Estimation of the daily intake of nitrates and nitrites which may be consumed by students 12-17 years old in secondary schools in the city of Havana

In the present article we offer informations regarding the estimated amounts of nitrates and nitrites which may be consumed by 12,000 students 12 to 17 years old, who attend boarding schools. The method of analysis used to determine nitrates and nitrites is that reported by the Joint FAO/WHO Expert Committee using a cadmium reducing column. The estimated quantities of nitrates and nitrites which these students may consume according to their food intake are smaller than those recommended as admissible daily intake by the Joint FAO/WHO Expert Committee on Food Additives.     

Estimation of the daily intake of nitrates and nitrites which may be consumed by students 12–17 years old in secundary schools in the City of Havana

In the present article we offer informations regarding the estimated amounts of nitrates and nitrites which may be consumed by 12000 students 12 to 17 years old, who attend boarding schools. The method of analysis used to determine nitrates and nitrites is that reported by the Joint FAO/WHO Expert Committee using a cadmium reducing column. The estimated quantities of nitrates and nitrites which these students may consume according to their food intake are smaller than those recommended as admissible daily intake by the Joint FAO/WHO Expert Committee on Food Additives.     

Evaluation of the cadmium content in sedimented and floating dust as factors in contamination of the biosphere]

In a territory being 3.500 km2, the cadmium deposits from the atmosphere were determined at 63 sites in 52 towns and communities. These determinations yielded a mean value ranging from 0.13 to 0.15 mg/m2 . 30 d. On the contrary, the mean value (-x) was 0.33 mg/m2. 30 d in the region of heavy-metal-emitting industries. The mean cadmium content in the aerosol was between 0.003 and 0.004 microgram m-3 and, respectively, 0.016 microgram m-3 in case of cadmium emission. It was calculated that the mean proportion of cadmium in the sedimentary dust was between 13 and 16 p.p.m. The cadmium burden, as estimated as cadmium sediment, correlated with the extent of the developmental area. The authors recommend for the present the following maximum permissible values: 0.05 microgram m-3 in the aerosol, and 0.15 mg/m2. 30 d. The cadmium content in the sedimentary dust may be considered to be a permanent burden applied via the food chain, whereas the content in the aerosol is of less importance to the total uptake in man. The calculation of the daily pulmonary uptake yielded a value of 0.075 microgram, from which an absorption of 0.038 microgram is estimated.     

Cadmium in organs and tissues of horses slaughtered in Italy

The cadmium content of muscle, liver, kidney and blood samples from 62 horses slaughtered in Italy was investigated. Cadmium was determined by graphite furnace atomic absorption spectrometry (GFAAS) after wet digestion of the samples. The mean and median contents of all samples were (on a fresh weight basis) 75 and 41 μgkg^-1 for muscle, 2.46 and 2.10 mgkg^-1 for liver, 20.0 and 13.5 mgkg^-1 for kidney. The cadmium level in blood samples was always below 6 μgl^-1. The cadmium concentrations in muscle, liver and kidney were found to be related to the life span of the specimens and increased with age. Females exhibited higher levels than males, but this difference was significant only in the case of muscle tissue. The geographical origin was recognized as the main factor influencing the cadmium content of the equine specimens analysed. The differences between horses coming from the three main breeding countries considered in this study (Poland, Lithuania, Hungary) were marked and statistically significant. The average intake of cadmium from equine meat was estimated for the general population and for population groups resident in areas with high consumption of this food item. While the cadmium intake from equine meat for the average consumer accounts for about 1% of the total cadmium intake estimated for Italy, in the latter case the enhanced consumption of equine muscle is often accompanied with the consumption of substantial quantities of equine liver and this may lead to high cadmium intakes.     

