Concentrations of 137Cs and 40K in mushrooms consumed in Japan and radiation dose as a result of their dietary intake

Mushrooms are known to accumulate radiocesium. To estimate the intake of radiocesium through the eating of mushrooms, about 30 samples belonging to 4 commonly consumed species (Lentinula edodes, Hypsizigus marmoreus, Grifola frondosa, and Tricholoma matsutake), were analyzed for (137)Cs and (40)K. The concentration ranges were 0.060-29 Bq kg(-1) (wet wt) for (137)Cs and 38-300 Bq kg(-1) (wet wt) for (40)K. The geometric mean concentration for (137)Cs was 0.56 Bq kg(-1) (wet wt), and the mean concentration for (40)K was 92 Bq kg(-1) (wet wt). The (137)Cs concentrations in L. edodes cultivated in mushroom beds (sawdust-rice bran media) were lower than those cultivated on bed logs (natural wood with bark). The annual intake of (137)Cs per person through mushrooms was calculated, by using the current analytical results and food consumption data in Japan, to be 3.1 Bq for (137)Cs, which is about 28% of the total dietary intake of this nuclide. The effective dose equivalent of (137)Cs through mushrooms was estimated to be 4.0 currency 10(-8) Sv, which is about the half the value obtained in our previous study. The decrease of the (137)Cs intake through mushrooms is probably related to changes in cultivation methods in recent years, from the use of bed logs to mushroom beds.     

Natural and anthropogenic radioactivity levels and the associated radiation hazard in the soil of Oodalia Tea Estate in the hilly region of Fatickchari in Chittagong,Bangladesh

Radioactivity in the soil of a tea garden in the Fatickchari area in Chittagong, Bangladesh, was measured using a high-resolution HPGe detector. The soil samples were collected from depths of up to 20 cm beneath the soil surface. The activity concentrations of naturally occurring ²³⁸U and ²³²Th were observed to be in the range of 27 ± 7 to 53 ± 8 Bq kg⁻¹ and 36 ± 11 to 72 ± 11 Bq kg⁻¹, respectively. The activity concentration of ⁴⁰K ranged from 201 ± 78 to 672 ± 81 Bq kg⁻¹, and the highest activity of fallout ¹³⁷Cs observed was 10 ± 1 Bq kg⁻¹. The average activity concentration observed for ²³⁸U was 39 ± 8 Bq kg⁻¹, for ²³²Th was 57 ± 11 Bq kg⁻¹, for ⁴⁰K was 384 ± 79 Bq kg⁻¹ and for ¹³⁷Cs was 5 ± 0.5 Bq kg⁻¹. The radiological hazard parameters (representative level index, radium equivalent activity, outdoor and indoor dose rates, outdoor and indoor annual effective dose equivalents, and radiation hazard index) were calculated from the radioactivity in the soil.     

Radioactive trace measurements of some exported foods from the South of Brazil

Investigation of radioactive traces in foods produced and exported mainly in Paraná State, Brazil, was carried out by gamma-ray spectrometry, a non-destructive nuclear method. The redistribution of ⁴⁰K concentration during the processing of soy (Glycine max) primary products (745±9 Bq kg⁻¹ for soybean, 1473±15 Bq kg⁻¹ for soy bran, and ⩽8.8 Bq kg⁻¹ for commercial refined soy oil) was verified. The ⁴⁰K activity for all oil stages analyzed was lower than the limits of detection. Others foods such as sulfite-treated sugar, mate tea, and mint were analyzed. The activities for the natural nuclear chain (²²⁸Th and ²²⁶Ra) and the ¹³⁷Cs (artificial radionuclide) were presented.     

