Chemical composition, sources, solubility, and transport of aerosol trace elements in a tropical region

Abstract

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.

Size-segregated particulate matter and carboxylic acids over urban and rural sites in Londrina City, Brazil

“…[32][33][34][35][36][37][38] For example, Vasconcellos et al 39 recently performed a comparative study of the atmospheric chemical composition of Bogotá, Buenos Aires and São Paulo Cities and found that samples from São Paulo showed the highest concentrations of species analyzed on PM 10 (n-alkanes, water-soluble ions, polycyclic aromatic hydrocarbon, metals and metalloids) among all the sites. Also, Gioda et al 40 performed studies concerning chemical composition, sources, solubility and transport of aerosol trace elements in Rio de Janeiro City. Although these large urban areas concentrate a large portion of population, investigations on urban cities with potential to become a large urban conglomeration as well as rural sites (typically used for grain cultivation) are very important since they contribute with information to understand the impacts of anthropic activities (e.g.…”

Concentration Profiles of Regulated and Unregulated Pollutants Emitted from the Combustion of Soybean Biodiesel and Diesel/Biodiesel Blend Originating of a Diesel Cycle Engine

“…Photochemical processes associated with the decomposition organic species, e.g., HC, are important secondary sources. [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] The formaldehyde/acetaldehyde ratios were compared with those cited in the literature 37 and the results were consistent. The lowest average rate in this study was 0.7 for B5.…”

“…Filters containing PM were extracted with 3.00 mL of bidistilled nitric acid, digested for 2 hours at 95 °C and cooled to 20-25 °C. 25 Then, the extracts were centrifuged to separate insoluble particles and diluted with ultrapure water. The metals quantified in the extracts were Al, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Cd, Sb, Pb, Ti, Ba, Na, Mg, Ca, Co, and K. Calibration solutions were prepared from multielement standard solutions 1000 µg L .…”

“…The metals quantified in the extracts were Al, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Cd, Sb, Pb, Ti, Ba, Na, Mg, Ca, Co, and K. Calibration solutions were prepared from multielement standard solutions 1000 µg L . 25 For the determination of metals in the fuels, 0.7417 g of B5, 0.7896 g of B100 Adt, and 0.7952 g of B100 were weighed and transferred to Teflon tubes with the addition of 5.0 mL of bidistilled nitric acid. The flasks were placed in a block digester (DAH-904, Berghof, Germany) with programmed temperature starting at 100 °C for 30 minutes residence time followed by 10 °C for 30 minutes up to 160 °C.…”

Biomonitoring of metals for air pollution assessment using a hemiepiphyte herb (Struthanthus flexicaulis)

“…In Brazil, urban areas, such as Rio de Janeiro, suffer from PM air pollution (Gioda et al, 2011;Käffer et al, 2011). Researchers have employed biomonitoring by herbs to assess source apportionment, such as biomass burning (Giodarmo et al, 2013;García et al, 2009).…”