Journal of Radioanalytical and Nuclear Chemistry, 2005
Summary Rib bones of Brazilian people were analyzed by neutron activation analysis to evaluate e... more Summary Rib bones of Brazilian people were analyzed by neutron activation analysis to evaluate element composition. Freeze-dried cortical and trabecular tissues, separately, and calcinated total rib tissues were analyzed. The concentrations of the Ba, Br, Ca, Cl, Fe, K, Mg, Mn, Na, P, Rb, Sr, and Zn elements were determined. Comparisons between the results obtained in cortical and trabecular bones indicated significant differences in the concentration for several elements. Results obtained in cortical and trabecular bones were also compared with literature values.
This study used the radiotracer method to measure the initial enamel wear caused by low- and high... more This study used the radiotracer method to measure the initial enamel wear caused by low- and high-fusing porcelains after glazing or polishing. It also tested the correlation between enamel wear and porcelain surface roughness (Ra). Surface morphology was assessed by optical microscopy. Cylindrical specimens of three porcelains (two high-fusing, one low-fusing) were either autoglazed or polished. Flattened enamel specimens were irradiated with neutrons and submitted to the wear assay for 2,500 cycles in distilled water using a 285 g load; the released beta 32P particles were measured for 10 minutes. For all samples, Ra was recorded with a profilometer before and after testing. Enamel wear was not significantly different for porcelain or finishing method but there was a trend of interaction between the two variables (p = 0.08). A positive correlation was found between enamel wear and the initial Ra of porcelain (r = 0.71). The glazed surfaces of high-fusing porcelains were wavy and h...
This study presents results of instrumental neutron activation analysis (INAA) of nails from heal... more This study presents results of instrumental neutron activation analysis (INAA) of nails from healthy adult individuals living in São Paulo city, Brazil. Concentrations of As, Br, Ca, Co, Cr, Fe, K, La, Na, Sb, Se and Zn were determined in fingernails and toenails and their variations with gender, age, body mass index among individuals and inter-element correlations were evaluated. These results indicated that several factors might affect in the nail element composition. In addition, there are few published data for finger and toenails analyses. However, comparisons made between the concentrations of elements obtained in fingernails were reasonable within the range of literature values. The findings of this study may contribute to establish an appropriate protocol to obtain data of nail element composition to be used as reference values.
Heavy metals are natural and essential elements of the environment and living beings, produced fr... more Heavy metals are natural and essential elements of the environment and living beings, produced from natural (e.g. volcanic activity and cosmic ray-induced spallation) and anthropogenic processes (e.g. industrial and fossil fuel combustion). Studies showed increase of heavy metal and Polonium-210 concentrations in lung autopsies linked to urban and industrial air pollution. In this preliminary study, we analyzed the levels of heavy metals and Polonium-210 (210Po) in lung tissues in autopsies from residents of the city of Sao Paulo, SP, Brazil. In order to identify the generating sources of the heavy metals in lung a factor analysis was performed. Of the first four factors, which explain 66% of the total variability, three were associated with vehicular sources. The fitting of a regression model with Polonium-210 as the response variable and with the four factors as explanatory variables, controlling for age, sex and tobacco, showed a significant association between the concentration ...
In IPEN’s Neutron Activation Laboratory (LAN/IPEN), thin stainless steel sample holders are used ... more In IPEN’s Neutron Activation Laboratory (LAN/IPEN), thin stainless steel sample holders are used for gamma spectrometry in NAA measurements. This material is very practical, but its chemical composition may be troublesome, as it presents large amounts of elements with intermediate atomic number, with attenuation factors for low-energy gamma-rays that must not be neglected. In this study, count rates obtained using different sample holders were compared. To accomplish that, an Am-241 source, with 59-keV gamma emission, was used so that low-energy gamma attenuation differences can be determined. Moreover, in order to study the energy dependence of these differences, a Ho-166m source was also used. From these results, it was possible to analyze the experimental error associated to the variations between sample holders, with the aim of introducing an addictive term to the uncertainty analysis of comparative Neutron Activation Analysis results.
Work-exacerbated asthma (WEA) is defined as preexisting asthma that worsens with exposure to irri... more Work-exacerbated asthma (WEA) is defined as preexisting asthma that worsens with exposure to irritants [e.g., chlorine (Cl) derivatives] in the workplace. The maximum allowable concentration in the workplace of Cl exposure is 3 mg/ m (described in OSHA). We investigated in an experimental asthma model in mice the effects of a single exposure to a sodium hypochlorite dose with this allowed chlorine concentration and a tenfold higher dose. Acute chlorine exposure at 3.3 mg/m in the OVA-sensitized group increased eosinophils in the peribronquial infiltrate, cytokine production, nasal mucus production and the number of iNOS positive cells in the distal lung compared to only sensitized mice. The exposure to a higher dose of 33.3 mg/m in the OVA-sensitized group resulted in an increase in respiratory system elastance, in the total and differential numbers of inflammatory cells in bronchoalveolar lavage fluid, IL-4, IL-5, and IL-17 in the lungs, eosinophils in peribronquial infiltrate and ...