广东省居民主要膳食镉暴露风险的初步评估

目的分析主要食物中镉含量水平,对广东省居民通过膳食途径暴露镉的健康风险进行初步的评估。方法 2009年在全省21地市采集15类食物共2 200份,用石墨炉原子吸收光谱法测定食物中镉的含量,结合居民膳食消费数据,比照镉的暂定每月耐受摄入量(PTMI)及安全限值(MOS)初步评估广东省居民主要食物的镉暴露风险。结果 15类食物中紫菜中镉含量最高,为1 830.0μg/kg。城乡居民通过大米、蔬菜类、鱼虾类、动物内脏类四类食物每月膳食镉暴露量分别为1 314.6和1 394.3μg。大米对城市和农村居民膳食镉的贡献率最高,分别为50.1%和64.9%,且以粤北地区最高。结论主要食品对居民膳食镉的平均贡献水平未超过PTMI值,MOS值大于1,居民膳食镉暴露水平总体上安全。由于我国南方地区居民大米的消费量大及其对居民膳食镉贡献率最高,有必要加强大米可能的镉污染问题研究,并从源头上预防污染。     

Determination of cadmium binding proteins in the edible mushroom (Agaricus arvensis Schff, ex Fr.) (author's transl)

The isolation and characterization of cadmium compounds from Agaricus arvensis Schff. ex Fr. are described. These compounds were extractable with buffers. Ultrafiltrations and protein precipitations suggested protein bound cadmium. The mushroom proteins were separated by gel chromatography and the cadmium content in the corresponding fractions was determined by flameless atomic absorption. Two cadmium containing protein fractions were found with cadmium concentrations of 2.1 and 1 mg/g protein, respectively. The molecular weights of both cadmium containing proteins were estimated to be about 2,000 and 15,000--20,000, respectively by comparison with standard proteins.     

Cadmium intake and cadmium in the human kidney

The diet and cigarette smoking are the main sources of cadmium intake in people not occupationally exposed to cadmium. Using data gathered from the literature, it is shown that there is a statistically significant relationship between the average cadmium intake in various countries and the average kidney cadmium concentration in 40-60 year old people living in those countries. It is estimated that a regular dietary intake of cadmium of 175 micrograms/day would cause the concentration of cadmium in the renal cortex to reach the critical level in 50 years.     

江苏地区克氏原螯虾中镉的膳食暴露及风险评估

为量化江苏地区人群克氏原螯虾镉的膳食暴露量,以江苏地区克氏原螯虾为研究对象并运用石墨炉原子吸收光谱法进行检测,同时结合获得镉的检测数据和江苏地区人群的膳食消费量,运用点评估和概率评估两种方法评价江苏地区克氏原螯虾中镉的膳食暴露及风险。结果显示:江苏地区705个克氏原螯虾样品中镉含量的平均值为0.068 mg/kg,有2个样品的镉含量超标,超标率为0.28%。点评估结果显示,江苏地区人群克氏原螯虾镉的暴露量的平均值、75分位数和90分位数分别占暂定每月耐受摄入量(provisional tolerable monthly intake,PTMI)的0.07%、0.05%和0.32%。概率评估结果显示,江苏地区人群食用克氏原螯虾的镉暴露量的平均值、75分位数和90分位数分别占PTMI的0.08%、0.10%和0.21%,江苏地区91.6%人群镉的暴露量处于安全水平。江苏地区人群克氏原螯虾镉的膳食暴露量总体处于安全水平范围内,长期食用克氏原螯虾不会增加总膳食镉的摄入量。     

累积风险评估方法在典型人群饮料中铅和镉联合暴露评估中的应用

目的利用典型人群饮料中铅和镉的暴露数据,研究不同累积风险评估方法在评价化学物质联合暴露风险中的应用。方法以中学生、大学生和白领人群为对象,利用饮料中铅和镉的专项监测数据和3类人群饮料消费量数据计算暴露量;检索科学文献获得2种重金属污染物的毒理学数据和健康指导值等参数,假定饮料中重金属污染物的风险控制水平低于健康指导值的5%。基于分级评估原则,分别采用危害指数(HI)法、靶器官毒性剂量(TTD)法和证据权重(WOE)法3种累积风险评估方法,评估饮料中铅和镉联合暴露的健康风险,并与2种污染物的单独暴露风险进行比较。结果以健康指导值的5%比较,中学生通过饮料的铅暴露超过该值。HI法评估结果发现,白领人群饮料消费者的HI值小于1,中学生和大学生饮料消费者的HI值大于1。基于各效应终点的TTD法评估结果发现,铅和镉联合暴露对3类人群的肾脏效应的HI值均大于1,对心血管系统和神经系统,仅中学生人群HI值大于等于1;对于其他作用终点,3类人群的HI值均小于1。WOE法评估结果发现,铅和镉联合暴露仅对中学生的心血管系统和神经系统的交互作用校正后的HI值大于1。结论不同累积风险评估方法可用于评估食品中不同化学物质联合暴露的累积风险,可根据支持数据的充分性和管理需要,采用分级评估原则选择合适的累积风险评估方法。     

