"reduce air quality" is correct and can be used in written English.
It is used to describe a situation in which the air becomes less clean and healthy for breathing. Example: The constant emissions from the factory have led to a significant reduction in air quality in the surrounding areas.
These hazardous pollutants reduce air quality and can trigger respiratory problems.
Depending on meteorological conditions, fire emissions can efficiently reduce air quality and visibility, even far away from emission sources.
Repeated loss of fine soil particles by dust emission from arable fields caused by tillage operations, decline soil fertility and reduce air quality.
Mayor Michael R. Bloomberg has been a proponent of helping buildings meet cleaner fuel requirements and instituted the NYC Clean Heat program in 2011, when the city adopted new regulations to phase out the use of Nos. 4 and 6 heating oils, which he has said emit soot, reduce air quality and can contribute to asthma.
Some of these gases, such as sulphur dioxide, reduce air quality and cause breathing problems, especially among risk groups such as asthmatics.
Anthropogenic pollutants reduce air quality and visibility.
Average health damages from reduced air quality are equivalent to US$121t−11 of harvested maize grain, which is 62% of the US$195t−11 decadal average maize grain market price.
Inundated infrastructure, including that with toxic substances, would lead to pollution of water and reduced air quality.
Heat waves and rainstorms are becoming more deadly, disease outbreaks last longer and are seen in new regions, wildfire smoke from tinder-dry forests reduces air quality, and food and water security are threatened by extreme weather.
Energy production, particularly from fossil fuels, has reduced air quality and threatened public health around the world.
MacNamara argues that a growth in Uber vehicles is clogging up the streets of central London while they wait to pick up passengers, also reducing air quality.