Assessment of radionuclides in the soil of residential areas of the Chittagong metropolitan city,Bangladesh and evaluation of associated radiological risk

Soil samples from the three residential hubs of Chittagong city, Bangladesh were analyzed using gamma spectrometry to estimate radiation hazard due to natural radioactive sources and anthropogenic nuclide ¹³⁷Cs. The activity concentration of ²²⁶Ra was found to be in the range 11–25 Bq.kg⁻¹, ²³²Th in the range 38–59 Bq.kg⁻¹ and ⁴⁰K in the range 246–414 Bq.kg⁻¹. These results were used to calculate the radiological hazard parameters including Excess of Lifetime Cancer Risk (ELCR). The estimated outdoor gamma exposure rates were 40.6–63.8 nGy.h⁻¹. The radiation hazard index (radium equivalent activity) ranged from 90–140 Bq.kg⁻¹. The average value of the ELCR was found to be 0.21 × 10⁻³, which is lower than the world average. Sporadic fallout of ¹³⁷Cs was observed with an average value of 2.0 Bq.kg⁻¹.     

β-Alanine supplementation elevates intramuscular carnosine content and attenuates fatigue in men and women similarly but does not change muscle l-histidine content

β-Alanine (BA) supplementation results in elevated intramuscular carnosine content, enhancing buffering capacity during intense exercise. Although men have greater muscle carnosine content than women, elevations still appear to occur despite high baseline levels. Recent research has suggested that BA supplementation may also reduce muscle l-histidine. Thus, the purpose of this investigation was to compare 28 days of BA (6 g·d⁻¹) supplementation in men and women on performance and muscle carnosine, l-histidine, and BA. We hypothesized that supplementation would result in similar elevations in carnosine and performance between sexes and decrease l-histidine. Twenty-six men and women were assigned either BA or placebo (PLA). At baseline, a trend toward greater carnosine (P = .069) was observed in men, and intramuscular BA content was significantly (P ≤ .05) greater in men. Statistical analysis was performed using magnitude-based inferences. Changes in muscle carnosine were likely and very likely greater after BA supplementation compared with PLA in men and women, respectively, but changes were unclear between sexes (mean sex difference: 2.50 ± 4.30 mmol·kg⁻¹ ww). The attenuation of exercise fatigue was likely greater in BA compared with PLA, but the change was unclear between sexes (mean sex difference: 14.0 ± 39.0 Nm). Changes in muscle BA following supplementation was unclear in men, likely elevated in women, but unclear between sexes (mean sex difference: 0.03 ± 0.42 mmol·kg⁻¹ ww). Changes in muscle l-histidine were unclear in men and women, and unclear between sexes (mean sex difference: 0.09 ± 0.13 mmol·kg⁻¹ ww). In conclusion, BA supplementation increased muscle carnosine and attenuated fatigue in men and women similarly but did not reduce muscle l-histidine.     

广西食品中人工核素137Cs放射性水平及健康风险评估

目的 调查和掌握广西食品中人工放射性核素¹³⁷Cs放射性水平,估算不同人群由膳食摄入所致年待积有效剂量并进行健康风险评估。方法 依据国标GB/T 16145-1995《生物样品中放射性核素的γ能谱分析方法》和国标GB/T 11713-2015《高纯锗γ能谱分析通用方法》,对广西粮食、蔬菜、海产品、淡水鱼类、禽畜肉类、茶叶和奶粉7大类202个样品进行监测分析,并对数据进行分析和比较。结果 ¹³⁷Cs的检出率为91.6%（185/202）,检出的比活度范围为0.011~0.931 Bq/kg（鲜重）。所检样品中以茶叶中¹³⁷Cs含量最高,其均值为（0.263±0.067）Bq/kg,检出范围为0.164~0.735 Bq/kg。¹³⁷Cs摄入致学龄婴儿、儿童、男青年/成年男人和女青年/成年女人的平均年待积有效剂量分别为0.141、0.189、0.251、0.152 μSv/a;人群摄入¹³⁷Cs一生癌症风险范围为（0.74~1.33）×10^-6。结论 广西食品中¹³⁷Cs放射性水平远低于国家标准限值,人群剂量负担轻微,不会对人体的健康造成影响。     

