probabilistic estimation

概率估计
  • 文章类型: Journal Article
    关于大小的研究很少,可变性,以及人类暴露于空气中的微米和纳米塑料(AMNP)的不确定性,尽管它们在人类暴露于MNPs中起关键作用。我们通过三种主要途径对全球AMNP的摄入量进行概率估计:室内吸入,户外吸入,以及在室内用餐时的摄入,对于儿童和成人。儿童和成人的AMPs吸入中位数为1,207.7(90%CI,42.5-8.48×104)和1,354.7(90%CI,47.4-9.55×104)N/人均/天,分别。儿童的AMPS年摄入量为13.18毫克/人均/a,成人为19.10毫克/人均/a,大约是标准邮票质量的五分之一和三分之一,假设每天的中位数摄入量一致。大多数AMP数量的摄入是通过吸入发生的,而在进餐期间摄入沉积的AMP在质量方面贡献最大。此外,儿童和成人通过室外吸入的平均ANP摄入量为9,638.1N/天(8.23×10-6μg/d)和5,410.6N/天(4.62×10-6μg/d),分别,室内吸入分别为5.30×105N/天(5.79×10-4μg/d)和6.00×105N/天(6.55×10-4μg/d)。考虑到较小MNPs的毒性增加,吸入的大量ANP值得高度重视。必须共同努力,以进一步阐明和应对当前的MPN风险。
    Little research exists on the magnitude, variability, and uncertainty of human exposure to airborne micro- and nanoplastics (AMNPs), despite their critical role in human exposure to MNPs. We probabilistically estimate the global intake of AMNPs through three main pathways: indoor inhalation, outdoor inhalation, and ingestion during indoor meals, for both children and adults. The median inhalation of AMPs is 1,207.7 (90% CI, 42.5-8.48 × 104) and 1,354.7 (90% CI, 47.4-9.55 × 104) N/capita/day for children and adults, respectively. The annual intake of AMPs is 13.18 mg/capita/a for children and 19.10 mg/capita/a for adults, which is approximately one-fifth and one-third of the mass of a standard stamp, assuming a consistent daily intake of medians. The majority of AMP number intake occurs through inhalation, while the ingestion of deposited AMPs during meals contributes the most in terms of mass. Furthermore, the median ANP intake through outdoor inhalation is 9,638.1 N/day (8.23 × 10-6 μg/d) and 5,410.6 N/day (4.62 × 10-6 μg/d) for children and adults, respectively, compared to 5.30 × 105 N/day (5.79 × 10-4 μg/d) and 6.00 × 105 N/day (6.55 × 10-4 μg/d) via indoor inhalation. Considering the increased toxicity of smaller MNPs, the significant number of ANPs inhaled warrants great attention. Collaborative efforts are imperative to further elucidate and combat the current MPN risks.
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  • 文章类型: Journal Article
    家庭保存取决于食物基质,冰箱设计/技术,消费者行为,和环境温度。在产品相关的冰箱位置存储不同的食物矩阵,产生不同的温度历史,可用于开发冰箱技术的指标,消费者习惯,和环境条件影响冰箱的食品保鲜性能。在这项研究中,家禽,特别容易腐败,反映其pH值,营养可用性,和高aw,用于评估受压缩机技术(单[SS]和变速[VS])影响的冰箱保存性能,环境温度(21.1°C[LT]和32.2°C[HT]),和冰箱负荷(22.5公斤[RL]和39公斤[HL])。收集的鸡胸肉的时间-温度值储存在独立控制在0°C的冰箱中5°C,和假单胞菌预测微生物学模型,用于估计归一化冰箱性能指标(RPI)。值<1,1和>1描述为优秀,不错,或者性能不佳,分别。首次分析表明,高达54%的鸡胸肉温度高于其建议的冷藏存储值。当忽略可变性来源时,SS技术产生的RPI值范围为0.61-0.70,而更节能的VS压缩机产生的值范围为0.86-1.14。较高和较宽的VSRPI范围反映了为符合能效而优化的压缩机控制逻辑,同时忽略了对食品保存的影响。当通过单侧95%置信区间考虑模型参数和温度测量的可变性时,RPI达到1.16。尽管独立控制的抽屉保存性能接近最佳,它可以通过优化压缩机速度控制协议时考虑能源使用和保存影响来改进。实际应用:全球禽肉消费量已达到每人15公斤。制冷因其安全性和质量保存而被广泛使用。效率法规使家用冰箱的能耗减少了近十倍,尽管它们的尺寸在过去的半个世纪中增加了50%。在这项研究中,我们提供了定量证据,证明它们的保存性能必须得到改善。对于通常配备有更安静和更节能的变速压缩机的上端单元尤其如此。可以使用相同的方法来评估存储单元的保存性能,卡车,和陈列柜用于冷藏产品。
    Home preservation depends on the food matrix, refrigerator design/technology, consumer actions, and ambient temperature. Storing different food matrices in product-relevant refrigerator locations generating different temperature histories can be used to develop an indicator of how refrigerator technology, consumer habits, and environment conditions impact the refrigerator food preservation performance. In this study, poultry, particularly prone to spoilage reflecting its pH, nutrient availability, and high aw, was used to evaluate refrigerator preservation performance as affected by compressor technology (single [SS] and variable speed [VS]), ambient temperature (21.1°C [LT] and 32.2°C [HT]), and refrigerator load (22.5 kg [RL] and 39 kg [HL]). Time-temperature values collected for chicken breast stored in a drawer independently controlled