Measurements of indoor 222Rn concentration in two art galleries

It is point out that radon and their decay products in environment give high dose to human lung. Studies indicate that the indoor radon inhalation by humans has been considered probably the second most important cause of lung cancer after of smoking. A passive-type radon detector was used for measuring indoor radon concentration in two art galleries at Rio de Janeiro city during 90 days January to March, 2009. The aim of this study is to evaluate the occupational and public radon exposure in art galleries and museums. This paper shows the preliminary results of samples collected at two art galleries located in Gávea, Rio de Janeiro city. 30 LEXAN (GE) track detectors were exposed in the air (indoor as well as outdoor). The samples were collected in the same building which is a construction of XIX century. The analysis of the results suggests that the 222Rn concentration levels are different in both sampling site, in closed environmental, demonstrating that, although the construction materials are the same the absence of circulating air is a factor very important to increase the concentration of indoor Rn

Utilização do método pixe para a caracterização de aerossol urbano

Apresenta os resultados de um estudo preliminar para avaliar a poluição urbana usando o método PIXE (Proton Induced X ray Emission) como técnica analítica e o impactador em cascata como amostrador dos particulados. O método PIXE tem por análise multielementar com limite de detecção da ordem de nanograma para todos os elementos da tabela periódica acima do 11Na. As amostras de aerossóis para determinação do tamanho dos particulados e da concentração elementar foram coletadas com imapactador em cascata que separa os particulados em seis faixas de tamanhos diferentes nas frações respirável e inalável do aerossol. As amostras foram coletadas junto ao Planetário da Gávea na cidade do Rio de Janeiro, localizado na Auto estrada Lagoa-Gávea, por ser afastado de áreas industriais. Os resultados deste estudo preliminar indicam que os particulados coletados continham Ti, Fe. Ca, Cu, K, V, Cr, Zn, Ni, e Mn. Estes particulados estavam na fração respirável do aerossol com MMAD (Mass Median Aerodynamic Diameter) menor que 2,0 mm. Os resultados obtidos indicam a necessidade de um estudo mais detalhado da qualidade do ar das áreas urbanas e que o método PIXE, no arranjo experimental usado, apresentou alta sensibilidade para análise de aerossóis urbanos

Study of Worker’s Exposure to Tantalum-bearing Particles in a Mining and Metallurgical Plant

Submitted by Sherillyn Lopes ([email protected]) on 2016-07-04T22:29:46Z No. of bitstreams: 1 EGAH-D-15-00251_R1-1.pdf: 877174 bytes, checksum: 416fdefeca3047e6c239217edd649770 (MD5)Made available in DSpace on 2016-07-04T22:29:47Z (GMT). No. of bitstreams: 1 EGAH-D-15-00251_R1-1.pdf: 877174 bytes, checksum: 416fdefeca3047e6c239217edd649770 (MD5) Previous issue date: 2002The objective of this study was to assess worker exposure to mineral dust particles and a metabolic model, based on the model adopted by ICRP, was applied to assess human exposure to Ta, and predicted values of Ta concentrations in excreta. The occupational exposure to Th, U, Nb, and Ta bearing particles during routine tasks to obtain Fe-Nb alloys was estimated using air samplers and excreta samples. Ta concentrations in food samples and in drinking water were also determined. The results support that workers were occupationally exposed to Ta bearing particles, and also indicate that a source of Ta exposure for both workers and the control group was the ingestion of drinking water containing soluble compounds of Ta. Therefore, some Ta compounds should be considered soluble compounds in gastrointestinal tract. Consequently the metabolic model based on ICRP metabolic model and/or the transfer factor f1 for Ta should be reviewed and the solubility of Ta compounds in gastrointestinal should be determined

Inferring episodic atmospheric iron fluxes in the Western South Atlantic

Iron (Fe) and other trace elements such as Zn, Mn, Ni and Cu are known as key-factors in marine biogeochemical cycles. It is believed that ocean primary productivity blooms in iron deficient regions can be triggered by iron in aeolian dust. Up to now, scarce aerosol elemental composition, based on measurements over sea at the Western South Atlantic (WSA), exist. An association between the Pata-gonian semi-desert dust/Fe and chlorophyll-a variability at the Argentinean continental shelf is essen-tially inferred from models. We present here experimental data of Fe enriched aerosols over the WSA between latitudes 22 Se62 S, during 4 oceanographic campaigns between 2002 and 2005. These data allowed inferring the atmospheric Fe flux onto different latitudinal bands which varied from 30.4 to 1688 nmolFe mÀ2 dayÀ1 (October 29 theNovember 15th, 2003); 5.83e1586 nmolFe mÀ2 dayÀ1 (February15theMarch 6th, 2004) and 4.73e586 nmolFe mÀ2 dayÀ1(October 21 steNovember 5th, 2005)