乐山市食品中放射性核素含量及其所致居民有效待积剂量当量

目的调查乐山市食品中放射性核素含量，并估算其所致居民有效待积剂量当量。方法按照国家标准规定的分析方法，采用美国ORTEC公司生产的ADCAM^TM 918型γ谱仪进行检测分析。结果对乐山市主要粮食和蔬菜进行了6种放射性核素的检测，其活度大小依次为^40K〉。^238U〉^226Ra〉。^232Th〉^235U〉^137Cs。居民从稻谷、麦类、玉米、豆类食物和蔬菜摄入天然放射性核索成年男女分别为16963．5、15800．6Bq／a，所致有效待积剂量当量202．2、158．9μSv。摄入人工放射性核素^137Cs成年男、女分别为30．9、24．0Bq／a，所致有效待积剂量当量0．883、0．802μ5v。结论乐山市主要食品中U、Th、Ra、K天然放射性核素含量及所致居民的有效待积剂量当量，相对高于国内相关调查资料报道的正常地区平均值，仍属天然辐射水平。人工放射性核素^137Cs含量在世界大气沉降范围。     

Bioconcentration of fallout 137Cs by fungi and red-backed voles (Clethrionomys gapperi)

Cesium-137 and 40K concentrations were measured in vegetation and in red-backed voles (Clethrionomys gapperi) in southeastern Manitoba, Canada, following the Chernobyl accident in 1986. Voles from wet coniferous habitats contained concentrations of 137Cs twenty- to fiftyfold higher than voles from deciduous habitats. Maximum 137Cs values were observed in autumn. Voles captured in a spruce bog at this time contained an average body burden of about 11 Bq. Concentrations in vegetation samples were similar to those found by other researchers. Overall, there was only minimal evidence of contamination attributable to Chernobyl in either vegetation or voles. The primary source of 137Cs in voles appeared to be dietary, particularly mushrooms that contained up to 74 Bq g-1 ash. Based on physiological constraints, mushrooms were the only plausible source of 137Cs in autumn diets. Elevated values at other times in coniferous areas may have been related to the consumption of epiphytic lichens. These findings suggest that fungi, or the animals that consume them, can serve as sensitive indicators of 137Cs contamination in the environment.     

Reference measurements of mercury species in seafood using isotope dilution inductively coupled plasma mass spectrometry

Species-specific isotope dilution inductively coupled plasma mass spectrometry (SS ID ICP-MS) and high-performance liquid chromatography (HPLC) were used to obtain accurate and SI traceable results for methyl mercury in seafood samples such as clam, oyster and fish homogenate. The mass fractions of (62.3 ± 2.3) μg kg⁻¹, (5.44 ± 0.36) μg kg⁻¹ and (531 ± 19) μg kg⁻¹ were obtained for MeHg (as Hg) in IAEA-461, IAEA-470 and IAEA-476, respectively. Direct isotope dilution mass spectrometry was performed for total mercury content then the content of inorganic mercury in selected samples was obtained by calculation. It was found that the content of inorganic Hg in IAEA-461, IAEA-470, and IAEA-476 was as: 328 μg kg⁻¹, 16 μg kg⁻¹, and 62 μg kg⁻¹, respectively. Mathematical modelling of analytical procedure and evaluation of all parameters influencing final results were adequate for validation of measurement procedure, establishing traceability and estimating expanded uncertainty. Developed procedures were successfully applied in the characterization process of fish homogenate candidate reference material and in the calculation of assigned values in the frame of IAEA-476 inter-laboratory comparison study. Compatibility between obtained results and those derived from the certification campaign, organized by International Atomic Energy Agency on the same sample matrix (<2.6 % difference) further validated performed ID ICP-MS protocols.     

