This is getting a very interesting debate. First of all, if you read closely, I said "The air of Santiago is very polluted, simply unbreathable (for me)"
So this is my personal opinion, you're not entitled to believe what I said. However, I stand behind my words, I went several times to Santiago and
I repeat, Santiago is indeed very polluted to me and more than LA (I think). Actually there is some logic in this. When you look at the large number of motoconchos and guaguas that roam Santiago, you might expect higher levels of pollution. See again, "I think". You're free to think the opposite, actually you'll welcome to do so, this is a bulletin board afterall.
Now since you guys worry so much about what I smoke in Sosua, I did a quick study on Google to get an overview of what my fellow santiagueros
have been smoking these days. This part requires some knowledge in spanish. If you can read spanish, feel free to take a few minutes and read the entire articles, it gives a good insight of what's really going on down there :
http://www.hoy.com.do/app/article.aspx?id=27122
Also here :
http://www.listin.com.do/antes/mayo03/270503/cuerpos/regiones/reg3.htm
I'm not trying to give a bad rap to this city like others would do for Sosua with no reason or back up evidence. Ignorance does enough damages all around the world already. It's a question of seeking the Truth.
To sum it up, I believe there are some tradeoffs when you live in Santiago. It's indeed the place where you can meet very beautiful, educated women . It's also a place where you can do business, find furnitures, cars, anything you want, at a very good price. However, on the other side, just like any other industrialized city, it's heavily polluted compared to smaller cities. So if you're looking for cleaner air, you might want to head for Sosua or any other city that is not that industrialized. As for a difference in pollution between Santo Domingo and Santiago, I believe SD being much closer to the sea is less polluted. Just like Santa Monica has less pollution than Downtown LA.