RESUMO
Perfluorinated compounds (PFCs) are widely distributed in nature and have many applications due to their unique chemical and physicochemical properties. While, PFCs are present in soil, water, and air, their pathway for entry into the human body is circumstantially via contaminated food. The demand for seafood has been increasing. In this study, we investigated via LC-MS/MS, the content of 19 different types of PFCs in 302 samples belonging to five different categories of the typical South Korean seafood. The highest levels of PFOA, PFTrDA, PFOS, and PFPeA were found in dried seafood, canned and salted seafood, processed fish food, and seasoned laver, respectively. The levels of PFOA and PFOS were compared on the basis of various criteria including the nomenclature, biological classification, and habitat of the source of seafood. High levels of PFOA and PFOS were detected in anchovy, sea squirt, and mackerel based on the nomenclature of raw seafood, in crustaceans based on the biological classification, and in demersal organisms based on the habitat. The human intake values of PFOA and PFOS from the processed marine products in South Korea were lower than the tolerable daily intake, indicating that the consumption of these processed seafood poses no immediate harm.
Assuntos
Fluorocarbonos/química , Contaminação de Alimentos/análise , Alimentos Marinhos/análise , Animais , Cromatografia Líquida , Humanos , República da Coreia , Espectrometria de Massas em TandemRESUMO
We analyzed 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and 12 dioxin-like polychlorinated biphenyls (DL-PCBs) in samples from various fish species available at food markets in nine Korean cities. The estimated dietary intake of these chemicals was calculated from the raw concentrations of PCDD/Fs and DL-PCBs in each sample and from the food consumption of the Korean general population, and a comparison was made with the provisional tolerable monthly intake (PTMI). The average daily dietary exposure and the 95th percentile of intake of PCDD/Fs and DL-PCBs were 0.21 and 0.49 pg WHO05-toxic equivalents (TEQ) kg(-1) body weight d(-1) representing 5.27% and 12.26%, respectively, of the Korean tolerable daily intake (TDI). We applied the monthly fish consumption limits to the evaluation of improved risk assessment and concluded that unlimited consumption of most fish species does not contribute to the elevated cancer risk. This investigation was the first such large-scale study in Korea, and incorporated 37 species, including a species of whale, and 480 samples. The major aims of this study were to demonstrate the health risks associated with fish intake and to ensure food safety through total analysis of PCDD/Fs and DL-PCBs using gas chromatography/high-resolution mass spectrometry (GC-HRMS).
Assuntos
Benzofuranos/análise , Peixes , Contaminação de Alimentos/análise , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análogos & derivados , Poluentes Químicos da Água/análise , Adulto , Animais , Dibenzofuranos Policlorados , Dieta , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Dibenzodioxinas Policloradas/análise , República da Coreia , Medição de RiscoRESUMO
A total of 175 samples, composed of 35 different foodstuffs, were obtained from retail markets in Korea and analyzed to investigate the contamination status and dietary intake of Dechlorane compounds. The concentrations of Dechlorane Plus (DP), mirex, Dechlorane (Dec) 602 and 603 ranged from ND to 169.85 pg/g wet weight (ww), 107.30 pg/g ww, 20.81 pg/g ww, 0.41 pg/g ww, respectively, while Dechlorane (Dec) 604 was not detected in any samples. Strong correlations between anti- and syn-DP and between mirex and Dec 602 were observed. The average anti-isomer fractional abundance (fanti) was 0.78±0.11 which was larger than the technical DP value (fanti=0.75). The estimated dietary daily intake of DP, 11.2×10(3) pg/day, was one to three orders of magnitude higher than other Dechloranes. Grain was the most contributed food group to dietary daily intake of DP for Korean population.