Distribution of essential and non-essential elements in rice located in a Protected Natural Reserve “Marjal de Pego-Oliva”

Anthropogenic agronomic practices could negatively affect the agricultural soil which is the main source for inorganic arsenic (i-As) contamination in rice fields due to flooding. The presence of essential elements could be impacted by food industry units operations. The aim of this study was to evaluate the effect of husking and polishing on mineral essential elements and inorganic As species in rice from Protected Natural Reserve “Marjal de Pego-Oliva”. The amount of all studied elements was significantly affected by husking (a decrease of Ca, Na and Pb, 360 to 101 mg kg⁻¹, 202 to 46.9 mg kg^-1 and 17.9 to 5.70 μg kg⁻¹, respectively) and by polishing (a reduction of Na, Mg, P, K, Ca and Cu, 46.9–26.8 mg kg⁻¹, 1600 to 481 mg kg⁻¹, 4050 to 1530 mg kg⁻¹, 2780 to 882 mg kg⁻¹, 101 to 53.7 mg kg⁻¹, and 3600 to 2840, μg kg⁻¹, respectively).The replacement of white rice (WR) to brown rice (BR) could enhance the daily dietary intake of essential elements to reach the dietary reference values and the maximum i-As (40.9 and 44.9 i-As μg kg^-1 for BR and WR, respectively) was below the maximum level recently established by European Food Safety Agency.     

Total Mercury Content—Fish Weight Relationship in Swordfish (Xiphias gladius) Caught in the Southwest Atlantic Ocean

The total mercury content in the edible part of swordfish (Xiphias gladius) was determined in 192 specimens ranging from 10 to 412 kg, in the period January 1997–December 1999. Total mercury values between 0.04 and 2.21 mg kg⁻¹, with a mean value of 0.62±0.35 mg kg⁻¹, were obtained. Data were analyzed in two subsets. One of them, for specimens under 100 kg, yielded a mean value for total mercury content of 0.53±0.02 mg kg⁻¹, and the other, for specimens above 100 kg, had a mean value of 0.94±0.06 mg kg⁻¹. The existence of these subsets of data is related with the rate of mercury incorporation into swordfish flesh, in accordance with a potential model for total mercury bioaccumulation. Swordfish weighing below 100 kg can be considered safe for human consumption, according to international regulations.     

Preliminary assessment of ecological exposure of adult residents in Fukushima Prefecture to radioactive cesium through ingestion and inhalation

Objective

This study aims to estimate the ecological exposure of adult residents of Fukushima Prefecture to ¹³⁴cesium (Cs) and ¹³⁷Cs through ingestion and inhalation between July 2 and July 8, 2011.

Methods

Fifty-five sets of meals with tap water, each representing one person’s daily intake, were purchased in local towns in Fukushima Prefecture. Locally produced cow’s milk (21 samples) and vegetables (43 samples) were also purchased. In parallel, air sampling was conducted at 12 different sites using a high-volume sampler. Nineteen sets of control meals were collected in Kyoto in July 2011. ¹³⁴Cs and ¹³⁷Cs levels in the samples were measured using a germanium detector.

Results

Radioactivity was detected in 36 of the 55 sample meals from Fukushima, compared with one of 19 controls from Kyoto. The median estimated dose level (μSv/year) was 3.0, ranging from not detectable to 83.1. None of the cow’s milk (21) or vegetable (49) samples showed levels of contamination above the current recommended limits (Bq/kg) of 200 for milk and 500 for vegetables. The total effective dose levels by inhalation were estimated to be <3 μSv/year at nine locations, but samples at three other locations close to the edge of the 20-km radius from the crippled nuclear power plant showed higher levels of contamination (μSv/year): 14.7 at Iitate, 76.9 at Namie, and 27.7 at Katsurao.

Conclusions

Levels of exposure to ¹³⁴Cs and ¹³⁷Cs in Fukushima by ingestion and inhalation are discernible, but generally within recommended limits.

Electronic supplementary material

The online version of this article (doi:10.1007/s12199-011-0251-9) contains supplementary material, which is available to authorized users.     

