983691 - Source Apportionment and Risk Assessment of Trace Elements in Rainwater Collected Around the Industrial Complex Puchuncaví-ventanas

The Puchuncaví-Ventanas industrial complex (IC), and surrounding areas, located on the central coast of Chile (32°40’S, 71°24’O), have been strongly affected for many years by gaseous pollutants and atmospheric particulate emissions from the industrial activities. In this work, we analysed the chemical composition (pH, conductivity, and trace elements) of rainwater, as the main input pathway of potentially toxic substances from the atmosphere to soil and water surfaces, collected during winter months (May-September) of 2010 and 2011 (n=47), in three different locations around the IC (La Greda-LG, Los Maitenes-LM, and Valle Alegre-VA), using automatic wet only collector sampler. The goal of this work was to obtain the source apportionment and risk assessment to humans and ecological resources. The pH and conductivity were analyzed as well as 18 traces and main elements (As, Pb, Cd, Hg, V, Mn, Cu, Zn, Sr, Sb, Cr, Co, Co, Co, Ba, Ca, Mg, Fe and Na) by ICP-MS. Principal Component Analysis and varimax orthogonal rotation was performed with the data to identify factors explaining the sources of the elemental composition of rainwater in the IC. The average values of rainwater pH were 5.4, 5.3, and 5.2 in LG, LM and VA, respectively, without significant differences among locations (p>0.05 in all cases), indicating acidification risk from industrial atmospheric emissions. The allocation of sources based on principal component analysis revealed factors related to the activities of the metallurgical industry, and especially the copper smelting operating in the area, with some contribution of crustal material. The risk assessment to human health from rainwater contamination revealed As values above WHO guideline values for drinking water in LG. Regarding ecological risks , the contribution of Pb and Cd in rainwater to critical soil loads turned out to be relatively low, with a maximum of 22.1% for Pb in LG. The set of chemical variables and environmental factors quantified in this work show the significant impact of the chemical composition of rainwater as a result of industrial emissions in the IC, supporting the need to address preventive and corrective measures additional to those already being applied.

Acknowledgements
This work was supported by Junta de Extremadura, Spain (project IB16114), European Regional Development Funds, and the Projects: 781301007-Inserción de Capital Humano Avanzado en el Sector Productivo y Centros de Investigación, and Redes PCI, N° 170166, both from CONICYT, Chile. Support from the AES-GENER company (Puchuncaví-Ventanas) is also acknowledged.