Hypoxia inducing visual function deficits have been reported in aircrews at altitude of 10,000 feet or less, which is not required oxygen supply system. However, there are limited data concerning effect of lower blood oxygen saturation on visual function. Therefore, we evaluated the contrast sensitivity changes in mild hypoxia. Eight healthy non-smokers (5 male, 3 female, age range 31 to 51) who had normal vision participated in this study. The participants were exposed to hypobaric hypoxia for about 50 minutes in a hypobaric chamber at a simulated altitude of 5,000 feet (1,524 m) and 8,000 feet (3,048 m) on separate days, respectively. Blood oxygen saturation based on pulse oxymetry (SPO2) and heart rate (HR) were recorded during the hypoxia exposure experiment. The contrast sensitivity at 1.5, 3, 6, 12, and 18 cycle per degree(cpd) spatial frequencies was measured before exposure and at both altitudes, using functional acuity contrast test (FACT). The contrast sensitivity was not significantly impaired at both altitudes, inducing significant SPO2 decrement (91% at 8,000feet). Although no significant increase was observed in the HR, 50% of the participants reported feeling warm at the altitude of 8,000 feet. The results suggested that the contrast sensitivity measured by FACT was not sensitive enough to detect mild hypoxia effect.

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To characterize occupational exposures to carcinogenic chemicals in flight line personnel, nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) were determined in JP-4 fueled aircraft emissions both from F-15J and C-130H by using gas chromatography coupled to mass spectrometry with negative ion chemical ionization. We determined three nitro-PAHs, 1-nitronaphthalene, 2-nitronaphthalene and 9-nitroanthracene, which were not classifiable as to carcinogenicity to humans by International Agency for Research on Cancer. There was no carcinogenic nitro-PAH in the emissions. The concentrations of both nitronaphthalenes in the emissions were over 6 times higher in the C-130H than the F-15J.

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