Seasonal distribution of airborne trace elements and water-soluble ions in São Paulo Megacity, Brazil

Abstract

Neste trabalho, as distribuições sazonais de Al, Ca, Cu, Fe, K, Mg, Na, Pb, Zn e de íons majoritários (Cl -, Cl -and PO 4 3-while the main organic anions were oxalate and formate. Atmospheric levels for elements were: Fe > Al > Ca > K > Na > Mg > Zn > Cu > Pb. Some sources were predominant for some species: (i) fuel burning and/or biomass burning (NO 3 -, HCOO -, C 2 O 4 2-, K + , Mg 2+ , Ca 2+ , Fe, Pb, Zn, Al, Ca, K and Mg), (ii) gas-to-particle conversion (SO 4 2-and NH 4 + ) and (iii) sea salt spray (Cl -, Na + and Na).

Airborne particles in the Brazilian city of São Paulo: One-year investigation for the chemical composition and source apportionment

“…Ammonium concentrations were not significantly different (p ~ 0.3) and were slightly higher in Int 2.5 (1712 ng m -3 ) than in Ext 2.5 (1370 ng m -3 ). Ratio ∑cations/∑anions (ion balance) was calculated similarly to what was done in the previous study by da Rocha et al (2012). In the present study, the ratios were lower than 1.0 in all the campaigns, and considerably higher in Int 2.5 .…”

“…Na + was strongly correlated with Clin Ext 2.5 (R = 0.78) and had relatively higher correlations with this species (R = 0.35) in the coarse fraction. These species are often associated with marine aerosol, which is mainly in the coarse mode (Godoy et al, 2009;da Rocha et al, 2012). Although it was observed that ocean influence is not the only source of Na + in the site, this species may have vehicular sources (Vieira-Filho et al, 2016).…”

“…The average concentration of PM 2.5 was higher in Int 2.5 than in Ext 2.5 , which can be explained by the fact that the campaign took place in the dry season (winter). In winter, the meteorological conditions are more unfavorable to the dispersion of pollutants and also due to the predominance of sugarcane burning (da Rocha et al, 2005(da Rocha et al, , 2012Sánchez-Ccoyllo and Andrade, 2002;Vasconcellos et al, 2010).…”

“…A previous study performed in São Paulo in 1989 highlights the relative importance of the emissions from residual oil and diesel in PM 2.5 and soil dust in the coarse grain size (Andrade et al, 1994). Da Rocha et al (2012) studied the emission sources of fuel and biomass burning, the gas-to-particle conversion, and sea spray emissions in PM in São Paulo, in one year period (between 2003 and 2004). Another study conducted in the winter of 2003 pointed out a strong impact of local sources in three sites in the state of São Paulo, besides the influence of remote sources (Vasconcellos et al, 2007).…”

Caracterização molecular e ocorrência de HPA, oxi, nitro-HPA, íons inorgânicos e traçadores de queima de biomassa em três sítios urbanos latino-americanos

“…Cu, Zn, As, Se, Cd, Sn, Tl, Pb e Bi; sugerindo que tais elementos podem ser atribuídos às fontes antrópicas neste sítio (emissões veiculares e industriais). Os elementos com valores mais baixos que 10 foram: K, Mn, Ni, Rb, Sr, Cs, Li, Mg, Ca, Fe, Co e Sr, atribuídos à ressuspensão do solo(DA ROCHA et al, 2012) PEREIRA et al, 2017a)…”