysis. The free water 3H (FWT) concentrations in those samples were determined and compared with 3H concentrations in diet samples and precipitation. The long-term variation pattern of the FWT concentrations in the serum samples was similar to patterns in the diet samples and precipitation, but the FWT concentrations in the serum samples were slightly higher than those in the latter two. A single compartment model calculation showed that the apparent mean residence time of serum FWT was 1.4 y using precipitation as an input to the compartment.     

武汉市外环境中禽流行性感冒病毒分布及禽类职业暴露人群H5N1抗体水平调查

目的 监测武汉市外环境中禽流行性感冒(简称禽流感)病毒的分布情况,了解禽类职业暴露人群高致病性禽流感病毒(H5N1)的感染状况.方法 2010年从3个野生候鸟柄息地和5个城乡活禽市场采集78份外环境标本(水、禽类粪便及笼具表面标本),从13个禽流感监测点采集禽类职业暴露人群的血清标本249份.采用实时荧光定量RT-PCR方法,对禽流感外环境标本进行甲型流感病毒检测,对于甲型流感病毒阳性的标本,进一步采用多重RT-PCR方法,进行H3、H5、H7、H9亚型禽流感病毒分型.采用马红细胞凝集抑制试验和2种禽流感灭活抗原(A/Hubei/1/10和A/Anhui/1/05)对职业暴露人群血清中高致病性禽流感H5N1抗体水平进行检测.结果 采自城乡活禽市场的50份外环境标本中,17份(34.0％)为甲型流感病毒阳性,其中H5亚型单纯阳性标本4份,H9亚型单纯阳性标本3份,H3、H5亚型混合阳性标本4份,H3、H9亚型混合阳性标本2份,H5、H9亚型混合阳性标本2份,H3、H5、H9亚型混合阳性标本2份,未检测到H7阳性标本.采自野生候鸟栖息地的28份外环境标本,未检测到甲型流感病毒阳性标本.不同类型外环境标本甲型流感病毒阳性率分别为:水标本37.5％ (6/16),笼具表面标本16.7％( 5/30),粪便标本l8.8％ (6/32).对A/Hubei/1/10抗原抑制效价≥40的血清标本共100份,占标本总数的40.2％,而对A/Anhui/1/05抗原抑制效价≥40的血清标本共36份,占标本总数的14.5％,两组间差异有统计学意义(x2=41.433,P＜0.05).249份职业暴露人群血清标本中,针对A/Hubei/1/10抗原的H5N1抗体阳性标本5份(抑制效价≥160),均来自城乡活禽市场,而针对A/Anhui/1/05抗原则无H5N1抗体阳性标本.结论 武汉市城乡活禽市场内流行着多种亚型禽流感病毒,外环境禽流感病毒分布与禽类职业暴露人群H5N1抗体水平检测结果一致.     

浙江省临海市洪灾后生活饮用水水质调查分析

目的 通过监测水样,了解临海市洪灾后生活饮用水卫生情况,分析风险因素,保证灾区群众饮用水安全.方法 在洪水退后的第1 d、3 d、7 d、14 d、21 d、30 d 各采集水样若干份,依据GB/T 5750-2006《生活饮用水标准检验方法》对采集的水样进行菌落总数、总大肠菌群、色度、浑浊度、臭和味、肉眼可见物、pH...     

Effects of acute ethanol on urinary excretion of 5-methyltetrahydrofolic acid and folate derivatives in the rat

Acute ethanol treatment enhances the urinary excretion of endogenous folate. This effect has been implicated in the development of folate deficiency associated with chronic alcoholism. Previous studies have shown that urinary excretion of total [3H]-label after administration of [3H]folic acid is slightly higher in ethanol-treated rats because of conversion of the tracer to forms whose excretion is not affected by ethanol. Since [3H]folic acid is not the physiological substrate for the kidney, studies were performed using a high specific activity 5-methyltetrahydrofolic acid ([3H]5-CH3-H4 folic acid). Male Sprague-Dawley rats were given four consecutive hourly doses of ethanol at 1 g/kg, followed by infusion of [3H]5-CH3-H4 folic acid at 5 h. Urine samples were collected to 6 h, when rats were killed, and plasma, liver and kidney samples were collected. Endogenous urinary folate excretion and the fractional urinary excretion of both endogenous and [3H]5-CH3-H4 folic acid at the 5-6 h time period were significantly higher in ethanol-treated rats. The kidney had a tenfold greater specific incorporation of [3H]-label than did the liver. High performance liquid chromatography (HPLC) analysis of the plasma obtained at 6 h showed that 68% of the label was [3H]5-CH3-H4 folic acid, and HPLC analysis of the urine obtained from 5-6 h showed that only 10% of the label was [3H]5-CH3-H4 folic acid. The data indicate that [3H]5-CH3-H4 folic acid was rapidly taken up by the kidney and metabolized to other folate and nonfolate forms, which were then secreted into the renal tubule for excretion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evidence suggesting that difructose anhydride III is an indigestible and low fermentable sugar during the early stages after ingestion in humans