Monitoring the content and intake of trace elements from food in Denmark

The content of cadmium, lead, nickel, mercury and selenium in 83 foods was monitored from 1993 to 1997. In comparison with similar results from 1988 to 1992, a general decrease in lead levels had occurred, whereas the contents of cadmium, nickel, mercury and selenium were stable or declined only slightly. The distribution in dietary intake of the five trace elements was estimated by combining the mean trace element concentrations with food consumption data from 1837 Danes aged 15-80 years. The lead intake for 1993-97 showed a decrease in comparison with similar estimates from the previous monitoring cycles: 1983-87 and 1988-92. The intake of cadmium and mercury decreased to a lesser extent, whereas the intake of selenium and nickel remained unchanged in the same period. The dietary intake of trace elements was compared with the provisional tolerable weekly intake (PTWI). The 95th percentile of the distribution in cadmium intake amounts to 34% of PTWI, which is relatively high, and therefore calls for a more detailed future risk assessment. The intakes of lead and mercury were 11% of PTWI and, like the intake of nickel, did not cause any health concern in the adult population. The Danes ingest close to 100% of the Nordic Nutrition Recommendation for selenium at 50 μg day -1 , and no individuals had an intake less than the lower limit of 20 μg day -1 .     

Mercury, arsenic, lead and cadmium in fish and shellfish from the Adriatic Sea

The aim was to measure concentrations of total mercury, total arsenic, lead and cadmium in common edible fresh fish and shellfish from various areas of the Adriatic Sea. Estimates of intake of these elements were made through seafood consumption by the general population. Samples were either wet digested for mercury and arsenic, or dry ashed for lead and cadmium analysis. Mercury was measured by cold vapour atomic absorption spectrometry (CV AAS) and arsenic, lead and cadmium by electrothermal atomic absorption spectrometry (ET AAS). Quality control procedures of analytical methods, which included analyses of dogfish muscle-certified reference material DORM-2, confirmed the acceptability of methods. The highest mercury and arsenic concentrations were found in hake ( Merluccius merluccius ) and the lowest in mackerel ( Scomber scombrus ). The respective values in hake were 0.373 ±0.075 and 23.3 ±3.6, and in mackerel 0.153 ±0.028 and 1.06 ±0.29 mg kg -1 fresh weight (mean ±SD). Lead and cadmium concentrations were about 10 times higher in shellfish than in analysed fish. The highest lead and cadmium concentrations were found in mussel ( Mytilus galloprovincialis ) and the lowest in hake. Respective lead and cadmium values in mussel were 0.150 ±0.009 and 0.142 ±0.017, and in hake were 0.007 ±0.004 and 0.002 ±0.001 mg kg -1 fresh weight. The concentrations of analysed elements were below acceptable levels for human consumption set by the Croatian Ministry of Health, except for total arsenic. The estimated intake of those trace elements included in this study through seafood consumption by the general population did not exceed the provisional tolerable weekly intake recommended by the Joint FAO/WHO Expert Committee on Food Additives.     

重庆市万州区市售鲜辣椒中镉和铬污染现状评价

目的 了解重庆市万州区市售鲜辣椒中镉和铬元素污染情况, 对辣椒食用的安全性进行评价, 为后期进行食品风险预警提供依据。方法 采用石墨炉原子化法测定辣椒中的镉和铬元素的含量, 利用单因子污染指数法和内梅罗指数法对辣椒中重金属镉、铬污染进行评价。结果 20份辣椒样品中镉元素平均检出浓度为(0.094±0.042) mg/kg, 最高值为0.195 mg/kg, 超标率为85%。单项因子污染指数分析显示, 重庆市万州区鲜辣椒属于镉元素的轻度污染范围内。内梅罗指数分析显示, 重庆万州区鲜辣椒属于轻度污染范围内, 且镉元素的单项因子污染指数对内梅罗指数贡献较大。结论 重庆市万州区市售辣椒存在镉元素超标的现象, 可能与土壤中镉元素超标有关。     

