Titanium Dioxide=Sunscreen and Smog-Eater?

While reading Time magazine last November, I came across a blurb about the very cool invention of smog-eating cement. In a town near Milan, cement was mixed with titanium dioxide, which broke down smog, thus negating its power. An eager beaver of excitement, I headed to my laptop, where I found this article, also about titanium dioxide's smog-reducing ability.

Both of these stories beckon the question: Can makeup, moisturizers, and sunscreen with titanium dioxide—a mineral sunscreen that naturally protects against UVA and UVB rays—then prevent free radical damage from pollution on the face (aka aging)? I'm no scientist and don't have the answer, but it can't hurt to try, right?

Need some recommendations? My titanium dioxide-containing picks are Jane Iredale Dream Tint SPF 15 tinted moisturizer, Juice Beauty Green Apple Moisturizer SPF 15, and the new John Masters SPF 30 Mineral Sunscreen. It contains reparative moisturizers and humectants like aloe, shea butter, and hyaluronic acid, plus antioxidant-rich green tea and healing calendula. Happy days of sunshine this summer!