Analysis of particulate matter in anthropized areas characterized by the presence of crude oil pre-treatment plants: The case study of the Agri Valley (Southern Italy)

Simultaneous measurements of PM10, PM2.5 and PM1 (i.e., aerosol particles with aerodynamic diameter less than 10, 2.5 and 1?m, respectively) daily mass concentrations and daily particle number concentration were performed for the first time in Agri Valley (Basilicata Region - Southern Italy) from July to November 2011. This area is characterized by anthropogenic activities having high potential environmental and human health impacts. In fact, the Agri Valley houses the largest European on-shore reservoir and the largest crude oil pre-treatment plant within an anthropized area. The PM measurements were analyzed combining an innovative statistical methodology, the Singular Spectral Analysis, with forecast models and remote sensing observations. Our findings show that most of the PM collected was made up of particles in the fine and sub-micrometric fractions (i.e., PM2.5 and PM1, respectively) very likely originated by common anthropogenic sources. Moreover, PM2.5 and PM1 daily mass concentrations were characterized by a slightly increasing trend that could be related to the contribution of local sources, such as the crude oil pre-treatment plant, whose combustion processes also produce the emission of particles mainly in the fine and sub-micrometric size ranges. The integrated use of model forecasts, satellite observations and in-situ measurements shows that the only PM10 exceedance was affected by the contribution of Saharan dust, while the three PM2.5 exceedances were mainly due to local anthropogenic sources. Finally, the analysis of the PM10 and PM2.5 Air Quality Index (AQI) values shows that air quality was always "good" with respect to PM10 and "moderate" with respect to PM2.5 suggesting that fine particles, if they will be not kept under control, should represent a real problem also posing health risks to the population living close to the crude oil pre-treatment plant.