Health effects of occupational exposure to jet fuels used in the military: A systematic review of the epidemiologic literature.

Background: Jet fuels are a common chemical exposure in occupational settings involving aircraft. Jet fuels are heterogeneous mixtures of aromatic and aliphatic hydrocarbons, as well as non-hydrocarbon performance additives. Several components of jet fuels have been linked to adverse health outcomes. The "Sergeant First Class Heath Robinson Honoring Our Promise to Address Comprehensive Toxins Act of 2022" required the U.S. Department of Veterans Affairs (VA) to develop a report to Congress on the health effects of jet fuels used in the military.

Objectives: This investigation assessed the epidemiologic evidence of the health effects associated with occupational exposure to jet fuels in military and non-military settings using robust and reproducible systematic review methods.

Methods: Two scientific databases (PubMed and EBSCOhost), 17 gray literature sources and five review articles were searched for relevant, primary epidemiologic studies through May, 2024. Risk of bias and strength of evidence were evaluated according to the U.S. Environmental Protection Agency's (EPA) Integrated Risk Information System (IRIS) assessment framework for systematic reviews and evidence synthesis.

Results: Twenty-eight studies met the inclusion criteria, including 18 studies in military settings and 10 studies in non-military occupational settings. It was determined that there was slight evidence of associations between jet fuel exposure and neurologic, cognitive and behavioral, respiratory, and cancer outcomes. For all other health outcome categories, the available evidence of jet fuels effect on humans was considered indeterminate.

Discussion: To our knowledge, this is the first systematic review of epidemiologic evidence on the health effects of occupational jet fuel exposure. Available data were sparse for multiple health outcomes, and most studies tended to be of lower quality. Future work will include expanding the scope of the review to integrate toxicological and mechanistic evidence.