D J A Lobo

Publications (4)4.53 Total impact

• Source

  Available from: Isabel Silva

  Article: Micronucleus formation induced by biomass burning particles derived from biomass burning induce high micronucleus frequency in Tradescantia pallida assay (TRAD-MN)

  I.C. Silva, M.C.C Peron, M.A. Arbex, A.J.F.C. Lichtenfels, D.J.A. Lobo, M.P. Giocondo, M. MACCHIONE, M. SAIKI, P.H.N. Saldiva, C.P. Soares
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  ABSTRACT: Manual harvesting is usually done after to sugar cane burning which is responsible for seasonal emission of air pollutants in Brazil and it is believed to be responsible for deleterious health effects in exposed populations. The mutagenic potential of sugar cane burning harvesting particulate and particle surrogates of residual oil fly ash (ROFA) were evaluated in assays measuring micronuclei (MN) in the pollen mother cells of Tradescantia pallida (TRAD-MN). Micronuclei frequencies in TRAD-MN to sugar cane burning residues (SCBR) at doses 0.3 and 0.03 mg/mL were respectively 2.18 ± 0.35 and 5.53 ± 1.04, whereas to ROFA from incinerator and ROFA from an electrostatic precipitator installed in one of the chimneys of a steel plant, MN frequencies were, respectively, 3.43 ± 0.7 and 4.90 ± 1.07. Significant differences were detected among the groups (p < 0.001), demonstrating that SCBR was at least as genotoxic as the fossil fuel derived particles. The results suggest that the burning process to harvest sugar cane should be better controlled.
  Journal of the Brazilian Society of Ecotoxicology. 01/2012; 7:1-7.
• Source

  Available from: ipen.br

  Article: Diesel emissions significantly influence composition and mutagenicity of ambient particles: a case study in São Paulo, Brazil.

  R Carvalho-Oliveira, R M K Pozo, D J A Lobo, A J F C Lichtenfels, H A Martins-Junior, J O W V Bustilho, M Saiki, I M Sato, P H N Saldiva
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  ABSTRACT: In 2003, a bus strike paralyzed the fleet of buses in Sao Paulo, Brazil during 3 days, from 6 to 8 of April, the complete interruption of services being achieved on the 7th. We evaluated the effect of the absence of this source of pollution on the composition, mutagenicity, and toxicity of the fine particulate material collected during this period. Particles were sampled in glass fiber filters on days 7 and 15 of April of 2003 (strike and nonstrike days, respectively), using a high-volume sampler. Trace element determinations (As, Br, Co, Cl, Fe, La, Mn, Sb, Sc, and Th) of particulate material samples were carried out by neutron activation analysis. Sulfur determination was done by X-ray fluorescence analysis. The ratio between nonstrike/strike concentrations of hydrocarbons associated with automotive emissions (benzene, toluene, ethyl-benzene, and xylenes; BTEX) was determined by gas chromatography/mass spectrometry. Mutagenesis of testing solutions was determined by means of the Tradescantia micronucleus assay in early tetrads of Tradescantia pallida. The inhibition of mitosis of the cells of the primary meristema of the root tips of Allium cepa was used as an index of the toxicity. Fine particle trace element contents were lower during the strike. The concentrations of sulfur and BTEX were 50% and 39.3% lower, respectively, on the strike day. A significant (P=0.038) reduction of micronuclei induced by fine particles sampled during the strike was observed. No effect of the strike on toxicity was detected. These results indicate that a program aiming to reduce emissions of the bus fleet in our town may impact positively the air quality by reducing the mutagenic potential of ambient particles.
  Environmental Research 06/2005; 98(1):1-7. · 3.40 Impact Factor
• Article: Pollen mother cells of Tradescantia clone 4430 and Tradescantia pallida var. purpurea are equally sensitive to the clastogenic effects of X-rays.

  F Suyama, E T Guimarães, D-J A Lobo, G S Rodrigues, M Domingos, E S Alves, H A Carvalho, P H N Saldiva
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  ABSTRACT: The Tradescantia micronucleus test is a sensitive bioassay for mutagenesis that may be employed both under field and laboratory conditions. This test has been standardized mostly on the basis of the results obtained with clone 4430. However, this clone is not well adapted to tropical weather, frequently showing problems with growth and flowering. In addition, it is attacked by parasites and insects, a fact that limits its use in field studies aiming at the biomonitoring of air pollution. In the city of São Paulo, Tradescantia pallida (Rose) Hunt. var. purpurea Boom is widely distributed as an ornamental plant in gardens and along roadsides and streets, mostly because of its natural resistance and its easy propagation. In this report, we present dose-response curves indicating that the sensitivity of T. pallida and clone 4430 to X-radiation (1, 10, 25 and 50 cGy) is similar. The results confirm our previous suggestion that T. pallida represents a good alternative for in situ mutagenesis testing in tropical regions, especially biomonitoring studies in which the exposure conditions may not be fully controllable.
  Brazilian Journal of Medical and Biological Research 02/2002; 35(1):127-9. · 1.13 Impact Factor
• Article: Diesel emissions significantly influence composition and mutagenicity of ambient particles: a case study in São Paulo, Brazil

  R. Carvalho-Oliveira, R.M.K. Pozo, D.J.A. Lobo, A.J.F.C. Lichtenfels, H.A. Martins-Junior, J.O.W.V. Bustilho, M. Saiki, I.M. Sato, P.H.N. Saldiva
  [show abstract] [hide abstract]
  ABSTRACT: In 2003, a bus strike paralyzed the fleet of buses in São Paulo, Brazil during 3 days, from 6 to 8 of April, the complete interruption of services being achieved on the 7th. We evaluated the effect of the absence of this source of pollution on the composition, mutagenicity, and toxicity of the fine particulate material collected during this period. Particles were sampled in glass fiber filters on days 7 and 15 of April of 2003 (strike and nonstrike days, respectively), using a high-volume sampler. Trace element determinations (As, Br, Co, Cl, Fe, La, Mn, Sb, Sc, and Th) of particulate material samples were carried out by neutron activation analysis. Sulfur determination was done by X-ray fluorescence analysis. The ratio between nonstrike/strike concentrations of hydrocarbons associated with automotive emissions (benzene, toluene, ethyl-benzene, and xylenes; BTEX) was determined by gas chromatography/mass spectrometry. Mutagenesis of testing solutions was determined by means of the Tradescantia micronucleus assay in early tetrads of Tradescantia pallida. The inhibition of mitosis of the cells of the primary meristema of the root tips of Allium cepa was used as an index of the toxicity. Fine particle trace element contents were lower during the strike. The concentrations of sulfur and BTEX were 50% and 39.3% lower, respectively, on the strike day. A significant (P=0.038) reduction of micronuclei induced by fine particles sampled during the strike was observed. No effect of the strike on toxicity was detected. These results indicate that a program aiming to reduce emissions of the bus fleet in our town may impact positively the air quality by reducing the mutagenic potential of ambient particles.
  Environmental Research.