Seasonal bioaccumulation of toxic trace elements in economically important fish species from the Caspian Sea using GFAAS

This study aimed to determine the concentrations of aluminium, cadmium, lead and nickel in edible muscle of three commercially valuable fish species (Rutilus frisii kutum, Liza aurata and Cyprinus carpio) from four fishing sites of Iranian coastal waters of the Caspian Sea during winter and summer. The samples were analyzed using graphite furnace atomic absorption spectrometry (GFAAS) after wet-ashing digestion. The results were expressed as ??g/g of wet weight. The resulted range of metals in fish species was between 0.89?C2.46???g/g for aluminium, 0.03?C0.17???g/g for cadmium, 0.21?C0.38???g/g for lead and 0.12?C0.52???g/g for nickel. Seasonal variation influenced concentration of the metals in fish samples of some fishing sites. The highest concentrations found were 4.63???g/g for aluminium in winter and 0.82???g/g for lead in summer in Cyprinus carpio; while cadmium (0.49???g/g) and nickel (1.14???g/g) were the highest in Rutilus frisii kutum in winter. This demonstrates that estimated daily and weekly intakes of aluminium, lead and nickel and estimated monthly intake of cadmium via consumption of fish flesh are below the established PTDI, PTWI and PTMI values.     

Consumption of bivalve molluscs in Italy: estimated intake of cadmium and lead.

Concentrations of cadmium and lead were determined in nine different species of mollusc bivalves (Modiolus barbatus, Venus verrucosa, Scapharca inaequivalvis, Tapes decussatus, Callista chione, Pecten jacobeus, Ensis siliqua, Venus gallina, Cardium tubercolata) collected from different coastal areas of the Adriatic Sea (north, middle and south Adriatic). The levels of cadmium and lead found in bivalves from the north Adriatic Sea were significantly (P < 0.001) higher than those detected in those from the middle and south Adriatic Sea. In some species of molluscan bivalves (M. barbatus and T. decussatus) from the north Adriatic Sea, concentrations of cadmium and lead exceeded the maximum limit (2 mg/kg w.w.) established by the Italian legislation. Weekly intakes were estimated and compared with the Provisional Tolerable Weekly Intake (PTWI) recommended by the FAO/WHO Expert Committee on Food Additives.     

表没食子儿茶素没食子酸酯对米饭中污染物镉的肠吸收转运的影响

近年随着水体和土壤污染的加剧,我国大米镉污染的形势也愈发严峻。人体的镉暴露途径主要是膳食,镉消化后主要在机体内的小肠部位吸收。本研究首先测定大米及蒸煮米饭中污染物镉的含量,利用已建立的体外口腔-胃-肠消化模型来测定米饭消化后镉的生物可给性,最后采用Caco-2/HT-29细胞共培养肠吸收模型来研究表没食子儿茶素没食子酸酯（(-)-epigallocatechin-3-gallate,EGCG）干预对米饭中镉吸收转运率的影响。结果表明：胃消化2 h的生物可给性为（73.58±1.92）%,肠消化7 h的生物可给性为（36.29±1.25）%;EGCG干预后米饭消化液中镉的吸收转运率显著降低,与对照组相比,21.82 μmol/L和43.64 μmol/L EGCG使镉的吸收转运率分别降低了5.56%和13.89%,该研究为镉暴露地区人群的膳食策略提供了新的思路。     

吉林省部分地区食品中铅、镉污染状况分析

通过监测吉林省2001～2004年6个地区食品中铅、镉含量,了解铅、镉的污染状况,并提出铅、镉可能的污染来源.按照国家标准方法GB/T5009对样品进行前处理,采用石墨炉原子吸收光谱法检测铅、镉含量.2001年～2004年共监测13类917份食品中铅、镉含量,铅超标率为9.49%,镉超标率在6.24%.结果显示目前食品中铅、镉污染不严重,但由于各类食品中铅、镉都有检出,说明存在不同程度的积累,对人体健康存在潜在的威胁。     

