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Particle pollution from urban and industrialized regions in Rio de Janeiro (RJ), Brazil was analyzed for toxic and pro-inflammatory (cytokines: IL-6, IL-8, IL-10) responses in human bronchial epithelial cells. Trace elements contribution was studied. Airborne particulate matter was collected at: three industrial sites Ind-1 (PM10) and Ind-2a and 2b (PM2.5); Centro urban area (PM10) and two rural sites (PM2.5, PM10). PM10 acetone extracts were toxic and did not elicit cytokine release; aqueous extracts were less toxic and stimulated the release of IL-6 and IL-8. PM2.5 aqueous extracts from Ind-2 decreased the release of IL-6 and IL-8. Zinc concentration was higher at the industrial and rural reference sites (Ref-1-2) although metals were not associated to cytokines changes. These results demonstrate that PM from RJ can either increase or decrease cytokine secretion in vitro while being site specific and time dependent.

Aerosol particle samples (PM10) were collected at urban, industrial and rural sites located in Rio de Janeiro, Brazil, between October 2008 and September 2009. Aerosol samples for each site were analyzed for total and soluble metals, water-soluble ions, carboxylic acids, and water-soluble organic carbon (WSOC). The results showed that the mean PM10 concentrations were 34 μg m(-3); 47 μg m(-3) and 71 μg m(-3) at the rural, urban and industrial sites, respectively. An increase in the average concentration of these particles due to air stagnation was observed during the period from May to September for all sites, and an increase in hospitalization for respiratory problems was also reported. On average, the anions species represented 4 to 14% of total content, while cations species corresponded to 1 to 11% and 7.5% for WSOC. The overall metal content at the industrial site was nearly the double that at the rural site. The concentrations of the studied species are influenced mainly by site location and the specific characteristics present at each site. However, higher concentrations of some species were observed on particular dates and were probably due to biomass burning and African dust events. The acid/aqueous percentiles showed that the most efficiently extracted metals from the aqueous phase were V and Ni (40%), while Al and Fe represented a lower percentage (<3%). Analysis of the aqueous fraction provides important information about the bioavailability of metals that is associated with the inflammatory process in the lungs.

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Toxicological responses of exhaust emissions of biodiesel are different due to variation in methods of generation and the tested biological models. A chemical profile was generated using ICP-MS and GC-MS for the biodiesel samples obtained in Brazil. A cytotoxicity assay and cytokine secretion experiments were evaluated in human bronchial epithelial cells (BEAS-2B). Cells were exposed to polar (acetone) and nonpolar (hexane) extracts from particles obtained from fuel exhaust: fossil diesel (B5), pure soybean biodiesel (B100), soybean biodiesel with additive (B100A) and ethanol additive (EtOH). Biodiesel and its additives exhibited higher organic and inorganic constituents on particles when compared to B5. The biodiesel extracts did not exert any toxic effect at concentrations 10, 25, 50, 75, and 100 μg mL -1. In fact quite the opposite, a cell proliferation effect induced by the B100 and B100A extracts is reported. A small increase in concentrations of inflammatory mediators (Interleukin-6, IL-6; and Interleukin-8, IL-8) in the medium of biodiesel-treated cells was observed, however, no statistical difference was found. An interesting finding indicates that the presence of metals in the nonpolar (hexane) fraction of biodiesel fuel (B100) represses cytokine release in lung cells. This was revealed by the use of the metal chelator. Results suggest that metals associated with biodiesel’s organic constituents might play a significant role in molecular mechanisms associated to cellular proliferation and immune responses.

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This study evaluated the concentration profiles of regulated and unregulated pollutants emitted from a stationary diesel engine cycle, operating at the speed of 1800 rpm and 0% load, using biofuels and binary blends. The experimental test considered fuel burning time on three different periods and storage times. The operation of the engine when it is still cold, for example at 15 minutes, showed negative effect on particulate matter (PM), benzene and ethylbenzene emissions in pure soybean biodiesel (B100) compared to the blend of diesel with 5% biodiesel (B5). Regarding to the concentration of mono aromatics, aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAH), this study showed similar results to those reported in the literature, where B5 fuel emits more pollutants than pure biodiesel. However, comparing some pollutants individually, benzene and ethylbenzene emissions were higher for B100 and pure soybean biodiesel with butil-hydroxyanisol additive (B100 Adt). The B5 showed the highest concentration profile for the PAH sum in the gaseous and particulate phases in longer engine operation periods.