Characterization of piston-engine aircraft emissions and their impacts on local air quality

The gaseous ((carbon monoxide(CO), carbon dioxide (CO2), nitrogen dioxide (NOx), total hydrocarbons (THC)) and trace element emissions of a piston-engine aircraft during ground operations at different engine states and three different air/fuel mixtures full (rich, best power, best economy) representing certain flight phases were concurrently measured from the exhaust duct and corresponding emission factor were determined. An active biomonitoring study by moss bags (Sphagnum Sp.) at points close to the airport in the campus area for 3 sampling period were also carried out. At low engine speeds, while CO and THC concentrations were high, NOx concentrations increased with increasing power level. When examining the EF results for gas pollutants, the higher values generally belong to 750 and 1000 RPM in all fuel mixes. When the EF values of THC at 750 and 1000 RPM at three fuel mixes, at BP fuel mixture and 1000 RPM for the EF values of CO, and for EF-NOx values, it was observed that the EF values especially at BP and BE fuel mixtures were high. In the biomonitoring study, while the trace element concentrations in the 3 different sampling periods are not completely similar to each other, it is thought that Ca, Na, Al, S species, which are found in high concentrations in general, may originate from aircraft engines. Higher Pb concentrations were measured at points close to the airport due to the high lead content of the fuel used by reciprocating-engine aircraft.