Interesting. When I toured several companies in Singapore, including Google, most of the staff were from Europe or the States. If Singaporeans are indeed doing well in their own schools, my guess is many are still leaving to work elsewhere. I frequently attended programming meetups where about 90% of the attendees were non-Singaporean.
But then, most of the Singaporeans I've known were quite happy to live and work in a Western country; I lived there briefly and was frequently asked by locals, "why would you want to live here, it's so small."
Regarding pollution, it was actually Singapore's air pollution that caused me to leave. I think I'm not alone with that sentiment.