Perchlorate, nitrate, thiocyanate, and iodide levels in chicken feed, water, and eggs from three farms

Perchlorate is an inhibitor of iodide uptake that is found widely in the environment. Given the potential for perchlorate accumulation during egg formation and the widespread consumption of eggs, it is important to examine eggs as a source of exposure to perchlorate and other potential inhibitors of iodide uptake (nitrate and thiocyanate). This study was conducted to determine potential human exposure to perchlorate from eggs produced by chicken flocks consuming differing amounts of perchlorate. The mean concentrations of perchlorate (7.16 ( 1.99 microg/kg of dry weight), nitrate (2820 ( 2100 microg/kg of dry weight), thiocyanate (574 +/- 433 microg/kg of dry weight), and iodide (2980 ( 1490 microg/kg of dry weight) in eggs (n = 180) from 15 chicken houses on 3 U.S. farms were determined. Chickens secreted into eggs an average of 23% of the perchlorate ingested from feed and water. Perchlorate levels in eggs were positively correlated with perchlorate intake (p < 0.001). Increased intake of perchlorate, nitrate, and thiocyanate was associated with decreased iodide levels in eggs, possibly indicating a competitive transport mechanism, such as sodium-iodide symporter. It was estimated that egg consumption contributes minimal perchlorate (approximately 0.040 microg) compared to the average total intake of approximately 10.5 microg for U.S. adults. Additionally, it was found that egg consumption was not associated with increased perchlorate exposure in 2820 individuals from the National Health and Nutrition Examination Survey (p value for the difference of least-squares means, pDiff = 0.225). From these findings it was concluded that, although chickens secrete perchlorate in eggs, eggs do not appear to be a significant source of perchlorate exposure for adults in the United States.     

不同水稻品种对五氯酚钠的吸收累积特征研究

五氯酚钠（PCP-Na）作为典型的氯代有机污染物,结构稳定难以降解且具有生物积累性,因而对环境生态系统及人体健康具有潜在风险。然而目前典型农作物对PCP-Na的吸收迁移及代谢特征的研究还不足。本研究采用温室水培实验,研究了15种水稻品种对PCP-Na的吸收差异,进而明确水稻对其体内PCP-Na的代谢能力。结果表明,水培浓度显著影响水稻对PCP-Na的吸收行为,且在胁迫的1-2天内水稻根部的PCP-Na累积浓度达到最大值。粳稻、籼稻、杂交稻品种的根部累积浓度分别为399-603、199-315、186-271 mg/kg;茎叶累积浓度分别为6.3-10.8、2.1-8.3、2.5-3.2 mg/kg。扬粳687号（粳稻）、农香24号（籼稻）、泰两优217号（杂交稻）是PCP-Na耐受性最强的三大水稻品种。研究还发现,水稻本体对PCP-Na具有较强的降解能力,水稻根部的PCP-Na在14天内从355下降至2.6mg/kg,茎叶内的PCP-Na在11天内从14.6下降至0.1 mg/kg。本研究有助于理解水稻对PCP-Na的吸收累积特征和降解能力,同时对水稻的安全生产和耐性育种提供一定的依据。     

Occurrence of ochratoxin A in cocoa products and chocolate

In this work, the occurrence of ochratoxin A (OTA) in 170 samples of cocoa products of different geographical origins was studied. An immunoaffinity column with HPLC separation was developed to quantify low levels of OTA in cocoa bean, cocoa cake, cocoa mass, cocoa nib, cocoa powder, cocoa shell, cocoa butter, chocolate, and chocolate cream with >80% recoveries. The method was validated by performing replicate analyses of uncontaminated cocoa material spiked at three different levels of OTA (1, 2, and 5 microg/kg). The data obtained were related on the acceptable safe daily exposure for OTA. The highest levels of OTA were detected in roasted cocoa shell and cocoa cake (0.1-23.1 microg/kg) and only at minor levels in the other cocoa products. Twenty-six cocoa and chocolate samples were free from detectable OTA (<0.10 microg/kg). In roasted cocoa powder 38.7% of the samples analyzed contained OTA at levels ranging from 0.1 to 2 microg/kg, and 54.8% was contaminated at >2 microg/kg (and 12 samples at >3 microg/kg). Ochratoxin A was detected in cocoa bean at levels from 0.1 to 3.5 microg/kg, the mean concentration being 0.45 microg/kg; only one sample exceeded 2 microg/kg (4.7%). In contrast, 51.2% of cocoa cake samples contained OTA at levels > or =2 microg/kg, among which 16 exceeded 5 microg/kg (range of 5-9 microg/kg). These results indicate that roasted cocoa powder is not a major source of OTA in the diet.     