Element analysis of dried figs (Ficus carica L.) from the Mediterranean areas

The minerals content of 36 dried figs samples collected from three Mediterranean areas in 2018 was presented in this study. The aim of this research was to evaluate whether the mineral elements amounts were significantly different among the production regions. Samples grown in Italy, Greece and Turkey were analyzed in this study. Samples were found to be a good source of potassium (average content between 3.5 ± 0.2 g kg⁻¹ and 8.12 ± 0.88 g kg⁻¹), calcium (between 1.46 ± 0.24 g kg⁻¹ and 4.49 ± 0.28 g kg⁻¹), magnesium (between 0.84 ± 0.04 g kg⁻¹ and 1.28 ± 0.15 g kg⁻¹), and sodium (between 0.45 ± 0.04 g kg⁻¹ and 0.70 ± 0.11 g kg⁻¹). Cadmium ad lead concentrations were always below the regulated values and below the quantification limit in all Italian samples, whereas chromium was detected in all samples from Greece (0.05 ± 0.01 mg kg⁻¹) and Turkey (0.03 ± 0.01 mg kg⁻¹), and in 65 % of samples from Italy (0.08 ± 0.02 mg kg⁻¹). Results confirm the good figs quality related to their essential trace elements content and they highlight the safety of these food products correlated to the intake of toxic elements. Furthermore, statistical analysis of the results pointed out that the mineral elements amount is significantly different among the three sample groups, hence it is possible to discriminate figs according to their geographical origin by PCA.     

Hypoenergetic feeding does not improve outcomes in critically ill patients with premorbid obesity: a post hoc analysis of a randomized controlled trial

Optimal energy goals for adult, obese critically ill surgical patients are unclear. To date, there has been little data comparing feeding regimens for obese and non-obese critically ill surgical patients and the effect on outcomes. The objective was to compare the effect of hypoenergetic and euenergetic feeding goals in critically ill obese patients on outcomes, including infection, intensive care unit length of stay, and mortality. We hypothesized that hypoenergetic feeding of patients with premorbid obesity (body mass index ≥ 30 kg•m⁻²) during critical illness does not affect clinical outcomes. Post hoc analyses were performed on critically ill surgical patients enrolled in a randomized controlled trial. Patients were randomized to receive 25-30 kcal•kg⁻¹•d⁻¹ (105-126 kJ.kg⁻¹•d⁻¹, euenergetic) or 12.5-15 kcal•kg⁻¹•d⁻¹ (52-63 kJ.kg⁻¹ •d⁻¹, hypoenergetic), with equal protein allocation (1.5 g•kg⁻¹•d⁻¹). The effect of feeding regimen on outcomes in obese and nonobese patients were assessed. Of the 83 patients, 30 (36.1%) were obese (body mass index ≥ 30 kg•m⁻²). Average energy intake differed based on feeding regimen (hypoenergetic: 982±61 vs euenergetic: 1338±92 kcal•d⁻¹, P = .02). Comparing obese and nonobese patients, there was no difference in the percentage acquiring an infection (66.7% [20/30] vs 77.4% [41/53], P = .29), intensive care unit length of stay (16.4±3.7 vs 14.3±0.9 days, P = .39), or mortality (10% [3/30] vs 7.6% [4/53], P = .7). Within the subset of obese patients, the percentage acquiring an infection (hypoenergetic: 78.9% [15/19] vs euenergetic: 45.5% [5/11], P = .11) was not affected by the feeding regimen. Within the subset of nonobese patients, there was a trend toward more infections in the euenergetic group (hypoenergetic: 63.6% [14/22] vs euenergetic: 87.1% [27/31], P = .05). Hypoenergetic feeding does not appear to affect clinical outcomes positively or negatively in critically ill patients with premorbid obesity.     

