CHRONIC NITROGEN EXPOSURE STUDY 



Christian J. Lambertsen, M.D. 



Institute for Environmental Medicine 



University of Pennsylvania, Philadelphia, Pa. 



ABSTRACT 



The study encompassed a series of interrelated 

 physiological, hematological, chemical, and psycho- 

 logical studies carried out before, during, and after 

 exposure of subjects for 14 days to an increased atmo- 

 spheric density and increased inspired nitrogen pres- 

 sure equivalent to 100 feet of sea water. Inspired 

 oxygen was maintained at sea level pressure to avoid 

 oxygen toxicity during the exposure. 



Six subjects were used throughout the study in order to 

 permit statistical treatment of most of the findings. 

 No performance-limiting influences of the increased 

 atmospheric density were found. 



OBJECTIVES 



1. To study the increased respiratory airway resistance produced by the 

 four-fold increase in density of respired gas . At rest and in exercise this 

 airway resistance should lead to an increase in work of breathing and, at some 

 elevated ambient pressure, to a decrement in alveolar ventilation at work and 

 even at rest. Such decrement, by interfering with uptake of oxygen from the 

 lungs by the blood and elimination of carbon dioxide from the blood and lungs, 

 should lead to hypoxia, elevation of arterial carbon dioxide tension, and 

 decrease in motor and intellectual performance. 



2. To study the narcotic influences of nitrogen , 



3. To appraise the influence of ambient pressure and increased nitrogen 

 partial pressure upon blood cellular constituents, body fluid volumes, and 

 blood chemical composition . 



FACILITIES 



This program was carried out in the recently completed hyperbaric chamber com- 

 plex at the Institute for Environmental Medicine of the University of 

 Pennsylvania. A schematic of this facility is shown in Figure 1. A functional 

 schematic of the complex during the experimental period is shown in Figure 2. 



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