Phytoestrogen content of beverages, nuts, seeds, and oils

Phytoestrogens are secondary plant metabolites that have received increasing attention for their bioactivity, in particular due to their structural and functional similarity to 17beta-estradiol. Although urinary and plasma phytoestrogens can be used as biomarkers for dietary intake, this is often not possible in large epidemiological studies or in the assessment of general exposure in free-living individuals. Accurate information about dietary phytoestrogens is therefore important, but there are very limited data concerning food contents. In this study was analyzed a comprehensive selection of tea, coffee, alcoholic beverages, nuts, seeds, and oils for their phytoestrogen content using a newly developed sensitive method based on LC-MS incorporating (13)C 3-labeled standards. Phytoestrogens were detected in all foods analyzed, although the contents in gin and bitter (beer) were below the limit of quantification (1.5 microg/100 g). Lignans were the main type of phytoestrogens detected. Tea and coffee contained up to 20 microg/100 g phytoestrogens and beer (except bitter) contained up to 71 microg/100 g, mainly lignans. As these beverages are commonly consumed, they are a main source of dietary lignans. The results published here will contribute to databases of dietary phytoestrogen content and allow a more accurate determination of phytoestrogen exposure in free-living individuals.     

天津污灌区水稻土壤汞形态特征及其食品安全评估

选择天津污水灌溉区作为研究区域,该文的主要研究目的是分析土壤不同形态汞对水稻不同组织中总（THg）和甲基汞MeHg富集的影响以及评估污灌区稻米食用汞暴露风险,并对污灌区土壤溶解与可交换态汞安全阀值进行了初步分析。结果表明,北塘、大沽和北京污灌区稻田土壤THg和MeHg浓度显著高于对照区海河土壤THg浓度。大沽、北京河污灌区和海河土壤汞的形态为残渣态浓度最高,而北塘污灌区为有机结合态浓度最高。由于水稻地上组织中THg浓度受到大气汞浓度影响,各组织中汞浓度在不同污灌区分布规律不同。水稻籽粒的 MeHg 富集系数为1.63～3.70,通过人体每天摄入MeHg量的安全值计算得出土壤溶解与可交换态汞质量分数应低于9.19 ng/g。污灌区食用稻米MeHg暴露对居民健康存在较大风险,人体MeHg每天摄入量超标率达到20.83%。因此,可以对超标土壤进行治理或改变耕作方式来降低土壤污染对人体MeHg暴露造成的影响。     

Lead dietary intake in a Spanish population (Canary Islands)

For most people diet is the main route of exposure to trace metals, so information about dietary intake is also important to assess risks to human health for these elements. The purpose of this study was to determine the levels of Pb in the foods and drinks of highest consumption in the authors' our community to estimate daily intakes of Pb for each of the seven Canary Islands. Four hundred and twenty samples were analyzed using GFAAS. The total Pb intake of the Canarian population is 72.8 microg/day, 29.12% (for a person of 70 kg body weight) of the provisional tolerable weekly intake limit of 25 microg/kg fixed by the FAO/WHO. The island that presents the highest lead intake is La Gomera, followed by Lanzarote, Tenerife, and Gran Canaria islands. These four islands present a lead dietary intake over the mean Pb intake for the whole archipelago. The islands with lower Pb intakes are La Palma and Fuerteventura, with intakes under 70 microg/day. These results have also been compared with the values found for other national and international communities.     

Formation and availability of methylmercury in mercury-contaminated sediment: effects of activated carbon and biochar amendments

Journal of Soils and Sediments - As the formation of toxic and bioaccumulative methylmercury (MeHg) in Hg-contaminated sediments is of great concern worldwide, suitable remediation options are...     

