Is PM(10) mass measurement a reliable index for air quality assessment? An environmental study in a geographical area of north-eastern Italy

Impact of the global economic crisis on metal levels in particulate matter (PM) at an urban area in the Cantabria Region (Northern Spain)

Air pollution by particulate matter is well linked with anthropogenic activities; the global economic crisis that broke out in the last year may be a proper indicator of this close relationship. Some economic indicators show the regional effects of the crisis on the Cantabria Region. The present work aims to evaluate the impact of the economic crisis on PM10 levels and composition at the major city of the region, Santander. Some metals linked to anthropogenic activities were measured at Santander and studied by Positive Matrix Factorization; this statistical analysis allowed to identify three main factors: urban background, industrial and molybdenum-related factor. The main results show that the temporal trend of the levels of the industrial tracers found in the present study are well agree with the evolution of the studied economic indicators; nevertheless, the urban background tracers and PM10 concentration levels are not well correlated with the studied economic indicators.

Evaluation of the contribution of local sources to trace metals levels in urban PM2.5 and PM10 in the Cantabria region (Northern Spain)

The aim of this study was to evaluate the contribution of local emission sources to the selected trace metals levels (As, Ni, Cd, Pb, Ti, V, Mn, Cu, Mo and Hg) in urban particulate matter, PM10 and PM2.5, in the Cantabria region (Northern Spain) during the year 2008. PM10 and PM2.5 samples were collected and characterized in an urban sampling site at Santander (Cantabria); additional PM10 samples were collected at a rural site at Los Tojos (50 Km SW) to evaluate both the urban and rural environment. The particulate matter and the metals regulated by the EC air quality directives (Pb, As, Ni and Cd) did not exceed the EC limit or target values in the Cantabria region. The metal concentrations were much lower at the rural site except for Ni. Different techniques were used to analyse the possible sources of the studied metals: enrichment factor, urban impact, wind and pollutant roses and principal component analysis (PCA). A combination of these techniques allowed us to demonstrate that the local emission sources of metals in the particulate matter at Santander city were the most important. Ti, Ni, As and V were identified as the main urban background tracers while Mn and Pb were the main local industrial tracers. The urban background was found to be the major contributor to PM10. The relationship between the emission tracers and the major air pollutants (NO(2), NO, CO, SO(2),O(3) and PM(10)) was also studied by PCA; a significant relationship between tracers and the major air pollutants was not found, showing a decoupled relationship between major pollutants and metal species in particulate matter.