Assuntos
Poluentes Ambientais/análise , Retardadores de Chama/análise , Contaminação de Alimentos/análise , Dieta , Monitoramento Ambiental , Humanos , Hidrocarbonetos Clorados/análise , Mirex/análise , Compostos Policíclicos/análise , República da CoreiaRESUMO
A total of 214 samples, consisting of brown rice, barley, mixed grains, corn, wheat and wheat flour were analysed for T-2 and HT-2 toxins using high-performance liquid chromatography with fluorescence detection. Recovery and repeatability were 79.9%-107.5% and 4.9%-14.5% for T-2, and 74.0%-106.1% and 5.0%-17.9% for HT-2, respectively. T-2 toxin was detected in 11 (5.1%) of all samples. The highest incidence was found in corn (21.7%) followed by mixed grains and brown rice. Mean of all samples was 1.5-4.1 µg kg⻹, the maximum level being 41.5 µg kg⻹ in corn. HT-2 toxin was detected in 126 (58.9%) of all samples, and the mean values were 26.4-59.2 µg kg⻹. The estimated daily intakes for the sum of T-2 and HT-2 toxins were 2.56, 3.22, 2.53, 0.03, 0.01 and 2.45 ng (kg bw)⻹ day⻹ in brown rice, barley, mixed grains, corn, wheat and wheat flour, respectively.
Assuntos
Grão Comestível/química , Farinha/análise , Contaminação de Alimentos , Inspeção de Alimentos/métodos , Imunossupressores/análise , Sementes/química , Toxina T-2/análise , Cromatografia Líquida de Alta Pressão , Dieta/efeitos adversos , Dieta/etnologia , Grão Comestível/economia , Farinha/economia , Hordeum/química , Hordeum/economia , Humanos , Imunossupressores/toxicidade , Limite de Detecção , Oryza/química , Oryza/economia , Venenos/análise , Venenos/toxicidade , Reprodutibilidade dos Testes , República da Coreia , Medição de Risco , Espectrometria de Fluorescência , Espectrometria de Massas por Ionização por Electrospray , Toxina T-2/análogos & derivados , Toxina T-2/toxicidade , Triticum/química , Triticum/economia , Zea mays/química , Zea mays/economiaRESUMO
Type-B trichothecenes (deoxynivalenol (DON), nivalenol (NIV), fusarenone-X (FUS-X), 15-acetyldeoxynivalenol (15ADON), and 3-acetyldeoxynivalenol (3ADON)) were determined in 338 cereal-based products. Detection limit, quantification limit and mean recovery for five toxins were in the ranges 0.7-2.6 µg kg(-1), 2.1-7.8 µg kg(-1) and 73-110%, respectively. The range of occurrence and average level in samples were, respectively, 21-88% and 5.2-121.8 µg kg(-1) for NIV, 10-96% and 1.7-109.5 µg kg(-1) for DON, 2-39% and 0.4-3.6 µg kg(-1) for FUS-X, 0-80% and 0-17.3 µg kg(-1) for 15ADON, and 0-29% and 0-1.5 µg kg(-1) for 3ADON. Regarding co-occurrence, 64% of samples had more than two type-B trichothecenes. The estimated daily intakes of NIV, DON, FUS-X, 15ADON, and 3ADON were 0.077, 0.048, 0.004, 0.006 and 0.002 µg kg(-1) bw day(-1), respectively. These results suggest that current exposure levels do not indicate the possibility of adverse effects, but consideration of the combined exposure of type-B trichothecenes may be required due to the high frequency of co-occurrence.
Assuntos
Grão Comestível/química , Contaminação de Alimentos/análise , Tricotecenos/análise , Cromatografia Gasosa , Limite de Detecção , República da CoreiaRESUMO
The most massive globular cluster in the Milky Way, omega Centauri, is thought to be the remaining core of a disrupted dwarf galaxy, as expected within the model of hierarchical merging. It contains several stellar populations having different heavy elemental abundances supplied by supernovae-a process known as metal enrichment. Although M 22 appears to be similar to omega Cen, other peculiar globular clusters do not. Therefore omega Cen and M 22 are viewed as exceptional, and the presence of chemical inhomogeneities in other clusters is seen as 'pollution' from the intermediate-mass asymptotic-giant-branch stars expected in normal globular clusters. Here we report Ca abundances for seven globular clusters and compare them to omega Cen. Calcium and other heavy elements can only be supplied through numerous supernovae explosions of massive stars in these stellar systems, but the gravitational potentials of the present-day clusters cannot preserve most of the ejecta from such explosions. We conclude that these globular clusters, like omega Cen, are most probably the relics of more massive primeval dwarf galaxies that merged and disrupted to form the proto-Galaxy.
