Concerns over use of leaded aviation gasoline (AVGAS) fuel

Abstract

Tetraethyl Lead (TEL) is an added substance in 100 Low Lead (100LL) (AVGAS) to help in detonation as detonation creates very high pressures inside the engine which can easily cause engine shutdown with major damages. Without the added substance of TEL, the octane levels would be too low for AVGAS, and utilisation of a lower octane fuel than required could prompt catastrophic engine failure as they work at higher power settings and temperatures. Friends of the Earth (FOE) documented a ''Petition for Rulemaking Seeking the Regulation of Lead Emissions from General Aviation Aircraft Under Clean Air Act" to make a finding that lead emissions from general aviation is harmful to the nature and human being. FOE suggested a proposed emission standard for lead from general aviation (GA) aircraft under the Clean Air Act (CAA). Environmental Protection Agency (EPA), United States of America (USA) believes that insufficient information exists to make such a finding. EPA USA insists to commence a study and investigation of the health and environmental impacts of lead emissions from GA aircraft, including impacts to humans, animals and ecosystems under the CAA and issue a public report on the findings of the study and investigation. EPA in 2008, decreased the level of the primary National Ambient Air Quality Standard (NAAQS) for lead from 1.5 µg/m3 to 0.15 µg/m3 in order to provide increased protection for children and other at-risk populations against an array of adverse health effects, most notably neurological effects in children, including neurocognitive and neurobehavioral effects. Federal Aviation Administration's (FAA) William J. Hughes Technical Center tested 245 fuels overseen by the Coordinating Research Council (CRC) with 45 of the most promising blends were examined more closely in full-scale engine testing. None of the fuels could satisfy all the performance requirements of AVGAS 100LL for safe and reliable operations without further polluting the environment. In this study, a comprehensive review will be conducted to analyse serious concerns raised by the lead emissions caused by the GA aircrafts using AVGAS 100LL as the fuel. Concerns of EDB exposure, TEL exposure, health issues, at-risk populations and life stages, terrestrial eco-system issues, aquatic eco-system issues, societal and economic impacts, operational safety issues, inadequate lead emissions inventory and limited data on lead monitoring. The findings of this review suggest the seriousness of finding an unleaded alternative fuel for environmental sustainability with the fact that lead emissions should also be given equal concentration with proper studies and findings to help in the elimination efforts as per serious concerns given to emissions of carbon dioxide, carbon monoxide, oxides of nitrogen and other particulates emissions in aviation.