We investigated the influences of difructose anhydride III (DFAIII), a novel commercially available disaccharide, on sugar metabolism, breath hydrogen and serum acetate in the early stages after ingestion to determine whether DFAIII is an indigestible sugar and to what degree it is fermentable in humans. This study was designed as a randomized controlled single-blind crossover test with 9 healthy subjects, who drink a 200 mL water solution containing 10 g of DFAIII, lactulose or sucrose following overnight fasting. Blood samples (for analysis of glucose, fructose, insulin, triacylglycerol, free fatty acids, and acetate) were collected at 0, 0.5, 1, 2, 4, 8 h after the ingestion and breath samples (for analysis of hydrogen and methane gases) were collected at 1 h intervals until 8 h after the ingestion. We also interviewed each subject hourly about the incidence and severity of specific abdominal complaints and other symptoms. The results revealed that ingestion of 10 g of DFAIII did not change the serum levels of glucose, fructose, and insulin, similarly to the case with lactulose, and no increase in breath hydrogen excretion was comparable to the case with sucrose. The incidence of specific abdominal symptoms tended to be lower after DFAIII ingestion than after lactulose ingestion. It thus turned out that DFAIII was indigestible and low fermentable in the early stages after ingestion.     

Bioaccumulation factor for 32P measured in bluegill, Lepomis macrochirus, and catfish, Ictalurus punctatus

The ratio of the bioaccumulation factors for 32P and phosphorus was determined for edible tissue in two species of freshwater fish by measuring the specific activity (32P activity per milligram phosphorus) in muscle relative to feed. The 32P tracer was added to the feed at a uniform level throughout the study. Feeding was at two levels: ad libitum and at a lower but constant intake per body weight. In the main experiment, bluegill were maintained in a large flow-through tank and sacrificed at approximately weekly intervals for 51 d of 32P accumulation and 28 d of depuration to compare the specific activity with values predicted with a calculational model. In experiments performed in smaller aquaria, the specific activity in bluegill and catfish muscle was compared at two feeding levels and two temperatures. In addition, unfed fish were exposed to 32P in water at a known specific activity to determine the extent of phosphorus uptake directly from water. The pattern of specific activity increase and decrease in fish muscle during the accumulation/depuration experiment was consistent with a one-compartment model, so that specific activity ratios at steady state could be predicted from measurements during relatively brief exposures. On this basis, the ratio of the bioaccumulation factors of 32P and phosphorus in fish feeding ad libitum was 0.081 for bluegill and 0.17 for catfish. Hence, at a mean phosphorus bioaccumulation factor of 70,000, the factors for 32P are 6,000 and 12,000, respectively. The ratios were less at lower phosphorus intakes associated with lower feeding rates; moreover, the lesser value for bluegill occurred at a much lower phosphorus intake than by catfish. The bioaccumulation factor ratio was lower by an order of magnitude at a water temperature of 11 degrees C than at 16-27 degrees C, and was lower by two orders of magnitude when phosphorus uptake was from water by unfed fish.     

Modeled concentrations in rice and ingestion doses from chronic atmospheric releases of tritium

The expansion of nuclear power programs in Asia has stimulated interest in the improved modeling of concentrations of tritium in rice, a staple crop grown throughout the far east. Normally, the specific activity model is used to calculate concentrations of tritium in the tissue water of edible plants to assess ingestion dose from chronic releases. However, because rice, like other grains, has much lower water content than most crops, the calculation must also account for organically bound tritium. This paper reviews ways to calculate steady-state concentrations of tritium in rice, including the methods of Canadian and United States regulatory models, and the assumptions behind them. Concentrations in rice and resulting ingestion doses are compared for the various methods, and equations for calculating concentrations are recommended. The regulatory models underestimate doses received from ingestion of rice contaminated with tritium since they do not account explicitly for organically bound tritium. The importance of including organically bound tritium is illustrated in a comparison of doses from rice, leafy vegetables and milk for an Asian diet. Dose factors from tritium for these foods are estimated to be 135, 47, and 20 nSv y(-1)/(Bq m(-3)), respectively. Assuming known air concentrations, tritium concentrations in rice, calculated with the recommended equations, are uncertain by less than a factor 2 when tritium concentrations in the rice paddy water are known, and by less than a factor of 2.3 when concentrations in paddy water are unknown.