The Po Valley of northern Italy represents an important non attaining zone for PM, NO2 and O3. This zone covers the territory of Italian northern Regions and includes several urban agglomerates such as Milan, Turin and Bologna. The area is densely populated and heavily industrialized. Tons of NOx, PM and NH3 are emitted in the atmosphere by a wide variety of pollution sources mainly related to traffic, domestic heating, industry and energy production sectors. [ click to continue ]