A spokeswoman for the mayor's office, Joanna Dovan,says the Pittsburgh area has been working to improve its air quality.

VOA: special.2009.07.13

So, if you want to attack urban air quality, this is probably moving in the wrong direction, OK?

所以如果你想攻击都市的空气质量，这可能是一个错误的方向，对吗？

麻省理工公开课 - 固态化学导论课程节选

A spokesperson for the Cruise Lines International Association says other air quality depends on the requirements of the nation where a ship was built.

VOA: special.2009.07.14

The relationship between climate,weather, air quality and health is the theme of this year's World Meteorological Day, which is observed Monday.

VOA: standard.2009.03.23

WHO says declining air quality worsens illnesses and deaths from asthma,heart disease, and lung cancer.

VOA: standard.2009.03.23

Dr.Kausalya Pendyal tells her patients in Richmond, Virginia before they go outside to check the Air Quality Index - a U.S.government assessment of pollutants in the air.

VOA: standard.2010.08.04

It says air quality is an important factor as well.

VOA: standard.2009.03.23

Allen Hershkowitz with the Natural Resources Defense Council, a private environmental group, says air quality around landfill sites must be carefully checked when oil-contaminated waste is added to normal household trash.

VOA: standard.2010.08.05

And that in turn leads to additional emissions of harmful pollutants and our area is very concerned about improving air quality as one of the key ways to make our communities even better places to live and work."

VOA: standard.2010.07.26

Planting trees around poultry farms can improve air and water quality and relations with neighbors.

VOA: special.2009.09.08

"But,it is also many of the gases, which are the greenhouse gases that are also influencing the quality of the air when they are abundant in the lower atmosphere."

VOA: standard.2009.03.23