Production of polyclonal antibodies against ochratoxin A and its detection in chilies by ELISA

Polyclonal antibodies were produced for Ochratoxin A (OA) by injecting OA-bovine serum albumin (BSA) conjugate subcutaneously at multiple sites into a New Zealand White inbred rabbit. Antiserum could be used at a dilution exceeding 1:100 000 in an indirect competitive enzyme-linked immunosorbent assay (ELISA), and detected OA concentrations up to 0.1 ng/mL. The 50% inhibition binding (I(50)) of OA was 5 ng/mL. Antibodies did not react with ochratoxin B, coumarin, 4-hydroxycoumarin, L-phenylalanine, and aflatoxin B1. OA contamination in chilies (Capsicum annum L.) collected from commercial markets and cold storage units was determined. The mean recoveries from OA-free chilies spiked with 1 to100 microg of OA per kg of chili sample were 90-110% with a standard deviation of <10%. Of 100 chili samples tested, 26 were found to contain over 10 microg/kg of OA. In 12 samples the OA concentration varied from 10 to 30 microg/kg, in 10 samples from 30 to 50 microg/kg, in 3 samples from 50 to100 microg/kg, and in one sample it was 120 microg/kg. This is the first record in India of OA in chilies, a major component of cooked foods in this country, and it is noteworthy that OA contamination exceeded the permissible limit for human consumption of less than 20 microg/kg in over 26% of the market samples tested.     

Analysis of acrylamide,a carcinogen formed in heated foodstuffs

Reaction products (adducts) of acrylamide with N termini of hemoglobin (Hb) are regularly observed in persons without known exposure. The average Hb adduct level measured in Swedish adults is preliminarily estimated to correspond to a daily intake approaching 100 microg of acrylamide. Because this uptake rate could be associated with a considerable cancer risk, it was considered important to identify its origin. It was hypothesized that acrylamide was formed at elevated temperatures in cooking, which was indicated in earlier studies of rats fed fried animal feed. This paper reports the analysis of acrylamide formed during heating of different human foodstuffs. Acrylamide levels in foodstuffs were analyzed by an improved gas chromatographic-mass spectrometric (GC-MS) method after bromination of acrylamide and by a new method for measurement of the underivatized acrylamide by liquid chromatography-mass spectrometry (LC-MS), using the MS/MS mode. For both methods the reproducibility, given as coefficient of variation, was approximately 5%, and the recovery close to 100%. For the GC-MS method the achieved detection level of acrylamide was 5 microg/kg and for the LC-MS/MS method, 10 microg/kg. The analytic values obtained with the LC-MS/MS method were 0.99 (0.95-1.04; 95% confidence interval) of the GC-MS values. The LC-MS/MS method is simpler and preferable for most routine analyses. Taken together, the various analytic data should be considered as proof of the identity of acrylamide. Studies with laboratory-heated foods revealed a temperature dependence of acrylamide formation. Moderate levels of acrylamide (5-50 microg/kg) were measured in heated protein-rich foods and higher contents (150-4000 microg/kg) in carbohydrate-rich foods, such as potato, beetroot, and also certain heated commercial potato products and crispbread. Acrylamide could not be detected in unheated control or boiled foods (<5 microg/kg). Consumption habits indicate that the acrylamide levels in the studied heated foods could lead to a daily intake of a few tens of micrograms.     

Analysis of ochratoxin A in foods consumed by inhabitants from an area with balkan endemic nephropathy: a 1 month follow-up study

In the 1950s, a series of publications from Bulgaria, Yugoslavia, and Romania locally described a kidney disease called Balkan Endemic Nephropathy (BEN). In Bulgaria, the exposure of populations to ochratoxin A (OTA) was supported by analysis of individual food items demonstrating a higher prevalence and higher levels of OTA in food from the high-incidence areas of BEN. In this work, food consumption from a series of individuals from two villages of the BEN area during 1 month was followed using the duplicate diet method. Meals consumed by volunteers from both villages showed uneven OTA contents, spreading from below the limit of quantification (<0.07 microg/kg) to 2.6 microg/kg. The average weekly intake of OTA varies from 1.86 to 92.7 ng/kg of body weight. Some of these levels approach the provisional tolerable weekly intake (PTWI) established by the JECFA at 100 ng/kg of body weight. These results confirm previous studies performed in the same area and demonstrate the high exposure of this population to OTA, thus strengthening the hypothesis of the involvement of this mycotoxin in BEN etiology.     