at 0°C in a refrigerator set 5°C, and a Pseudomonas predictive microbiology model, were used to estimate a normalized refrigerator performance indicator (RPI). Values <1, ∼1, and >1 described excellent, good, or poor performance, respectively. A first analysis revealed that up to 54% of chicken breast temperatures were above its recommended refrigerated storage value. When ignoring variability sources, SS technology yielded RPI values ranging 0.61-0.70, whereas the more energy efficient VS compressor yielded values ranging 0.86-1.14. The higher and wider VS RPI range reflects a compressor control logic optimized for energy efficiency compliance while disregarding effects on food preservation. When considering the variability of model parameters and temperature measurements through one-sided 95% confidence intervals yielded RPI reaching 1.16. Although the independently controlled drawer preservation performance was near optimal, it can improve by considering energy use and preservation impact when optimizing the compressor speed control protocol. PRACTICAL APPLICATION: Worldwide poultry meat consumption has reached 15 kg per person. Refrigeration is widely used for its safety and quality preservation. Efficiency regulations decreased the energy use of residential refrigerators by nearly tenfold even though their size increased by 50% in the last half century. In this study, we provide quantitative evidence that their preservation performance must be improved. This is particularly true for upper end units typically equipped with quieter and more energy-efficient variable speed compressors. The same methodology can be used to evaluate the preservation performance of the storage units, trucks, and display cases used for refrigerated products.
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  • 文章类型: Journal Article
    通过蒙特卡罗模拟,使用210种鱼样品中甲基汞浓度的数据以及从日本国家健康和营养调查中提取的有关鱼类消费的数据,估算了鱼类饮食中甲基汞的摄入量。根据调查中使用的类别将分析的鱼分为5组。使用来自每组的鱼的消耗分布而不拟合统计分布。对数正态分布适用于每个鱼群中甲基汞浓度的分布。生成了两个遵循这些分布的随机数,并通过乘以这些随机数来计算试验值。将试验值除以体重(50千克),以得出膳食甲基汞摄入量的估计值。总共进行了100,000次蒙特卡罗模拟迭代。估计甲基汞的平均每日摄入量为0.093µg/kg体重(bw)/天。该值远低于日本食品安全委员会确定的可容忍每周摄入量(2.0µg/kgbw/周)计算的可容忍每日摄入量0.292µg/kgbw/天。甲基汞的每日摄入量超过可容忍的每日摄入量的概率为7.6%。由于没有连续几天的鱼类消费量数据,估计每周甲基汞的摄入量是未来研究的主题。
    Dietary intake of methylmercury from fish was estimated via Monte Carlo simulation using data for methylmercury concentrations in 210 fish samples and data regarding fish consumption extracted from the Japanese National Health and Nutrition Survey. The fish analyzed were classified into 5 groups according to categories used in the survey. The distribution of consumption of fish from each group was used without fitting to statistical distributions. A log-normal distribution was fitted to the distribution of methylmercury concentration in each fish group. Two random numbers that followed these distributions were generated, and a trial value was calculated by multiplying these random numbers. The trial value was divided by the body weight (50 kg) to arrive at an estimate of dietary methylmercury intake. A total of 100,000 Monte Carlo simulation iterations were performed. The estimated mean daily intake of methylmercury was 0.093 µg/kg body weight (bw)/day. This value is well below the tolerable daily intake of 0.292 µg/kg bw/day calculated from the tolerable weekly intake (2.0 µg/kg bw/week) established by the Food Safety Commission of Japan. The probability that the daily intake of methylmercury exceeds the tolerable daily intake was 7.6%. As there are no data regarding fish consumption for consecutive days, estimation of the weekly intake of methylmercury is a subject for future studies.
