It is difficult to determine (or prove) how much overflights decrease air quality because the standards and measurement protocols are outdated. It is known that commercial jet overflights create and spread submicron particulates and greenhouse gases.
The World Health Organization issued (2012) a warning that numerous epidemiological studies showed that health risks and mortality are steeply increased for 10 miles around busy jet airports. The warning discounted annual daily average noise intensity (DNL) as the direct cause.
This (the WHO Warning) and other reports led the Federal Inter-Agency Committee on Airport Noise (FICAN) to contract with MIT to study if and how noise exposure was linked to health risk. The study was inconclusive: the theory that noise disturbance increases stress and stress caused heart disease was not affirmed or denied.
The Environmental Protection Agency found ‘commercial aviation’ endangers public health by contributing more than one-eighth of all U.S. carbon emissions. The form is “greenhouse gases” and the impact is global warming.
The Federal approach, ‘cleaner’ fuels and ‘fuel economy’ is unlikely to reduce annual emissions, because flight hours are likely to increase more quickly. Fuel efficiency is desirable (less pollution and fuel consumption per flight-hour) certainly, but FAA is struggling with how to reduce GHG emissions because jets cannot operate solely at fuel-efficient cruise altitudes.
We need to look at near-airport operations more closely. At MSP since 2010, low-altitude maneuvers have steadily increased. SMAAC holds that this is not worth the costs and not necessary to support Minnesota economic growth.