Modelling Environmental Impacts of Cesium-137 Under a Hypothetical Release of Radioactive Waste

Waste tanks at the nuclear facility located at Sellafield, UK, represent a nuclear source which could release radionuclides to the atmosphere. A model chain which combines atmospheric transport, deposition as well as riverine transport to sea has been developed to predict the riverine activity concentrations of ¹³⁷Cs. The source term was estimated to be 9 × 10⁴ TBq of ¹³⁷Cs, or 1% of the assumed total ¹³⁷Cs inventory of the HAL (Highly Active Liquid) storage tanks. Air dispersion modelling predicted ¹³⁷Cs deposition reaching 127 kBq m⁻² at the Vikedal catchment in Western Norway. Thus, the riverine transport model predicted that the activity concentration of ¹³⁷Cs in water at the river outlet could reach 9000 Bq m⁻³ in the aqueous phase and 1000 Bq kg⁻¹ in solid phase at peak level. The lake and river reaches showed different transport patterns due to the buffering effects caused by dilution and slowing down of water velocity.

     

Assessment of Natural Radioactivity in Phosphate Ore,Phosphogypsum and Soil Samples Around a Phosphate Fertilizer Plant in Nigeria

The radionuclides present in phosphate ore, phosphogypsum and soil samples in the vicinity of a phosphate fertilizer plants in Nigeria were identified and their activity concentration determined to assess the potential radiation impact on the environment due to fertilizer production. The mean activity concentration of ²³⁸U, ²³²Th, and ⁴⁰K radionuclides in phosphate ore samples were 616 ± 38.6, BDL (Below Detection Level) and 323.7 ± 57.5 Bq kg⁻¹ respectively. For the phosphogypsum, 334.8 ± 8.8, 4.0 ± 1.4, and 199.9 ± 9.3 Bq kg⁻¹ respectively and for soil samples range from 20.5 ± 7.3 to 175.7 ± 10.5 Bq kg⁻¹ for ²²⁶Ra, 15.5 ± 1.5 to 50.4 ± 0.6 Bq kg⁻¹ for ²³²Th and 89.5 ± 8.1 to 316.1 ± 41.3 Bq kg⁻¹ for ⁴⁰K respectively. The mean absorbed dose rate was 71.4 nGy h⁻¹. The mean annual effective dose was 86 μSv.     

Reduced water intake deteriorates glucose regulation in patients with type 2 diabetes

Epidemiological research has demonstrated that low daily total water intake is associated with increased diagnosis of hyperglycemia. Possible mechanisms for this increase include hormones related to the hypothalamic pituitary axis as well as the renin-angiotensin-aldosterone system (RAAS). Therefore, the hypothesis of the present study was that acute low water intake would result in differential hormonal profiles and thus impaired blood glucose regulation during an oral glucose tolerance test (OGTT) in people with type 2 diabetes mellitus (T2DM). Nine men (53 ± 9 years, 30.0 ± 4.3 m∙kg⁻², 32% ± 6% body fat) diagnosed with T2DM completed OGTTs in euhydrated (EUH) and hypohydrated (HYP) states in counterbalanced order. Water restriction led to hypohydration of −1.6% of body weight, with elevated plasma (EUH: 288 ± 4, HYP: 298 ± 6 mOsm·kg⁻¹; P < .05) and urine (EUH: 512 ± 185, HYP: 994 ± 415 mOsm·kg⁻¹; P < .05) osmolality. There was a significant main effect of condition for serum glucose (at time 0 minute 9.5 ± 4.2 vs 10.4 ± 4.4 mmol∙L⁻¹ and at time 120 minutes 19.1 ± 4.8 vs 21.0 ± 4.1 mmol∙L⁻¹ for EUH and HYP, respectively; P < .001) but not insulin (mean difference between EUH and HYP −12.1 ± 44.9 pmol∙L⁻¹, P = .390). An interaction between time and condition was observed for cortisol: decrease from minute 0 to 120 in EUH (−85.3 ± 82.1 nmol∙L⁻¹) vs HYP (−25.0 ± 43.0 nmol∙L⁻¹; P = .017). No differences between conditions were found within RAAS-related hormones. Therefore, we can conclude that 3 days of low total water intake in people with T2DM acutely impairs blood glucose response during an OGTT via cortisol but not RAAS-mediated glucose regulation.     

