New research focusing on the Houston area suggests that widespread urban development alters wind patterns in a way that can make it easier for pollutants to build up during warm summer weather instead of being blown out to sea. The international study could have implications for the air quality of fast-growing coastal cities in the United States and other midlatitude regions overseas. The reason: the proliferation of strip malls, subdivisions, and other paved areas may interfere with breezes needed to clear away smog and other pollution.