air quality 
noun
The degree to which the air in a particular place is pollution-free.Both air quality and meteorological data are hourly whereas traffic data are daily....
- The archaeologists have also obtained computer data on the air quality and soil composition of the tomb.
- The district heating companies will be able to reduce energy and water losses and improve the air quality in Pernik.
- quart pot
- quart-pot tea
- quartumvirate
- quartz
- quartz clock
- quartz crystal
- quartz glass
- quartz gold
- quartz-halogen
- quartziferous
- quartzin
- quartzine
- quartz-iodine
- quartzite
- quartzitic
- quartz lamp
- quartzless
- quartz-locked
- quartzofeldspathic
- quartzoid
- quartzose
- quartzous
- quartz porphyry
- quartz reef
- quartz reefing