Determination of selenium concentration of rice in china and effect of fertilization of selenite and selenate on selenium content of rice

A method of hydride generation atomic fluorescence spectrometry was applied to the determination of the selenium concentration of regular polished rice in China and selenium-enriched polished rice obtained by foliar application of selenium-enriched fertilizer in the forms of selenite and selenate. The average selenium content of regular rice was 0.025 +/- 0.011 microg g(-)(1). On the basis of a daily dietary rice intake of 300-500 g suggested by the China Nutrition Society, the total selenium intake from regular rice was calculated to be 7.5-12.5 microg per person per day for an adult. The selenium contents of rice were significantly increased to 0.471-0.640 microg g(-)(1) by foliar application of selenium-enriched fertilizer at rate of 20 g of Se ha(-)(1) in the forms of sodium selenite and sodium selenate. The selenium content of rice by application of a fertilizer of selenate was 35.9% higher than that by a fertilizer of selenite, which showed that Se-enriched fertilizer in selenate exhibited greater efficiency in increasing Se content in rice products. The Se-enriched rice products can increase daily Se intake on average by 100-200 microg of Se per day by the consumption of 400 g of rice products if the Se level of rice products is controlled at 0.3-0.5 microg of Se g(-)(1). Because rice is a staple food in China, selenium-enriched rice obtained by bioenrichment of selenium to increase the Se content of rice could be a good selenium source for the population in selenium-deficient regions.     

Dietary acrylamide exposure estimates for the United Kingdom and Ireland: comparison between semiprobabilistic and probabilistic exposure models

Since the discovery of acrylamide in foods, there have been many calculations of dietary exposure. Total diet studies have been commonly used to estimate consumer exposure of acrylamide; however, these often fall short in evaluating true exposure levels because of limitations in small occurrence data sets. Dietary exposure to acrylamide can also be estimated by use of modeling packages. The U.K. Food Standards Agency and the Food Safety Authority of Ireland have prepared estimates for dietary acrylamide exposure using semiprobabilistic and probabilistic modeling. Occurrence data were obtained from the European Union acrylamide monitoring database, whereas consumption data were obtained from the relevant U.K. and Irish National Diet and Nutrition Surveys. The mean adult U.K. consumer exposure was estimated as 0.61 microg/kg of body weight (bw)/day and high-level adult consumer exposure (P97.5) as 1.29 microg/kg of bw/day. The mean adult Irish consumer exposure was estimated as 0.59 microg/kg of bw/day and the high-level adult consumer exposure (P97.5) as 1.75 microg/kg of bw/day. Owing to the wide range of acrylamide levels in foods, semiprobabilistic modeling does not always provide an accurate picture of dietary exposure levels and patterns. Therefore, a comparison of semiprobabilistic assessments to probabilistic assessments of U.K. and Irish dietary exposure estimates of certain food groups is provided.     

Exposure to mercury in Canada: A multimedia analysis

A thorough assessment of Canadian exposure to mercury (Hg) has not been undertaken since 1970. A multimedia approach was used to update estimates of Hg exposure to members of the general population in Canada, based on currently available information. Adult Canadians have an estimated intake of all Hg species via all routes of 7.7μg/day (0.11μg/kg body weight/day), which equated to an absorbed dose of 5.3μg/day (0.076μg/kg bw/day). Fish consumption accounts for much of this exposure (27% of intake, 40% of absorbed dose), in the form of methylmercury. However, dental amalgam appears to account for a greater proportion of total Hg exposure than fish consumption. Exposure from amalgam was estimated for intake and absorbed doses (of Hg⁰) at 2.81 and 2.25μg/day, respectively. This represents 36% of total Hg intake and 42% of absorbed dose. Hg²⁺ arises principally from foods other than fish. Intake of Hg²⁺ by adults was determined to be 1.82μg/day and absorbed dose only 0.18μg/day. Exposures for four other age groups of the population were also evaluated.     

