title: Air quality across a European hotspot: Spatial gradients, seasonality, diurnal cycles and trends in the Veneto region, NE Italy.
abstract: The Veneto region (NE Italy) lies in the eastern part of the Po Valley, a European hotspot for air pollution. Data for key air pollutants (CO, NO, NO2, O3, SO2, PM10and PM2.5) measured over 7years (2008/2014) across 43 sites in Veneto were processed to characterise their spatial and temporal patterns and assess the air quality. Nitrogen oxides, PM and ozone are critical pollutants frequently breaching the EC limit and target values. Intersite analysis demonstrates a widespread pollution across the region and shows that primary pollutants (nitrogen oxides, CO, PM) are significantly higher in cities and over the flat lands due to higher anthropogenic pressures. The spatial variation of air pollutants at rural sites was then mapped to depict the gradient of background pollution: nitrogen oxides are higher in the plain area due to the presence of strong diffuse anthropogenic sources, while ozone increases toward the mountains probably due to the higher levels of biogenic ozone-precursors and low NO emissions which are not sufficient to titrate out the photochemical O3. Data-depth classification analysis revealed a poor categorization among urban, traffic and industrial sites: weather and urban planning factors may cause a general homogeneity of air pollution within cities driving this poor classification. Seasonal and diurnal cycles were investigated: the effect of primary sources in populated areas is evident throughout the region and drives similar patterns for most pollutants: road traffic appears the predominant potential source shaping the daily cycles. Trend analysis of experimental data reveals a general decrease of air pollution across the region, which agrees well with changes assessed by emission inventories. This study provides key information on air quality across NE Italy and highlights future research needs and possible developments of the regional monitoring network.
authors: Center for Air Resources Engineering and Science, Clarkson University, Box 5708, Potsdam, NY 13699-5708, USA; Division of Environmental Health and Risk Management, School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom. Electronic address: mauro.masiol@gmail.com.
authors: Mauro
authors: M
authors: Masiol
authors: Center for Air Resources Engineering and Science, Clarkson University, Box 5708, Potsdam, NY 13699-5708, USA; Dipartimento Scienze Ambientali, Informatica e Statistica, Università Ca' Foscari Venezia, Campus Scientifico via Torino 155, 30170 Venezia, Italy.
authors: Stefania
authors: S
authors: Squizzato
authors: Dipartimento Regionale Laboratori, Agenzia Regionale per la Prevenzione e Protezione Ambientale del Veneto, Via Lissa 6, 30174 Mestre, Italy.
authors: Gianni
authors: G
authors: Formenton
authors: Division of Environmental Health and Risk Management, School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
authors: Roy M
authors: RM
authors: Harrison
authors: Dipartimento di Matematica, Università degli Studi di Trento, via Sommarive 14, Povo, Trento, Italy.
authors: Claudio
authors: C
authors: Agostinelli
keywords: Air pollution; Nitrogen oxides; Particulate matter; Trends; Veneto