镉暴露对人体骨骼影响的研究进展

镉是一种环境重金属污染物,在环境中不能进行生物降解,在人体内半衰期长达10-30年。骨骼是镉的重要靶器官,已有研究证实镉是诱发骨密度降低和骨质疏松症发生的危险因素之一。本文综述了镉暴露对人体骨骼影响的国内外相关文献。结果表明,镉暴露对人体骨骼的影响因目标人群的不同而存在差异,且主要受影响人群为中老年人,因此研究时应对目标人群进行合理分组,将镉污染区内尿镉浓度较高的人群划分为高暴露组较为合适。此外,高钙摄入量是人体骨密度的保护因素,但是目前罕有研究将目标人群的钙摄入量的状况和镉暴露状况相结合考虑,这可能造成了对镉暴露所致骨质疏松症和骨折的风险的高估,研究中应一同考虑目标人群的钙摄入量状况,才能对镉暴露所致骨质疏松症和骨折的风险作出正确评估。     

江苏省典型地区芦蒿中铅、镉的检测结果分析与污染状况评价

目的 分析检测江苏省典型地区芦蒿和土壤中铅、镉的含量,并评价其污染状况。方法 在南京市、镇江市采用分层随机抽样方法抽取175份芦蒿,采集40份地产(种植)芦蒿生长所在的土壤,用石墨炉原子吸收光谱法检测铅、镉的含量。采用单项污染指数法和综合污染指数法对芦蒿中铅、镉的污染状况进行评价。结果 175份芦蒿中铅、镉的检出率分别为26.3%、100%,超标率分别为9.7%、13.7%;40份土壤中镉的超标率为22.5%。南京市地产(种植)芦蒿污染等级为警戒限,污染水平为尚清洁;镇江市地产(种植)芦蒿污染等级为轻污染,污染水平为开始受污染。南京市市售芦蒿污染等级为安全,污染水平为清洁;镇江市市售芦蒿污染等级为警戒限,污染水平为尚清洁。结论 江苏省典型地区芦蒿受到重金属铅、镉的污染,其中受到镉污染的威胁更大,可能与土壤中镉的污染有关。南京市居民食用芦蒿较安全;镇江市居民食用市售芦蒿较安全,食用地产(种植)芦蒿存在一定的健康风险。     

Theoretical calculation of product contents: battery and cathode ray tube examples

Most product environmental assessments are based on manufacturer-supplied data on the material content of the product. This paper explores the potential for the material content of key components to be estimated with theoretical calculations. Two examples, the amount of cadmium in a nickel-cadmium battery and the amount of lead in a TV or computer CRT monitor, are developed. Both an upper and a lower limit on the amount of cadmium in a nickel-cadmium battery are calculated on the basis of the battery's chemical reaction. The amount of lead shielding needed in a TV or CRT computer monitor is estimated on the basis of the potential difference through which electrons are accelerated and the absorption length of photons in lead. Such calculations can be used as benchmarks in product environmental assessments, providing validation of manufacturer-supplied data and providing insight into the composition and design of products.     

Study on the Removal of Cadmium in Rice Using Microbial Fermentation Method

This work mainly examined how to remove cadmium in rice by fermentation, the removal mechanisms, and the quality of fermented rice in order to utilize cadmium‐contaminated rice. The fermentation time, temperature, liquid ratio, inoculant levels, and number of washes were varied to optimize the efficiency of cadmium removal. The optimum fermentation process, in which the rate of cadmium removal from the rice is 80.84%, required an inoculant amount of 0.1%, a liquid ratio of 1:1, a period of 60 h at 37 °C, and subsequently washed with water 4 times. The physicochemical properties of raw cadmium‐contaminated rice and fermented rice were studied. Results showed that the pasting temperature of the fermented rice became lower, and temperature at which pasting starts dropped but the endothermic enthalpy increased, implying that the protein content in the rice decreased during the fermentation. It suggested that the crystal structure of rice starch changed and fermentation did not result in the formation of new chemical bonds or functional groups in the rice. Microbial fermentation method can therefore effectively reduce cadmium level in contaminated rice.