Distribution of total aflatoxins in milled fractions of hulled rice

Two varieties of hulled rice artificially contaminated with aflatoxins at five different levels were processed by dehulling and polishing methods. Contamination levels ranged from 356 to 818 microg/kg and from 244 to 645 microg/kg in medium and long grain rice, respectively. After physical processing, four different milled fractions were obtained (hull, bran, polished broken grains, and polished whole kernels). The fractions were analyzed for total aflatoxins (B1, B2, G1, and G2) by enzyme-linked immunosorbent assay (ELISA). Aflatoxins were removed in fractions intended for human consumption (polished broken grains and polished whole kernels) at rates up to 97%. They were found throughout all fractions, but higher contamination levels were detected in hull and bran fractions than in unprocessed kernels and polished fractions. Regardless of the rice variety, the aflatoxin distribution pattern depended on the initial contamination level and type of milled fraction but not on the duration of polishing.     

工业和农业污染稻田土壤重金属的赋存形态及水稻吸收运移比较

[目的]稻田土壤重金属污染是当前农产品安全生产关注的重要问题.本文比较分析工业和农业污染源稻田土壤重金属的赋存形态及水稻吸收运移,以期为稻田土壤重金属污染控制提供参考.[方法]在长江中下游地区调查选取工业源和农业源重金属污染稻田各27块,在水稻成熟期使用抖根法采集根际土壤及水稻根系和籽粒样品,采用Tessier七步提取...     

Incidence of Fusarium verticillioides and levels of fumonisins in corn from main production areas in Iran

A total of 52 corn samples collected in 2000 from four main corn production provinces of Iran (Fars, Kermanshah, Khuzestan, and Mazandaran) were analyzed for contamination with Fusarium verticillioides and fumonisins (FB(1), FB(2), FB(3), and 3-epi-FB(3)). The mean incidence of F. verticillioides (percent of kernels infected) for these four areas was 26.7, 21.4, 24.9, and 59.0%, respectively. The incidence in Mazandaran was significantly (p < 0.05) above that of the other areas. All samples from Mazandaran were contaminated with fumonisins with a mean level of total fumonisins of 10674 microg/kg. In contrast, the incidence of fumonisin contamination above 10 microg/kg was 53 (8/15), 42 (5/12), and 57% (8/14) in the samples from Fars, Kermanshah, and Khuzestan, respectively, and the corresponding mean total fumonisin levels were 215, 71, and 174 microg/kg, respectively. No statistical differences (p > 0.05) were observed in the fumonisin levels of the corn samples from these three provinces, which were significantly (p < 0.05) lower than the fumonisin contamination in samples from Mazandaran.     

Carotenoid esters in vegetables and fruits: a screening with emphasis on beta-cryptoxanthin esters

Carotenoids are found in food plants in free form or as fatty acid esters. Most studies have been carried out after saponification procedures, so the resulting data do not represent the native carotenoid composition of plant tissues. Therefore, nonsaponified extracts of 64 fruits and vegetables have been screened to determine the amount of carotenoid esters in food plants. Because one of the major problems in the quantitation of carotenoids is the availability of pure standard material, the total carotenoid ester content was calculated as lutein dimyristate equivalents. Lutein dimyristate was independently synthesized from lutein and myristoyl chloride. The highest ester concentrations were found in red chili (17.1 mg/100 g) and orange pepper (9.2 mg/100 g); most of the investigated fruits and vegetables showed concentrations up to 1.5 mg/100 g. Special attention was dedicated to beta-cryptoxanthin esters. To enable an accurate detection of the beta-cryptoxanthin ester content, beta-cryptoxanthin was purified from papaya and used for synthesis of beta-cryptoxanthin laurate, myristate, and palmitate, representing the major beta-cryptoxanthin esters in food plants. The study proved tropical and subtropical fruits to be an additional source of beta-cryptoxanthin esters in the human diet. The contents ranged from 8 microg/100 g beta-cryptoxanthin laurate in Tunisian orange to 892 microg/100 g beta-cryptoxanthin laurate in papaya.     

