Precise estimates at municipality level of airborne pollutant emissions due to road traffic

In Central Italy, road traffic emissions of airborne pollutants (i.e. Corinair Group 7) account for more than 50% of overall emissions. The principal pollutants emitted into the atmosphere by cars and trucks are: particulate matter (PM, PM10, and PM2.5), Nitrogen oxides (NOx), Volatile Organic Compounds (VOC) and Carbon monoxide (CO). For this kind of emissions, emission estimate is the only way to assess local impact. Unfortunately, precise estimates at small scales (e.g. county or municipality) rely upon the knowledge of several data such as number and type of vehicles, road transits, fuel consumption etc. detailed for the same scale. Such data are difficult to collect (almost impossible for transits) and update. Moreover, car leasing, national and local polices, and taxex force several people to possess and drive cars that are namely registered and licensed elsewhere. Nevertheless, assessing emission contributions of the various vehicle classes at township level becomes crucial to implement proper limitation policies and regulations. The aim of this study is to compare different methods able to disaggregate airborne pollutant emissions using different proxy variables (e.g. population, number of vehicles, and car registrations) to allow a routinely estimate at local level based on the regional emission data and reliable and easy-to-obtain proxy variables. We analyzed mobility and vehicles of the Marche Region to calculate emissions for the year 2010 using COPERT 4 (COmputer Programme to estimate Emissions from Road Traffic), the choice methodology indicated by the EMEP/CORINAIR Emission Inventory Guidebook. The emissions were estimated at regional level (NUTS2) and provincial level (NUTS3) and we checked several methodologies to allow an accurate estimate at township level.In Central Italy, road traffic emissions of airborne pollutants (i.e. Corinair Group 7) account for more than 50% of overall emissions. The principal pollutants emitted into the atmosphere by cars and trucks are: particulate matter (PM, PM10, and PM2.5), Nitrogen oxides (NOx), Volatile Organic Compounds (VOC) and Carbon monoxide (CO). For this kind of emissions, emission estimate is the only way to assess local impact. Unfortunately, precise estimates at small scales (e.g. county or municipality) rely upon the knowledge of several data such as number and type of vehicles, road transits, fuel consumption etc. detailed for the same scale. Such data are difficult to collect (almost impossible for transits) and update. Moreover, car leasing, national and local polices, and taxex force several people to possess and drive cars that are namely registered and licensed elsewhere. Nevertheless, assessing emission contributions of the various vehicle classes at township level becomes crucial to implement proper limitation policies and regulations. The aim of this study is to compare different methods able to disaggregate airborne pollutant emissions using different proxy variables (e.g. population, number of vehicles, and car registrations) to allow a routinely estimate at local level based on the regional emission data and reliable and easy-to-obtain proxy variables. We analyzed mobility and vehicles of the Marche Region to calculate emissions for the year 2010 using COPERT 4 (COmputer Programme to estimate Emissions from Road Traffic), the choice methodology indicated by the EMEP/CORINAIR Emission Inventory Guidebook. The emissions were estimated at regional level (NUTS2) and provincial level (NUTS3) and we checked several methodologies to allow an accurate estimate at township level.