Smoking attenuates the amount of oxygen that diffuses from the lung tissue and oxygenates the blood (Guyton, 1996). High altitudes attenuate the oxygen available for transport to the blood. However, little has been reported on the combined effects of these two forms of hypoxia (inadequate oxygenation of the blood). It may be that, together, these two hypoxic conditions react exponentially to critically affect human performance. Fifty-two participants were screened for cotinine serum values >200 ng/dl-1 , to flesh out nicotine usage, through urine sampling. Nineteen participants were entered into the smoker's group and 33 into the non-smoker's group. All of the participants were active student pilots. All of them held current instrument ratings and all of them had approximately the same amount of time and experience in instrument meteorological conditions (IMC). Data were analyzed using Microsoft Excel and SPSS computer software statistic programs. The criterion for significance (alpha) was set at 0.05. The test was a non-directional t-test (two-tailed), which means that an effect in either direction was interpreted. Statistical significance existed when comparing the mean effective performance times between smoking pilots and nonsmoking pilots t = 3.541 (39), p = .05 in the experimental (simulated altitude) groups. Within the limitations of this study it can be concluded that the combined hypoxic effects of smoking and high altitude result in a statistically significant detriment in pilot effective performance time.
Fletcher, James F.
"Comparison of Simulated High Altitude Pilot Effective Performance Time Between Habitual Smokers and Non-Smokers,"
Journal of Human Performance in Extreme Environments:
2, Article 5.
Available at: http://docs.lib.purdue.edu/jhpee/vol7/iss2/5