City Pavement Affects Weather, Boosting Smog: Study

FRIDAY, June 10 (HealthDay News) — Urban development is exacerbating air pollution in coastal regions, new research says.

The study, led by researchers at the U.S. National Center for Atmospheric Research (NCAR), found that the sprawl of strip malls and other paved areas can affect weather patterns, trapping pollutants and hurting air quality during the summer months.

In conducting the nine-day study, which focused on the Houston area, the investigators used atmospheric measurements and computer simulations to analyze how paved surfaces affected breezes. They found that pavement, which heats up and keeps land warmer overnight, reduced night-time winds. The reason for this, the study authors explained, is that when land temperatures rise, the contrast between land and sea temperatures is reduced and winds die down.

The study, published in June in the Journal of Geophysical Research — Atmospheres, also noted that buildings impede local winds, resulting in stagnant air in the afternoons. As a result, pollutants accumulate, instead of being blown out to sea.

“The developed area of Houston has a major impact on local air pollution,” study author Fei Chen, an NCAR scientist, said in a news release from the journal publisher. “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 study authors noted that the development of paved areas such as strip malls and subdivisions, which impede the clearing of smog and air pollution, could have implications for the air quality of growing coastal cities in the United States as well as other regions overseas.

Although the researchers pointed out that more study is needed to better understand the link between wind patterns and urban development, they suggested that the findings may inspire city planners to take new approaches to development.

The study found that drought conditions could also worsen air pollution since dry soil heats up more quickly during the day than wet soil.

More information

The U.S. Environmental Protection Agency provides more information on air quality.

– Mary Elizabeth Dallas

SOURCE: American Geophysical Union, news release, June 7, 2011

Last Updated: June 10, 2011