RESUMO
Reducing the particle size of materials is an efficient and reliable tool for improving the bioavailability of a gene or drug delivery system. In fact, nanotechnology helps in overcoming the limitations of size and can change the outlook of the world regarding science. However, a potential harmful effect of nanomaterial on workers manufacturing nanoparticles is expected in the workplace and the lack of information regarding body distribution of inhaled nanoparticles may pose serious problem. In this study, we addressed this question by studying the body distribution of inhaled nanoparticles in mice using approximately 50-nm fluorescent magnetic nanoparticles (FMNPs) as a model of nanoparticles through nose-only exposure chamber system developed by our group. Scanning mobility particle sizer (SMPS) analysis revealed that the mice were exposed to FMNPs with a total particle number of 4.89 x 10(5) +/- 2.37 x 10(4)/cm(3) (low concentration) and 9.34 x 10(5) +/- 5.11 x 10(4)/cm(3) (high concentration) for 4 wk (4 h/d, 5 d/wk). The body distribution of FMNPs was examined by magnetic resonance imaging (MRI) and Confocal Laser Scanning Microscope (CLSM) analysis. FMNPs were distributed in various organs, including the liver, testis, spleen, lung and brain. T2-weighted spin-echo MR images showed that FMNPs could penetrate the blood-brain-barrier (BBB). Application of nanotechnologies should not produce adverse effects on human health and the environment. To predict and prevent the potential toxicity of nanomaterials, therefore, extensive studies should be performed under different routes of exposure with different sizes and shapes of nanomaterials.
Assuntos
Poluentes Ocupacionais do Ar/farmacocinética , Exposição por Inalação/efeitos adversos , Nanopartículas/efeitos adversos , Exposição Ocupacional , Animais , Barreira Hematoencefálica/fisiologia , Modelos Animais de Doenças , Feminino , Fluorescência , Imageamento por Ressonância Magnética , Masculino , Camundongos , Microscopia ConfocalRESUMO
PURPOSE: The purpose of this study was to investigate the proton metabolic differences of the right parietal cortex with experimental brain contusions of ICR mouse induced by fluid percussion injury (FPI) compared to normal controls and to test the possibility that 1H magnetic resonance spectroscopy (MRS) findings could provide neuropathologic criteria in the diagnosis and monitoring of traumatic brain contusions. MATERIALS AND METHODS: A homogeneous group of 20 ICR male mice was used for MRI and in vivo 1H MRS. Using image-guided, water-suppressed in vivo 1H MRS with a 4.7 T MRI/MRS system, we evaluated the MRS measurement of the relative proton metabolite ratio between experimental brain contusion of ICR mouse and healthy control subjects. RESULTS: After trauma, NAA/Cr ratio, as a neuronal marker decreased significantly versus controls, indicating neuronal loss. The ratio of NAA/Cr in traumatic brain contusions was 0.90+/-0.11, while that in normal control subjects was 1.13+/-0.12 (P=0.001). The Cho/Cr ratio had a tendency to rise in experimental brain contusions (P=0.02). The Cho/Cr ratio was 0.91+/-0.17, while that of the normal control subjects was 0.76+/-0.15. However, no significant difference of Glx/Cr was established between the experimental traumatic brain injury models and the normal controls. DISCUSSION AND CONCLUSIONS: The present 1H MRS study shows significant proton metabolic changes of parietal cortex with experimental brain contusions of ICR mouse induced by FPI compared to normal controls. In vivo 1H MRS may be a useful modality for the clinical evaluation of traumatic contusions and could aid in better understanding the neuropathologic process of traumatic contusions induced by FPI.