Factors That Modify Internal Dose of JP

FACTORS THAT MODIFY INTERNAL DOSE OF JP-8 Dermal Absorption 

Air Force personnel are most likely to be exposed to JP-8 vapors, although mixed vapor and aerosol exposures may occur during aircraft cold starts or specialized situations such as when the fuel is sprayed as a dust suppressant (CDC 1999). Inhalation of JP-8 vapors or aerosols will result in respiratory tract deposition and systemic absorption of some fuel components. 

Although of questionable relevance for determining or assessing a PEL for JP-8, oral-toxicity studies with fuels have the advantage of administering the sample without prior fractionation of components. However, other factors related to fractional absorption, oral uptake rates,metabolic clearance, and tissue storage of the individual components lead to differential systemic doses of individual components that might influence toxicity. 

JP-8 is a complex distillate fuel and, therefore, specific exposure scenarios in the workplace, in controlled human studies, and in experimental animal toxicology studies can lead to preferential enhancement of high- or low-volatility components of the fuel. When evaluating human and animal toxicology studies, it is important to know how exposures in workers, volunteers, or animals were generated from liquid JP-8. The process used to generate specific atmospheres of JP-8 will cause enrichment of specific groups of com- 

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