Urban gardening is a growing global phenomenon with a positive impact on society. Despite several... more Urban gardening is a growing global phenomenon with a positive impact on society. Despite several associated benefits, growing vegetables in urban gardens that are localized in highly polluted areas poses questions about the safety of the produced food. Therefore, the identification of risk factors that result in possible deleterious effects to human health is important for realizing all of the benefits to society. We evaluated the use of two biomonitoring methods in ten urban gardens of Sao Paulo city and one control site: the micronuclei frequencies for early tetrads of Tradescantia pallida (Rose) Hunt. cv. "Purpurea" Boom (hereafter, Trad-MCN) as a short-term indicator of genotoxic response and tree barks to quantify the accumulation of traffic-related chemical elements as a long-term biomarker of air pollution in urban gardens. Mature plants of Tradescantia pallida were exposed in each garden, and their inflorescences were sampled over three months. A random set of 300...
Este trabalho apresenta os resultados analíticos da determinação de elementos químicos em materia... more Este trabalho apresenta os resultados analíticos da determinação de elementos químicos em materiais plásticos metalizados, obtidos por análise por ativação com nêutrons (NAA) e os resultados da identificação de polímeros por espectroscopia no infravermelho (IR) e calorimetria exploratória diferencial (DSC). Foram coletadas amostras de plásticos metalizados de embalagens de alimentos e cosméticos. Os resultados dos testes IR e DSC indicaram que os tipos de polímeros usados em plásticos metalizados são polietileno, polipropileno, poli(tereftalato de etileno) e poliestireno. A NAA consistiu em irradiar as amostras e padrões com fluxo de nêutrons térmicos do reator nuclear IEA-R1, seguido da medida da atividade dos raios gama induzidos usando um detector de Germânio hiperpuro acoplado ao espectrômetro de raios gama. Elementos tóxicos como arsênio, cádmio, cromo, níquel e antimônio assim como elementos não tóxicos como bário, cálcio, cobalto, ferro, escândio, selênio e zinco foram determ...
Journal of Radioanalytical and Nuclear Chemistry, 2005
Summary Rib bones of Brazilian people were analyzed by neutron activation analysis to evaluate e... more Summary Rib bones of Brazilian people were analyzed by neutron activation analysis to evaluate element composition. Freeze-dried cortical and trabecular tissues, separately, and calcinated total rib tissues were analyzed. The concentrations of the Ba, Br, Ca, Cl, Fe, K, Mg, Mn, Na, P, Rb, Sr, and Zn elements were determined. Comparisons between the results obtained in cortical and trabecular bones indicated significant differences in the concentration for several elements. Results obtained in cortical and trabecular bones were also compared with literature values.
This study used the radiotracer method to measure the initial enamel wear caused by low- and high... more This study used the radiotracer method to measure the initial enamel wear caused by low- and high-fusing porcelains after glazing or polishing. It also tested the correlation between enamel wear and porcelain surface roughness (Ra). Surface morphology was assessed by optical microscopy. Cylindrical specimens of three porcelains (two high-fusing, one low-fusing) were either autoglazed or polished. Flattened enamel specimens were irradiated with neutrons and submitted to the wear assay for 2,500 cycles in distilled water using a 285 g load; the released beta 32P particles were measured for 10 minutes. For all samples, Ra was recorded with a profilometer before and after testing. Enamel wear was not significantly different for porcelain or finishing method but there was a trend of interaction between the two variables (p = 0.08). A positive correlation was found between enamel wear and the initial Ra of porcelain (r = 0.71). The glazed surfaces of high-fusing porcelains were wavy and h...
This study presents results of instrumental neutron activation analysis (INAA) of nails from heal... more This study presents results of instrumental neutron activation analysis (INAA) of nails from healthy adult individuals living in São Paulo city, Brazil. Concentrations of As, Br, Ca, Co, Cr, Fe, K, La, Na, Sb, Se and Zn were determined in fingernails and toenails and their variations with gender, age, body mass index among individuals and inter-element correlations were evaluated. These results indicated that several factors might affect in the nail element composition. In addition, there are few published data for finger and toenails analyses. However, comparisons made between the concentrations of elements obtained in fingernails were reasonable within the range of literature values. The findings of this study may contribute to establish an appropriate protocol to obtain data of nail element composition to be used as reference values.
