Sentences with phrase «background air pollution levels»

But in humid places with relatively low background air pollution levels, such as over the Amazon, supersaturation is common, she says.

Not exact matches

This, Oxford City Council said, would result in air pollution levels falling to «near - background levels.»

In a typical urban area with a high level of background air pollution — for example, around 15 micrograms of fine particulate matter (PM2.5) per cubic metre, or a nitrogen dioxide concentration around 33 micrograms per cubic metre — an extra 300 trees per square kilometre was associated with around 50 fewer emergency asthma cases per 100,000 residents over the 15 year study period.

In a study of 6,654 middle - aged and older U.S. adults from diverse ethnic backgrounds, participants living in areas with high levels of traffic - related air pollution tended to have lower HDL levels.

Another study has found that idling vehicles do create serious pollution: «The concentration of air pollutants near schools may significantly exceed community background levels, particularly in the presence of idling school buses.»