The map below shows where the low emission zones are in Lombardia:
orange shaded areas, comunes that are affected by the 'main city schemes', which affect most vehicles (see the main city for each of these areas) (209 comunes)
yellow shaded areas - comunes that are affected by the motorcycle schemes (see Lombardia outside the cities page) (all together 331 comunes)
To see which communes are affected you can go to this spreadsheet.
For more details on the large towns and cities, see the list of cities on the right hand side of this page.