Abstract Description: In recent years, the production and use of sustainable aviation fuels (SAFs) increased as the aviation industry gears up to reduce jet engine greenhouse gas (GHG) emissions and environmental impacts. In 2018, the production of SAFs reached a total volume of approximately 15 million liters, representing less than 0.1% of the total consumption of aviation fuel, and only 1% of the 363 billion liters of aviation fuel used in 2019 was SAF. This statistic shows that while SAF is gaining popularity, its use is still low compared to traditional aviation fuels. As efforts to reduce aviation's environmental impact gain momentum and national action plans and legislation in the European Economic Area, the US, Canada, and other jurisdictions take shape in the coming years, the International Energy Agency (IEA) predicts a significant increase in SAF production and use by 2030. SAF use in the aviation industry is expected to reach 65% of total fuel requirements or 449 billion liters by 2050.
The increasing use of SAFs and their blends in aviation engines requires the investigation of aviation engine exhaust emissions and fugitive emissions from SAG use. Human exposure to pesticides that may survive the combustion process, and which are used in producing feedstock biomass for SAFs, is also largely unknown. The impact of these emissions and exposures along the entire chain of SAF production and use on human health must be explored. Aviation engines are impractical to use in research laboratories for generating and investigating exhaust. Therefore, an alternative approach to burning aviation fuels in the laboratory in a way that closely matches the combustion process in aviation engines is needed. One such approach is using laboratory-scale burners that accurately replicate real-world combustion processes and allow the generation of combustion emissions that replicate those produced by real-world aviation engines.
The changing landscape of chemical exposures in the aviation industry associated with the transition to the increasing use of sustainable aviation fuels requires a multidisciplinary in-depth investigation to protect the health of workers in the aviation industry and the public. Likewise, the expected differences in the aerosol size distribution of exhaust emissions when SAF blends and SAFs are burnt compared to the combustion of fossil aviation fuels also need to be investigated for their potential different health risks, especially in light of the recent and increasing evidence of adverse health effects associated with exposure to airborne nanoparticles.
