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| Author(s): |
Jôse Mára de Brito
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina (FM/SBD) |
| Defense date: | 2014-09-22 |
| Examining board members: |
Paulo Hilario Nascimento Saldiva;
Sandra Helena Poliselli Farsky;
Elnara Márcia Negri;
Luiz Alberto Amador Pereira
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| Advisor: | Paulo Hilario Nascimento Saldiva |
| Abstract | |
Background: In urban environments, the exhaust of diesel cars is an important source of particles and gases that directly affect people\'s health. As the addition of biodiesel to diesel is recent, it is necessary to evaluate the toxicological profile of these emissions and the possible adverse health effects. Moreover, the concentration of air pollutants and their physico-chemical composition suffer direct influences of weather conditions. This study aims to evaluate the toxicological profile of primary pollutants (emitted directly from the source) and secondary (generated from the weather conditions) through two studies. Objectives: (Study I) Evaluate the acute exposure of diesel and biodiesel exhaust in pulmonary and systemic inflammatory profile. (Study II) Evaluated whether acute exposure to low levels of concentrated ambient particles (CAPs) promotes cardiopulmonary and systemic effects; and whether the magnitude of these observed changes is influenced by periods (cold/dry and warm/humid). Methods: (Study I) Balb/C mice were exposed for two hours to filtered air (FA) and two doses (600 and 1200 ?g/m3) of both diesel (D) and biodiesel (BD) fuels. The PM2.5, NO, and NO2 concentrations, air temperature and humidity were monitored in real time. HRV (time and frequency domain), HR and BP parameters were collected after 30 minutes of exposure. After 24 hours were available the bronchoalveolar lavage (BALf), lung histology, blood and bone marrow for pulmonar and systemic inflammation analysis. The cytokines expression (ET-Ar, ET-Br, INOs, ISO, VCAM, IL-8) were available on peribronchiolar vessels and bronchial epithelium. (Study II) Balb/C mice were exposed to 200 ?g/m3 to concentrated ambient particles (CAPs) and filtered air (FA) in cold/dry and warm/humid periods. Lung hyper-responsiveness, heart rate, heart rate variability and blood pressure were evaluated 30 minutes after the exposures. After 24 hours, blood and tissue sampling were performed. Results: (Study I) Emissions of NO and NO2 were higher in the biodiesel compared to diesel oil exhaust. There was an increase in HRV for the BD600, D600 and D1200 compared to FA, already BP reduced the D1200 compared to FA. There was an increase on the erythrocytes, hematocrit, RDW-SD and reticulocytes in BD1200 and D1200 compared to FA; increase in erythrocytes, lymphocytes and RDW-SD on D600 compared to FA; and reduction of MCHC in BD1200 and D1200 compared to FA. BAL and lung histology was evidenced an increase on the neutrophils BD600 compared to FA. In peribronchiolar vessels there was increased of the expression on ET-Ar and ET-Br on the BD600 compared to FA. In the bronchial epithelium there was increased expression of ET-Br in BD600, BD1200, D600 and D1200 compared to FA, increased VCAM on the BD1200 and D600 compared to FA. (Study II) CAPs generated during both periods (warm/humid and cold/dry) induced alterations in red blood cells and lung inflammation. CAPs during the cold/dry period reduced the mean corpuscular volume (MCV) levels and increased erythrocytes, hemoglobin, mean corpuscular hemoglobin concentration (MCHC) and red cell distribution width coefficient variation (RDW-CV) levels compared to the FA group. Similarly, CAPs during the warm/humid period decreased MCV levels and increased erythrocytes, hemoglobin, haematocrit and RDW-CV levels compared to the FA group. CAPs during the cold/dry period increased the influx of neutrophils in the alveolar parenchyma. No differences were obtained on vasoconstrictors of pulmonary vessels. Conclusion: The exposure to biodiesel caused lung inflammation, bronchoconstriction of the peribronchiolar vessels and bronchial epithelium; already the exposure of the diesel caused systemic inflammation, increased of the parasympathetic stimulation and bronchoconstriction of the bronchial epithelium. Short-term exposures to low concentrations of CAPs elicited modest but significant pulmonary inflammation and, into a lesser extent, changes in blood parameters. In addition, our data support the concept that changes in climate conditions modify slightly particle toxicity, since equivalent doses of CAPS of the cold/dry period produced a more exacerbated response (AU) | |