Aflatoxins and fumonisins in corn from the high-incidence area for human hepatocellular carcinoma in Guangxi, China

A comparative study on the natural occurrence of aflatoxins and Fusarium toxins was conducted with corn samples from high- and low-incidence areas for human primary hepatocellular carcinoma (PHC) in Guangxi, China. In samples from the high-risk area, aflatoxin B(1) was the predominant toxin detected in terms of quantity and frequency, with its concentration ranging between 9 and 2496 microg/kg and an 85% incidence of contamination. Among the samples, 13 (76%) exceeded the Chinese regulation of 20 microg/kg for aflatoxin B(1) in corn and corn-based products intended for human consumption. Significant differences in aflatoxin B(1), B(2), and G(1) and total aflatoxin concentrations in corn between the areas were found (P < 0.05). The average daily intake of aflatoxin B(1) from corn in the high-risk area was 184.1 microg, and the probable daily intake is estimated to be 3.68 microg/kg of body weight/day, 3.20 times the TD(50) in rats. Corn samples from both areas were simultaneously contaminated with fumonisins B(1), B(2), and B(3). Aflatoxin B(1) may play an important role in the development of PHC in Guangxi.     

Xanthophylls in commercial egg yolks: quantification and identification by HPLC and LC-(APCI)MS using a C30 phase

The xanthophylls lutein and zeaxanthin have attracted a lot of interest since it was presumed that an increased nutritional uptake may prevent adult macula degeneration (AMD). Although egg yolks serve as an important dietary source of lutein and zeaxanthin, data on xanthophyll concentrations in commercial egg yolks are not available. Thus, an high-performance liquid chromatography-diode array detector (HPLC-DAD) method was developed allowing for simultaneous separation of eight xanthophylls used to fortify poultry feed. Peak identification was carried out by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry [LC-(APCI)MS]. Egg yolks of four types of husbandry (seven batches each) were examined. Lutein and zeaxanthin were the predominant xanthophylls in egg yolks produced in accordance with ecological husbandry (class 0) because the concentrations of these xanthophylls ranged from 1274 to 2478 microg/100 g and from 775 to 1288 microg/100 g, respectively. Analysis of variance (ANOVA) proved that both mean lutein and mean zeaxanthin concentrations of eggs from class 0 were statistically discriminable from mean lutein and zeaxanthin concentrations from eggs of all other classes (P < 0.01). Mean concentrations of synthetic xanthophylls in eggs of classes 1 (free range), 2 (barn), and 3 (cage) were as follows: canthaxanthin, 707 +/- 284 microg/100 g; beta-apo-8'-carotenoic acid ethyl ester, 639 +/- 391 microg/100 g; and citranaxanthin, 560 +/- 231 microg/100 g. Experiments with boiled eggs proved that beta-apo-8'-carotenoic acid ethyl ester was the xanthophyll with the highest stability, whereas lutein was degraded to the largest extent (loss of 19%). Detailed knowledge about the xanthophyll amounts in eggs is indispensable to calculate the human uptake.     

Phytoestrogen content of foods of animal origin: dairy products, eggs, meat, fish, and seafood

Dietary phytoestrogens may be involved in the occurrence of chronic diseases. Reliable information on the phytoestrogen content in foods is required to assess dietary exposure and disease risk in epidemiological studies. However, existing analyses have focused on only one class of these compounds in plant-based foods, and there is only little information on foods of animal origin, leading to an underestimation of intake. This is the first comprehensive study of phytoestrogen content in animal food. We have determined the phytoestrogen content (isoflavones: biochanin A, daidzein, formononetin, genistein, and glycitein; lignans: secoisolariciresinol and matairesinol; coumestrol; equol; enterolactone; and enterodiol) in 115 foods of animal origin (including milk and milk-products, eggs, meat, fish, and seafood) and vegetarian substitutes using liquid chromatography-mass spectrometry (LC-MS) with (13)C-labeled internal standards. Phytoestrogens were detected in all foods analyzed; the average content was 20 microg/100 g of wet weight (isoflavones, 6 microg/100 g; lignans, 6 microg/100 g; equol, 3 microg/100 g; and enterolignans, 6 microg/100 g). In infant soy formula, 19 221 microg/100 g phytoestrogens were detected (compared to 59 microg/100 g in non-soy formula). Our study shows that all foods analyzed contained phytoestrogens and most foods (except for fish, seafood, and butter) contained mammalian phytoestrogens (enterolignans and equol). This is the first comprehensive study of phytoestrogen content of foods of animal origin and will allow for a more accurate estimation of exposure to dietary phytoestrogens.