Chemical characterization of atmospheric particulate matter in Friuli Venezia Giulia (NE Italy) by exploratory data analysis with multisite and multivariate approach.

The chemical composition of atmospheric particulate (PM10) in the Friuli Venezia Giulia (FVG) region (NE Italy) has been characterized for the first time with the help of exploratory data analysis (EDA) techniques (uni-, bi-, and multivariated, i.e., principal components analysis), molecular and elemental diagnostic ratios, and seasonal trends. Despite that the available analytical data was limited to the parameters routinely analyzed on PM10 by ARPA FVG (11 elements and 16 PAH congeners), the large number of samples and of measured chemical parameters, together with the applied techniques of data analysis, allowed us to extract useful latent information from the dataset, resulting in a greater knowledge of both regional and local features. Specifically, we succeeded in matching data patterns to the known pollution sources of some sampling stations, both industrial (two secondary fusion steelworks and one coke oven) and urban (traffic and domestic heating), and in defining the mainly urban or mainly industrial feature of some questionable sampling stations. This is of paramount importance to check for possible industrial inputs in urban stations, allowing policymakers to implement the most appropriate response.