Spatial distribution, sources, and risk assessment of major ions ad trace elements in rainwater at Puchuncaví Valley, Chile: The impact of industrial activities

摘要

This article presents the results of a study on the chemical composition of rainwater as an environmental pollution factor in the surroundings of the Puchuncaví - Ventanas industrial complex (V Region, Chile), with the main objectives of assessing acidification and neutralisation factors, measuring elemental pollutant levels including calculation of enrichment factors and pollution sources assignment, and assessing the risk derived from elemental pollutant loads in rainwater, both for human use and natural ecosystems. Forty-seven weekly rainwater samples were collected during the winter (May–August) 2010 (24 samples) and 2011 (23 samples) at three sampling location with different degree of impact from the main emission sources. The pH, conductivity and major ions were analyzed by ion chromatography, as well as 18 traces and main elements by ICP-MS. Most rainwater samples had pH below 5.6, indicating the risk of acidification, but neutralisation factors, mainly by Na+ and NH4+ were also noticed. The elements emitted by anthropogenic activities had significant enrichment values in the rainwater of the area studied, and the principal component analysis (PCA) identified four sources related to the metallurgical industry – crustal material, marine material, traffic -industry and industrial activities. The risk assessment showed that As content in rainwater is above the WHO guideline value for drinking water at some points in the study area. The contribution of Pb and Cd in rainwater to the soil critical loads turned out to be relatively low, with a maximum of 22.1% for Pb in the vicinity of the industrial complex.