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  • 文章类型: Journal Article
    这项研究旨在估算比利时消费者由于使用陶瓷器皿而对铅和镉的摄入量。我们采用了关于移民集中度的精致暴露场景,陶瓷器皿的使用,和金属释放特性。最初进行了确定性估计,其次是概率估计,如果确定性估计值超过毒理学参考值。根据欧洲食品安全局(EFSA)确定的参考剂量,铅和镉暴露的风险以暴露裕度(MOE)和可耐受的每周摄入量(TWI)为特征,分别。每天铅的概率中位数和第95百分位数摄入量分别为0.02和5.77μg/kgb.w.儿童每天0.07和17.3微克/千克体重。神经毒性的MOEs,普通消费者的肾毒性和心血管作用分别为7.1、27和64,高消费者为0.02、0.1和0.3。成人每日镉的确定性平均值和第95百分位数分别为0.026(7%TWI)和0.03(8%TWI)μg/kg体重。儿童每天0.08(22%TWI)和0.09(25%TWI)μg/kg体重。考虑到比利时人口从食品中的暴露,导致TWI的超标多达20倍。比利时消费者接触铅和镉的风险建议采取措施,例如降低陶瓷器的迁移限制,应该把风险降到最低。
    This study was aimed at estimating the intake of lead and cadmium by the Belgian consumers due to the use of ceramic ware. We adopted refined exposure scenarios with respect to migrant concentration, ceramic ware usage, and metal release characteristics. A deterministic estimation was initially performed, followed by probabilistic estimation, if the deterministic estimate exceeds toxicological reference values. Based on the reference doses established by the European Food Safety Authority (EFSA), the risk of lead and cadmium exposure was characterized by the margin of exposure (MOE) and the tolerable weekly intake (TWI), respectively. The probabilistic median and 95th percentile intake of lead were 0.02 and 5.77 μg/kg b.w. per day for adults, and 0.07 and 17.3 μg/kg b.w. per day for children. The MOEs for neurotoxicity, nephrotoxicity and cardiovascular effects were 7.1, 27 and 64 for average consumers, and 0.02, 0.1 and 0.3 for high consumers. The deterministic mean and 95th percentile intake of cadmium were 0.026 (7% TWI) and 0.03 (8% TWI) μg/kg b.w. per day for adults, and 0.08 (22 % TWI) and 0.09 (25 % TWI) μg/kg b.w. per day for children. Considering the exposure of the Belgian population from foodstuffs resulted in the exceedance of the TWI by as much as 20-fold. The risk of exposure to lead and cadmium of the Belgian consumers suggests measures, such as lowering the migration limits for ceramic ware, should be taken to minimize the risk.
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  • 文章类型: Journal Article
    生物测定功能,由国际辐射防护委员会提供,用于估计放射性核素的摄入活度;然而,它们在特定个体的内部剂量测定方面包括相当大的不确定性。在实际的内部剂量评估中,由于定量困难,通常不会引入生物测定功能的不确定性。因此,为了澄清生物测定功能中不确定性的存在,并为剂量测定者提供对这种不确定性的洞察,这项研究试图量化放射性碘暴露时甲状腺滞留功能的不确定性.通过蒙特卡罗模拟技术传播生物动力学参数的分布,使用甲状腺保留功能的概率估计来量化不确定性。甲状腺滞留功能的不确定性,用散射因子表示,在24小时内和24小时后的范围为1.55-1.60和1.40-1.50,分别。此外,将24小时内的甲状腺保留功能与实际测量数据进行比较,以确认在生物动力学模型计算中使用一级动力学导致的不确定度.在实际测量中观察到明显更高的甲状腺摄取量(1.9倍)。这项研究表明,考虑甲状腺保留功能的不确定性可以避免内部剂量的显着高估和低估,特别是当预测高剂量时。
    Bioassay functions, which are provided by the International Commission on Radiological Protection, are used to estimate the intake activity of radionuclides; however, they include considerable uncertainties in terms of the internal dosimetry for a particular individual. During a practical internal dose assessment, the uncertainty in the bioassay function is generally not introduced because of the difficulty in quantification. Therefore, to clarify the existence of uncertainty in the bioassay function and provide dosimetrists with an insight into this uncertainty, this study attempted to quantify the uncertainty in the thyroid retention function used for radioiodine exposure. The uncertainty was quantified using a probabilistic estimation of the thyroid retention function through the propagation of the distribution of biokinetic parameters by the Monte Carlo simulation technique. The uncertainties in the thyroid retention function, expressed in terms of the scattering factor, were in the ranges of 1.55-1.60 and 1.40-1.50 for within 24 h and after 24 h, respectively. In addition, the thyroid retention function within 24 h was compared with actual measurement data to confirm the uncertainty due to the use of first-order kinetics in the biokinetic model calculation. Significantly higher thyroid uptakes (by a factor of 1.9) were observed in the actual measurements. This study indicates that consideration of the uncertainty in the thyroid retention function can avoid a significant over- and under-estimation of the internal dose, particularly when a high dose is predicted.
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