TITLE:
Elemental Composition of PM2.5 in Araraquara City (Southeast Brazil) during Seasons with and without Sugar Cane Burning
AUTHORS:
Flavio Soares Silva, Ricardo Henrique Moreton Godoi, Romà T auler, Paulo Afonso de André, Paulo Hilário Nascimento Saldiva, Rene van Grieken, Mary Rosa Rodrigues de Marchi
KEYWORDS:
Sugar-Cane Burning, PM2.5, Individual Particle Analysis, EDXRF, Cluster Analysis, Principal Components Analysis
JOURNAL NAME:
Journal of Environmental Protection,
Vol.6 No.5,
May
4,
2015
ABSTRACT: Particulate
matter with an aerodynamic diameter below 2.5 μm (PM2.5), present in
polluted air, has been associated with a large spectrum of health impairments,
mainly because of its deep deposition into the lungs. Araraquara City (Southeast
Brazil) is surrounded by sugar-cane plantations, which are burned to facilitate
the harvesting; this process causes environmental pollution due to the large
amounts of soot that are released into the atmosphere. In this work, the
elemental composition of PM2.5 was studied in two scenarios, namely
in sugar-cane harvesting (HV) and in non-harvesting (NHV) seasons. The sampling
strategy included one campaign in each season. PM2.5 was collected
using a dichotomous sampler (10 L·min-1, 24 h) with PTFE
filters. Information concerning the bulk elemental concentration was provided
by energy-dispersive X-ray fluorescence. Enrichment factor analysis indicated
that S, Cl, K, Cr, Ni, Cu, Zn, As, Cd and Pb were highly enriched relative to
their crustal ratios (to Al). Principal component analysis was used to get some
insight about the sources of the elements. Principal component 1 (PC1)
explained 30.5% of data variance. The elements that had high loading (>0.7)
were: S, Cr, As, and Pb; these are associated with combustion of fossil fuels.
In principal component 2 (PC2), Cl, Cu, Zn, and Cd showed high loadings; these
elements are associated with biomass burning. The Ni concentration found is
three times larger than the threshold of risk for lung cancer, as recommended
by the World Health Organization.