Proliferating pavement may be making urban air pollution worse, a U.S. study suggests.

Researchers led by the National Center for Atmospheric Research in Boulder, Colorado, focused on the air in smoggy Houston.

The research team crunched atmospheric measurements with computer simulations to examine pavement's impact on breezes. The data showed, they said, that paved surfaces keep on-land temperatures artificially high, causing a reduction in cleansing nighttime sea breezes.

Furthermore, buildings and other structures block and redirect air movement, contributing to relatively stagnant afternoon weather conditions, the researchers said.

"The developed area of Houston has a major impact on local air pollution," said NCAR scientist Fei Chen, lead author of the new study. "If the city continues to expand, it's going to make the winds even weaker in the summertime, and that will make air pollution much worse."

The article will be published this month in the Journal of Geophysical Research-Atmospheres, a publication of the American Geophysical Union. The research was funded by the U.S. Air Force Weather Agency, the U.S. Defense Threat Reduction Agency and the National Science Foundation.