The US Air Force has implemented the widespread use of
JP-8 jet fuel in its operations, although a thorough understanding of its potential effects upon exposed personnel is unclear. Previous work has reported that JP-8 exposure is immunosuppressive. Exposure of mice to JP-8 for 1 h/day resulted in immediate secretion of two
immunosuppressive agents; namely,
interleukin-10 (IL-10) and
prostaglandin E2 (
PGE2). Thus, it was of interest to determine if jet fuel exposure might promote
tumor growth and
metastasis. The syngeneic B16
tumor model was used for these studies. Animals were injected intravenously with
tumor cells, and lung colonies were enumerated. Animals were also examined for metastatic spread of the
tumor. Mice were either exposed to 1000 mg/m3 JP-8 (1 h/ day) for 7 days before
tumor injection or were exposed to JP-8 at the time of
tumor injection. All animals were killed 17 days after
tumor injection. In the present study, JP8 exposure potentiated the growth and
metastases of B16
tumors in an animal model. Exposure of mice to JP-8 for 1 h/day before
tumor induction resulted in an approximately 8.7-fold increase in
tumors, whereas those mice exposed to JP8 at the time of
tumor induction had a 5.6-fold increase in
tumor numbers. Thus, low concentration
JP-8 jet fuel exposures have significant immune suppressive effects on the immune system that can result in increased
tumor formation and
metastases. We have now extended the observations to an experimental subcutaneous
tumor model. JP8 exposure at the time of
tumor induction in this model did not affect the growth of the
tumor. However, JP8-exposed,
tumor-bearing animals died at an accelerated rate as compared with air-exposed,
tumor-bearing mice.