Heavy metals are natural and essential elements of the environment and living beings, produced fr... more Heavy metals are natural and essential elements of the environment and living beings, produced from natural (e.g. volcanic activity and cosmic ray-induced spallation) and anthropogenic processes (e.g. industrial and fossil fuel combustion). Studies showed increase of heavy metal and Polonium-210 concentrations in lung autopsies linked to urban and industrial air pollution. In this preliminary study, we analyzed the levels of heavy metals and Polonium-210 (210Po) in lung tissues in autopsies from residents of the city of Sao Paulo, SP, Brazil. In order to identify the generating sources of the heavy metals in lung a factor analysis was performed. Of the first four factors, which explain 66% of the total variability, three were associated with vehicular sources. The fitting of a regression model with Polonium-210 as the response variable and with the four factors as explanatory variables, controlling for age, sex and tobacco, showed a significant association between the concentration ...
In IPEN’s Neutron Activation Laboratory (LAN/IPEN), thin stainless steel sample holders are used ... more In IPEN’s Neutron Activation Laboratory (LAN/IPEN), thin stainless steel sample holders are used for gamma spectrometry in NAA measurements. This material is very practical, but its chemical composition may be troublesome, as it presents large amounts of elements with intermediate atomic number, with attenuation factors for low-energy gamma-rays that must not be neglected. In this study, count rates obtained using different sample holders were compared. To accomplish that, an Am-241 source, with 59-keV gamma emission, was used so that low-energy gamma attenuation differences can be determined. Moreover, in order to study the energy dependence of these differences, a Ho-166m source was also used. From these results, it was possible to analyze the experimental error associated to the variations between sample holders, with the aim of introducing an addictive term to the uncertainty analysis of comparative Neutron Activation Analysis results.
Work-exacerbated asthma (WEA) is defined as preexisting asthma that worsens with exposure to irri... more Work-exacerbated asthma (WEA) is defined as preexisting asthma that worsens with exposure to irritants [e.g., chlorine (Cl) derivatives] in the workplace. The maximum allowable concentration in the workplace of Cl exposure is 3 mg/ m (described in OSHA). We investigated in an experimental asthma model in mice the effects of a single exposure to a sodium hypochlorite dose with this allowed chlorine concentration and a tenfold higher dose. Acute chlorine exposure at 3.3 mg/m in the OVA-sensitized group increased eosinophils in the peribronquial infiltrate, cytokine production, nasal mucus production and the number of iNOS positive cells in the distal lung compared to only sensitized mice. The exposure to a higher dose of 33.3 mg/m in the OVA-sensitized group resulted in an increase in respiratory system elastance, in the total and differential numbers of inflammatory cells in bronchoalveolar lavage fluid, IL-4, IL-5, and IL-17 in the lungs, eosinophils in peribronquial infiltrate and ...
Urban gardening is a growing global phenomenon with a positive impact on society. Despite several... more Urban gardening is a growing global phenomenon with a positive impact on society. Despite several associated benefits, growing vegetables in urban gardens that are localized in highly polluted areas poses questions about the safety of the produced food. Therefore, the identification of risk factors that result in possible deleterious effects to human health is important for realizing all of the benefits to society. We evaluated the use of two biomonitoring methods in ten urban gardens of Sao Paulo city and one control site: the micronuclei frequencies for early tetrads of Tradescantia pallida (Rose) Hunt. cv. "Purpurea" Boom (hereafter, Trad-MCN) as a short-term indicator of genotoxic response and tree barks to quantify the accumulation of traffic-related chemical elements as a long-term biomarker of air pollution in urban gardens. Mature plants of Tradescantia pallida were exposed in each garden, and their inflorescences were sampled over three months. A random set of 300...
Este trabalho apresenta os resultados analíticos da determinação de elementos químicos em materia... more Este trabalho apresenta os resultados analíticos da determinação de elementos químicos em materiais plásticos metalizados, obtidos por análise por ativação com nêutrons (NAA) e os resultados da identificação de polímeros por espectroscopia no infravermelho (IR) e calorimetria exploratória diferencial (DSC). Foram coletadas amostras de plásticos metalizados de embalagens de alimentos e cosméticos. Os resultados dos testes IR e DSC indicaram que os tipos de polímeros usados em plásticos metalizados são polietileno, polipropileno, poli(tereftalato de etileno) e poliestireno. A NAA consistiu em irradiar as amostras e padrões com fluxo de nêutrons térmicos do reator nuclear IEA-R1, seguido da medida da atividade dos raios gama induzidos usando um detector de Germânio hiperpuro acoplado ao espectrômetro de raios gama. Elementos tóxicos como arsênio, cádmio, cromo, níquel e antimônio assim como elementos não tóxicos como bário, cálcio, cobalto, ferro, escândio, selênio e zinco foram determ...
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