辽宁徐大堡核电站运行前周边食品放射性水平调查

目的 调查辽宁徐大堡核电站运行前周边地区食品放射性本底水平,掌握当地居民主要食品中放射性核素水平。方法 通过采集核电站周边30 km范围的食品样品,采用高纯锗（HPGe）能谱仪对样品进行γ核素分析。结果 当地食品中的放射性核素主要为天然核素²³⁸U、²²⁶Ra、²³²Th、⁴⁰K以及人工核素¹³⁷Cs,其中天然核素²³⁸U、²²⁶Ra、²³²Th、⁴⁰K的平均活度水平为（1.2×10⁻¹ ±2.6×10⁻¹）、（9.2×10⁻² ±1.6×10⁻¹）、（3.6×10⁻¹ ±6.5×10⁻²）、（9.0×10¹ ±5.8×10¹）Bq/kg,人工核素 ¹³⁷Cs平均活度水平（1.2×10⁻² ±9.0×10⁻³）Bq/kg。结论 核电站周边地区采集的食品中除微量¹³⁷Cs外,未发现其他人工γ核素,食品中放射性核素水平均低于国家标准限值,居民由食入¹³⁷Cs所致年有效剂量为6.0×10⁻² μSv/a。     

Activity levels of 137Cs and 40K in the skin and the cutaneous organs of a cow

We have performed an extensive study to determine the activity distributions of radiocesium (137Cs) and of the radioisotope 40K of potassium in the whole body of a cow. ICRP assumes that cesium and potassium are distributed homogeneously throughout the whole body of an organism. The current investigation measured concentrations of 137Cs and 40K in components of the skin, horns, and hooves of a cow. Activity levels of 137Cs were caused by the long-term ingestion following the Chernobyl fallout, whereas the naturally occurring potassium (40K) is an essential part of cow's normal diet. The cow was born at the time of the fallout following the Chernobyl accident and had ingested heavily contaminated forage during its entire lifetime. Activities of 137Cs and 40K were determined simultaneously by gamma spectrometry. All activities are related to the day of slaughter and include also corrections for self attenuation of photons caused by the different densities of the samples. Radionuclide concentrations in samples were corrected for moisture losses incurred during freezing and sample preparation. Surface contamination on the skin was estimated by rinsing it in heated water followed by removal of the epidermis and hair. In comparison with the activities of the components of the skin we observed a considerable amount of external contamination on the surface of the skin. But with respect to whole body countings of the animal this amount of external contamination appears to be negligible. It was found that activity ratios of 137Cs to 40K are greater than 1 in all measured components. The average activity concentrations of 137Cs and 40K in the common integument are 23.3 Bq kg(-1) and 13.3 Bq kg(-1), respectively. The highest activity concentrations of 137Cs and 40K were measured in clean hair and hypodermis. Despite being its largest organ, the cow's skin contains probably less than 1% of the animal's whole body 137Cs activity.     

Concentrations and health risk assessment of total mercury in canned tuna marketed in Southest Brazil

The aim of this research was to determine total mercury (Hg) content in 69 canned tuna of 13 brands marketed in southwest Brazil. All values are reported in μg.g⁻¹ wet weight basis. Potential health risk was estimated on the basis of mercury concentration and average consumption (175 g/per week) of fish in Brazil comparing to PTWI of 1.6 μg.kg⁻¹ (FAO/WHO, 2010). A large variation in the concentration of mercury in different species was observed. Mean mercury concentration was 0.256 ± 0.215 μg.g⁻¹ with a highest value of 1.060 μg.g⁻¹ in a single can. In general average concentration was below the legislation of 1.0 μg.g⁻¹ for predatory species (BRASIL, 2010). Estimate weekly intake (EWI) varied 0.2–1.7 μg.kg⁻¹. For the analyzed brands and Brazilian fish consumption, no human health risk is likely to occur. However one brand was higher than PTWI of 1.6 μg.kg⁻¹ showing no safety for specific risk group. Further studies including specific data on canned tuna consumption in specific populations will be needed as well as the fish type, fish size and fishing location.