Smog-eating cement

Italy has produced cement that will eat smog. This is a fine way to clear [in presence of light] "air pollutants such as carbon monoxide, nitrogen oxide, benzene, and others through a natural chemical process called photocatalysis." We can recover more quickly from pollution effects than I first thought.

Considering the 2008-2012 forecast, I believe the C rating has just climbed to a C+.